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Background: Bacterial growth rate, commonly reported in terms of doubling time, is frequently determined by one of two techniques: either by measuring optical absorption of a growing culture or by taking samples at different times during their growth phase, diluting them, spreading them on agar plates, incubating them, and counting the colonies that form. Both techniques require measurements of multiple repeats, as well careful assessment of reproducibility and consistency. Existing literature using either technique gives a wide range of growth rate values for even the most extensively studied species of bacteria, such as Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. This work aims to apply several methods to reliably determine the growth rate of a recently identified species of Enterobacteriaceae, called Enterobacter sp. SM3, and to compare that rate with that of a well-known wildtype E. coli strain KP437. Results: We extend conventional optical density (OD) measurements to determine the growth rate of Enterobacter sp. SM3. To assess the reliability of this technique, we compare growth rates obtained by fitting the OD data to exponential growth, applying a relative density method, and measuring shifts in OD curves following set factors of dilution. The main source of error in applying the OD technique is due to the reliance on an exponential growth phase with a short span. With proper choice of parameter range, however, we show that these three methods yield consistent results. We also measured the SM3 division rate by counting colony-forming units (CFU) versus time, yielding results consistent with the OD measurements. In lysogeny broth at 37oC, SM3 divides every 21 ± 3 min, notably faster than the RP437 strain of E. coli, which divides every 29 ± 2 min. Conclusion: The main conclusion of this report is that conventional optical density (OD) measurements and the colony-forming units (CFU) method can yield consistent values of bacterial growth rate. However, to ensure the reproducibility and reliability of the measured growth rate of each bacterial strain, different methods ought to be applied in close comparison. The effort of checking for consistency among multiple techniques, as we have done in this study, is necessary to avoid reporting variable values of doubling time for particular species or strains of bacteria, as seen in the literature. [ABSTRACT FROM AUTHOR]

Background: Many Gram-negative enterobacteria translocate virulence proteins (effectors) into intestinal epithelial cells using a type III secretion system (T3SS) to subvert the activity of various cell functions possess. Many T3SS effectors have been extensively characterized, but there are still some effector proteins whose functional information is completely unknown. Methods: In this study, two predicted effectors of unknown function, EspN and EspS (Escherichia coli secreted protein N and S), were selected for analysis of translocation, distribution and structure prediction. Results: The TEM1 (β-lactamase) translocation assay was performed, which showed that EspN and EspS are translocated into host cells in a T3SS-dependent manner during bacterial infection. A phylogenetic tree analysis revealed that homologs of EspN and EspS are widely distributed in pathogenic bacteria. Multiple sequence alignment revealed that EspN and its homologs share a conserved C-terminal region (673–1133 a.a.). Furthermore, the structure of EspN (673–1133 a.a.) was also predicted and well-defined, which showed that it has three subdomains connected by a loop region. EspS and its homologs share a sequence-conserved C-terminal (146–291 a.a.). The predicted structure of EspS (146–291 a.a.) is composed of a β-sheet consisting of four β-strands and several short helices, which has a TM score of 0.5014 with the structure of the Vibrio cholerae RTX cysteine protease domain (PDBID: 3eeb). Conclusions: These results suggest that EspN and EspS may represent two important classes of T3SS effectors associated with pathogen virulence, and our findings provide important clues to understanding the potential functions of EspN and EspS. [ABSTRACT FROM AUTHOR]

The swine production chain can be a reservoir of antimicrobial-resistant Escherichia coli, which transfers resistance genes to other bacteria, serving as an important biomarker in the One Health approach. This study aimed to identify the frequency and antimicrobial resistance profile of E. coli in the swine production chain, assess the presence of extended-spectrum beta-lactamases (ESBL), and compare resistance profiles across different sample types. A total of 622 samples of swine carcasses from various points of the slaughter process (n = 400), swine feces (n = 100), commercial cuts (n = 45), environment (n = 67), and feces from employees (n = 10) of a pig slaughterhouse certified by the Federal Inspection Service, located in São Paulo state, Brazil, were collected. A total of 1260 E. coli isolates were obtained from the samples, with 73.6% of the samples testing positive. The agar disk diffusion test was performed with 10 different classes of antimicrobials. To confirm the production of ESBLs, the isolates were submitted to a double-disk synergism test using cefotaxime, ceftazidime, and amoxicillin with clavulanic acid. Of the total isolates, 80.71% were multidrug resistant. All ESBL-producing isolates were multidrug resistant and resistant to amoxicillin, tetracycline, and chloramphenicol. Isolates from human feces samples had less chance of being multidrug resistant than samples from other sources. The diversity of resistance profiles was verified in the samples, not clustering according to the sources, except for human feces isolates that clustered, evidencing lower antimicrobial resistance variability of these samples. Antimicrobial resistance is significantly present in the pork production chain, necessitating a comprehensive multidisciplinary approach to effectively mitigate risks within the One Health framework. [ABSTRACT FROM AUTHOR]

The preservation of microorganisms is pivotal in microbiological practice. Currently, cryopreservation is assumed to be an effective and inexpensive approach for the storage of microorganisms, including bacteria. The key point of cryopreservation is optimal cryoprotectant selection. In the present study, different cryoprotectant compositions were tested for long-term storage of 15 Enterobacterales bacterial strains at − 20 °C. The survival rates of the bacterial strains were evaluated in four different cryoprotectant solutions containing 70% glycerin only (cryoprotectants 1 and 4), 10% dimethyl sulfoxide (DMSO) with 70% glycerin (cryoprotectant 2), and 10% DMSO (cryoprotectant 3). In addition, cryoprotectants 1 and 2 contained peptone and yeast extract as nutritional supplements. The general survival rates of the bacterial strains were evaluated after 12 months of storage. After 12 months, the survival rates of the different cryoprotectants were as follows: cryoprotectant 1—88.87%; cryoprotectant 2—84.85%; cryoprotectant 3—83.50%; and cryoprotectant 4—44.81%. Thus, the composition of cryoprotectant 1 (70% glycerin with nutrient supplements) was optimal for preserving 15 tested strains of the order Enterobacterales. Despite these findings, the biochemical properties of the tested strains changed after cryopreservation for 12 months in the presence of 1 or 3 cryoprotectants. Alterations in the biochemical profile could be related to changes in environmental conditions and cold adaptation. We assume that the composition of cryoprotectant 1 can be optimal for storing the order Enterobacterales at − 20 °C. However, further investigations are needed to elucidate the problem of cryopreservation and to support our assumption. [ABSTRACT FROM AUTHOR]

The Enterobacteriaceae is a large family of bacteria that includes many important bacterial pathogens known for their high virulence and contributions to the global antimicrobial resistance threat. We aimed, through this study, to provide a comparative overview of the genomes, resistance determinants, and stress signaling pathway of 22 enterobacterial clinical isolates. Our results showed that Escherichia coli harbored the lowest percentage of core genes (44 % versus 58 % in Salmonella enterica, and 52 % in Klebsiella pneumoniae) and the highest percentage of strain- specific genes (31 % versus 18 % in S. enterica and 24 % in K. pneumoniae). All bacterial strains included in the analysis encoded genes for resistance to commonly used antibacterials, including cell envelope acting antibiotics, aminoglycosides, quinolones, and sulphonamide. The resistance genes showed different distributions among the core, dispensable and/or strain-specific genomes, ranging from an almost equal distribution in E. coli and S. enterica to higher occurrence in the dispensable/ strain specific genome in K. pneumoniae. Depending on the bacterial genus, cell envelope acting antibiotics occupied between 15 % - 30 % of the core genome resistome. In addition, the sequence diversity of different proteins of the signalling pathway “the regulator of colanic acid capsule synthesis” (Rcs), which is involved in sensing and responding to cell envelope threats was examined. High diversity of two domains in Rcs system proteins (i.e., IgaA first cytosolic domain and RcsD pseudokinase) was observed despite high conservation of all other proteins. All these differences might point out to specific adaptation strategies of the studied bacterial isolates to antibiotic exposure and ecological niche variation.

