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BackgroundThe emergence of ESBLs producing cephalosporin-resistant Escherichia coli isolates poses a threat to public health. This study aims to decipher the genetic landscape and gain insights into ESBL-producing E. coli strains belonging to the high-risk clone ST410 from pediatric patients.Methods29 E. coli ST410 isolates were collected from young children and subjected to antimicrobial susceptibility testing, Whole-genome sequencing (WGS), serotype analysis, MLST, ESBL genes, virulence genes, and plasmid profiling.ResultsAntimicrobial susceptibility testing demonstrated a high level of resistance to cephalosporins followed by aminoglycoside, sulfonamide, carbapenem and penicillin group of antibiotics. However, n=20/29 shows MDR phenotype. Phylogenetic group B2 (n=15) dominated, followed by group D (n=7), group A (n=4), and group B1 (n=3). Serotyping analysis identified O1:H7 (n=8), O2:H1 (n=6), O8:H4 (n=5), O16:H5 (n=4), and O25:H4 (n=3). Other serotypes identified included O6:H1, O15:H5, and O18:H7 (n=1 each). The most commonly detected ESBL genes were blaCTX-M, (n=26), followed by blaTEM (n=23), and blaSHV (n=18). Additionally, blaOXA-1 (n=10), blaOXA-48 (n=5), blaKPC-2 (n=3), blaKPC-3 (n=2), blaNDM-1 (n=4), blaNDM-5 (n=1), blaGES-1 (n=2), blaGES-5 (n=1), and blaCYM-1 (n=3). Notable virulence genes identified within the ST410 isolates included fimH (n=29), papC (n=24), hlyA (n=22), and cnf1 (n=18), among others. Diverse plasmids were observed including IncFIS, IncX4, IncFIA, IncCol, IncI2 and IncFIC with transmission frequency ranges from 1.3X10-2 to 2.7X10-3.ConclusionThe ST410 clone exhibited a complex resistance profile, diverse serotypes, the presence of specific resistance genes (ESBL genes), virulence gene repertoire, and diverse plasmids. The blaCTX-M was the most prevalent ESBL gene detected.

Introduction: Plasmid-mediated class C ß-lactamase (pAmpC) is a member of broad-spectrum ß-lactamase that spreads worldwide. However, its prevalence was under-evaluated. Objective: To characterize the prevalence and distribution of pAmpC types in 294 cefoxitin (FOX) and third-generation cephalosporin (3GC) resistant Enterobacteriaceae collected in several regions of Thailand and Vietnam in 2018 and 2020. Methods: Multiplex Polymerase Chain Reaction (PCR) for pAmpC identification was utilized to investigate prevalence and diversification of pAmpC among 294 cefoxitin and third-generation cephalosporin resistant Enterobacteriaceae isolated from Thailand (n= 197) and Vietnam (n= 97). Results: The prevalence of pAmpC was 37.1 % found in second and third-generation cephalosporin resistant Enterobacteriaceae. CMY-2 like was prominent in Thailand and Vietnam; however, prevalence of CMY-2 was varied in each hospital. DHA contributed 25.7 %, ACT/MIR rate was dominant in Chiang Rai hospital, reached 100 % in Thanh Hoa Pediatrics hospital. Worrisome, 3.7 % - isolates carried two types of pAmpC. The incidence of pAmpC in Vietnam was significantly higher than those in Thailand. Conclusions: These findings provide evidence-based of highly spreading and diversified distribution of transferable AmpC among Enterobacteriaceae in two Asia-Pacific countries.

