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The study determined the prevalence, antimicrobial resistant (AMR) determinants, and genetic characteristics of Escherichia coli and Klebsiella pneumoniae isolates from patients with diabetic foot infection (DFI) in a Tunisian hospital. A total of 26 Escherichia spp. and Klebsiella spp. isolates were recovered and identified by MALDI-TOF-MS. Antimicrobial susceptibility testing, the detection of AMR determinants and Shiga-like toxin genes, phylogenetic grouping, and molecular typing were performed. Twelve E. coli, 10 K. pneumoniae, 3 K. oxytoca, and 1 E. hermanii were isolated. A multidrug-resistant phenotype was detected in 65.4% of the isolates. About 30.8% of isolates were extended-spectrum β-lactamase (ESBL) producers and mainly carried blaCTX-M-15 and blaCTX-M-14 genes. One blaNDM-1-producing K. pneumoniae-ST1 strain was identified. Class 1 integrons were detected in 11 isolates and 5 gene cassette arrangements were noted: dfrA1+aadA1 (n = 1), dfrA12+aadA2 (n = 3), and dfrA17+aadA5 (n = 1). Other non-β-lactam resistance genes detected were as follows (number of isolates): aac(3')-II (3), aac(6')–Ib-cr(8), qnrB (2), qnrS (4), cmlA (2), floR (4), sul1 (11), sul2 (11), and sul3 (2). The phylogroup B1 was the most frequent (41.7%) among E. coli, and two ESBL-producing isolates corresponded to the ST131-B2 lineage. The ESBL- and carbapenemase-producing Enterobacteriaceae in DFIs are described for the first time in Tunisia. [ABSTRACT FROM AUTHOR]

Objective: Identification of MBL, AmpC and ESBLs in colistin intrinsic and acquired resistant uropathogenic gram negative bacteria. Method: Urine samples were collected from Hayatabad Medical Complex, Peshawar during 17 January to 30 June 2019. Collected urine samples were aseptically transported microbiology lab of Health Research Institution (HRI), National Institute of Health (NIH), Khyber Medical College, Peshawar and streaked on different media. Positive growth was identified by API-10s. Antibiotic sensitivity profile was done by Modified Kirby Bauer disc diffusion method. Detection of metallo βlactamases (MBL) production by Imipenem EDTA synergy test, Double Disc Synergy Test (DDST) for detection of ESBLs and D-test for the detection of inducible AmpC beta lactamases test was used. Colistin resistance was identified via broth micro dilution according to CLSI manual. Colistin resistant bacteria was divided in two categories; acquired and intrinsic resistant bacteria according to CLSI manual. Results: Out of 2000 urine samples, 281(14%) gram-negative bacteria were isolated. Among positive samples, acquired colistin resistant bacteria were 241 and intrinsic resistant bacteria were 40 isolates. MBL was produce by twenty one (11.7%) E.coli and seventeen (40.5%) Pseudomonas aeruginosa. E.coli, Pseudomonas aeruginosa, Klebsiella Pneumoniae, Serratia Oderifora and Proteus Marblis were ESBLs producing bacteria. AmpC production was prevalent in fourteen (7.8%) E. coli and twelve (28.6%) Pseudomonas aeruginosa. Fifty-five samples showed resistance to colistin out of 241 samples. In colistin resistant bacteria, two E.coli were MBL, ESBLs, while one E.coli was ESBLs, AmpC coproducing bacteria. The most prevalent extended drug resistant bacteria were Pseudomonas aeruginosa (28.6%) and Escherichia coli (6.1%), While 155(86.6%) Escherichia coli, 25 (59.5%) Pseudomonas aeruginosa and 22 (95.7%) Serratia Oderifora was multi drug resistant bacteria. Conclusion: Current study concluded that ESBL, MBL AmpC enzymes and their co-expression was observed with colistin resistance in E.coli and Pseudomonas aeruginosa. [ABSTRACT FROM AUTHOR]

Noha A Kamel,1 Mahmoud S Abdalla,2 Amer Al Ali,3 Mohammad Y Alshahrani,4 Khaled M Aboshanab,5,6 Mervat I El Borhamy1,7 1Department of Microbiology, Faculty of Pharmacy, Misr International University (MIU), Cairo, Egypt; 2Hematology and Bone Marrow Transportation (BMT) Unit, International Medical Center (IMC), Cairo, Egypt; 3Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, University of Bisha, Bisha, 67714, Saudi Arabia; 4Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, Abha, 9088, Saudi Arabia; 5Microbiology and Immunology Department, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt; 6Department of Pharmaceutical Life Sciences, Faculty of Pharmacy, University Technology MARA (Uitm), Campus Puncak Alam, Bandar Puncak Alam, Selangor, 42300, Malaysia; 7International Medical Center, Clinical Microbiology Laboratory, Cairo, EgyptCorrespondence: Khaled M Aboshanab, Tel +20-01007582620, Fax +20-(202)24051107, Email aboshanab2012@pharma.asu.edu.eg; khaledaboshanab@uitm.edu.egObjective: Owing to the rising incidence of multidrug-resistant organisms (MDRO) and the high mortality rates associated with such bacterial infections post-hematopoietic stem cell transplantation (HSCT), we investigated the MDRO colonization rate prior to transplantation using an active surveillance approach and determined its impact on subsequent infection during the pre-engraftment period.Methods: A single-center observational study was conducted, and surveillance cultures from multiple body sites, including the rectum, nasal cavity, and groin, were performed at admission to determine MDRO colonization. Serological tests were used to detect certain viruses and toxoplasmosis before HSCT.Results: In the pre-transplant setting, 59 MDRO were recovered from the 40 HSCT recipients. Of the 59 isolates recovered from one or more body sites, 29 were positive for methicillin-resistant Staphylococcus aureus (MRSA), 7 for carbapenem-resistant Enterobacterales (CRE), and 23 were positive for extended-spectrum β-lactamase (ESBLs). Serological assessment before HSCT revealed active or reactivation of latent infection with cytomegalovirus (7.5%), Epstein–Barr virus (EBV; 5%), and Toxoplasma gondii (2.5%) among HSCT patients. In terms of factors associated with pre-engraftment infections, the type of transplant (p=0.04) was statistically significant, whereas other factors, such as age, sex, and underlying conditions, were not. In post-transplant settings, bloodstream infections (BSIs) were documented in 2 allogeneic HSCT patients (5%), and the isolated microorganisms were ESBL-producing E. coli and non-MDR Acinetobacter baumannii.Conclusion: Active screening cultures are a helpful tool for identifying patients colonized by MDRO or relevant viruses before HSCT, and for predicting those at risk of developing subsequent pre-engraftment infections. Additionally, active screening may aid in predicting those who are likely to develop subsequent pre-engraftment infections Our findings highlight the importance of pre-transplant screening for high-priority multidrug-resistant pathogens and the application of infection control interventions after HSCT.Keywords: pre-transplant screening, MRSA, ESBLs, CRE, pre-engraftment infections

Abstract Background Proteus mirabilis is an opportunistic pathogen that has been held responsible for numerous nosocomial and community-acquired infections which are difficult to be controlled because of its diverse antimicrobial resistance mechanisms. Methods Antimicrobial susceptibility patterns of P. mirabilis isolates collected from different clinical sources in Mansoura University Hospitals, Egypt was determined. Moreover, the underlying resistance mechanisms and genetic relatedness between isolates were investigated. Results Antimicrobial susceptibility testing indicated elevated levels of resistance to different classes of antimicrobials among the tested P. mirabilis clinical isolates (n = 66). ERIC-PCR showed great diversity among the tested isolates. Six isolates (9.1%) were XDR while all the remaining isolates were MDR. ESBLs and AmpCs were detected in 57.6% and 21.2% of the isolates, respectively, where bla TEM, bla SHV, bla CTX−M, bla CIT−M and bla AmpC were detected. Carbapenemases and MBLs were detected in 10.6 and 9.1% of the isolates, respectively, where bla OXA−48 and bla NDM−1 genes were detected. Quinolone resistant isolates (75.8%) harbored acc(6')-Ib-cr, qnrD, qnrA, and qnrS genes. Resistance to aminoglycosides, trimethoprim-sulfamethoxazole and chloramphenicol exceeded 80%. Fosfomycin was the most active drug against the tested isolates as only 22.7% were resistant. Class I or II integrons were detected in 86.4% of the isolates. Among class I integron positive isolates, four different gene cassette arrays (dfrA17- aadA5, aadB-aadA2, aadA2-lnuF, and dfrA14-arr-3-bla OXA−10-aadA15) and two gene cassettes (dfrA7 and aadA1) were detected. While class II integron positive isolates carried four different gene cassette arrays (dfrA1-sat1-aadA1, estXVr-sat2-aadA1, lnuF- dfrA1-aadA1, and dfrA1-sat2). Conclusion P. Mirabilis ability to acquire resistance determinants via integrons may be held responsible for the elevated rates of antimicrobial resistance and emergence of XDR or even PDR strains limiting the available therapeutic options for management of infections caused by those strains.

Background: The escalating prevalence of ESBL-producing Enterobacteriaceae in Qatar's pediatric population, especially in community-onset febrile urinary tract infections (FUTIs), necessitates a comprehensive investigation into this concerning trend. Results: Over the course of one year, a total of 459 infants were diagnosed and subsequently treated for UTIs. Cases primarily occurred in infants aged over 60 days, predominantly non-Qatari females born from term pregnancies. Notably, E. coli and K. pneumoniae were the most frequently identified organisms, accounting for 79.7% and 9.8% in the ESBL group and 57.2% and 18.7% in the non-ESBL group, respectively. Interestingly, hydronephrosis emerged as the most prevalent urological anomaly detected in both ESBL (n = 10) and other organism (n = 19) groups. Methods: In this retrospective cohort study conducted in Qatar, we meticulously evaluated the prevalence of pediatric FUTIs. Our study focused on febrile infants aged less than 1 year, excluding those with urine samples not obtained through a catheter. Conclusions: E. coli and K. pneumoniae prevailed as the predominant causative agents in febrile children in Qatar, with hydronephrosis being identified as the most common urological anomaly. Moreover, our findings suggested that gentamicin served as a viable non-carbapenem option for hospitalized ESBL cases, while oral nitrofurantoin showed considerable promise for uncomplicated ESBL UTIs. [ABSTRACT FROM AUTHOR]