Abstract The preservation of microorganisms is pivotal in microbiological practice. Currently, cryopreservation is assumed to be an effective and inexpensive approach for the storage of microorganisms, including bacteria. The key point of cryopreservation is optimal cryoprotectant selection. In the present study, different cryoprotectant compositions were tested for long-term storage of 15 Enterobacterales bacterial strains at − 20 °C. The survival rates of the bacterial strains were evaluated in four different cryoprotectant solutions containing 70% glycerin only (cryoprotectants 1 and 4), 10% dimethyl sulfoxide (DMSO) with 70% glycerin (cryoprotectant 2), and 10% DMSO (cryoprotectant 3). In addition, cryoprotectants 1 and 2 contained peptone and yeast extract as nutritional supplements. The general survival rates of the bacterial strains were evaluated after 12 months of storage. After 12 months, the survival rates of the different cryoprotectants were as follows: cryoprotectant 1—88.87%; cryoprotectant 2—84.85%; cryoprotectant 3—83.50%; and cryoprotectant 4—44.81%. Thus, the composition of cryoprotectant 1 (70% glycerin with nutrient supplements) was optimal for preserving 15 tested strains of the order Enterobacterales. Despite these findings, the biochemical properties of the tested strains changed after cryopreservation for 12 months in the presence of 1 or 3 cryoprotectants. Alterations in the biochemical profile could be related to changes in environmental conditions and cold adaptation. We assume that the composition of cryoprotectant 1 can be optimal for storing the order Enterobacterales at − 20 °C. However, further investigations are needed to elucidate the problem of cryopreservation and to support our assumption.

Background. The outcome of complex treatment of implant-associated infection (IAI) depends on various factors, but one of the most important is the etiology of the inflammatory process. Treatment of orthopedic infection caused by Gram-negative microorganisms in general and representatives of the family Enterobacteriaceae in particular causes many difficulties, one of which is the rapid growth of antibiotic resistance. Aim of the study — to evaluate the factors affecting the course and prognosis of implant-associated infection caused by Klebsiella spp. Methods. We performed a retrospective analysis of case histories of 85 patients who underwent treatment of IAI caused by Klebsiella spp. in the clinical departments of the center from January 1, 2017 to December 31, 2021. According to the results of the telephone survey, the patients were divided into 2 main groups depending on the outcome of the 2-year follow-up period determined in accordance with the Delphi criteria. Results. It was found that the prognosis was significantly worsened by the number of sanitizing surgical interventions in the anamnesis (p = 0.022), the need for sanitizing intervention in the early postoperative period (p0.001) and the presence of Klebsiella spp. growth in postoperative culture tests (p = 0.002), hypoalbuminemia on 7-14 days after the surgery (p = 0.008). The administration of trimethoprim-sulfamethoxazole for the outpatient treament stage significantly improved the outcome (p = 0.038), which is most likely due to a high proportion of polymicrobial associations — 69.5%. Conclusions. There is a statistically significant direct relationship between the probability of an unfavorable treatment outcome of patients with IAI caused by Klebsiella spp. and the number of sanitizing surgical interventions in the anamnesis, low serum albumin (g/l) on 7-14 days after the operation, revision intervention in the early postoperative period, positive growth of Klebsiella spp. in postoperative culture tests. The probability of a favorable outcome was increased by the prescription of trimethoprim-sulfamethoxazole for oral administration at the outpatient stage.

Today, enterobacteria constitute one of the most predominant causes of nosocomial and acquired infections in our communities. The bactericidal action of antibiotics on bacteria is used therapeutically, unfortunately the latter have started to develop resistances. Antibiotic resistance remains a major global public health issue, a serious problem in some of the world's poorest countries such as Chad. The objective of this study is to identify the strains of enterobacteria coming from samples of patients admitted to the Moundou and Sarh health centers, and to report their resistance profiles. A total of 278 samples consisting of urine (133) and stools (145) were collected in the laboratories of the two provincial hospitals of Sarh and Moundou between September and December 2021. The samples were processed and analyzed according to standard microbiology methods. The study of the sensitivity of different strains of enterobacteria with 14 antibiotic disks was evaluated by the disk diffusion method in agar medium. A total of 278 samples (urine, stool) including 111 strains of Enterobacteria, including 55 strains of E. coli, Enterobacter spp (n=17), klebsiella (n=11), Salmonella (n=9), Serratia ( n=7), Citrobacter (n=6) and Shigella (n=2) were isolated in the laboratory in the towns of Moundou and Sarh in Chad. The antibiogram carried out on all isolated strains of enterobacteria expressed a resistance ranging between 33.3% and 83.3% to 3rd generation cephalosporins, 30.3% and 50.0% to aminoglycosides. On the other hand, a strain of Salmonella is resistant to imipenem in Sarh. This study shows a high level of resistance acquired to different families of antibiotics by our bacterial strains studied. This resistance highlights the need to adapt therapeutic regimens to local epidemiology. [ABSTRACT FROM AUTHOR]

This study aimed to identify contamination sources in raw milk and cheese on small farms in Brazil by isolating Escherichia coli at various stages of milk production and cheese manufacturing. The study targeted EAEC, EIEC, ETEC, EPEC, STEC, and ExPEC pathotypes, characterizing isolates for the presence of virulence genes, phylogroups, antimicrobial susceptibility, and phylogenetic relationships using PFGE and MLST. The presence of antimicrobial resistance genes and serogroups was also determined. Three categories of E. coli were identified: pathogenic, commensal, and ceftriaxone-resistant (ESBL) strains. Pathogenic EPEC, STEC, and ExPEC isolates were detected in milk and cheese samples. Most isolates belonged to phylogroups A and B1 and were resistant to antimicrobials such as nalidixic acid, ampicillin, kanamycin, streptomycin, sulfisoxazole, and tetracycline. Genetic analysis revealed that E. coli with identical virulence genes were present at different stages within the same farm. The most frequently identified serogroup was O18, and MLST identified ST131 associated with pathogenic isolates. The study concluded that E. coli was present at multiple points in milk collection and cheese production, with significant phylogroups and high antimicrobial resistance. These findings highlight the public health risk posed by contamination in raw milk and fresh cheese, emphasizing the need to adopt hygienic practices to control these microorganisms. [ABSTRACT FROM AUTHOR]

During the COVID-19 pandemic, changes occurred within the surgical patient population. An increase in the frequency of resistant Gram-negative bacteria has since been recorded worldwide. After the start of the COVID-19 pandemic, microbiological diagnostics in our institution was performed using MALDI-TOF mass spectrometry. With this study, we wanted to confirm whether it contributed to a greater number of pathogenic bacteria detected in surgical ICU patients. A total of 15,033 samples taken from 1781 surgical patients were compared during the period from 2016 to February 2020 and during the COVID-19 pandemic from March 2020 to February 2023. On patients' admission, pathogenic bacteria were mostly isolated from the respiratory system (43.1% and 44.9%), followed by urine cultures (18.4 vs. 15.4%) before and during the pandemic. After the onset of the COVID-19 pandemic, there was a significant increase in the frequency of isolation of Enterobacter spp. (5.4 before vs. 9%, p = 0.014) and other enterobacteria (6.9 vs. 10.8%, p = 0.017) on patients' admission to the ICU, respectively. Despite this change, mortality in the ICU during the post-COVID-19 period was reduced from 23 to 9.6% (p < 0.001). The frequency of bacterial isolation did not change with the application of MALDI-TOF technology. By identifying the microorganism while simultaneously recognizing some resistance genes, we were able to start targeted therapy earlier. With the application of other infection control methods, MALDI-TOF may have contributed to the reduction in mortality in surgical ICU patients during the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