ABSTRACT: We investigated the cephalosporin resistance of Escherichia coli from waterfowl among different breeding mode farms. In 2021, we isolated 200 strains of E. coli from waterfowl feces samples collected from Sichuan, Heilongjiang, and Anhui provinces. The key findings are: Out of the 200 strains, 80, 80, and 40 strains were isolated from waterfowl feces samples in intensive, courtyard, and outdoor breeding mode farms, respectively. The overall positive rate of the ESBL phenotype, detecting by the double disk diffusion method, was 68.00% (136/200). In particular, the rates for intensive, courtyard, and outdoor breeding modes were 98.75%, 36.25%, and 70.00%, respectively. Results of MIC test showed drug resistance rates in the intensive breeding mode: 100.00% for cephalothin, 38.75% for cefoxitin, 100.00% for cefotaxime, and 100.00% for cefepime. In courtyard breeding mode, the corresponding rates were 100.00%, 40.00%, 63.75%, and 45.00%, respectively. In outdoor breeding mode, the corresponding rates were 100.00%, 52.50%, 82.50%, and 77.50%, respectively. The PCR results for blaCTX-M, blaTEM, blaOXA, and blaSHV showed the detection rate of blaCTX-M was highest at 75.50%, with blaCTX-M-55 is the main subtype gene, followed by blaTEM at 73.50%. We screened 58 donor strains carrying blaCTX-M-55, including 52 strains from the intensive breeding mode. These donor bacteria can transfer different plasmids to recipient E. coli J53, resulting in recipient bacteria acquiring cephalosporin resistance, and the conjugational transfer frequency ranged from 1.01 × 10-5 to 6.56 × 10-2. The transferred plasmids remained stable in recipient bacteria for up to several days without significant adaptation costs observed. During molecular typing of E. coli with conjugational transfer ability, the blaCTX-M-55 was found to be widely present in different ST strains with several phylogenetic groups. In summary, cephalosporin resistance of E. coli carried by waterfowl birds in intensive breeding mode farm was significantly higher than in courtyard and outdoor mode farms. The blaCTX-M-55 subtype gene was the prevalent ARGs and can be horizontally transferred through plasmids, which plays a key role in the spread of cephalosporin drug resistance.

It was in the 1800s when the first public publications about the infection and treatment of gonorrhoea were released. However, the first prevention programmes were only published a hundred years later. In the 1940s, the concept of vaccination was introduced into clinical prevention programmes to address early sulphonamide resistance. Since then, tons of publications on Neisseria gonorrhoeae are undisputed, around 30,000 publications today. Currently, the situation seems to be just as it was in the last century, nothing has changed or improved. So, what are we doing wrong? And more importantly, what might we do? The review presented here aims to review the current situation regarding the resistance mechanisms, prevention programmes, treatments, and vaccines, with the challenge of better understanding this special pathogen. The authors have reviewed the last five years of advancements, knowledge, and perspectives for addressing the Neisseria gonorrhoeae issue, focusing on new therapeutic alternatives.

Third generation cephalosporin-resistant (3GCR) Enterobacterales are known to be prevalent in Madagascar, with high colonization or infection rates in particular in Madagascan patients. Extended spectrum beta-lactamases (ESBLs) have been reported to be the predominant underlying resistance mechanism in human isolates. So far, little is known on antimicrobial resistance and its molecular determinants in Enterobacterales and other bacteria causing enteric colonization of Madagascan wild animals. To address this topic, swabs from 49 animal stool droppings were collected in the Madagascan Tsimanapesotsa National Park and assessed by cultural growth of bacterial microorganisms on elective media. In addition to 7 Acinetobacter spp., a total of 31 Enterobacterales growing on elective agar for Enterobacterales could be isolated and subjected to whole genome sequencing. Enterobacter spp. was the most frequently isolated genus, and AmpC-type beta-lactamases were the quantitatively dominating molecular resistance mechanism. In contrast, the blaCTX-M-15 gene, which has repeatedly been associated with 3GC-resistance in Madagascan Enterobacterales from humans, was detected in a single Escherichia coli isolate only. The identification of the fosfomycin-resistance gene fosA in a high proportion of isolates is concerning, as fosfomycin is increasingly used to treat infections caused by multidrug-resistant bacteria. In conclusion, the proof-of-principle assessment indicated a high colonization rate of resistant bacteria in stool droppings of Madagascan wild animals with a particular focus on 3GCR Enterobacterales. Future studies should confirm these preliminary results in a more systematic way and assess the molecular relationship of animal and human isolates to identify potential routes of transmission.