Background: Proteus mirabilis is an opportunistic pathogen that has been held responsible for numerous nosocomial and community-acquired infections which are difficult to be controlled because of its diverse antimicrobial resistance mechanisms. Methods: Antimicrobial susceptibility patterns of P. mirabilis isolates collected from different clinical sources in Mansoura University Hospitals, Egypt was determined. Moreover, the underlying resistance mechanisms and genetic relatedness between isolates were investigated. Results: Antimicrobial susceptibility testing indicated elevated levels of resistance to different classes of antimicrobials among the tested P. mirabilis clinical isolates (n = 66). ERIC-PCR showed great diversity among the tested isolates. Six isolates (9.1%) were XDR while all the remaining isolates were MDR. ESBLs and AmpCs were detected in 57.6% and 21.2% of the isolates, respectively, where blaTEM, blaSHV, blaCTX−M, blaCIT−M and blaAmpC were detected. Carbapenemases and MBLs were detected in 10.6 and 9.1% of the isolates, respectively, where blaOXA−48 and blaNDM−1 genes were detected. Quinolone resistant isolates (75.8%) harbored acc(6')-Ib-cr, qnrD, qnrA, and qnrS genes. Resistance to aminoglycosides, trimethoprim-sulfamethoxazole and chloramphenicol exceeded 80%. Fosfomycin was the most active drug against the tested isolates as only 22.7% were resistant. Class I or II integrons were detected in 86.4% of the isolates. Among class I integron positive isolates, four different gene cassette arrays (dfrA17- aadA5, aadB-aadA2, aadA2-lnuF, and dfrA14-arr-3-blaOXA−10-aadA15) and two gene cassettes (dfrA7 and aadA1) were detected. While class II integron positive isolates carried four different gene cassette arrays (dfrA1-sat1-aadA1, estXVr-sat2-aadA1, lnuF- dfrA1-aadA1, and dfrA1-sat2). Conclusion: P. Mirabilis ability to acquire resistance determinants via integrons may be held responsible for the elevated rates of antimicrobial resistance and emergence of XDR or even PDR strains limiting the available therapeutic options for management of infections caused by those strains. [ABSTRACT FROM AUTHOR]

Background Investigations into antibiotics for extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) bloodstream infections (BSIs) have focused on bla CTX-M genes. Patient outcomes from non–CTX-M-producing ESBL-E BSIs and optimal treatment are unknown. Methods A multicenter observational study investigating 500 consecutive patients with ceftriaxone-resistant Enterobacterales BSIs during 2018–2022 was conducted. Broth microdilution and whole-genome sequencing confirmed antibiotic susceptibilities and ESBL gene presence, respectively. Inverse probability weighting (IPW) using propensity scores ensured patients with non–CTX-M and CTX-M ESBL-E BSIs were similar before outcome evaluation. Results 396 patients (79.2%) were confirmed to have an ESBL-E BSI. ESBL gene family prevalence was as follows: bla CTX-M (n = 370), bla SHV (n = 16), bla OXY (n = 12), and bla VEB (n = 5). ESBL gene identification was not limited to Escherichia coli and Klebsiella species. In the IPW cohort, there was no difference in 30-day mortality or ESBL-E infection recurrence between the non–CTX-M and CTX-M groups (odds ratio [OR], 0.99; 95% confidence interval [CI],.87–1.11; P =.83 and OR, 1.10; 95% CI,.85–1.42; P =.47, respectively). In an exploratory analysis limited to the non–CTX-M group, 86% of the 21 patients who received meropenem were alive on day 30; none of the 5 patients who received piperacillin-tazobactam were alive on day 30. Conclusions Our findings suggest that non–CTX-M and CTX-M ESBL-E BSIs are equally concerning and associated with similar clinical outcomes. Meropenem may be associated with improved survival in patients with non–CTX-M ESBL-E BSIs, underscoring the potential benefit of comprehensive molecular diagnostics to enable early antibiotic optimization for ESBL-E BSIs beyond just bla CTX-M genes. [ABSTRACT FROM AUTHOR]

Background: Escherichia coli is the most common etiological agent of urinary tract infections (UTIs). Meanwhile, plasmid-mediated quinolone resistance (PMQR) is reported in E. coli isolates producing extended-spectrum β-lactamases (ESBLs). Furthermore, the reservoirs and mechanisms of acquisition of uropathogenic Escherichia coli (UPEC) strains are poorly understood. On the other hand, UTIs are common in pregnant women and the treatment challenge is alarming. Methods and results: In the present study, 54 pregnant women with acute cystitis were included. A total of 108 E. coli isolates, 54 isolates from UTI and 54 isolates from faeces of pregnant women (same host) were collected. In the antimicrobial susceptibility test, the highest rate of antibiotic resistance was to nalidixic acid (77%, 83/108) and the lowest rate was to imipenem (9%, 10/108). Among the isolates, 44% (48/108) were ESBLs producers. A high frequency of PMQR genes was observed in the isolates. The frequency of PMQR genes qnrS, qnrB, aac(6′)-Ib-cr, and qnrA was 58% (63/108), 21% (23/108), 9% (10/108), and 4% (4/108), respectively. Meanwhile, PMQR genes were not detected in 24% (20/85) of isolates resistant to nalidixic acid and/or fluoroquinolone, indicating that other mechanisms, i.e. chromosomal mutations, are involved in resistance to quinolones, which were not detected in the present study. In ESBL-producing isolates, the frequency of PMQR genes was higher than that of non-ESBL-producing isolates (81% vs. 53%). Meanwhile, UTI and faeces isolates mainly belonged to phylogenetic group B2 (36/54, 67% and 25/54, 46%, respectively) compared to other phylogenetic groups. In addition, virulence factors and multidrug-resistant (MDR) were mainly associated with phylogenetic group B2. However, predominant clones in faeces were not found in UTIs. Rep-PCR revealed the presence of 85 clones in patients. Among the clones, 40 clones were detected only in faeces (faeces-only), 35 clones only in UTI (UTI-only) and 10 clones in both faeces and UTI (faeces-UTI). We found that out of 10 faeces-UTI clones, 5 clones were present in the host's faeces flora. Conclusion: This study revealed a high rate of resistance to the quinolone nalidixic acid and a widespread distribution of PMQR genes in MDR E. coli strains producing ESBLs. The strains represented virulence factors and phylogenetic group B2 are closely associated with abundance in UTI and faeces. However, the predominant clones in faeces were not found in UTIs and it is possible that rep-PCR is not sufficiently discriminating clones. [ABSTRACT FROM AUTHOR]

Introduction: Beta-lactamase producing bacterial infection has been on surge due to selection pressure and injudicious antibiotics usage. Organisms that co-produced more than one beta lactamase enzyme posed diagnostic challenges which may result in inadequate treatment. To date, there is no standardised guideline offering phenotypic detection of AmpC β-lactamase. The purpose of this study was to determine the prevalence of ESBLs, AmpC β-lactamase and co-producer organisms in a teaching hospital. Materials and Methods: Three hundred and four isolates of E. coli and Klebsiella sp. had been selected via convenient sampling. These isolates were identified using conventional laboratory methods and their antimicrobial susceptibilities were determined using disc diffusion method. Those isolates were then proceeded with ESBL confirmatory test, cloxacillin-containing Muller Hinton confirmatory test, modified double disk synergy test and AmpC disk test. Results: Out of 304 isolates, 159 isolates were E. coli and 145 were Klebsiella sp. The prevalence of organisms which co-produced AmpC β-lactamase and ESBL enzymes were 3.0%. Besides that, 39 cefoxitin resistant and three cefoxitin susceptible isolates (13.8%) were proven to produce AmpC β-lactamase through AmpC disk test. Through the CLSI confirmatory test, 252 (82.9%) isolates were identified as ESBLs producers and the prevalence increased slightly when cloxacillin-containing Muller Hinton were used. Only three ESBLs positive organisms were positive for modified double disk synergy test. Conclusion: Distinguishing between AmpC β-lactamase and ESBL-producing organisms has epidemiological significance as well as therapeutic importance. Moreover, AmpC β-lactamase and ESBLs co-producing organisms can lead to false negative ESBL confirmatory test. Therefore, knowing the local prevalence can guide the clinician in navigating the treatment. [ABSTRACT FROM AUTHOR]

Background: Detection of K. pneumoniae superbugs carrying Extended-spectrum β-lactamase (ESBL) and Carbapenemase resistance genes among hospitalized patients is crucial for infection control and prevention. The aim of this molecular study was to investigate the spread of ESBL and Carbapenemase-producing K. pneumoniae in two hospitals located in Southwest Iran. Methods: One hundred clinical isolates of K. pneumoniae were randomly collected from two hospitals over a period of five months, from November 2023. The isolates were confirmed using biochemical and genotypic tests. According to the CLSI 2022 guidelines, K. pneumoniae isolates that exhibited resistance to at least one of the three indicator cephalosporins or carbapenems were selected for evaluation of ESBL and carbapenemase production. This was done using a combination disk confirmatory test and the modified carbapenem inactivation method (mCIM). Finally, the presence of ESBLs and carbapenemase resistance encoding genes was assessed using PCR and specific primers. Results: Out of the 100 isolates, the percentage of antibiotic resistance was cefoxitin (29 %), cefixime (28 %), ceftazidime (26 %), cefotaxime (24 %), cefepime (22 %), ceftriaxone (21 %), imipenem (20 %), and meropenem (17 %). Additionally, thirty isolated strains were found to be multidrug-resistant. Out of these, twenty-seven strains demonstrated a potential for ESBLs, twenty strains for Carbapenemase, and seventeen strains for both ESBLs and Carbapenemase production. Moreover, the occurrence of ESBLs and carbapenemase genes was as follows: blaSHV (25 %), blaTEM (23 %), blaCTX-M (20 %), blaOXA-48 (17 %), and blaVIM (13 %). It is important to mention that we did not detect the blaIMP and blaKPC. resistant genes among clinical isolates. Conclusion: Based on the results, the existence of this type of resistance in hospital centers needs to be reevaluated in terms of empirical antibiotic prescribing. Additionally, it is recommended that infection control measures should be taken for public health. Also, it's suggested that hospital-acquired infections caused by superbug K. pneumoniae resistant strains should be addressed.

The recent approach towards combating the antimicrobial resistance has led to the use of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and associated sequence to overcome the challenges of antimicrobial resistance. Thus, this study aimed to detect the underlying resistance mechanisms such as ESBLs and carbapenemases and whether there is a correlation between multidrug, extensive drug and pan drug resistance and the occurrence of CRISPR loci. A total of one hundred study isolates were subjected to antimicrobial susceptibility testing using the AST card of the Vitek technique to detect resistance patterns involving ESBLs and carbapenemase (CRE). An investigation of the genes encoding CRISPR/Cas systems using PCR was achieved. Out of 81 (81.0%) resistant Klebsiella pneumoniae isolates, 71 (71%) and 21 (21.0%) produced ESBLs and carbapenemases, respectively. Also, 53 (53.0%), 19 (19.0%) and 9 (9.0%) were MDR, XDR, and PDR respectively. It was noted that Cas1, Cas3, CRISPR1, CRISPR2 and CRISPR3 were positive in 38 (38.0%) of the isolates, while CRISPR1 for incomplete CRISPR1-Cas systems alone was detected in 78 (78.0%). Further, the number of intact CRISPR1, intact CRISPR2 and intact CRISPR3 types were 7 (27.0%), 34 (34%) and 18 (18.0%) respectively. It is concluded that antibiotic resistance levels were inversely correlated with the existence of CRISPR/Cas systems. The absence of the CRISPR/Cas system increases the prevalence of MDR, XDR and PDR in ESBL and carbapenem-producing Klebsiella pneumoniae. With the increase in the degree of antibiotic resistance (MDR, XDR to PDR), the occurrence ratio of the (CRISPR)/CRISPR-associated sequence decreased.