During the COVID-19 pandemic, the occurrence of carbapenem-resistant Klebsiella pneumoniae increased in human clinical settings worldwide. Impacted by this increase, international high-risk clones harboring carbapenemase-encoding genes have been circulating in different sources, including the environment. The blaKPC gene is the most commonly disseminated carbapenemase-encoding gene worldwide, whose transmission is carried out by different mobile genetic elements. In this study, blaKPC-2-positive Klebsiella pneumoniae complex strains were isolated from different anthropogenically affected aquatic ecosystems and characterized using phenotypic, molecular, and genomic methods. K. pneumoniae complex strains exhibited multidrug-resistant and extensively drug-resistant profiles, spotlighting the resistance to carbapenems, ceftazidime-avibactam, colistin, and tigecycline, which are recognized as last-line antimicrobial treatment options. Molecular analysis showed the presence of several antimicrobial resistance, virulence, and metal tolerance genes. In-depth analysis showed that the blaKPC-2 gene was associated with three different Tn4401 isoforms (i.e., Tn4401a, Tn4401b, and Tn4401i) and NTEKPC elements. Different plasmid replicons were detected and a conjugative IncN-pST15 plasmid harboring the blaKPC-2 gene associated with Tn4401i was highlighted. K. pneumoniae complex strains belonging to international high-risk (e.g., ST11 and ST340) and unusual clones (e.g., ST323, ST526, and ST4216) previously linked to clinical settings. In this context, some clones were reported for the first time in the environmental sector. Therefore, these findings evidence the occurrence of carbapenemase-producing K. pneumoniae complex strains in aquatic ecosystems and contribute to the monitoring of carbapenem resistance worldwide. [ABSTRACT FROM AUTHOR]

ABSTRACT Promiscuous biotin ligases derived from the bacterial enzyme BirA are used to identify proteins vicinal to a bait protein, thereby defining its proxisome. Despite the popularity of this approach, surprisingly little is known about its use in prokaryotes. Here, we compared the activity of four widely used promiscuous biotin ligases in the cytoplasm of Shigella flexneri, a pathogenic subgroup of Escherichia coli. Our data indicate that the kinetics of TurboID’s biotinylating activity is the highest of those tested. In addition, TurboID showed reduced interaction with the natural BirA binding partners, BccP and the biotin operator, when compared to its ancestor BioID. We therefore evaluated the ability of TurboID to probe the proxisome of the type III secretion system (T3SS) chaperone IpgC and the transcriptional activator MxiE. When the T3SS is inactive (off-state), these proteins are inhibited by forming complexes with the T3SS substrates OspD1 and IpaBC, respectively. In contrast, when the T3SS is active (on-state), OspD1 and IpaBC are secreted allowing MxiE and IpgC to interact together and activate their target genes. The results obtained with the IpgC and TurboID fusions capture a good fraction of these known interactions. It also suggests that the availability of IpgC increases in the on-state, resulting in a greater number of proteins detected in its vicinity. Among these is the T3SS ATPase SpaL (also known as Spa47 or SctN), further supporting the notion that chaperones escort their substrate to the T3SS. Interestingly, a specific subset of proteins conserved in E. coli completes the IpgC proxisome in the on-state.IMPORTANCEPromiscuous biotin ligases are widely used to study protein function in eukaryotes. Strikingly, their use in prokaryotes has been rare. Indeed, the small volume and the cytoplasmic location of the biotin ligase’s natural binding partners in these organisms pose unique challenges that can interfere with the study of the proxisome of proteins of interest. Here, we evaluated four of the most common promiscuous biotin ligases and found TurboID was best suited for use in the cytoplasm of Shigella flexneri. Using this method, we extended the proxisome of IpgC beyond its known direct binding partners involved in the regulation of the type III secretion system (T3SS) signaling cascade. Of particular interest for further study are transcription factors and housekeeping proteins that are enriched around IpgC when the T3SS is active. We propose a model in which the increased availability of IpgC in the on-state may allow cross-talk of the T3SS with other cellular processes.

Prevention of morbidity in the child population from septic foodborne infections caused by the new bacterial pathogen Enterobacter sakazakii (according to the new classification - Cronobacter spp.) is becoming increasingly relevant due to an expanding contingent of susceptible individuals and the proven ability of low doses of the pathogen to quickly increase a population in dry specialized products for formula feeding after rehydration. In this regard, it is important to assess the risk of accumulation of thermoresistant coliform enterobacteria, including Cronobacter spp., in residual microflora of such products during their production in order to determine ways to minimize it. To identify a hazardous factor in specialized infant formula of domestic production, we summarized and analyzed expert data on contamination of 245 samples of infant formula and 182 cereals with the entire spectrum of coliform enterobacteria, which were previously identified as Enterobacter sakazakii (Cronobacter spp.). Cronobacter spp. was detected in 4 samples of instant formula (1.6 %) in amounts ranging from 0.04 to 0.5 CFU/g, which is above the hazardous level (≥ 0.003 CFU/g) for susceptible children. No pathogen was isolated from dry mixtures for cooking and instant porridges produced by dry mixing but the content of heat-resistant Enterobacter spp. was 10 times higher than those produced during the full cycle. Using a risk process model and assuming the content of coliforms in raw milk at the level of the regulated microbial number, probability of pathogen survival in dry mixtures was assessed under standard parameters of spray drying technology. The calculation results showed that under this scenario of raw material contamination, 0.3–0.5 CFU of heat-resistant E.sakazakii (Cronobacter spp.) can be retained in 1 g of a finished product. This substantiates the necessity to introduce the strongest possible requirements for the microbiological quality of raw milk.

Introduction. The multifactorial etiology of gastroenteritis emphasizes the need for different laboratory methods to identify or exclude infectious agents and evaluate the severity of diarrheal disease. Objective. To diagnose the infectious etiology in diarrheic children and to evaluate some fecal markers associated with intestinal integrity. Materials and methods. The study group comprised 45 children with diarrheal disease, tested for enteropathogens and malabsorption markers, and 76 children whose feces were used for fat evaluation by the traditional and acid steatocrit tests. Results. We observed acute diarrhea in 80% of the children and persistent diarrhea in 20%. Of the diarrheic individuals analyzed, 40% were positive for enteropathogens, with rotavirus (13.3%) and Giardia duodenalis (11.1%) the most frequently diagnosed. Among the infected patients, occult blood was more evident in those carrying pathogenic bacteria (40%) and enteroviruses (40%), while steatorrhea was observed in infections by the protozoa G. duodenalis (35.7%). Children with diarrhea excreted significantly more lipids in feces than non-diarrheic children, as determined by the traditional (p

We examined the effects of elevated temperatures and biocides on survivability of food isolates of Cronobacter spp. (C. sakazakii) and concomitant enterobacteriaceae obtained in microbiological control of infant nutrition products. Increased resistance of certain strains of Cronobacter, Enterobacter cloacae, and Pantoea spp. to thermal processing was revealed. Salmonella, Pantoea, and Cronobacter bacteria were least sensitive to antimicrobial action of chlorine-containing agents. The above properties varied in the strains of the same species. Specifically, only two of three examined isolates of Cronobacter spp. demonstrated lower sensitivity to heat in comparison with the enterobacterial test-cultures of other species. [ABSTRACT FROM AUTHOR]

The problem of bacterial resistance to antibiotics has become a global issue and a major health challenge that requires continuous studies on how this resistance develops and spreads, and its relationship to resistance to other factors such as heavy metals and biocides. The current study aimed to determine the prevalence and distribution of antibiotics, heavy metals, and biocides-resistant genes on the chromosomes and plasmids of some Enterobacteria species. The results showed that antibiotics resistant genes (blaCTXxS, sul 1) were present in all isolates except for Klebsiella pneumoniae chromosome, while for heavy metals resistant genes, czcA detected in all isolates except for K. pneumoniae plasmid, ncc gene was only detected in the chromosome of Escherichia coli O157.H7 and E. coli, and plasmid of E. coli O157.H7. biocides gene (qacEΔ1) was present in all isolates except for the E. faecalis chromosome. The current study resulted that the studied resistance genes spread clearly among the types of Enterobacteria, and this reflects the possibility of transmission of these genes among the bacteria present in this habitat. [ABSTRACT FROM AUTHOR]