Among 114 clinical Neisseria gonorrhoeae isolates collected in Vietnam during 2019–2020, we detected 15 of subclone sequence type 13871 of the FC428 clonal complex. Fourteen sequence type 13871 isolates with mosaic penA allele 60.001 were ceftriaxone or cefixime nonsusceptible, and 3/14 were azithromycin nonsusceptible. Emergence of this subclone threatens treatment effectiveness.

ABSTRACT Enterococcus faecalis is an opportunistic pathogen and a major cause of severe nosocomial infections. Treatment options against enterococcal infections are declining due to the resistance of enterococci to numerous antibiotics. A key risk factor for developing enterococcal infections is treatment with cephalosporin antibiotics, to which enterococci are intrinsically resistant. For susceptible organisms, cephalosporins inhibit bacterial growth by acylating the active site of penicillin-binding proteins (PBPs), key enzymes that catalyze peptidoglycan cross-linking. Two specific PBPs of enterococci, Pbp4(5) and PbpA(2b), exhibit low reactivity toward cephalosporins, allowing these PBPs to cross-link peptidoglycan in the presence of cephalosporins to drive resistance in enterococci, but the mechanisms by which these PBPs are regulated are poorly understood. The CroS/R two-component signal transduction system (TCS) is also required for cephalosporin resistance. Activation of CroS/R by cephalosporins leads to CroR-dependent changes in gene expression. However, the specific genes regulated by CroS/R that are responsible for cephalosporin resistance remain largely unknown. In this study, we characterized CroR-dependent transcriptome remodeling by RNA-seq, identifying pbp4(5) as a CroR regulon member in multiple, diverse lineages of E. faecalis. Through genetic analysis of the pbp4(5) and croR promoters, we uncovered a CroR-dependent regulatory motif. Mutations in this motif to disrupt CroR-dependent upregulation of pbp4(5) in the presence of cell wall stress resulted in a reduction of resistance to cephalosporins in E. faecalis, demonstrating that enhanced production of Pbp4(5) and likely other proteins involved in peptidoglycan biogenesis by the CroS/R system drives enterococcal cephalosporin resistance. IMPORTANCE Investigation into molecular mechanisms used by enterococci to subvert cephalosporin antibiotics is imperative for preventing and treating life-threatening infections. In this study, we used genetic means to investigate the functional output of the CroS/R TCS required for enterococcal resistance to cephalosporins. We found that enhanced production of the penicillin-binding protein Pbp4(5) upon exposure to cell wall stress was mediated by CroS/R and was critical for intrinsic cephalosporin resistance of E. faecalis.

Abstract By 2010, systems set up to monitor the antimicrobial resistance of pathogenic bacteria and antimicrobial usage identified a sustained increase regarding third‐ and fourth‐generation cephalosporin resistance in French pig production. This sector mobilised and collectively committed to responsible action in the following months. This led to a multi‐professional voluntary stewardship programme that was started in 2011. A consensus of veterinary opinion led to the definition of restrictive rules on the prescription of the third‐ and fourth‐generation cephalosporins targeted by the antimicrobial stewardship programme (ASP). All pig sector professionals, including farmers, were informed. Existing monitoring systems for usage and resistance were supplemented by data from the records of veterinarians' cephalosporin deliveries and from individual pig farm surveys investigating antimicrobial usage. The second step, from 2014, entailed regulatory measures that consolidated the programme by setting quantitative reduction objectives and specifying the terms and conditions for prescribing and dispensing a list of critical antimicrobial molecules including cephalosporins. All the data sources confirmed a significant fall of more than 90% in cephalosporin usage in the French pig production sector between 2010 and 2016. Monitoring systems recorded that the resistance of commensal and pathogenic Escherichia coli isolates also tended to decrease over the same period. The stewardship programme proved highly effective in reducing usage and containing resistance, illustrating the efficiency of a well‐defined multi‐professional strategy.