BackgroundAntimicrobial resistant infections continue to be a leading global public health crisis. Mobile genetic elements, such as plasmids, have been shown to play a major role in the dissemination of antimicrobial resistance (AMR) genes. Despite its ongoing threat to human health, surveillance of AMR in the United States is often limited to phenotypic resistance. Genomic analyses are important to better understand the underlying resistance mechanisms, assess risk, and implement appropriate prevention strategies. This study aimed to investigate the extent of plasmid mediated antimicrobial resistance that can be inferred from short read sequences of carbapenem resistant E. coli (CR-Ec) in Alameda County, California. E. coli isolates from healthcare locations in Alameda County were sequenced using an Illumina MiSeq and assembled with Unicycler. Genomes were categorized according to predefined multilocus sequence typing (MLST) and core genome multilocus sequence typing (cgMLST) schemes. Resistance genes were identified and corresponding contigs were predicted to be plasmid-borne or chromosome-borne using two bioinformatic tools (MOB-suite and mlplasmids).ResultsAmong 82 of CR-Ec identified between 2017 and 2019, twenty-five sequence types (STs) were detected. ST131 was the most prominent (n = 17) followed closely by ST405 (n = 12). blaCTX-M were the most common ESBL genes and just over half (18/30) of these genes were predicted to be plasmid-borne by both MOB-suite and mlplasmids. Three genetically related groups of E. coli isolates were identified with cgMLST. One of the groups contained an isolate with a chromosome-borne blaCTX-M-15 gene and an isolate with a plasmid-borne blaCTX-M-15 gene.ConclusionsThis study provides insights into the dominant clonal groups driving carbapenem resistant E. coli infections in Alameda County, CA, USA clinical sites and highlights the relevance of whole-genome sequencing in routine local genomic surveillance. The finding of multi-drug resistant plasmids harboring high-risk resistance genes is of concern as it indicates a risk of dissemination to previously susceptible clonal groups, potentially complicating clinical and public health intervention.

ABSTRACT: Objectives: Recently, blaCTX-Ms have become the dominant ESBLs for E. coli strains worldwide. We aim to provide a systematic study on the relationships between sequence types (STs), clinical origins, and the blaCTX-Ms genotypes of E. coli strains. Methods: Totally, 1005 complete sequences of clinical E. coli were collected from NCBI. Multilocus sequence typing (MLST) and antibiotic resistance genes screening were performed. Results: Faeces (26.27%), urine (16.02%), and blood (8.26%) were shown to be the main sources of clinical E. coli isolates. The isolates belong to 153 STs and 26 clonal complexes (CCs). The most prevalent STs were ST2 (11.3%), ST43 (8.6%), and ST8 (5.7%). The positive rate for blaCTX-Ms was 34.7%. Different samples showed significantly different blaCTX-Ms positive rates (P

Abstract Objectives Pseudomonas aeruginosa (P. aeruginosa) is one of the most serious pathogens implicated in antimicrobial resistance, and it has been identified as an ESKAPE along with other extremely significant multidrug resistance pathogens. The present study was carried out to explore prevalence, antibiotic susceptibility phenotypes, virulence-associated genes, integron (int1), colistin (mcr-1), and β-lactamase resistance' genes (ESBls), as well as biofilm profiling of P. aeruginosa isolated from broiler chicks and dead in-shell chicks. Design A total of 300 samples from broiler chicks (n = 200) and dead in-shell chicks (n = 100) collected from different farms and hatcheries located at Mansoura, Dakahlia Governorate, Egypt were included in this study. Bacteriological examination was performed by cultivation of the samples on the surface of both Cetrimide and MacConkey’s agar. Presumptive colonies were then subjected to biochemical tests and Polymerase Chain Reaction (PCR) targeting 16S rRNA. The recovered isolates were tested for the presence of three selected virulence-associated genes (lasB, toxA, and exoS). Furthermore, the retrieved isolates were subjected to phenotypic antimicrobial susceptibility testing by Kirby–Bauer disc diffusion method as well as phenotypic detection of ESBLs by both Double Disc Synergy Test (DDST) and the Phenotypic Confirmatory Disc Diffusion Test (PCDDT). P. aeruginosa isolates were then tested for the presence of antibiotic resistance genes (ARGs): int1, mcr-1, and ESBL genes (OXA-10, OXA-2, VEB-1, SHV, TEM, and CTX-M). Additionally, biofilm production was examined by the Tube Adherent method (TA) and Microtiter Plate assay (MTP). Results Fifty –five isolates were confirmed to be P. aeruginosa, including 35 isolates from broiler chicks and 20 isolates from dead in-shell chicks. The three tested virulence genes (lasB, toxA, and exoS) were detected in all isolates. Antibiogram results showed complete resistance against penicillin, amoxicillin, ceftriaxone, ceftazidime, streptomycin, erythromycin, spectinomycin, and doxycycline, while a higher sensitivity was observed against meropenem, imipenem, colistin sulfate, ciprofloxacin, and gentamicin. ESBL production was confirmed in 12 (21.8%) and 15 (27.3%) isolates by DDST and PCDDT, respectively. Antibiotic resistance genes (ARGs): int1, mcr-1, and ESBL genes (OXA-10, SHV, TEM, and CTX-M), were detected in 87.3%, 18.2%, 16.4%, 69.1%, 72.7%, and 54.5% of the examined isolates respectively, whereas no isolate harbored the OXA-2 or VEB-1 genes. Based on the results of both methods used for detection of biofilm formation, Kappa statistics [kappa 0.324] revealed a poor agreement between both methods. Conclusions the emergence of mcr-1 and its coexistence with other resistance genes such as β-lactamase genes, particularly bla OXA-10, for the first time in P. aeruginosa from young broiler chicks and dead in-shell chicks in Egypt pose a risk not only to the poultry industry but also to public health. Graphical Abstract

Abstract Background Hospital-acquired infections caused by multidrug-resistant Pseudomonas aeruginosa incline hospital stay and costs of treatment that resulted in an increased mortality rate. The frequency of P. aeruginosa high-risk clones producing carbapenemases was investigated in our clinical samples. Methods In this cross-sectional study, 155 non-repetitive P. aeruginosa isolates were included from different medical centers of Iran. Antibiotic susceptibility testing was determined, and the presence of β-lactamases were sought by phenotypic and genotypic methods. The clonal relationship of all isolates was investigated, and multi-locus sequence typing (MLST) was used for finding the sequence types of carbapenemase-producers. Results The agent with highest percent susceptibility rate was recorded for colistin (94.9%). MOX and FOX were found both as low as 1.95% (3/155). The most frequent narrow spectrum β-lactamase was SHV with 7.7% (12/155) followed by PER, OXA-1, and TEM with the frequency of 7.1% (11/155), 3.2% (5/155), and 1.3% (2/155), respectively. Carbapenemases were detected in 28 isolates (18%). The most frequent carbapenemase was IMP with 9% (14/155) followed by NDM, 8.4% (13/155). OXA-48 and VIM were also detected both per one isolate (0.65%). MLST of carbapenem resistant P. aeruginosa isolates revealed that ST244, ST664, ST235, and ST357 were spread in subjected clinical settings. REP-PCR uncovered high genomic diversity in our clinical setting. Conclusion Clonal proliferation of ST235 strain plays a key role in the propagation of MDR pattern in P. aeruginosa. Our data showed that high-risk clones has distributed in Iran, and programs are required to limit spreading of these clones.

Objectives: Pseudomonas aeruginosa (P. aeruginosa) is one of the most serious pathogens implicated in antimicrobial resistance, and it has been identified as an ESKAPE along with other extremely significant multidrug resistance pathogens. The present study was carried out to explore prevalence, antibiotic susceptibility phenotypes, virulence-associated genes, integron (int1), colistin (mcr-1), and β-lactamase resistance' genes (ESBls), as well as biofilm profiling of P. aeruginosa isolated from broiler chicks and dead in-shell chicks. Design: A total of 300 samples from broiler chicks (n = 200) and dead in-shell chicks (n = 100) collected from different farms and hatcheries located at Mansoura, Dakahlia Governorate, Egypt were included in this study. Bacteriological examination was performed by cultivation of the samples on the surface of both Cetrimide and MacConkey's agar. Presumptive colonies were then subjected to biochemical tests and Polymerase Chain Reaction (PCR) targeting 16S rRNA. The recovered isolates were tested for the presence of three selected virulence-associated genes (lasB, toxA, and exoS). Furthermore, the retrieved isolates were subjected to phenotypic antimicrobial susceptibility testing by Kirby–Bauer disc diffusion method as well as phenotypic detection of ESBLs by both Double Disc Synergy Test (DDST) and the Phenotypic Confirmatory Disc Diffusion Test (PCDDT). P. aeruginosa isolates were then tested for the presence of antibiotic resistance genes (ARGs): int1, mcr-1, and ESBL genes (OXA-10, OXA-2, VEB-1, SHV, TEM, and CTX-M). Additionally, biofilm production was examined by the Tube Adherent method (TA) and Microtiter Plate assay (MTP). Results: Fifty –five isolates were confirmed to be P. aeruginosa, including 35 isolates from broiler chicks and 20 isolates from dead in-shell chicks. The three tested virulence genes (lasB, toxA, and exoS) were detected in all isolates. Antibiogram results showed complete resistance against penicillin, amoxicillin, ceftriaxone, ceftazidime, streptomycin, erythromycin, spectinomycin, and doxycycline, while a higher sensitivity was observed against meropenem, imipenem, colistin sulfate, ciprofloxacin, and gentamicin. ESBL production was confirmed in 12 (21.8%) and 15 (27.3%) isolates by DDST and PCDDT, respectively. Antibiotic resistance genes (ARGs): int1, mcr-1, and ESBL genes (OXA-10, SHV, TEM, and CTX-M), were detected in 87.3%, 18.2%, 16.4%, 69.1%, 72.7%, and 54.5% of the examined isolates respectively, whereas no isolate harbored the OXA-2 or VEB-1 genes. Based on the results of both methods used for detection of biofilm formation, Kappa statistics [kappa 0.324] revealed a poor agreement between both methods. Conclusions: the emergence of mcr-1 and its coexistence with other resistance genes such as β-lactamase genes, particularly blaOXA-10, for the first time in P. aeruginosa from young broiler chicks and dead in-shell chicks in Egypt pose a risk not only to the poultry industry but also to public health. [ABSTRACT FROM AUTHOR]