Antimicrobials serve as crucial treatments in both veterinary and human medicine, aiding in the control and prevention of infectious diseases. However, their misuse or overuse has led to the emergence of antimicrobial resistance, posing a significant threat to public health. This review focuses on extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in animals and their associated food products, which contribute to the proliferation of antimicrobial-resistant strains. Recent research has highlighted the presence of ESBL-producing E. coli in animals and animal-derived foods, with some studies indicating genetic similarities between these isolates and those found in human infections. This underscores the urgent need to address antimicrobial resistance as a pressing public health issue. More comprehensive studies are required to understand the evolving landscape of ESBLs and to develop strategic public health policies grounded in the One Health approach, aiming to control and mitigate their prevalence effectively. [ABSTRACT FROM AUTHOR]

Background: Pink coloration of breast milk is uncommon and it's associated with colonization by Serratia marcescens, which is most frequently isolated in intensive care settings. Misinterpretation of the pink coloration may lead to premature cessation of breastfeeding. The objective is to present four cases of pink discoloration. Methods: Two retrospective and two prospective cases of pink discoloration in breast milk are described, which were reported to the lead author. Results: Four healthy mother-infant pairs with documented pink discoloration are presented. S. marcescens was isolated from breast milk samples. All four infants were asymptomatic and underwent enterobacteria cultures. The mothers received outpatient antibiotic treatment, and two infants received treatment as well. Subsequent cultures yielded negative results, and the pink discoloration ceased. All mothers successfully resumed breastfeeding. Conclusions: There are very few reported cases of pink breast milk in the global literature. Colonization by S. marcescens is not an indication for discontinuation of breastfeeding. [ABSTRACT FROM AUTHOR]

Copyright of Biomédica: Revista del Instituto Nacional de Salud is the property of Instituto Nacional de Salud of Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The consumption of seafood is crucial for food security, but poor hygiene along the food production chain can result in low microbiological quality, posing significant risks for public health and seafood quality. Thus, this study aimed to assess the microbiological quality and antimicrobial sensitivity of E. coli from 69 samples of illegally marketed shrimp and mussels in the Vitória Region, Brazil. These foods exhibited poor microbiological quality due to high counts of mesophilic, psychrotrophic, and enterobacteria microorganisms. While this issue is widespread in this area, shrimp samples displayed higher microbial counts compared to mussels, and fresh mussels had elevated counts of enterobacteria compared to frozen ones. Among the 10 E. coli isolates, none carried the genes blaCTX-M-1, blaCTX-M-2, blaCTX-M-3, blaCTX-M-15, mcr-1, mcr-2, mcr-3, mcr-4, and tet, associated with antibiotic resistance. Phenotypical resistance to tetracycline and fosfomycin was not observed in any isolate, while only 20% demonstrated resistance to ciprofloxacin. Regarding ampicillin and amoxicillin with clavulanic acid, 60% of isolates were resistant, 10% showed intermediate susceptibility, and 30% were sensitive. One isolate was considered simultaneously resistant to β-lactams and quinolones, and none were conserved as ESBL producers. These findings highlight the inherent risks to local public health that arise from consuming improperly prepared seafood in this area. [ABSTRACT FROM AUTHOR]

ABSTRACT: This investigation elucidated the presence of potentially zoonotic and antimicrobial-resistant bacteria in domestically reared psittacines. The present study was sanctioned by the Animal Ethics Committee of the State University of Ceará (CEUA-UECE) and bears registration number 03423745/2023. A total of 111 cloacal swab samples were procured from exotic psittacines encompassing six distinct species: the Australian budgerigar (Melopsittacus undulatus), cockatiels (Nymphicus hollandicus), lovebirds (Agapornis sp.), rose-ringed parakeets (Psittacula krameri), red-rumped parrots (Psephotus haematonotus), and rosellas (Platycercus eximius). The process encompassed the isolation and characterization of enterobacteria and ascertaining their resistance profiles. Among the collected specimens, 70.2% (78/111) yielded growth indicative of one or more enterobacterial agents. The collective isolates comprised 110 strains encompassing 13 distinct bacterial species. Foremost among these was Escherichia coli, accounting for a significant percentage of the total isolates at 30% (33/110), followed by Pantoea agglomerans at 27.2% (30/110). The study revealed that 35.4% (39/110) of the isolates exhibited resistance to tobramycin, with tetracycline and fosfomycin showing resistance rates of 34.5% (38/110) and 30.9% (34/110), respectively. Particularly noteworthy was that E. coli showed a heightened propensity for tetracycline resistance at 51.5% (17/33), while resistance rates to tobramycin and gentamicin were 36.6% (12/33) and 15.1% (5/33), respectively. A noteworthy subset of the enterobacterial cohort exhibited multidrug resistance patterns (28.9%, 32/110). Collectively, these outcomes underscore not only an elevated prevalence of enterobacterial strains but also the pervasive phenomenon of antimicrobial resistance across a diverse spectrum of antimicrobial agents.

Antibiotics have long been overused for non-therapeutic purposes. As a result, Escherichia, Enterobacter, Klebsiella, and Proteus in avian microbiomes have become reservoirs for genetic determinants of resistance, thus spreading resistance to antibiotics and contaminating raw materials and finished products. The food industry is looking for alternative means to preserve health and maintain high productivity of commercial poultry, e.g., probiotics, phytobiotics, organic acids, etc. The research featured the effect of antibiotics and phytobiotics on enteropathogenic bacteria in the microbiomes of broiler chicken. Escherichia coli bacteria were cultivated in vitro in subthreshold concentrations on nutrient media with antibiotics for 37 days to study the effect of low doses of antibiotics on the sensitivity of isolates. The study involved microbiocenoses of broiler chicken that received avilamycin A and a phytobiotic based on Brassica juncea, Linum usitatissimum, and Nigella sativa L. A set of experiments covered the species composition of opportunistic Enterobacteriaceae, the phenotypic sensitivity to antibiotics, and the genetic determinants of resistance, as well as the antimicrobial potential of phytobiotics. E. coli developed no resistance for 37 days when the antibiotic dose remained below minimal inhibitory. Opportunistic gram-negative Enterobacterales predominated in all litter samples. E. coli, Klebsiella pneumoniae, and Proteus mirabilis accounted for more than 30% of all isolated strains. Avilamycin A and the phytobiotic affected the coccal microflora but had no effect on the genus-species composition of Enterobacteriaceae. Litter samples from both experimental and control groups demonstrated K. pneumoniae with severe phenotypic resistance to ciprofloxacin, as well as blaDHA genes. In broiler farming, maintenance and circulation of resistance agents depends on litter microbiota. In this research, the chicken that received the phytobiotic showed the lowest level of resistance to ciprofloxacin while the groups that received avilamycin A had the highest resistance results. During a broiler’s life span, bacteria with no active resistance determinants in their genome remained sensitive to antibiotics, even though the contact with the latter was constant. Phytobiotics showed good prospects for broiler farming as food additive that could reduce and eventually eliminate the intake of antibiotics.

The swine production chain can be a reservoir of antimicrobial-resistant Escherichia coli, which transfers resistance genes to other bacteria, serving as an important biomarker in the One Health approach. This study aimed to identify the frequency and antimicrobial resistance profile of E. coli in the swine production chain, assess the presence of extended-spectrum beta-lactamases (ESBL), and compare resistance profiles across different sample types. A total of 622 samples of swine carcasses from various points of the slaughter process (n = 400), swine feces (n = 100), commercial cuts (n = 45), environment (n = 67), and feces from employees (n = 10) of a pig slaughterhouse certified by the Federal Inspection Service, located in São Paulo state, Brazil, were collected. A total of 1260 E. coli isolates were obtained from the samples, with 73.6% of the samples testing positive. The agar disk diffusion test was performed with 10 different classes of antimicrobials. To confirm the production of ESBLs, the isolates were submitted to a double-disk synergism test using cefotaxime, ceftazidime, and amoxicillin with clavulanic acid. Of the total isolates, 80.71% were multidrug resistant. All ESBL-producing isolates were multidrug resistant and resistant to amoxicillin, tetracycline, and chloramphenicol. Isolates from human feces samples had less chance of being multidrug resistant than samples from other sources. The diversity of resistance profiles was verified in the samples, not clustering according to the sources, except for human feces isolates that clustered, evidencing lower antimicrobial resistance variability of these samples. Antimicrobial resistance is significantly present in the pork production chain, necessitating a comprehensive multidisciplinary approach to effectively mitigate risks within the One Health framework.