In this study, the susceptibility to cephalosporins of 74 Salmonella isolates, including 16 isolates from farm animals and 58 isolates from poultry was assessed by the disc diffusion method. ESBL production was evaluated by combined disc diffusion method (CDDM) and double disc synergy test (DDST). The genetic relatedness of isolates was investigated by the Rep-PCR method. The highest prevalence of resistance was observed against cefotaxime (27%) and the least – against cefixime (4%). None of the isolates was ESBL positive. The Rep-PCR generated 54 reproducible fingerprint patterns for all isolates and grouped them in four clusters and six singletons. Due to public health risk of cross contamination, it is important to have sufficient information on the occurrence of these resis-tant isolates.

We evaluated the impact of the administration of two Escherichia coli probiotic strains (ED1a and Nissle 1917) to pigs on the gut carriage or shedding of extended-spectrum beta-lactamase-producing E. coli. The probiotics were given to four sows from 12 days before farrowing to the weaning day, and to the 23 piglets (infected treated group (IPro)) from birth to the age of 49 days. Four other sows and their 24 piglets (infected non-treated group (INT)) did not receive the probiotics. IPro and INT piglets (n = 47) were orally inoculated with the strain E. coli 17–348F-RifR carrying the blaCTX−M-1 gene and resistant to rifampicin. Cefotaxime-resistant (CTXR) E. coli and rifampicin-resistant (RifR) E. coli were cultured and excretion of probiotics was studied using PCR on individual faecal and post-mortem samples, and from manure collected after the challenge with resistant E. coli. CTXR and RifR E. coli isolates were characterized to detect transfer of the blaCTX−M-1 to other strains.. Overall, there was no significant reduction in faecal excretion of CTXR and RifR E. coli in IPro pigs compared with INT pigs, although the CTXR and RifR E. coli titres were slightly, but significantly lower in the colon, caecum and rectum at post mortem. Excretion of the probiotics decreased with age, but Nissle 1917 was detected in most pigs at post-mortem. No transfer of the blaCTX−M-1 gene to probiotic and other E. coli strains was detected. In conclusion, in our experimental conditions, the used probiotics did not reduce shedding of the challenge strain.

White stork (Ciconia ciconia) may act as a reservoir and vehicle of cephalosporin resistant (CR) Escherichia coli. Between 2011 and 2014, we sampled white storks from colonies exposed to different degrees of anthropic pressure across the major areas of natural distribution of white storks in Spain. Cloacal swab samples (n = 467) were obtained from individuals belonging to 12 different colonies from six different regions. Additionally, 70 samples were collected from recently deposited droppings at the base of nesting platforms. We phenotypically characterized E. coli isolates, confirmed presence of CR genes and classified plasmids. Risk factors for acquiring these genes were assessed. Overall, 8.8% (41 out of 467) storks carried CR E. coli in their cloaca and five (7.1%) were identified from recently deposited droppings; therefore, 46 isolates were further characterized. Of them, 20 contained blaCTX–M–1, nine blaCMY–2, six blaCTX–M–14, four blaSHV–12, three blaCTX–M–15, two blaCTX–M–32, one blaCTX–M–1 together with blaCMY–2, and one blaCTX–M–1 together with blaSHV–12. All were multidrug-resistant, and four harbored the plasmid-mediated colistin resistance mcr-1 gene. CR genes were associated with the presence of IncI1, IncFIB, and IncN replicon families. XbaI-macrorestriction analysis revealed a great diversity among most of the XbaI-PFGE types, but indistinguishable types were also seen with isolates obtained from different locations. Clonal complex 10 was the most common among CR E. coli and two blaCTX–M–15 positive isolates were identified as B2-ST131. Carriage of CR E. coli was significantly higher in colonies located close to solid urban waste disposal sites in which foraging on human waste was more likely and in one case to cattle grazing. The co-occurrence of blaCMY–2 and mcr-1 on plasmids of E. coli isolated from wild birds as early as 2011 is of note, as the earliest previous report of mcr-1 in wild birds is from 2016. Our study shows that foraging at landfills and in association with cattle grazing are important risk factors for the acquisition of CR E. coli in white storks.