Background: Hospital-acquired infections caused by multidrug-resistant Pseudomonas aeruginosa incline hospital stay and costs of treatment that resulted in an increased mortality rate. The frequency of P. aeruginosa high-risk clones producing carbapenemases was investigated in our clinical samples. Methods: In this cross-sectional study, 155 non-repetitive P. aeruginosa isolates were included from different medical centers of Iran. Antibiotic susceptibility testing was determined, and the presence of β-lactamases were sought by phenotypic and genotypic methods. The clonal relationship of all isolates was investigated, and multi-locus sequence typing (MLST) was used for finding the sequence types of carbapenemase-producers. Results: The agent with highest percent susceptibility rate was recorded for colistin (94.9%). MOX and FOX were found both as low as 1.95% (3/155). The most frequent narrow spectrum β-lactamase was SHV with 7.7% (12/155) followed by PER, OXA-1, and TEM with the frequency of 7.1% (11/155), 3.2% (5/155), and 1.3% (2/155), respectively. Carbapenemases were detected in 28 isolates (18%). The most frequent carbapenemase was IMP with 9% (14/155) followed by NDM, 8.4% (13/155). OXA-48 and VIM were also detected both per one isolate (0.65%). MLST of carbapenem resistant P. aeruginosa isolates revealed that ST244, ST664, ST235, and ST357 were spread in subjected clinical settings. REP-PCR uncovered high genomic diversity in our clinical setting. Conclusion: Clonal proliferation of ST235 strain plays a key role in the propagation of MDR pattern in P. aeruginosa. Our data showed that high-risk clones has distributed in Iran, and programs are required to limit spreading of these clones. [ABSTRACT FROM AUTHOR]

ABSTRACT: Objectives: Antibiotic resistance (AR) is a global health issue with multidimensional repercussions. There is a paucity of data regarding the molecular epidemiology of multidrug-resistant Enterobacterales (MDR-E) and extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-PE) in Africa, especially among people living with HIV (PLHIV). This study aimed at determining the prevalence, risk factors, phenotypic and genotypic profiles of MDR-E and ESBL-PE isolated from PLHIV in Yaoundé, Cameroon. Methods: In total, samples were collected from 185 PLHIV during a three-month period (April–June 2021) at the Yaoundé Central Hospital. Stool samples and rectal swabs were collected and cultured on MacConkey agar. The API 20E kit was used for the phenotypic identification of the isolates, whereas antibiotic susceptibility testing was performed using the Kirby-Bauer disk diffusion method. The ß-lactamase genes and genotypic relatedness were studied by PCR and ERIC-PCR, respectively. Results: The prevalence of MDR-E among PLHIV was 81%, of which 39% were ESBL-PE. A high level of resistance to fosfomycin (89%), chloramphenicol (63%), and gentamicin (56%) was observed. Escherichia coli was the predominant MDR non-ESBL-PE (80.8%) and MDR ESBL-PE (73.77%). The principal ß-lactamases genes in MDR non-ESBL and MDR ESBL-PE were blaTEM (62.90%) and blaCTX-M (40.86%), respectively. Genetic fingerprinting revealed high genetic relatedness among E. coli isolates. Conclusion: This study shows a high prevalence of MDR-E and ESBL-PE in the gut of PLHIV in Yaoundé, with blaTEM and blaCTX-M being the most prevalent. It demonstrates the need to strengthen real-time surveillance of these resistant bacteria in order to improve management of infection among PLHIV.

Abstract Background The 2017 World Health Organization (WHO) report has listed extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) as critical pathogens for public health and requiring urgently new antibiotics. The aim of this study was to characterize phenotypically and genotypically ESBL-E isolated among clinical samples in Dschang, Cameroon. Methods A cross-sectional study was conducted during a four-month periods from February to May 2022 in the two biggest hospitals of Dschang. Clinical samples were collected and cultured on Eosin Methylene Blue agar. Suspected growing colonies were biochemically identified using the Enterosystem Kit 18R. Antimicrobial susceptibility testing (AST) was done using the Kirby Bauer disc diffusion method and interpretated according to the CA-SFM recommendations. ESBL phenotypes were double screened using CHROMagar™ ESBL and double disk synergy test (DDST). The detection of resistance genes was performed using conventional and multiplex PCR methods. Results were analyzed with SPSS (version 21) and a p-value

Background: The CTX-M gene in ESBLs-producing Klebsiella pneumoniae is associated with virulence factors and encodes for antibiotic resistance. There are currently 128 different varieties of CTX-M, which gene can hydrolyze beta-lactam medicines like cefotaxime. Purpose: Identify the CTX-M gene in Klebsiella pneumoniae from patients with Urinary Tract Infections (UTI) at a private hospital in Banyumas Region of Central Java, Indonesia. Method: Cross-sectional survey method was employed in this study. The subjects of the study comprised 40 patients with UTI admitted to a private hospital in Banyumas Region, Central Java, Indonesia. Using a direct molecular approach called Polymerase Chain Reaction (PCR) directed against the CTX-M gene, DNA was isolated from isolates cultured in CHROMagarTM ESBLs obtained from catheter urine samples. Result: A total of 4 out of 40 urine samples (10%) tested positive for ESBL-producing Klebsiella pneumoniae. The PCR was performed to detect the CTX-M gene in 100% of the strains. Conclusion: These findings suggest the presence of CTX-M gene found in ESBLs-producing Klebsiella pneumoniae in individuals with urinary tract infections in a private hospital in Purwokerto, Banyumas regency, Central Java, Indonesia. This information can be used to assess antibiotic administration practices.

Background: Antibiotic resistance is a major global threat to the efficacy of bacterial infection treatment. Resistance to beta-lactam antibiotics in bacteria is primarily caused by the production of extended-spectrum-lactamases, with the CTX-M variant, particularly CTX-M-15, being the most common. The need for an effective CTX-M-15 inhibitor is currently pressing. Methods: This study screened a library of natural compounds from the ZINC database against the CTX-M-15 protein using the PyRx 0.8 tool. The SwissADME web platform was used to predict the ADMET properties of the five most promising compounds. Result: The identified hits compounds, ZINC1857626342, ZINC403692, ZINC408773, ZINC57926, and ZINC790938591 exhibited strong binding with CTX-M-15. These compounds interacted with crucial catalytic site residues in the CTX-M-15 protein, particularly Ser70 and Ser130. Notably, the binding energies of these compounds were higher than those of the reference compound avibactam. Furthermore, they exhibited pharmacologically favorable characteristics. Conclusion: These compounds show promise as potential CTX-M-15 inhibitors to combat bacterial resistance. However, more experimental research is needed to optimize these compounds for their role as CTX-M-15 inhibitors. [ABSTRACT FROM AUTHOR]

A rising incidence of clinical infections has been caused by Kluyvera, a significant opportunistic pathogen. Meanwhile, Kluyvera acts as an important reservoir of blaCTX-Ms, which are the dominant genes of class A extended-spectrum β-lactamases (ESBLs). In this work, 60 strains of Kluyvera were subjected to phylogenetic relationship reconstruction, antimicrobial susceptibility testing, and antibiotic resistance genes prediction. All mature blaCTX-Ms were gathered to perform subgroup reclassification. The findings demonstrate that Kluyvera has a large gene pool with significant genetic flexibility. Notably, 25% of strains showed simultaneous detection of ESBLs and carbapenem resistance genes. The genotypes of fourteen novel blaCTX-Ms were identified. A new subgroup classification approach for blaCTX-Ms was defined by using 20 amino acid site variants, which could split blaCTX-Ms into 10 subgroups. The results of the subgroup division were consistent with the phylogenetic clustering. More significantly, we proposed a novel blaCTX-M subgroup, KLUS, that is chromosomally encoded in K. sichuanensis and the new species put forward in this study, showing amino acid differences from the currently known sequences. Cloning and transformation tests demonstrated that the recipient bacteria had a robust phenotype of cefotaxime resistance. Closely related Kluyvera species had blaCTX-Ms in the same subgroup. Our research lays the groundwork for a deeper comprehension of Kluyvera and emphasizes how important a blaCTX-M reservoir it is. We provide an update on blaCTX-M subgroups reclassification from the aspects of phylogenetic relationship, amino acid differences, and the new subgroup KLUS, which needs to be strengthen monitored due to its strong resistance phenotype to cefotaxime. [ABSTRACT FROM AUTHOR]

Background The presence of drug-resistant Gram-negative pathogenic bacteria and Extended Spectrum P-Lactamase Producers (ESBLs) in hospital associated fomites like door handles can serve as vehicles in transmission and may be the key factor in epidemiology of ESBL producing bacterial infection not only in a hospital setting but also in the community. The aim of this study was to determine the prevalence of ESBLs and antibiotic resistance of Gram-Negative pathogenic Bacteria isolated from door-handles in two selected hospitals in Pokhara Metropolitan City, Nepal. The study was conducted in selected hospitals in Pokhara Metropolitan City, Western Nepal. A cross-sectional study design was used. The hospitals were selected randomly. A total of 100 swab samples were taken from door-handles. Isolation and identification of bacteria were done using standard microbiological procedures. An antibiotic susceptibility test, screening and confirmation of ESBLs were performed using the Clinical Laboratory Standard Institute's guidelines. Results Out of the 100 swab samples cultured, 96 (96%) showed bacterial growth. A total of one hundred and forty isolates were isolated in this study which were further identified based on cultural, morphological and biochemical characteristics. The study also found that door handles/knobs had higher level of contamination in Outpatient Departments (OPDs), Emergency, Laboratory, General wards and Toilets, in that order as compared to Radiology Room, Staff rooms, Intensive Care Unit and Operation Theatre which were lower. The level of contamination varies depending on the traffic exposure and the environment. The most prevalent Gram-negative bacteria identified was Escherichia coli 28.85%, followed by Klebsiella spp 21.15%, Pseudomonas aeruginosa 15.38%, Proteus spp 11.54%, Enterobacter spp 9.62%, Acenetobacter spp 7.69%, Citrobacter spp 5.77%. The most effective drug of choice was Amikacin, Nitrofurantoin, Norfloxacin, Ciprofloxacin, Tetracycline and Imipenem for many Gram-negative isolates. The overall prevalence of ESBLs in this study was 27.14%. Out of total 15 Escherichia coli isolated, 11(73.3%), Klebsiella spp 9/11 (81.8%); Pseudomonas spp 7/8 (87.5%), Proteus spp 4/6 (66.6%); Enterobacter spp 3/5 (60%), Acenetobacter spp 3/4 (75%) and Citrobacter spp 1/3 (33.3%) were found to be Extended P-Lactamase Producers (ESBLs). Conclusion The isolation of of pathogenic Gram-negative bacteria and ESBLs in hospital environments and subsequent detection of high drug resistance patterns indicates a potentially serious public health challenge that strengthens the need for the effective and routine cleaning of door-handles in hospitals. [ABSTRACT FROM AUTHOR]