Aim The objective of this study was to investigate the antimicrobial resistance genes (ARGs) in plasmids of Enterobacteriaceae from soil, sewage, and feces of food-producing animals and humans. Methods and results The plasmid sequences were obtained from the NCBI database. For the identification of ARG, comprehensive antibiotic resistance database (CARD), and ResFinder were used. Gene conservation and evolution were investigated using DnaSP v.6. The transfer potential of the plasmids was evaluated using oriTfinder and a MOB-based phylogenetic tree was reconstructed using Fastree. We identified a total of 1064 ARGs in all plasmids analyzed, conferring resistance to 15 groups of antibiotics, mostly aminoglycosides, beta-lactams, and sulfonamides. The greatest number of ARGs per plasmid was found in enterobacteria from chicken feces. Plasmids from Escherichia coli carrying multiple ARGs were found in all ecosystems. Some of the most abundant genes were shared among all ecosystems, including aph(6)-Id, aph(3′')-Ib, tet(A) , and sul2. A high level of sequence conservation was found among these genes, and tet(A) and sul2 are under positive selective pressure. Approximately 62% of the plasmids carrying at least one ARG were potentially transferable. Phylogenetic analysis indicated a potential co-evolution of Enterobacteriaceae plasmids in nature. Conclusion The high abundance of Enterobacteriaceae plasmids from diverse ecosystems carrying ARGs reveals their widespread distribution and importance. [ABSTRACT FROM AUTHOR]

Antibiotic resistance in Citrobacter freundii is a public health concern. This study evaluated the closed genome of a C. freundii isolated from the stool of a hospitalized patient initially related to a Salmonella outbreak. Confirmation of the isolate was determined by whole-genome sequencing. Nanopore sequencing was performed using a MinION with a Flongle flow cell. Assembly using SPAdes and Unicycler yielded a closed genome annotated by National Center for Biotechnology Information Prokaryotic Genome Annotation Pipeline. Genomic analyses employed MLST 2.0, ResFinder4.1, PlasmidFinder2.1, and VFanalyzer. Phylogenetic comparison utilized the Center for Food Safety and Applied Nutrition (CFSAN)-single nucleotide polymorphism pipeline and Genetic Algorithm for Rapid Likelihood Inference. Antimicrobial susceptibility was tested by broth microdilution following Clinical and Laboratory Standards Institute criteria. Multi-locus sequence type in silico analysis assigned the C. freundii as sequence type 64 and the bla CMY-41 gene was detected in resistome investigation. The susceptibility to antibiotics, determined using Sensititre® plates, revealed resistance to aztreonam, colistin, cefoxitin, amoxicillin/clavulanic acid, sulfisoxazole, ampicillin, and streptomycin. The genetic relatedness of the C. freundii CFSAN077772 with publicly available C. freundii genomes revealed a close relationship to a C. freundii SRR1186659, isolated in 2009 from human stool in Tanzania. In addition, C. freundii CFSAN077772 is nested in the same cluster with C. freundii clinical strains isolated in Denmark, Mexico, Myanmar, and Canada, suggesting a successful intercontinental spread. [ABSTRACT FROM AUTHOR]

Escherichia coli is a major player in foodborne illnesses, capable of forming biofilms on dairy facilities, leading to milk contamination. Thus, we examined the capacity of E. coli strains from raw milk bulk tanks to form biofilms on surfaces made of polystyrene, stainless steel, and silicone; the potential links between biofilm formation with genes responsible for fimbriae and virulence factors of extra-intestinal E. coli (ExPEC); and the susceptibility of biofilm-forming isolates to iodine and chlorhexidine digluconate. Out of 149 E. coli strains, 42.28% (63/149) formed biofilm on polystyrene, 56.38% (84/149) on silicone, and 21.48% (32/149) on stainless steel. The frequency of genes was: fimH (100%), hlyA (5.4%), irp2 (2.7%), sitA (10.7%), ompT (43.6%), and traT (98%). No biofilm developed when disinfectants were used prior to biofilm formation. However, iodine and chlorhexidine digluconate allowed 25.40% (16/63) of isolates displaying growth after a mature biofilm was formed. The presence of biofilm on different surfaces emphasizes the vital need for thorough equipment cleaning, both in farms and in industrial dairy settings. Rapid disinfection is crucial, given the reduced susceptibility of potentially pathogenic E. coli after biofilm maturity. [ABSTRACT FROM AUTHOR]

Escherichia coli is a major player in foodborne illnesses, capable of forming biofilms on dairy facilities, leading to milk contamination. Thus, we examined the capacity of E. coli strains from raw milk bulk tanks to form biofilms on surfaces made of polystyrene, stainless steel, and silicone; the potential links between biofilm formation with genes responsible for fimbriae and virulence factors of extra-intestinal E. coli (ExPEC); and the susceptibility of biofilm-forming isolates to iodine and chlorhexidine digluconate. Out of 149 E. coli strains, 42.28% (63/149) formed biofilm on polystyrene, 56.38% (84/149) on silicone, and 21.48% (32/149) on stainless steel. The frequency of genes was: fimH (100%), hlyA (5.4%), irp2 (2.7%), sitA (10.7%), ompT (43.6%), and traT (98%). No biofilm developed when disinfectants were used prior to biofilm formation. However, iodine and chlorhexidine digluconate allowed 25.40% (16/63) of isolates displaying growth after a mature biofilm was formed. The presence of biofilm on different surfaces emphasizes the vital need for thorough equipment cleaning, both in farms and in industrial dairy settings. Rapid disinfection is crucial, given the reduced susceptibility of potentially pathogenic E. coli after biofilm maturity.

This study aimed to identify contamination sources in raw milk and cheese on small farms in Brazil by isolating Escherichia coli at various stages of milk production and cheese manufacturing. The study targeted EAEC, EIEC, ETEC, EPEC, STEC, and ExPEC pathotypes, characterizing isolates for the presence of virulence genes, phylogroups, antimicrobial susceptibility, and phylogenetic relationships using PFGE and MLST. The presence of antimicrobial resistance genes and serogroups was also determined. Three categories of E. coli were identified: pathogenic, commensal, and ceftriaxone-resistant (ESBL) strains. Pathogenic EPEC, STEC, and ExPEC isolates were detected in milk and cheese samples. Most isolates belonged to phylogroups A and B1 and were resistant to antimicrobials such as nalidixic acid, ampicillin, kanamycin, streptomycin, sulfisoxazole, and tetracycline. Genetic analysis revealed that E. coli with identical virulence genes were present at different stages within the same farm. The most frequently identified serogroup was O18, and MLST identified ST131 associated with pathogenic isolates. The study concluded that E. coli was present at multiple points in milk collection and cheese production, with significant phylogroups and high antimicrobial resistance. These findings highlight the public health risk posed by contamination in raw milk and fresh cheese, emphasizing the need to adopt hygienic practices to control these microorganisms.