Escherichia coli carrying blaCTX–M–1 mediating resistance to extended-spectrum cephalosporins was recently described as a new genotype in Norwegian broiler production. The aim of this study was to characterize these isolates (n = 31) in order to determine whether the emergence of the genotype was caused by clonal expansion or horizontal dissemination of blaCTX–M–1-carrying plasmids. All included isolates were subjected to whole genome sequencing. Plasmid transferability was determined by conjugation, and plasmid replicons in the transconjugants were described using PCR-based replicon typing. Plasmid sizes were determined using S1 nuclease digestion. Plasmids in a subset of strains were reconstructed and compared to plasmids from broiler production in other European countries. The isolates belonged to nine different sequence types (STs), with the largest group being ST57 (n = 12). The vast majority of blaCTX–M–1-carrying plasmids were conjugative. All transconjugants were positive for the IncI1-Iγ replicon, and several also harbored the IncFIB replicon. Highly similar plasmids were present in different E. coli STs. Additionally, high similarity to previously published plasmids was detected. A reconstructed plasmid from an ST57 isolate harbored both IncI1-Iγ and IncFIB replicons and was considered to be co-integrated. The presence of one large plasmid was confirmed by S1 nuclease digestion. Our results show that dissemination of blaCTX–M–1 in Norwegian broiler production is due to both clonal expansion and horizontal transfer of plasmids carrying blaCTX–M–1. The blaCTX–M–1/IncI1-Iγ plasmids grouped into two main lineages, namely clonal complex (CC)-3 and CC-7. The genetic diversity at both strain and plasmid level indicates multiple introductions to Norway. We also show that the blaCTX–M–1 plasmids circulating in Norwegian broiler production are highly similar to plasmids previously described in other countries.

This study aims to investigate and compare the complete nucleotide sequences of the multidrug resistance plasmids pVb0267 and pVb0499, which were recovered from foodborne Vibrio parahaemolyticus isolates, and analyze the genetic environment of blaCTX–M–55 to provide insight into the dissemination mechanisms of this resistance element. Analysis of the sequences of plasmids pVb0267 (166,467 bp) and pVb0499 (192,739 bp) revealed that the backbones of these two plasmids exhibited a high degree of similarity with pR148, a recognized type 1a IncC plasmid recovered from Aeromonas hydrophila (99% identity). The resistance genes, found in both plasmids, included qacH, aadB, arr2, blaOXA–10, aadA1, sul1, tet(A), and blaCTX–M–55, which were mostly arranged in a specific region designated ARI-A. Plasmid pVb0499 was found to possess a larger size of ARI-A than pVb0267, which lacked a mer determination region, a qnr A segment, an aacC3 gene and several mobility-encoding genes. Comparative analysis of resistance island (RI) of these plasmids and others revealed the potential evolution route of these RI sequences. In conclusion, plasmids harboring the blaCTX–M–55 gene has been recovered in Vibrio parahaemolyticus strains of food origin. It is alarming to find that IncC plasmids harboring resistance islands are disseminating in aquatic bacterial strains. The continuous evolution of resistance genes in conjugative plasmid in aquatic bacteria could be due to bacterial adaption to aquaculture environment, where antibiotics were increasingly used.

Extensively drug-resistant (XDR) Salmonella Typhi has been reported in Sindh province of Pakistan since 2016. The potential for further spread is of serious concern as remaining treatment options are severely limited. We report the phenotypic and genotypic characterization of 27 XDR S. Typhi isolated from patients attending Jinnah Hospital, Lahore, Pakistan. Isolates were identified by biochemical profiling; antimicrobial susceptibility was determined by a modified Kirby–Bauer method. These findings were confirmed using Illumina whole genome nucleotide sequence data. All sequences were compared to the outbreak strain from Southern Pakistan and typed using the S. Typhi genotyping scheme. All isolates were confirmed by a sequence analysis to harbor an IncY plasmid and the CTX-M-15 ceftriaxone resistance determinant. All isolates were of the same genotypic background as the outbreak strain from Sindh province. We report the first emergence of XDR S. Typhi in Punjab province of Pakistan confirmed by whole genome sequencing.