Introduction: An extended-spectrum beta-lactamase (ESBL)-hypervirulent Klebsiella pneumoniae (HvKP) strain HKE9 was isolated from the blood in an outpatient. Methods: The effect of the global regulatory factor RpoS on antimicrobial resistance, pathogenicity, and environmental adaptability was elucidated. Results: HKE9 is a novel ST3355 (K20/O2a) hypervirulent strain with a positive string test and resistant to cephems except cefotetan. It has a genome size of 5.6M, including two plasmids. CTX-M-15 was found in plasmid 2, and only ompk37 was found in the chromosome. HKE9 could produce bacterial siderophores, and genes of enterobactin, yersiniabactin, aerobactin, and salmochelin have been retrieved in the genome. As a global regulatory factor, knockout of rpoS did not change antimicrobial resistance or hemolytic phenotype while increasing the virulence to Galleria mellonella larvae and showing higher viscosity. Moreover, rpoS knockout can increase bacterial competitiveness and cell adhesion ability. Interestingly, HKE9-M-rpoS decreased resistance to acidic pH, high osmotic pressure, heat shock, and ultraviolet and became sensitive to disinfectants (H2O2, alcohol, and sodium hypochlorite). Although there were 13 Type 6 secretion system (T6SS) core genes divided into two segments with tle1 between segments in the chromosome, transcriptomic analysis showed that rpoS negatively regulated T4SS located on plasmid 2, type 1, and type 3 fimbriae and positively regulate genes responsible for acidic response, hyperosmotic pressure, heat shock, oxidative stress, alcohol and hypochlorous acid metabolism, and quorum sensing. Discussion: Here, this novel ST3355 ESBL-HvKP strain HKE9 may spread via various clonal types. The important regulation effect of rpoS is the enhanced tolerance and resistance to environmental stress and disinfectants, which may be at the cost of reducing virulence and regulated by T4SS. [ABSTRACT FROM AUTHOR]

The increasing disparity between antimicrobial resistance (AMR) and the development of new antimicrobials continues to pose a significant global health concern. However, plant extracts have shown promise in combating this issue either through their inherent antimicrobial activity or by serving as potential reservoirs of effective antimicrobial compounds. These compounds have the ability to target pathogenic biofilms and inhibit the production of extended-spectrum β -lactamases (ESBLs). However, there is limited research available on the antibacterial properties of goldenrod extract. Thus, the objective of this study was to investigate the impact of S. virgaurea (SV) extract on the viability and ability to form biofilms of ESBL-Pseudomonas aeruginosa (P. aeruginosa). A cross-sectional study was conducted from August 2022 to March 2023. The broth microdilution method was employed to determine the minimum inhibitory concentration (MIC) of the (SV) extract. Subsequently, the minimum bactericidal concentration (MBC) was determined based on the MIC values obtained. The antibiotic susceptibility of bacteria was evaluated using the Kirby disk diffusion assay and an Antimicrobial Susceptibility Testing (AST) card in conjunction with the Vitek-2 compact system. Biofilm formation was evaluated using Congo red and a 96-well Elisa plate, while the presence of extended-spectrum β-lactamases (ESBLs) was estimated by measuring the reduction of nitrocefin at a wavelength of 390 nm. In addition, treatment of biofilm and ESBL activity with SV extract using 96-well Elisa plate and nitrocefin hydrolyzing, respectively. The resistance rates of P. aeruginosa isolates to the tested antibiotics were as follows: Levofloxacin 33%, Ciprofloxacin 40%, Amikacin 49%, Meropenem 50%, Cefepime 70%, Ceftazidime 75%, Cefotaxime 85%, Piperacillin-Tazobactam 90%, Amoxiclav 97%, Ampicillin 99%, Ceftriaxone 100%. The prevalence of MDR-P. aeruginosa, XDR-P. aeruginosa, PDR-P. aeruginosa and non-MDR-PA were 40% (n = 40), 7% (n = 7), 3% (n = 3) and 50% (n = 50), respectively. From the GC–MS results, it was observed that the presence of Octadecane, Clioquinol, Glycerol tricaprylate, hexadecanoic acid, cis-13-octadecenoic acid, oleic acid and Propanamide were the major components in the Solidago extract. In the determination of plant crude extracts, the values ranged between 0.25 and 64 mg/mL against bacteria. The resulting activity of the extract showed a significant statistical relationship at a p-value ≤ 0.01 against ESBL production and biofilm formation in P. aeruginosa. The S. virgaurea extract exhibited effectiveness in inhibiting biofilm formation and combating P. aeruginosa strains that produce extended-spectrum β-lactamases (ESBLs). [ABSTRACT FROM AUTHOR]

In 2022, we undertook a point prevalence screening study for Enterobacterales with extended-spectrum β-lactamases (ESBLs), high-level AmpC cephalosporinases and carbapenemases, and also methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) in a long-term care facility (LTCF) and the associated acute-care hospital Geriatrics unit in Bolzano, Northern Italy. Urine samples and rectal, inguinal, oropharyngeal, and nasal swabs were plated on selective agar plates. Metadata of the patients, including demographic data, were collected, and risk factors for colonization were determined. ESBL, AmpC, carbapenemase, and quinolone resistance genes were investigated by the HybriSpot 12 PCR AUTO System. The following colonization percentages by multidrug-resistant (MDR) bacteria have been found in LTCF residents: all MDR organisms, 59.5%; ESBL producers, 46.0% (mainly CTX-M-type enzymes); carbapenemase producers, 1.1% (one Klebsiella pneumoniae with KPC-type); MRSA, 4.5%; VRE, 6.7%. Colonization by MDR bacteria was 18.9% for LTCF staff and 45.0% for Geriatrics unit patients. Peripheral vascular disease, the presence of any medical device, cancer, and a Katz Index of 0 were significant risk factors for colonization of LTCF residents by MDR bacteria in univariate and/or multivariate regression analysis. To conclude, the ongoing widespread diffusion of MDR bacteria in the LTCF suggests that efforts should be strengthened on MDR screening, implementation of infection control strategies, and antibiotic stewardship programs targeting the unique aspects of LTCFs. ClinicalTrials.gov ID: 0530250-BZ Reg01 30/08/2022. [ABSTRACT FROM AUTHOR]

To investigate the death cause of a forest musk deer (Moschus berezovskii), samples of the dead forest musk deer were collected aseptically for bacterial isolation and drug resistance analysis. The isolate was identified by bacterial isolation and purification, biochemical identification,16S rDNA gene sequencing, disc diffusion test and antibiotic resistance genes detection. The results showed that Escherichia fergusonii was isolated from the samples of the dead deer. Drug sensitive test confirmed that the isolate was resistant to cefotaxime, cephalothin and penicillin, while it was sensitive to aminoglycosides, quinolones and aminopenicillins. The analysis of resistance genes detection showed that bla-OXA1/4/30, blaCTX-M and bla-SHV were all detected. In conclusion, this study provides a reference to prevention and treatment of pathogenic E. fergusonii in the cultivation of forest musk deer. [ABSTRACT FROM AUTHOR]

This study was conducted to identify the distribution of virulence determinants in uropathogenic Escherichia coli (UPEC) isolates obtained from kidney transplant (KTP) and non-transplant patients (non-KTP) with urinary tract infections (UTI). Additionally, the (GTG)5 fingerprinting technique was used to investigate the genetic diversity of Extended-Spectrum B-Lactamase (ESBL)-positive isolates.In this case-control study, 111 urine isolates were obtained from non-KTPs and KTPs, respectively. The presence of genetic markers encoding adhesion proteins, toxins and major E. coli phylogroups was assessed through PCR amplification. Molecular typing of ESBL-positive UPEC strains was performed using (GTG)5 fingerprinting and Multilocus sequence typing (MLST) techniques.Overall, 65 and 46 UPEC isolates were obtained from non-KTPs and KTPs, respectively. Among the studied isolates, traT (85.6%) gene was the most frequently observed virulence gene, followed by kpsMT (49.5%). Using the 80% cut-off point, all the 35 UPEC isolates were classified into four major clusters, namely A, B, C, and D. The majority of the Sequence Type (ST) 131 isolates belonged to cluster A. Additionally, three ST1193 isolates belonged to cluster A and phylogroup B2. Moreover, ST38, ST131 and ST10 were in different cluster.In general, we observed significant differences in the papA, ompT, sat, and vat genes between KTPs and non-KTPs. Furthermore, since all the isolates carried one or more virulence factors (VFs), these findings are concerning in the context of managing UTIs caused by the UPEC strain. Additionally, the distribution of ST and Clonal Complex (CC) among isolates in the main clusters revealed significant differences between MLST and (GTG)5 fingerprinting analysis.

Qian Wu,1 Jing Shi,2 Juan Huang,3 Delu Gan,1 Lijun Zhang,1 Pu Li1 1Department of Laboratory Medicine, The Second Hospital of Chongqing Medical University, Chongqing, People’s Republic of China; 2Department of Clinical Laboratory, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China; 3Department of Information Center, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of ChinaCorrespondence: Pu Li, Department of Clinical Laboratory, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, People’s Republic of China, Fax +86-23-63693195, Email lipu@hospital.cqmu.edu.cnBackground: Escherichia coli (E. coli) is a common pathogen in bloodstream infections (BSI), and the production of extended-spectrum beta-lactamases (ESBLs) is its main mechanism of resistance. However, the impact of different ESBL genotypes of E. coli on the resistance to Cefepime (FEP) remains unclear.Methods: A total of 2356 cases of BSI patients were collected. The experimental group included 188 ESBL-positive E. coli strains that were resistant to FEP but sensitive to ceftazidime (CAZ). Antibiotic usage and resistance rates were evaluated through antimicrobial susceptibility testing and antibiotic usage records. The ESBL genotypes were identified, and the minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) of FEP were determined.Results: In ESBL-positive E. coli, three ESBL genotypes were identified: 188 strains of CTX-M, 130 strains of TEM-1, and 26 strains of OXA-10. Among them, 124 strains carried both CTX-M-9 and TEM-1 genotypes, 22 strains carried two CTX-M genotypes (CTX-M-1 and CTX-M-2), 20 strains carried both CTX-M-9 and OXA-10, and 6 strains carried three genotypes (CTX-M-9, CTX-TEM-1, and OXA-10). The MIC50, MIC90, MPC50, and MPC90 of the 188 ESBL-positive E. coli were 64, 256, 128, and 528, respectively. The MIC values ranged from 32 to 256, while the MPC values ranged from 64 to 528. The MIC50, MIC90, MPC50, and MPC90 of the 40 ESBL-negative E. coli were 0.5, 1, 64, and 128, respectively; the MIC values ranged from 0.25 to 4, while the MPC values ranged from 32 to 256, respectively.Conclusion: ESBL-positive E. coli induces an increase in the MIC value of FEP, leading to an increase in FEP resistance. The inoculation effect also causes a significant increase in the MPC value of FEP, especially the increase in selection index value, indicating selective enrichment and amplification of drug-resistant mutants, resulting in clinical treatment failure.Keywords: Escherichia coli, cefepime, ESBLs, mutant prevention concentration

Urinary tract infections (UTIs) are among the most common infections diagnosed in clinical practice. Treatment is often initiated before microbiological confirmation and anti-microbial susceptibility testing. With the rapidly rising antibiotic resistance treatment failures are not uncommon. Beta-lactamase production by gram-negative bacteria causing UTI is the commonest mode of drug resistance. The aim of current study was to detect and determine the hospital based prevalence of UTI, causative uropathogens and their antimicrobial susceptibility patterns. A total of 9,518 clean catch, mid stream urine samples were processed over 2 years. Semi-quantitative urine cultures and AST were performed. Diverse underlying resistance mechanisms were determined by detecting ESBLs, Carbapenemases, AmpC β-Lactamases, and Metallo-β-Lactamases through various standardized phenotypic methods. Out of the 9,518 samples tested 1171 (12.3%) were culture positive. Majority (66.7%) were from female patients. Highest prevalence (60%) was seen in patients > 40 years of age. E. coli (48%) was the predominant causative organism, followed by Enterococcus spp. (23%). Among GNB high resistance rates were observed against Beta-lactams, Beta-lactam/β-lactamase inhibitor combinations, and fluoroquinolones. 34.5% of GNB were confirmed as ESBL, 40% as carbapenemase, 36.5% as AmpC β-Lactamase, and 41.5% as MBL producers. We found very high levels of resistance against a broad range of antibiotics including the most widely used β-lactam group. With the resistance slopes getting steeper and steeper empirical treatment of UTIs might be fraught with the danger of many failures. Culturing and performing AST for all patients with UTI might be a prudent step for their rationale treatment and a step forward in halting the emergence of further resistance.