Cell-free supernatant of Lactobacillus plantarum exhibit a strong antimicrobial effect against a number of pathogenic enterobacteria (E. coli, Shigella flexneri, Salmonella typhimurium, Proteus mirabilis, and Campylobacter jejuni). The degree of growth inhibition in broth culture reached a high level for all tested bacteria. The highest rates were noted for P. mirabilis (by 13 times) and the lowest for S. flexneri (by 5 times) and C. jejuni (by 4.5 times). Significant antiproliferative effect of the supernatant on cells of tumor-derived epithelial cell lines was shown. The highest degree of inhibition (by 22 times) was observed for HT-29 cells (colon carcinoma). Thus, inclusion of probiotics in traditional treatment schemes can increase the effectiveness of antibacterial and antitumor drug therapy. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) recently emerged as important players in the pathophysiology of parasitic infections. While the protist parasite Giardia duodenalis can produce EVs, their role in giardiasis remains obscure. Giardia can disrupt gut microbiota biofilms and transform commensal bacteria into invasive pathobionts at sites devoid of colonizing trophozoites via unknown mechanisms. We hypothesized that Giardia EVs could modify gut bacterial behaviour via a novel mode of trans‐kingdom communication. Our findings indicate that Giardia EVs exert bacteriostatic effects on Escherichia coli HB101 and Enterobacter cloacae TW1, increasing their swimming motility. Giardia EVs also decreased the biofilm‐forming ability of E. coli HB101 but not by E. cloacae TW1, supporting the hypothesis that these effects are, at least in part, bacteria‐selective. E. coli HB101 and E. cloacae TW1 exhibited increased adhesion/invasion onto small intestine epithelial cells when exposed to Giardia EVs. EVs labelled with PKH67 revealed colocalization with E. coli HB101 and E. cloacae TW1 bacterial cells. Small RNA sequencing revealed a high abundance of ribosomal RNA (rRNA)‐ and transfer RNA (tRNA)‐derived small RNAs, short‐interfering RNAs (siRNAs) and micro‐RNAs (miRNAs) within Giardia EVs. Proteomic analysis of EVs uncovered the presence of RNA chaperones and heat shock proteins that can facilitate the thermal stability of EVs and its sRNA cargo, as well as protein‐modifying enzymes. In vitro, RNase heat‐treatment assays showed that total RNAs in EVs, but not proteins, are responsible for modulating bacterial swimming motility and biofilm formation. G. duodenalis small RNAs of EVs, but not proteins, were responsible for the increased bacterial adhesion to intestinal epithelial cells induced upon exposure to Giardia EVs. Together, the findings indicate that Giardia EVs contain a heat‐stable, RNase‐sensitive cargo that can trigger the development of pathobiont characteristics in Enterobacteria, depicting a novel trans‐kingdom cross‐talk in the gut. [ABSTRACT FROM AUTHOR]

Little is known about the influence of the urban environments on bat species 'ecology. The urbanization process potentially lead to critical ecological changes in bat communities' intra and interspecific pathogenic transmissions dynamics. To date, the monitoring of pathogens in bats in Brazil has only been done with bats found dead or alive in households, from rabies surveillance systems. The present work aimed to investigate how urbanization influenced bat richness, relative abundance and pathogen occurrence. Most captured bats were Phyllostomidae, especially Sturnira lilium, Artibeus lituratus, A. fimbriatus, Glossophaga soricina, and Platyrrhinus lineatus, among others. From preserved-rural towards urban areas the lesser the bat richness, the higher the relative abundance of the captured bats. Noise level, luminosity and relative humidity correlated with bat abundance. The proportion of genders, sexually active bats and their size (weight, right forearm length, and body condition index) were stable throughout the investigation. Still, the proportion of pregnant females was higher in Spring and the number of juveniles in Summer, evidencing the seasonality of reproduction. Several Enterobacteria were isolated, evidencing a significant role of bats in the circulation of pathogens of medical and veterinary interest. These results are crucial in the pursuit of a harmonious coexistence between humans, bats and domestic animals in areas with different levels of anthropization. [ABSTRACT FROM AUTHOR]

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Alfalfa (Medicago sativa L.) is a crucial perennial forage plant with high protein and mineral content and may be mowed several times through the vegetation period. Along with having a large cultivation area in Türkiye, it constitutes approximately 61% of the total green forage produced. Silage is the most effective method for preserving herbage and using it as a source of roughage throughout the year. However, ensiling alfalfa, especially with low dry matter (DM) content, is difficult due to its low water-soluble carbohydrate (WSC) and buffering capacity. This study was carried out to improve the alfalfa plant’s silage fermentation process by inoculating new lactic acid bacteria (LAB) strains. When the alfalfa plant reached 50% flowering, six different LAB strains were inoculated and compared with the uninoculated alfalfa silage. According to the results obtained, it was determined that LAB inoculants improved the fermentation properties of alfalfa silage in general. All inoculated strains caused a significant decrease in the pH of the resulting silage. The strain Lactobacillus buchneri (LS-31-1-4) was superior in terms of DM recovery (96.82%) and protein recovery (94.00%). At the same time, Lactobacillus brevis (LS-55-2-2) and Leuconostoc citerum (LS-70-6-1) were the most restrictive strains of yeast and enterobacteria growth in silage, respectively.

The discovery and application of antibiotics in animal feeds have boomed the development of intensive animal husbandry in the last century, until the emergence of antibiotics-resistant bacteria. To alleviate the risks aroused by antibiotics-resistant bacteria, effective antibiotic substitutes are urgently needed to replace antibiotics. Essential oils (EOs) derived from plants are illustrated as the promising antibiotic substitutes used in animal feeds, as same as their current views for poultry and livestock industries in the future. It has been widely demonstrated that the phytochemicals in EOs show multiple biofunctionability and are less likely to induce resistance in bacteria. The beneficial effects of EOs feed supplementation on the intestinal inflammation, intestinal flora, immunity, digestion, and growth performances have been already extensively examined. However, the cost-effectiveness, odor, volatility, instability and bioavailability are the challenges in effectively utilizing EOs in animal intestines. Based on previous researches, and these challenges can partially be resolved by microencapsulation and nanotechnology are promising techniques to deal with these challenges. This article presents the feasibility and foundation of EOs application as antibiotic substitutes in animal feeds, and illustrates the mechanisms, functional performances and superiority of EOs compared with antibiotics.

Antimicrobials serve as crucial treatments in both veterinary and human medicine, aiding in the control and prevention of infectious diseases. However, their misuse or overuse has led to the emergence of antimicrobial resistance, posing a significant threat to public health. This review focuses on extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in animals and their associated food products, which contribute to the proliferation of antimicrobial-resistant strains. Recent research has highlighted the presence of ESBL-producing E. coli in animals and animal-derived foods, with some studies indicating genetic similarities between these isolates and those found in human infections. This underscores the urgent need to address antimicrobial resistance as a pressing public health issue. More comprehensive studies are required to understand the evolving landscape of ESBLs and to develop strategic public health policies grounded in the One Health approach, aiming to control and mitigate their prevalence effectively.

The consumption of seafood is crucial for food security, but poor hygiene along the food production chain can result in low microbiological quality, posing significant risks for public health and seafood quality. Thus, this study aimed to assess the microbiological quality and antimicrobial sensitivity of E. coli from 69 samples of illegally marketed shrimp and mussels in the Vitória Region, Brazil. These foods exhibited poor microbiological quality due to high counts of mesophilic, psychrotrophic, and enterobacteria microorganisms. While this issue is widespread in this area, shrimp samples displayed higher microbial counts compared to mussels, and fresh mussels had elevated counts of enterobacteria compared to frozen ones. Among the 10 E. coli isolates, none carried the genes blaCTX-M-1, blaCTX-M-2, blaCTX-M-3, blaCTX-M-15, mcr-1, mcr-2, mcr-3, mcr-4, and tet, associated with antibiotic resistance. Phenotypical resistance to tetracycline and fosfomycin was not observed in any isolate, while only 20% demonstrated resistance to ciprofloxacin. Regarding ampicillin and amoxicillin with clavulanic acid, 60% of isolates were resistant, 10% showed intermediate susceptibility, and 30% were sensitive. One isolate was considered simultaneously resistant to β-lactams and quinolones, and none were conserved as ESBL producers. These findings highlight the inherent risks to local public health that arise from consuming improperly prepared seafood in this area.