Introduction: Septicaemia is one of the significant causes of morbidity and mortality in Intensive Care Units (ICUs). The rate of antimicrobial resistance in ICU is very high compared to general hospital setting. Aim: To enumerate common bacterial pathogens causing sepsis and to identify their antimicrobial susceptibility pattern. Materials and Methods: This was a retrospective descriptive study done in patients with sepsis during January 2016 to December 2017. The Institutional Ethical Committee clearance was obtained. Data were collected from inpatient case files regarding clinical history, laboratory parameters with special reference to causative organisms and antibiotic sensitivity pattern. Data were entered in Microsoft Excel sheet and analysed using strata 14.0. Results: Among 216 subjects of sepsis admitted to ICU during study period, 130 (60.1%) were males, with mean age of 52.83 year (±16.6 SD). Pneumonia (31.94%) was the major cause of sepsis followed by urosepsis. Gram negative organisms were the major cause of sepsis accounting for 76.25% of organisms isolated. Escherichia coli was the most common organism isolated in urine (65.9%) and blood cultures (32%). All Gram negative bacteria had high level of resistance to Amoxicillin Clavulunic Acid (Amoxyclav) (85.9%), ampicillin sulbactum (66.7%) and third generation cephalosporins (70%). Conclusion: Gram negative organisms were the principal causes of septicaemia. Cephalosporin resistance was more than 70%. Acinetobacter species was resistant to most antibiotics. The knowledge of bacterial profile of sepsis and antibiotic susceptibility pattern not only helps in improving outcome but also prevents emergence of drug resistance strains.

A genomic analysis of Comamonas testosteroni S44 revealed a gene that encodes a LysR family transcriptional regulator (here named czoR, czo for cefazolin) located upstream of a putative class A β-lactamase encoding gene (here named czoA). A putative DNA-binding motif of the Fe–S cluster assembly regulator IscR was identified in the czoR–czoA intergenic region. Real-time RT-PCR and lacZ fusion expression assays indicated that transcription of czoA and czoR were induced by multiple β-lactams. CzoA expressed in Escherichia coli was shown to contribute to susceptibility to a wide range of β-lactams judged from minimum inhibitory concentrations. In vitro enzymatic assays showed that CzoA hydrolyzed seven β-lactams, including benzylpenicillin, ampicillin, cefalexin, cefazolin, cefuroxime, ceftriaxone, and cefepime. Deletion of either iscR or czoR increased susceptibility to cefalexin and cefazolin, while complemented strains restored their wild-type susceptibility levels. Electrophoretic mobility shift assays (EMSA) demonstrated that CzoR and IscR bind to different sites of the czoR–czoA intergenic region. Precise CzoR- and IscR-binding sites were confirmed via DNase I footprinting or short fragment EMSA. When cefalexin or cefazolin was added to cultures, czoR deletion completely inhibited czoA expression but did not affect iscR transcription, while iscR deletion decreased the expressions of both czoR and czoA. These results reveal that CzoR positively affects the expression of czoA with its own expression upregulated by IscR.