ABSTRACT: Objectives: Emergence of the plasmid-born mobile colistin resistance (mcr) gene is a growing concern in healthcare. Therefore, this study aimed to genomically characterise multidrug-resistant Escherichia coli and Klebsiella pneumoniae co-harbouring the mcr-1 and mcr-3 genes in young children. Methods: E. coli (n = 3) and K. pneumoniae (n = 2) were collected from abdominal secretions and blood, respectively. The isolates were screened using tryptone soy broth with 4 µL/mL polymyxin-B. Growing bacteria were identified using the VITEK-2 system, matrix-assisted laser desorption/ionisation time-of-flight, and 16s RNA sequencing, followed by antibiotic susceptibility testing. Metallo-β-lactamase (MBL) and extended-spectrum β-lactamase (ESBL) production was also detected. Afterwards, strains were subjected to molecular screening targeting mcr variants and ESBL/MBL-encoding genes. Conjugation, pulsed-field gel electrophoresis, Southern hybridisation, multilocus sequence typing, and phylogenic group detection were performed, along with plasmid-genome sequencing and bioinformatics analysis. Results: E. coli isolates (EC-19–322, 323, and 331) and K. pneumoniae isolates (KP-19–225 and 226) harboured both mcr-1 and mcr-3 genes. These strains were also found to be resistant to more than three classes of antibiotics. The conjugation experiment revealed the presence of mcr-1 and mcr-3 on a single plasmid, and the transmission frequency was 10–2 to 10–3. Both strains were found to be able to produce ESBLs and MBL. E. coli EC-19–322 and 323 were identified as ST131(O25a:H41); SP-19–331, as ST1577 (O16:H30); and K. pneumoniae, as ST231 (K2). All E. coli strains belonged to phylogenetic group B2, and the results of pulsed-field gel electrophoresis supported the multilocus sequence typing findings. Conclusion: This study reported the co-occurrence of mcr-1 and mcr-3 genes on a single plasmid in pathogenic ESBL/MBL-producing E. coli and K. pneumoniae isolated from young children.

Antimicrobial resistance is considered a major threat facing humanity. It doesn’t only affect public health, but also causes great losses in the dairy industry. Mastitis is a major threat to the dairy industry. The aim of this study was to monitor the antimicrobial resistance of Escherichia coli (E. coli) collected from raw milk of both healthy and mastitis cows and buffaloes in Egypt. In total, 450 milk samples were collected and examined in the period from 2018 to 2021. The samples were collected from healthy cows and buffaloes (30, 58), suffering from clinical mastitis (139, 223) respectively. E. coli was isolated from 33 mastitis milk samples (9.1%) and from 3 (3.4%) normal milk samples. The antibiotic susceptibility testing was performed using the disc diffusion method (Kirby-Bauer method). E. coli isolated from mastitis milk samples showed resistance to amoxicillin-clavulanic acid (75.8%), ceftazidime (75.8%), colistin (69.8%), ampicillin (39.4%), imipenem (24.2%), trimethoprim-sulfamethoxazole (24.2%), aztreonam (15.2%), cefotaxime (15.2%), tetracycline (15.2%), ciprofloxacin (12.2%), chloramphenicol (6%), and gentamicin (3%). E. coli isolated from normal milk samples showed resistance to ampicillin, and imipenem (66.7%), each, and amoxicillin-clavulanic acid, tetracycline, and trimethoprim-sulfamethoxazole (33.3%), each. The Extended Spectrum -Lactamases test (ESBL) performed on the E. coli isolates showed positive results in 9% of mastitis milk samples, but no results in normal milk samples. Out of 36 E. coli isolates, 34 possessed the ampC gene, but blaTEM and blaSHV were detected in 5 isolates with percentages of 94%, 1.4%, and 1.4%, respectively, while BlaIPM and Sul1 were found in one isolate (2.7%), for each.

Background: The escalating prevalence of ESBL-producing Enterobacteriaceae in Qatar’s pediatric population, especially in community-onset febrile urinary tract infections (FUTIs), necessitates a comprehensive investigation into this concerning trend. Results: Over the course of one year, a total of 459 infants were diagnosed and subsequently treated for UTIs. Cases primarily occurred in infants aged over 60 days, predominantly non-Qatari females born from term pregnancies. Notably, E. coli and K. pneumoniae were the most frequently identified organisms, accounting for 79.7% and 9.8% in the ESBL group and 57.2% and 18.7% in the non-ESBL group, respectively. Interestingly, hydronephrosis emerged as the most prevalent urological anomaly detected in both ESBL (n = 10) and other organism (n = 19) groups. Methods: In this retrospective cohort study conducted in Qatar, we meticulously evaluated the prevalence of pediatric FUTIs. Our study focused on febrile infants aged less than 1 year, excluding those with urine samples not obtained through a catheter. Conclusions: E. coli and K. pneumoniae prevailed as the predominant causative agents in febrile children in Qatar, with hydronephrosis being identified as the most common urological anomaly. Moreover, our findings suggested that gentamicin served as a viable non-carbapenem option for hospitalized ESBL cases, while oral nitrofurantoin showed considerable promise for uncomplicated ESBL UTIs.

Jiayu Shao, Hangdong Dai, Liwei Xu, Shuilong Zhu, Jufang Zhu, Hangyu Fu, Minxia Ge, Xianhong He Department of Clinical Laboratory, the Third People’s Hospital of Xiaoshan, Hangzhou, People’s Republic of ChinaCorrespondence: Xianhong He; Minxia Ge, Department of Clinical Laboratory, the Third People’s Hospital of Xiaoshan, 76 Zhishan North Road, Hangzhou, Zhejiang, People’s Republic of China, Tel +86 15088760041 ; +86 18057155059, Email miriam1023@163.com; cqmxszj@163.comPurpose: The isolation rate of extended spectrum β-lactamase (ESBL)-producing Escherichia coli is increasing, posing a challenge to clinical anti-infective therapy. This study aims to provide new insight into the genomic characteristics and antimicrobial resistance mechanisms of extended spectrum β-lactamase producing E. coli isolates recovered from a district hospital in China.Methods: A total of 36 ESBL-producing E. coli isolates were collected from body fluid samples from a Chinese district hospital. All isolates were subjected to whole genome sequencing to identify their antimicrobial resistance genes, virulence genes, serotypes, sequence types, and phylogenetic relationships by BacWGSTdb 2.0 webserver.Results: Among these isolates, all were resistant to cefazolin, cefotaxime, ceftriaxone, ampicillin, 24 (66.7%) were resistant to aztreonam, 16 (44.4%) were resistant to cefepime, and 15 were resistant (41.7%) to ceftazidime. The blaCTX-M gene was detected in all ESBL-producing E. coli isolates. Two isolates carrying two different types of blaCTX-M genes simultaneously. The carbapenem resistance gene blaKPC-2 was detected in one (2.8%) isolate. A total of 17 sequence types (STs) were found, with ST131 accounting for the majority (n =13; 36.1%). The most common serotype was O16:H5 associated with seven ST131 strains, followed by O25:H4/ST131 (n = 5) and O75:H5/ST1193 (n = 5). Evaluation of clonal relatedness revealed that all blaCTX-M gene-carrying E. coli had a difference of SNPs range from 7 to 79,198, which could be divided into four clusters. Only 7 SNPs could be found between EC266 and EC622, indicating that they are variants of the same clonal lineage.Conclusion: This study investigated the genomic characteristics of ESBL-producing E. coli isolates recovered from a district hospital in China. Continuous surveillance of ESBL-producing E. coli infections is imperative to create efficient strategies for controlling the transmission of these multi-drug resistant bacteria in clinical and community settings.Keywords: Escherichia coli, ESBLs, antimicrobial resistance, whole genome sequencing

Abstract Background Antimicrobial resistant infections continue to be a leading global public health crisis. Mobile genetic elements, such as plasmids, have been shown to play a major role in the dissemination of antimicrobial resistance (AMR) genes. Despite its ongoing threat to human health, surveillance of AMR in the United States is often limited to phenotypic resistance. Genomic analyses are important to better understand the underlying resistance mechanisms, assess risk, and implement appropriate prevention strategies. This study aimed to investigate the extent of plasmid mediated antimicrobial resistance that can be inferred from short read sequences of carbapenem resistant E. coli (CR-Ec) in Alameda County, California. E. coli isolates from healthcare locations in Alameda County were sequenced using an Illumina MiSeq and assembled with Unicycler. Genomes were categorized according to predefined multilocus sequence typing (MLST) and core genome multilocus sequence typing (cgMLST) schemes. Resistance genes were identified and corresponding contigs were predicted to be plasmid-borne or chromosome-borne using two bioinformatic tools (MOB-suite and mlplasmids). Results Among 82 of CR-Ec identified between 2017 and 2019, twenty-five sequence types (STs) were detected. ST131 was the most prominent (n = 17) followed closely by ST405 (n = 12). bla CTX−M were the most common ESBL genes and just over half (18/30) of these genes were predicted to be plasmid-borne by both MOB-suite and mlplasmids. Three genetically related groups of E. coli isolates were identified with cgMLST. One of the groups contained an isolate with a chromosome-borne bla CTX−M−15 gene and an isolate with a plasmid-borne bla CTX−M−15 gene. Conclusions This study provides insights into the dominant clonal groups driving carbapenem resistant E. coli infections in Alameda County, CA, USA clinical sites and highlights the relevance of whole-genome sequencing in routine local genomic surveillance. The finding of multi-drug resistant plasmids harboring high-risk resistance genes is of concern as it indicates a risk of dissemination to previously susceptible clonal groups, potentially complicating clinical and public health intervention.