Abstract Extracellular vesicles (EVs) recently emerged as important players in the pathophysiology of parasitic infections. While the protist parasite Giardia duodenalis can produce EVs, their role in giardiasis remains obscure. Giardia can disrupt gut microbiota biofilms and transform commensal bacteria into invasive pathobionts at sites devoid of colonizing trophozoites via unknown mechanisms. We hypothesized that Giardia EVs could modify gut bacterial behaviour via a novel mode of trans‐kingdom communication. Our findings indicate that Giardia EVs exert bacteriostatic effects on Escherichia coli HB101 and Enterobacter cloacae TW1, increasing their swimming motility. Giardia EVs also decreased the biofilm‐forming ability of E. coli HB101 but not by E. cloacae TW1, supporting the hypothesis that these effects are, at least in part, bacteria‐selective. E. coli HB101 and E. cloacae TW1 exhibited increased adhesion/invasion onto small intestine epithelial cells when exposed to Giardia EVs. EVs labelled with PKH67 revealed colocalization with E. coli HB101 and E. cloacae TW1 bacterial cells. Small RNA sequencing revealed a high abundance of ribosomal RNA (rRNA)‐ and transfer RNA (tRNA)‐derived small RNAs, short‐interfering RNAs (siRNAs) and micro‐RNAs (miRNAs) within Giardia EVs. Proteomic analysis of EVs uncovered the presence of RNA chaperones and heat shock proteins that can facilitate the thermal stability of EVs and its sRNA cargo, as well as protein‐modifying enzymes. In vitro, RNase heat‐treatment assays showed that total RNAs in EVs, but not proteins, are responsible for modulating bacterial swimming motility and biofilm formation. G. duodenalis small RNAs of EVs, but not proteins, were responsible for the increased bacterial adhesion to intestinal epithelial cells induced upon exposure to Giardia EVs. Together, the findings indicate that Giardia EVs contain a heat‐stable, RNase‐sensitive cargo that can trigger the development of pathobiont characteristics in Enterobacteria, depicting a novel trans‐kingdom cross‐talk in the gut.

Little has been published on the factors influencing the safety and quality of milk derived from water buffalo in Bangladesh. This study aims to describe the milk hygiene parameters and milk chain characteristics of unpasteurized raw milk sold to consumers in order to improve milk hygiene. A quantitative study design evaluated somatic cell counts, total bacterial counts, and specific gram-negative (Enterobacteria) and gram-positive (staphylococci) pathogens in 377 aseptically collected milk samples. Samples were collected at multiple nodes along the buffalo milk value chain: 122 bulk tank milk samples were collected at the farm level, 109 milk samples at the middlemen level, and 111 milk samples at the milk collection centers. In addition, 35 samples were taken from various milk products at the retail level. It was found that progressively increasing somatic cell counts and bacterial counts, including potential pathogens, occurred along the milk chain. A seasonal increase in spring was found, varying based on the farming system (semi-intensive versus intensive). Other factors included water purity and cleanliness of containers, mixing buffalo and cow’s milk, and the location of the water buffalo milk producer (coastal or river basin). This study demonstrated how improving udder health and milk hygiene along the water buffalo milk value chain would increase the safety and quality of water buffalo milk in the study area. [ABSTRACT FROM AUTHOR]

Antibiotic resistance is a public health problem. The emergence of carbapenemase-producing Enterobacterales (CPE) infections is a concern, particularly in Senegal. (1) Methods: Between January 2019 and July 2022, 240 isolates of enterobacteria resistant to third-generation cephalosporins and imipenem from biological samples from Fann Hospital (Dakar) and Hôpital Paix (Ziguinchor) were selected. The isolates were identified by MALDI-TOF mass spectrometry, and susceptibility tests were performed by the disk diffusion method. Antibiotic-resistance genes for class A beta-lactamases, carbapenemases, and plasmid resistance to colistin resistance (mcr-1–8) were screened by RT-PCR. (2) Results: The 240 enterobacteria were composed of: Escherichia coli (60.83%), Klebsiella pneumoniae (21.67%), Enterobacter cloacae (13.75%), Citrobacter freundii (2.08%), Serratia marcescens (0.83%), Klebsiella aerogenes (0.42%), and Proteus mirabilis (0.42%). Class A beta-lactamase genes were found in 229 isolates (70.41% blaTEM, 37.5% blaSHV, 83.75% blaCTX-A, and 0.42% blaCTX-B). The carbapenemase genes blaOXA-48 and blaNDM were found in 25 isolates, including 14 isolates with blaOXA-48, 13 isolates with blaNDM, and 2 isolates with both genes simultaneously. The mcr-8 gene was found in one isolate of E. cloacae. (3) Conclusions: The epidemiology of antibiotic-resistance genes in enterobacteria in Senegal shows the emergence of CPEs. This phenomenon is worrying, and rigorous surveillance is necessary to avoid further spread. [ABSTRACT FROM AUTHOR]

This study aimed to characterize the pathogenicity of bacteria isolated from the starter of two traditional beers produced and consumed in Benin. After standard microbial identification, species were identified by specific biochemical tests such as catalase, coagulase, and API 20 E. Antibiotic sensitivity was tested according to the French Society of Microbiology Antibiogram Committee. The crystal violet microplate technique evaluated the biofilm production and conventional PCR was used to identify genes encoding virulence and macrolide resistance. According to our data, the traditional starter known as kpètè-kpètè that is used to produce beer is contaminated by Enterobacteriaceae and staphylococci species. Thus, 28.43% of the isolated bacteria were coagulase-negative staphylococci (CNS), and 10.93% coagulase-positive staphylococci (CPS). Six species such as Klebsiella terrigena (1.38%), Enterobacter aerogens (4.14%), Providencia rettgeri (5.51%), Chryseomonas luteola (6.89%), Serratia rubidae (15.16%), and Enterobacter cloacae (27.56%) were identified among Enterobacteriaceae. Those bacterial strains are multi-resistant to conventional antibiotics. The hight capability of produced biofilms was recorded with Enterobacter aerogens, Klebsiella terrigena (100%), Providencia rettgeri (75%), and Staphylococcus spp (60%). Enterobacter cloacae (4%) and coagulase-negative Staphylococcus (5.55%) harbor the macrolide resistance gene. For other strains, these genes were not detected. Foods contaminated with bacteria resistant to antibiotics and carrying a virulence gene could constitute a potential public health problem. There is a need to increase awareness campaigns on hygiene rules in preparing and selling these traditional beers. [ABSTRACT FROM AUTHOR]

The microbiological quality control, of food, for human consumption is extremely important. SIM is focused on inspecting and verifying the microbiological quality of products of animal origin, routinely carrying out inspections and collecting samples for laboratory analysis. This is one of the alternatives to assess whether meat products available for sale are suitable for consumption. The objective was to investigate the microbiological quality of meat products sold in Jataí and inspected by the SIM. 65 results of microbiological tests of samples collected in the years 2019, 2021 and 2022 were analyzed. Of the tests performed, 05 samples were positive for Salmonella spp (7.9%), 05 positive for Staphylococcus Coagulase Positive (SCP) (12, 2%), 08 positive for Thermotolerant Coliforms(8.7%), 08 positive samples for Escherichia coli(26.6%) and 38(95%) for Viable Aerobic Mesophiles at 30°C. Of the total of 65 samples, 42 (64%) were positive for some microbiological contaminant. The existence of a Municipal Inspection Service implemented in the municipality and the adoption of Good Food Manufacturing Practices by the establishments is an important measure in the control of hygiene and food safety. However, as detected by this research, microbiological analyzes of marketed meat foods are essential to detect hazards and guide adjustment actions. [ABSTRACT FROM AUTHOR]