Objective: The aim of this study was to investigate the occurrence and molecular characterization of extended-spectrum β-lactamases (ESBL), plasmid-mediated AmpC β-lactamase (pAmpC) and carbapenemases as well as plasmid-mediated quinolone-resistant (PMQR) among extended-spectrum cephalosporin-resistant (ESC-R) Escherichia coli from dogs in Shaanxi province in China.Methods: A total of 40 ESC-R Escherichia coli selected from 165 Extraintestinal pathogenic E. coli (ExPEC) isolated from dogs were screened and characterized for the genes encoding for the ESBLs, pAmpC, carbapenemases and PMQR genes by PCR and sequencing. Phylogenetic groups, virulence gene profiles and multilocus sequence typing (MLST) were used to investigate the genetic background of the ESC-R E. coli isolates. Results: Among 40 ESC-R E. coli, the predominant β-lactamase gene was blaCTX-Ms (n=35), and followed by blaTEM-1 (n=31), blaSHV-12 (n=14), blaOXA-48 (n=8), blaTEM-30 (n=4), blaCMY-2 (n=3) and blaDHA-1 (n=2). The most common specific blaCTX-M gene subtype was blaCTX-M-15 (n=31), and followed by blaCTX-M-123 (n=14), blaCTX-M-1 (n=10), blaCTX-M-14 (n=10) and blaCTX-M-9 (n=7). PMQR genes were detected in 32 (80%) isolates, and the predominant PMQR gene was aac(6')-Ib-cr (n=26), followed by qnrS (n=12), qnrD (n=9), qnrB (n=8), qepA (n=4), and all PMQR genes were detected in co-existence with β-lactamase genes. traT (n=34) and fimH (n=32) were the most prevalent virulence genes, and virulence genes fimH, iutA, fyuA, malX, iha and sat were more prevalent in phylogenetic group B2. The 40 ESC-R isolates analyzed were assigned to 22 sequence types (STs), and the clonal lineages ST131 (n=10) and ST10 (n=9) were the predominant STs. Conclusion: High prevalence of β-lantamases and PMQR genes were detected among ESC-R E. coli from companion animals. This is also the first description of the co-existence of six β-lantamase genes and five PMQR genes in one E. coli isolate. Moreover, ten ST131 clones harboring CTX-M-15 were detected.

CMY-2 ß-lactamase is an important cause of ß-lactam resistance in Enterobacteriaceae and constitutes the most widespread pAmpC. Although CMY-2 has been previously recognized in our region, the real prevalence and epidemiology of this resistance marker was uncertain. During August-October 2009, we conducted a multicenter, prospective study to determine pAmpC prevalence and to characterize CMY-2 producing Escherichia coli associated plasmids. Plasmid-encoded AmpC prevalence was 0.9 % in enterobacteria in this period, being CMY- 2 prevalent and to a lesser extent DHA. Molecular typing of CMY-2- producing Escherichia coli isolates showed several lineages. Moreover, replicon typing of cmy-2- containing plasmids displayed a broad diversity in Inc/cmy- 2 links. Therefore, association of cmy-2 with specific transposon elements may be responsible for the spread of this resistance marker in Enterobacteriaceae.La ß-lactamasa de tipo AmpC de codificación plasmídica CMY-2 es la de mayor diseminación a nivel mundial en Enterobacteriaceae. Esta ha sido comunicada esporádicamente en nuestro país. Entre agosto y octubre de 2009 se llevó a cabo un estudio prospectivo y multicéntrico con el objetivo de determinar la prevalencia de pAmpC en nuestro medio y de caracterizar a los microorganismos productores y a los plásmidos portadores de estos marcadores de resistencia. La prevalencia de pAmpC plasmídicas en enterobacterias en este período fue de 0,9 %. La ß-lactamasa CMY-2 fue la enzima prevalente y, en menor medida, la DHA. La tipificación molecular de los aislamientos de Escherichia coli productores de CMY-2 mostró la presencia de distintos linajes, y los plásmidos portadores de cmy-2 pertenecieron a una amplia diversidad de grupos de incompatibilidad. Se determinó la asociación corriente arriba de cmy-2 con ISEcp1, el cual podría ser responsable de la amplia diseminación de este marcador de resistencia en Enterobacteriaceae.