Extended-spectrum beta-lactamase-producing Gram-negative bacteria are common in the community and hospitals. To monitor ESBLs mediated by the CTX-M genotype, we collected clinical ESBL pathogenic strains from a hospital in central China and observed a strain of Escherichia coli, namely Ec15103 carrying blaCTX-M-14, blaCTX-M-64 and blaTEM-1, isolated from the blood of a 7-day-old infant in 2015. Strain Ec15103 contains two drug resistance plasmids: pEc15103A, an IncFI-type plasmid that cannot be conjugatively transferred and carries the drug resistance genes blaTEM-1, aacC2, aadA5, sull, mph(A), sul2, strAB, and tetA(A); and pEc15103B, an IncK2/Z-type plasmid that carries the conjugation transfer gene and blaCTX-M-14. In addition, blaCTX-M-64 is located on the chromosome of Ec15103, and it is the first report of pathogen with blaCTX-M-64 located on its chromosome (the search terms used "blaCTX-M-64" and "chromosome"). blaCTX-M-14 and blaCTX-M-64 are carried by ISEcpl-mediated transposon Tn6503a and Tn6502, respectively. The conjugation transfer ability of pEc15103B was significantly inhibited by zidovudine (AZT) and linoleic acid (LA) and that expression of blaCTX-M-14, blaCTX-M-64 and blaTEM-1 at the mRNA level did not change based on the concentration of cefotaxime or ampicillin. Co-occurrence of blaCTX-M-14 and blaCTX-M-64 in a single isolate will enhance the drug resistance of bacteria, and the presence of blaCTX-M-64 in the chromosome may make the resistance more maintain. This fact will facilitate its dissemination and persistence under different antimicrobial selection pressures. It is essential to prevent these strains from further spreading in a hospital environment. [ABSTRACT FROM AUTHOR]

Urinary tract infections (UTIs) are among the most common infections diagnosed in clinical practice. Treatment is often initiated before microbiological confirmation and anti-microbial susceptibility testing. With the rapidly rising antibiotic resistance treatment failures are not uncommon. Beta-lactamase production by gram-negative bacteria causing UTI is the commonest mode of drug resistance. The aim of current study was to detect and determine the hospital based prevalence of UTI, causative uropathogens and their antimicrobial susceptibility patterns. A total of 9,518 clean catch, mid stream urine samples were processed over 2 years. Semi-quantitative urine cultures and AST were performed. Diverse underlying resistance mechanisms were determined by detecting ESBLs, Carbapenemases, AmpC b-Lactamases, and Metallo-b-Lactamases through various standardized phenotypic methods. Out of the 9,518 samples tested 1171 (12.3%) were culture positive. Majority (66.7%) were from female patients. Highest prevalence (60%) was seen in patients > 40 years of age. E. coli (48%) was the predominant causative organism, followed by Enterococcus spp. (23%). Among GNB high resistance rates were observed against Beta-lactams, Beta-lactam/b-lactamase inhibitor combinations, and fluoroquinolones. 34.5% of GNB were confirmed as ESBL, 40% as carbapenemase, 36.5% as AmpC b-Lactamase, and 41.5% as MBL producers. We found very high levels of resistance against a broad range of antibiotics including the most widely used b-lactam group. With the resistance slopes getting steeper and steeper empirical treatment of UTIs might be fraught with the danger of many failures. Culturing and performing AST for all patients with UTI might be a prudent step for their rationale treatment and a step forward in halting the emergence of further resistance. [ABSTRACT FROM AUTHOR]

Emergence of antimicrobial resistance in animal husbandry is of utmost concern as it has resulted in therapeutic failure and nowadays it is one of the latest challenges faced by scientific community across the world. Extensive use of antibiotics without performing antibiotic susceptibility testing may lead to development of multidrug resistant (MDR) organisms. This study was undertaken to assess the AMR pattern and their correlation with plasmid profiling in ESBL producing Klebsiella spp. from bovine origin. Total 160 samples (80 mastitic milk and 80 diarrhoeic faeces) were collected from 2 district of Eastern Plain Zone of Uttar Pradesh (India) and 63 (39.37%) isolates were confirmed as Klebsiella spp. by conventional methods (cultural characteristics on selective media & biochemical tests). Antimicrobial susceptibility testing of confirmed isolates revealed 82.0%-94.0% resistance to 3rd & 4th generation cephalosporin, 100% to ampicillin and all isolates were found 100% sensitive to aminoglycosides, chloramphenicol and polypeptides class of antibiotics. Total 49 (77.8%) isolates were confirmed as ESBL producers using DDST and ESBL E-strip test, out of which 45 (71.43%) isolates revealed the presence of bla-CTX-M gp genes by PCR analysis. On plasmid profiling, total 82.82% isolates revealed the presence of plasmid with molecular weight between 2.5 kb to >10 kb and number 1-2. These high molecular weight plasmids are mostly situated on conjugative plasmid, which are horizontally transferred from one species to another in highly populous country like India. [ABSTRACT FROM AUTHOR]

The antibiotics resistance of aquatic environmental bacteria is an established fact; however, in order to understand its origin and development, it is necessary to elucidate its mechanisms. Basing on the importance of beta-lactams in therapy and extendedspectrum beta-lactamases (ESBLs) as a resistance mechanism, the objective of this work was to investigate ESBLs in Gram negative bacilli recovered from seawaters of Algiers port. Twelve isolates, identified as Citrobacter freundii (n=4), Escherichia coli (n=1), Aeromonas hydrophila (n=2), Vibrio fluvialis (n=4) and Bordetella sp (n=1), were found producers of ESBLs CTX-M-3, CTX-M-15, PER-1, VEB-1, SHV2a and oxacillinase OXA-101. blaCTX-M and blaPER-1 genes were transferred in association with self-transferable plasmids of approximately >70kb and 138 kb, respectively. The class - integrons were present in 7 isolates and were transferable from 3 isolates. The insertion sequence ISEcp1B was found genetically linked to blaCTX-M genes. This study described different types of ESBLs in marine water which is related to anthropogenic inputs. This is an emerging concern around the world and requires implementation of serious resistance monitoring in environment. [ABSTRACT FROM AUTHOR]

Background: The 2017 World Health Organization (WHO) report has listed extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) as critical pathogens for public health and requiring urgently new antibiotics. The aim of this study was to characterize phenotypically and genotypically ESBL-E isolated among clinical samples in Dschang, Cameroon. Methods: A cross-sectional study was conducted during a four-month periods from February to May 2022 in the two biggest hospitals of Dschang. Clinical samples were collected and cultured on Eosin Methylene Blue agar. Suspected growing colonies were biochemically identified using the Enterosystem Kit 18R. Antimicrobial susceptibility testing (AST) was done using the Kirby Bauer disc diffusion method and interpretated according to the CA-SFM recommendations. ESBL phenotypes were double screened using CHROMagar™ ESBL and double disk synergy test (DDST). The detection of resistance genes was performed using conventional and multiplex PCR methods. Results were analyzed with SPSS (version 21) and a p-value < 0.05 was considered statistically significant. Results: A total of 152 Enterobacterales were isolated among 597 clinical samples including urine, blood, cervico-vaginal, urethral swabs and wound samples. The overall prevalence of ESBL-Enterobacterales was 29.61% (45/152). The most represented ESBL species were Escherichia coli (n = 23; 51.11%), Klebsiella pneumoniae (n = 8; 17.78%) and Citrobacter freundii (n = 6; 13.33%). Conclusion: This study reveals the high burden of ESBL-E among clinical samples in the regional hospital in Dschang with the most common species being E. coli and K. pneumoniae. It confirmed the high occurrence of blaCTX−M and blaTEM among ESBL-E. The study suggests that implementing antimicrobial stewardship program and real-time surveillance of antimicrobial resistance are needed in the Western region of Cameroon. Moreover, the implementation of infection prevention and control measures (IPC) is essential to curb the dissemination of these bacteria from community to hospital settings. Implementation of national action plan to fight against antimicrobial resistance at the local levels is urgently needed. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance is considered a major threat facing humanity. It doesn’t only affect public health, but also causes great losses in the dairy industry. Mastitis is a major threat to the dairy industry. The aim of this study was to monitor the antimicrobial resistance of Escherichia coli (E. coli) collected from raw milk of both healthy and mastitis-infected cows and buffaloes in Egypt. In total, 450 milk samples were collected and examined in the period from 2018 to 2021. The samples were collected from healthy cows and buffaloes (30, 58), suffering from clinical mastitis (139, 223), respectively. E. coli was isolated from 33 mastitis milk samples (9.1%) and from 3 (3.4%) normal milk samples. The antibiotic susceptibility testing was performed using the disc diffusion method (Kirby-Bauer method). E. coli isolated from mastitis milk samples showed resistance The Extended Spectrum b-Lactamases test (ESBL) performed on the E. coli isolates showed positive results in 9% of mastitis milk samples, but no results in normal milk samples. Out of 36 E. coli isolates, 34 possessed the ampC gene, but blaTEM and blaSHV were detected in 5 isolates with percentages of 94%, 1.4%, and 1.4%, respectively, while BlaIPM and Sul1 were found in one isolate (2.7%). [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa (P. aeruginosa) is one of the most common causative agents causing mastitis in dairy cattle, which is primarily responsible for the dairy farms' significant economic losses. The purpose of this study was to investigate the prevalence, antimicrobial sensitivity profiling, phenotypic detection of extended- spectrum ß-lactamase (ESBL) producing isolates, molecular identification of major virulence factors (toxA, lasB, and exoS), and biofilm profiles of P. aeruginosa strains isolated from mastitis milk. A total of 200 mastitic milk samples were collected from cows and subjected to bacteriological examination. Suspected colonies were confirmed by PCR targeting the 16S rRNA gene. Positive isolates were genotypically examined to determine the presence of virulence factors (toxA, lasB, and exoS). An antimicrobial susceptibility test was carried out on all positive isolates. The phenotypic detection of ESBL was done using the combination disc test (CDT) and the double disc synergy test (DDST). Finally, biofilm production was accessed through the tube adherent method (TA). Among the total samples, P. aeruginosa was identified in 15% (n = 30) of the retrieved isolates. Virulence genes (toxA, exoS, and lasB) were detected in 100%, 83.3%, and 66.6% of isolates, respectively. Antimicrobial susceptibility testing showed high sensitivity to imipenem, meropenem, ciprofloxacin, colistin, and gentamicin, while all isolates were completely resistant to amoxicillin, penicillin, ceftazidime, ceftriaxone, streptomycin, erythromycin, doxycycline, and spectinomycin. CDT confirmed ESBL production in 15 isolates (50%) and DDST confirmed it in 10 isolates (33.3%). Biofilm formation by the TA method revealed that 33.3% were strong, 33.3% were moderate, 16.6% were weak, and 16.6% were nonadherent isolates. In conclusion, P. aeruginosa strains on dairy farms that harbor virulence genes, produce biofilm, and are resistant to the most popular antimicrobial drug can be hazardous not only to the dairy industry but also for public health. [ABSTRACT FROM AUTHOR]