Studies have recently revealed the linoleic acid metabolic pathway of Lactobacillus plantarum , the representative gut bacterium in human gastrointestinal tract, and the anti-inflammatory effects of metabolites in this pathway. However, no clinical trials have evaluated the association between these metabolites and revascularization in patients who underwent percutaneous coronary intervention (PCI). We retrospectively reviewed patients who underwent PCI with subsequent revascularization or coronary angiography (CAG) without revascularization. Patients with frozen blood samples at the index PCI and revascularization or follow-up CAG were enrolled. Among 701 consecutive patients who underwent PCI, we enrolled 53 patients who underwent subsequent revascularization and 161 patients who underwent follow-up CAG without revascularization. Patients who underwent revascularization showed significantly lower plasma 10-oxo-octadecanoic acid (KetoB) levels (720.5 [551.6–876.5] vs. 818.4 [641.1–1103.6 pg/mL]; p = 0.01) at index PCI. Multivariate logistic regression analysis revealed that decreased plasma KetoB levels at the index PCI were independently associated with subsequent revascularization after PCI (odds ratio; 0.90 per 100 pg/mL increase, 95% confidence interval; 0.82–0.98). Additionally, in vitro experiments showed that the addition of purified KetoB suppressed the mRNA levels of IL-6 and IL-1β in macrophages and IL-1β mRNA in neutrophils. Plasma KetoB level at index PCI was independently associated with subsequent revascularization after PCI, and KetoB could act as an anti-inflammatory lipid mediator in macrophages and neutrophils. The assessment of gut microbiome-derived metabolites may help predict revascularization after PCI. [Display omitted] • KetoB, lipid metabolites generated from linoleic and oleic acid by gut microbiome. • Lower plasma KetoB level was associated with subsequent revascularization after PCI. • KetoB suppressed the mRNA expression of IL-1β and IL-6 in macrophages. • KetoB suppressed the mRNA expression of IL-1β in neutrophils. [ABSTRACT FROM AUTHOR]

Aims To evaluate the composition and functions of the gut microbiota in patients with decompensated alcohol-associated cirrhosis, with and without hepatic encephalopathy (HE). Methods and results Faecal samples from 31 inpatients (20 with HE, 11 without HE), and from 18 age-balanced healthy controls (HC), were included. Microbial composition was determined by 16S rRNA amplicon sequencing and analysed using QIIME2. Metabolic pathways were inferred by PICRUSt2, and short-chain fatty acids (SCFAs) quantification was performed by gas chromatography. The gut microbiota of patients with HE was characterized by a diminished α-diversity, compared to no-HE (P  < 0.01) and HC (P  < 0.001) groups; β-diversity also differed between HE vs no-HE patients (P  < 0.05), and between HE vs HC (P  < 0.001). In patients with HE, Escherichia / Shigella , Burkholderiales and Lactobacillales taxa predominated. In contrast, patients without HE were characterized by Veillonella and Bacteroides. Reduced levels of faecal SCFAs in both groups correlated with a depletion of beneficial taxa, such as Ruminococcus or Faecalibacterium. PICRUSt2 analysis showed both an enhanced catabolism of arginine through ammonia-producing pathways and chorismate biosynthesis in HE patients, a key precursor of aromatic amino acids. Conclusions The gut microbiota of HE patients exhibits a proinflammatory dysbiotic profile, plus metabolic pathways that produce potentially neurotoxic byproducts. [ABSTRACT FROM AUTHOR]

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Abstract Urban parks constitute one of the main leisure areas, especially for the most vulnerable people in our society, children, and the elderly. Contact with soils can pose a health risk. Microbiological testing is a key aspect in determining whether they are suitable for public use. The aim of this work is to map the spatial distribution of potential dangerous Enterobacteria but also bioremediation useful (lipase producers) isolates from soils in an urban park in the area of Valencia (Spain). To this end, our team has collected 25 samples of soil and isolated 500 microorganisms, using a mobile application to collect information of the soil samples (i.e. soil features, temperature, humidity, etc.) with geolocation. A combined protocol including matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) and 16S rDNA sequencing PCR has been established to characterize the isolates. The results have been processed using spatial statistical techniques (using Kriging method), taking into account the number of isolated strains, also proving the reactivity against standard pathogenic bacterial strains (Escherichia coli, Bacillus cereus, Salmonella, Pseudomonas and Staphylococcus aureus), and have increased the number of samples (to 896 samples) by interpolating spatially each parameter with this statistical method. The combined use of methods from biology and computer science allows the quality of the soil in urban parks to be predicted in an agile way, which can generate confidence in its use by citizens.

In silico genome mining provides easy access to secondary metabolite biosynthetic gene clusters (BGCs) encoding the biosynthesis of many bioactive compounds, which are the basis for many important drugs used in human medicine. However, the association between BGCs and other functions encoded in the genomes of producers have remained elusive. Here, we present a systems biology workflow that integrates genome mining with a detailed pangenome analysis for detecting genes associated with a particular BGC. We analyzed 3,889 enterobacterial genomes and found 13,266 BGCs, represented by 252 distinct BGC families and 347 additional singletons. A pangenome analysis revealed 88 genes putatively associated with a specific BGC coding for the colon cancer-related colibactin that code for diverse metabolic and regulatory functions. The presented workflow opens up the possibility to discover novel secondary metabolites, better understand their physiological roles, and provides a guide to identify and analyze BGC associated gene sets.

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In the present chapter, the synopsis of active botanicals and phytochemicals of the flora of Africa against drug-sensitive and drug-resistant strains of bacteria of the Enterobacteriaceae family, mainly Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, Providencia stuartii has been provided. Using the data obtained from the crude extracts of up to 179 plants and 103 derived molecules, the rationale cutoff points for the classification of antibacterial agents from natural sources against Enterobacteria were established. (i) For botanicals: outstanding activity when MIC ≤ 8 µg/mL; excellent activity when 8 < MIC ≤ 64 µg/mL; very good activity when 64 < MIC ≤ 128 µg/mL; good activity when 128 < MIC ≤ 256 µg/mL, average activity when 256 < MIC ≤ 512 µg/mL, weak activity when 512 < MIC ≤ 1024 µg/mL, and not active MIC > 1024 µg/mL. (ii) For phytochemicals: outstanding activity when MIC ≤ 2 µg/mL, excellent activity when 2 < MIC ≤ 4 µg/mL, very good activity when 4 < MIC ≤ 8 µg/mL, good activity when 8 < MIC ≤ 32 µg/mL, average activity when 32 < MIC ≤ 64 µg/mL, weak activity when 64 < MIC ≤ 512 µg/mL, and not active when MIC > 512 µg/mL. On this basis, we have identified the most active plant extracts and the most promising antibacterial phytochemicals acting on the documented Enterobacteria. Other plants as well as the phytochemicals identified as potential antibacterial agents if they are combined with efflux pumps inhibitors are also reported. [ABSTRACT FROM AUTHOR]

Alfalfa (Medicago sativa L.) is a crucial perennial forage plant with high protein and mineral content and may be mowed several times through the vegetation period. Along with having a large cultivation area in Türkiye, it constitutes approximately 61% of the total green forage produced. Silage is the most effective method for preserving herbage and using it as a source of roughage throughout the year. However, ensiling alfalfa, especially with low dry matter (DM) content, is difficult due to its low water-soluble carbohydrate (WSC) and buffering capacity. This study was carried out to improve the alfalfa plant's silage fermentation process by inoculating new lactic acid bacteria (LAB) strains. When the alfalfa plant reached 50% flowering, six different LAB strains were inoculated and compared with the uninoculated alfalfa silage. According to the results obtained, it was determined that LAB inoculants improved the fermentation properties of alfalfa silage in general. All inoculated strains caused a significant decrease in the pH of the resulting silage. The strain Lactobacillus buchneri (LS-31-1-4) was superior in terms of DM recovery (96.82%) and protein recovery (94.00%). At the same time, Lactobacillus brevis (LS-55-2-2) and Leuconostoc citerum (LS-70-6-1) were the most restrictive strains of yeast and enterobacteria growth in silage, respectively. [ABSTRACT FROM AUTHOR]