Gonorrhea, a disease of public health importance, not only leads to high incidence of acute infections and complications but also plays a major role in facilitating human immunodeficiency virus (HIV) acquisition and transmission. One of the major public health needs for gonorrhea control is appropriate, effective treatment. However, treatment options for gonorrhea are diminishing as Neisseria gonorrhoeae have developed resistance to several antimicrobial drugs such as sulfonamides, penicillin, tetracyclines and quinolones. Antimicrobial resistance (AMR) surveillance of N. gonorrhoeae helps establish and maintain the efficacy of standard treatment regimens. AMR surveillance should be continuous to reveal the emergence of new resistant strains, monitor the changing patterns of resistance, and be able to update treatment recommendations so as to assist in disease control. Current treatment guidelines recommend the use of single dose injectable or oral cephalosporins. The emergence and spread of cephalosporin resistant and multi drug resistant N. gonorrhoeae strains, represents a worrying trend that requires monitoring and investigation. Routine clinical laboratories need to be vigilant for the detection of such strains such that strategies for control and prevention could be reviewed and revised from time to time. It will be important to elucidate the genetic mechanisms responsible for decreased susceptibility and future resistance. There is also an urgent need for research of safe, alternative anti-gonococcal compounds that can be administered orally and have effective potency, allowing high therapeutic efficacy (greater than 95.0% cure rate).

Limited data identify the risk factors for infection with Enterobacteriaceae resistant to third-generation cephalosporins among residents of long-term-care facilities. Using a nested case-control study design, nursing home residents with clinical isolates of Enterobacteriaceae resistant to third-generation cephalosporins were compared to residents with isolates of Enterobacteriaceae susceptible to third-generation cephalosporins. Data were collected on antimicrobial drug exposure 10 weeks before detection of the isolates, facility-level demographics, hygiene facilities, and staffing levels. Logistic regression models were built to adjust for confounding variables. Twenty-seven case-residents were identified and compared to 85 controls. Exposure to any cephalosporin (adjusted odds ratio [OR] 4.0, 95% confidence interval [CI] 1.2 to13.6) and log percentage of residents using gastrostomy tubes within the nursing home (adjusted OR 3.9, 95% CI 1.3 to 12.0) were associated with having a clinical isolate resistant to third-generation cephalosporins.

Abstract A total of 318 Escherichia coli isolates obtained from different food-producing animals affected with colibacillosis between 2001 and 2006 were subjected to phylogenetic analysis: 72 bovine isolates, 89 poultry isolates and 157 porcine isolates. Overall, the phylogenetic group A was predominant in isolates from cattle (36/72, 50%) and pigs (101/157, 64.3%) whereas groups A (44/89, 49.4%) and D (40/89, 44.9%) were predominant in isolates from poultry. In addition, group B2 was not found among diseased food-producing animals except for a poultry isolate. Thus, the phylogenetic group distribution of E. coli from diseased animals was different by animal species. Among the 318 isolates, cefazolin resistance (minimum inhibitory concentrations: ≥32 μg/ml) was found in six bovine isolates, 29 poultry isolates and three porcine isolates. Of them, 11 isolates (nine from poultry and two from cattle) produced extended spectrum β-lactamase (ESBL). The two bovine isolates produced blaCTX-M-2, while the nine poultry isolates produced blaCTX-M-25 (4), blaSHV-2 (3), blaCTX-M-15 (1) and blaCTX-M-2 (1). Thus, our results showed that several types of ESBL were identified and three types of β-lactamase (SHV-2, CTX-M-25 and CTX-M-15) were observed for the first time in E. coli from diseased animals in Japan.

The objective of this study was to evaluate the susceptibility to cefepime of a large group of ESBL- producing enterobacteria recently isolated in a Brazilian teaching hospital . The study included 280 strains of ESBL-producing enterobacteria, isolated between 2005 and 2008. The presence of the genes blaCTX-M, blaTEM and blaSHV was determined by PCR and confirmed by nucleotide sequencing. Susceptibility testing for cefepime was performed by disc-diffusion, agar dilution method and E-test®. Among the isolates, 34 (12.1%) presented a cefepime inhibition zone > 21 and MIC < 8 mg/L by agar dilution and E-strip methods. The use of cefepime for the treatment of infections caused by ESBL-producing bacteria has been controversial. Some studies of PD/PK show the probability of achieving the required PD parameters for cefepime, when the MICs were < 8 mg/L, whereas others have reported therapeutic failure with the same MIC. Additional data is essential to come to terms about the report and treatment with cefepime in ESBL-producing organisms especially when these microorganisms are isolated from sterile sites and from critically ill patients.