Introduction: Nosocomial infections (NIs) are a major challenge worldwide. Identification of antibiotic resistance pattern extended spectrum beta-lactamases (ESBLs) and carbapenem-resistant Enterobacteriaceae (CRE) were the objectives of this study. Methods: In this cross-sectional study, the antimicrobial susceptibility pattern of bacterial isolates collected from patients with NIs in ICU was determined. Overall, 42 Escherichia coli and Klebsiella pneumoniae isolates from different infection sites were used to determine phenotypic tests of ESBLs, Metallo-β-lactamases (MBLs) and CRE. Detection of ESBLs, MBLs and CRE genes were performed by the polymerase chain reaction (PCR) method. Results: From 71 patients with NIs, 103 different bacterial strains were isolated. The most frequently isolated bacteria were E. coli (n = 29; 28.16%), Acinetobacter baumannii (n = 15; 14.56%), and K. pneumoniae (n = 13; 12.26%). Also, the rate of multidrug-resistant (MDR) isolates was 58.25% (60/103). Based on phenotypic confirmation tests, 32 (76.19%) isolates of E. coli and K. pneumoniae produced ESBLs, and 6 (14.28%) isolates were identified as CRE producers. PCR showed the high prevalence of the blaCTX-M (n = 29; 90.62%) in ESBL genes. In addition, blaNDM was detected in 4 (66.66%), blaOXA-23 in 3 (50%), and blaOXA-48 gene in 1 (16.66%) isolates. The blaVIM, blaKPC, and blaIMP genes were not detected in any of the isolates. Conclusion: The Gram-negative bacteria E. coli, A. baumannii, and K. pneumoniae with high resistance levels were the most common bacteria causing NIs in the ICU. This study for the first time identified blaOXA-11, blaOXA-23, and blaNDM-1 genes in E. coli and K. pneumoniae in Ilam city of Iran. [ABSTRACT FROM AUTHOR]

Abstract The ubiquitous emergence of bacterial resistance is a challenging problem in infectious diseases treatment. Recently, new research lines employed nano-drug delivery systems to enhance antibacterial activity of the existing antibiotics. Accordingly, the objective of this study is to optimize surfactant nanovesicles to improve the antimicrobial effect of meropenem, ertapenem and tigecycline against Carbapenemase Resistant Enterobacteriaceae (CRE) and extended spectrum beta-lactamases producing bacteria (ESBL). Klebsiella pneumoniae and Escherichia coli were used as the test organisms. In vivo and in vitro evaluations were conducted to prove the efficacy of niosome-encapsulated drugs formulations. The results revealed that surfactant vesicles were able to reduce the MIC values of the tested drugs by nine-fold change compared to their free forms. Scanning Electron Microscope (SEM) showed possible adhesion/fusion of the vesicles encapsulated drugs on the bacterial cells compared to its solution. In vivo investigations using animal skin model confirmed the superiority of nanovesicles drug encapsulation regarding both wound size and histopathological examination. Wound surface area was reduced from 24.6mm2 in absence of drug to reach 13.9, and 6.2mm2 in presence of ertapenem solution or niosomes, respectively. Nanovesicular formulations can be considered as effective drug delivery systems that can diminish bacterial resistance against β-lactams antibiotics.

Introduction: The emergence of multidrug-resistant Pseudomonas aeruginosa poses a global threat, but the distribution and resistance profiling are unclear, especially in young children. Infections due to P. aeruginosa are common, associated with high mortality, and increasingly b-lactam drug resistant. Methods: We studied the molecular epidemiology and antibiotic resistance mechanisms in 294 clinicalisolates of P. aeruginosa from a pediatric hospital in China. Non-duplicate isolates were recovered from clinical cases and were identified using an API-20 kit followed by antimicrobial susceptibility testing using the VITEK®2 compact system (BioMerieux, France) and also by broth dilution method. In addition, a double-disc synergy test for the ESBL/E-test for MBL was performed. The presence of beta-lactamases, plasmid types, and sequence types was determined by PCR and sequencing. Results: Fifty-six percent (n = 164) of the isolates were resistant to piperacillin–tazobactam, followed by cefepime (40%; n = 117), ceftazidime (39%; n = 115), imipenem (36%; n = 106), meropenem (33%; n = 97), and ciprofloxacin (32%; n = 94). Forty-two percent (n = 126) of the isolates were positive for ESBL according to the double-disc synergy test. The blaCTX-M-15 cephalosporinase was observed in 32% (n = 40/126), while 26% (n = 33/126) werepositive for blaNDM-1 carbapenemase. Aminoglycoside resistance gene aac(3)IIIawas observed in 16% (n = 20/126), and glycylcyclines resistance gene tet(A) was observed in 12% (n = 15/126) of the isolates. A total of 23 sequence types were detected, including ST1963 (12%; n = 16), followed by ST381 (11%; n = 14), ST234 (10%; n = 13), ST145 (58%; n = 10), ST304 (57%; n = 9), ST663 (5%; n = 7), and a novel strain. In ESBL-producing P. aeruginosa, 12 different Incompatibility groups (Inc) were observed, the most common being IncFI, IncFIS, and IncA/C. The MOBP was the most common plasmid type, followed by MOBH, MOBF, and MOBQ. Discussion: Our data suggest that the spread of antibiotic resistance is likely due toclonal spread and dissemination of different clinical strains of P. aeruginosa harbouring different plasmids. This is a growing threat in hospitals particularly in young children which needs robust prevention strategies. [ABSTRACT FROM AUTHOR]

Enterobacter species are members of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species) which are described as the leading cause of resistant nosocomial infections.Objectives: The present study aimed to estimate the frequency of Multi-Drug resistant Enterobacter species isolated from Patients with different Clinical manifestations in Khartoum state, Sudan.Methods: A cross-sectional laboratory-based study was conducted from February 2021 to October 2021. To isolate and identify Enterobacter species from different clinical specimens by conventional cultural methods, and to determine the antimicrobial profile of Enterobacter species by Kirby–Bauer disc diffusion technique.Result: A total of three hundred and eighty-four (n=384) different clinical specimens (urine 232(60%), wound swab 61 (16%), sputum 19(5%), and blood 72 (19%) specimens were collected from Yastabshiroon Hospital, Khartoum, 129(33.6%), Ribat Teaching Hospital, Khartoum, 255(66.4%), 173 (45.0%) were from males, while 212 (55.0%) from females, among 154(40%) bacterial isolate 22(14.3%) were identified as Enterobacter spp. All Enterobacter spp isolates (100%) were multidrug resistant, The Prevalence rates of resistance of the isolates among antibiotic classes were as follows; (Penicillin 100%, Cephalosporin 96.4%, Tetracycline group 100%, Aminoglycosides 47.7%, Sulfonamides and trimethoprin 86.4%, Nitrofuran 100%, Quinolone 72.75%, Glycopeptides 100%, Chloramphnicol 100%, Tetracycline 81.8% and Carbapenem 52.3%).Conclusion: This study is the first study reporting the frequency of Multi-drug resistance Enterobacter species in Sudan. The results of this study indicated the high prevalence of Enterobacter species resistant to the majority of assessed antibiotics, and high prevalence rates of carbapenemase and ESBL-producing Enterobacter species In Khartoum- Sudan. [ABSTRACT FROM AUTHOR]

Background: This study aimed to determine the epidemiology of gram-negative bacteria (GNB) isolated in the newborn intensive care unit (NICU) population, to assess their antibiotic susceptibility patterns and possible associated risk factors. Methods: All neonates admitted to the NICU of Abderrezak-Bouhara hospital (Skikda, Algeria) with a clinical diagnosis of neonatal infections from March to May 2019 were included in the study. The extended-spectrum β-lactamase (ESBLs), plasmidic cephalosporinase (pAmpC), and carbapenemases genes were screened by polymerase chain reaction (PCR) and sequencing. PCR amplification of oprD among carbapenem-resistant Pseudomonas aeruginosa isolates was also performed. The clonal relatedness of the ESBLs isolates was studied using multilocus sequence typing (MLST). Results: Among 148 clinical specimens, 36 (24.3%) GNB strains were isolated from urine (n = 22), wound (n = 8), stool (n = 3), and blood (n = 3) samples. The bacterial species identified were Escherichia coli (n = 13), Klebsiella pneumoniae (n = 5), Enterobacter cloacae (n = 3), Serratia marcescens (n = 3), Salmonella spp. (n = 3), Proteus mirabilis (n = 1), P. aeruginosa (n = 5), and Acinetobacter baumannii (n = 3). PCR and sequencing showed that eleven Enterobacterales isolates harbored the blaCTX-M-15 gene, two E. coli isolates harbored the blaCMY-2 gene, and three A. baumannii isolates harbored both blaOXA-23 and blaOXA-51 genes. Also, five strains of P. aeruginosa were found to harbor mutations in the oprD gene. MLST showed that the K. pneumoniae strains belonged to ST13 and ST189, E. coli belonged to ST69, and E. cloacae belonged to ST214. Different risk factors that could predict positive GNB cultures were found, including female sex, Apgar score <8 at 5 min of life, enteral nutrition, antibiotic use, and extended length of hospitalization. Conclusion: Our study highlights the importance of determining the epidemiology of pathogens causing neonatal infections, their sequence types (ST), and their antibiotic susceptibility patterns to address rapidly a correct antibiotic treatment regimen. [ABSTRACT FROM AUTHOR]

Escherichia coli are one of the most important pathogenic bacteria readily found in the livestock and widely studied as an indicator that carries drug-resistant genes between humans, animals, and the environment. The use of antimicrobials in the food chain, particularly in food-producing animals, is recognized as a significant contributor to the development and spread of antimicrobial resistance (AMR) and resistance genes can be transferred from the farm through the food-chain. The objective of this review is to highlight the background of the antimicrobials use in food-producing animals, more specifically, to study clonal lineages and the resistance profiles observed in E. coli, as well as in extended spectrum beta-lactamases (ESBL) producing E. coli, in a set of food-production animals with greater relevance in food consumption, such as pigs, poultry, cattle, fish farming and rabbits. Regarding the prevalence of ESBL-producing E. coli among farm animals, high-to-moderate prevalence was observed, and the highest resistance rates to tetracycline and ampicillin was detected in different farms in all geographic regions. Worldwide pandemic clones and high-risk zoonotic E. coli clones have been identified in most food-producing animals, and some of these clones are already disseminated in different niches, such as the environment and humans. A better understanding of the epidemiology of E. coli and ESBL-producing E. coli in livestock is urgently needed. Animal production is one of the major causes of the antibiotic resistance problem worldwide and a One Health approach is needed. [ABSTRACT FROM AUTHOR]