Epidemiology and prevalence of extended-spectrum β-lactamase- and carbapenemase-producing Enterobacteriaceae in humans, animals and the environment in West and Central Africa

Prevalence of ESBL-producing Escherichia coli in sub-Saharan Africa: A meta-analysis using a One Health approach

The rise in the prevalence of antimicrobial-resistant (AMR) pathogens globally has been a major concern, especially due to the increasing mortality associated with AMR. One of these pathogens -classified as a WHO priority pathogen- is extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. In this study, we aim to determine the prevalence of ESBL-producing E. coli in sub-Saharan Africa (SSA) as well as the genes responsible for its spread in the region. Based on the PRISMA guideline, we screened 6521 articles published between 2013 and 2023 from PubMed, AJOL, Google Scholar, Scopus, and Web of Science using pre-set eligibility criteria. The final meta-analysis included one hundred and ninety-six of these articles. In this study, we reported an overall ESBL-producing E. coli prevalence of 20.76 % in SSA. Subregion analysis showed that West Africa had the highest prevalence of 22.80 % while Southern Africa (13.76 %) has the lowest ESBL-producing E. coli prevalence in SSA. Among the countries in SSA, Burkina Faso (33.37 %) had the highest prevalence of ESBL-producing E. coli. Additionally, sample source subgroup analysis revealed animals as the highest source of ESBL-producing E. coli in SSA with a prevalence of 29.15 %. We also found that bla CTX-M-15 is the most reported ESBL gene in E. coli in SSA. Our study shows a high prevalence of ESBL-producing E. coli in SSA countries, with animals significantly contributing to the spread of ESBL resistance in the region compared to humans, the environment and food. This study further emphasizes the importance of an interdisciplinary and intergovernmental approach to reducing AMR spread in SSA. Additionally, we implore policymakers to implement policies that will encourage responsible use of antimicrobials in both the clinic and agriculture to prevent the widespread of AMR genes.

Drivers of the emergence and dissemination of high-risk resistance genes in cattle farm

Extended spectrum β-lactamase (ESBL)- and carbapenemase-producing Enterobacterales (CPE) are recognized by WHO as critical concerns. The high cephalosporin resistance rate in a cattle farm in 2018 prompted us to conduct long-term (2019-2023) and extensive monitoring to explore risk factors for the import and transmission of ESBLs and CPE in this farm. Among 1288 samples from cattle, the environment, milk, and biological vectors, 48.8 % carried blaCTX-M-positive Enterobacterales with blaCTX-M-55 being dominant (76.4 %), and blaNDM-5-positive strains emerged in 2022 with a 1.9 % detection rate. blaCTX-M-55 and blaNDM-5 were likely introduced through various routes, especially wild birds, and have persisted due to overuse of cephalosporins in the farm. The spread of these genes was driven by the horizontal transmission of IncHI2 and IncX3 plasmids and clonal dissemination of certain clones. Cross-regional and cross-border transmission of blaCTX-M-55- and/or blaNDM-5-bearing bacteria and plasmids possibly occurred via wild birds, animal trade, and other means. Our findings suggest that the import, persistence, and dissemination of these genes within and beyond this farm, were fueled by suboptimal biosecurity practices and inadequate antibiotic stewardship, highlighting the urgency for integrated public and ecosystem health policies to prevent the spread of resistance genes as part of a holistic One Health strategy. ENVIRONMENTAL IMPLICATION: The high prevalence and long-term persistence of extended-spectrum β-lactamases and the emergence of carbapenemases in cattle and the environment signify a critical risk of transmitting high-risk resistance genes, posing a significant threat to human health. Consequently, bacteria carrying these genes in animal farms should be regarded as "hazardous materials". Import, persistence, and dissemination of these genes within and beyond this farm were exacerbated by suboptimal biosecurity practices and inadequate antibiotic stewardship, highlighting the urgency for integrated public and ecosystem health policies to mitigate the environmental risks associated with gene transmission as part of a comprehensive One Health strategy.

Emerging threats: Antimicrobial resistance in extended-spectrum beta-lactamase and carbapenem-resistant Escherichia coli

Antimicrobial resistance (AMR) in Escherichia coli strains, particularly those producing Extended-Spectrum Beta-Lactamase (ESBL) and Carbapenemase (CR-Ec), represents a serious global health threat. These resistant strains have been associated with increased morbidity, mortality, and healthcare costs, as they limit the effectiveness of standard antibiotic therapies. The prevalence of ESBL- and CR-Ec-producing strains continues to rise, driven by the overuse and misuse of antibiotics in healthcare and agricultural settings, and facilitated by global interconnectedness through international travel, trade, and food distribution. This review article examines the molecular mechanisms behind ESBL and CR resistance, focusing on the key genes involved in these processes, such as blaCTX-M, blaKPC, and blaNDM, and the clinical challenges posed by these strains. Additionally, the public health impact, including the spread of infections in hospital and community environments, is highlighted. The discussion emphasizes the urgent need for improved diagnostic tools, robust surveillance systems, and innovative therapeutic strategies. Emerging treatments, including phage therapy and novel antibiotic combinations, show promise in addressing these challenges and offer potential breakthroughs in combating resistant strains. Lastly, the review calls for stronger antimicrobial stewardship and policy reforms to mitigate the spread of resistant E. coli strains and protect global public health. Effective intervention at multiple levels, from diagnostics to policy, is critical to controlling the threat posed by AMR.

Fecal carriage of carbapenemase and AmpC-β-lactamase producers among extended spectrum β-Lactamase-producing E. coli and Klebsiella spp. isolates in patients attending hospitals

BACKGROUND

Extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE), particularly Escherichia coli and Klebsiella pneumoniae, have been consistently associated with treatment failure, high mortality and morbidity. The emergence of carbapenem resistance among ESBL-PE strains exacerbates the antimicrobial resistance. However, data are very limited in developing countries as Burkina Faso. This study aimed to determine the prevalence of carbapenemase and AmpC-β-lactamase production among ESBL-producing E. coli (ESBL-Ec) and Klebsiella spp. (ESBL-K) isolated from patients' stool in Burkina Faso.

MATERIALS AND METHODS

From January 2020 to June 2022, we isolated 277 ESBL-PE from patients' stool in five hospitals in Burkina Faso. The strains were isolated on ESBL-selective chromogenic media and identified using API20E. The isolates were tested against 15 antimicrobial agents using the disc-diffusion method on Mueller-Hinton (MH) agar. ESBL production was confirmed by double disc synergy method. Carbapenemase and AmpC-β-lactamase production and phenotypic co-resistance were determined.

RESULTS

Among the 277 ESBL-PE strains isolated, 203 were E. coli, and 74 were Klebsiella spp. Of these bacteria, 2.9% were carbapenemase producers and 6.5% were AmpC-β-lactamase producers. The carbapenemase producers were detected at tertiary and secondary hospitals, mainly in hospitalized patients and females, whereas AmpC-β-lactamase producers were detected at all levels of healthcare, predominantly in non-hospitalized patients, male, and under 15 years of age. The co-resistance rates were as high as 82% for fluoroquinolones, 91% for aminoglycosides, and 94% for sulfonamides. Fosfomycin resistance was 2.5% for ESBL-Ec and 50% for ESBL-K.

CONCLUSION

This study showed that ESBL-PEs co-produce carbapenemase and/or AmpC-β-lactamase. High co-resistances were reported for commonly used antibiotic agents. Therefore, screening for carbapenem-resistant Enterobacterales (CRE) carriage is necessary to limit its spread within hospitals.

Risk of Colonization with Multidrug-Resistant Gram-Negative Bacteria Among Travellers and Migrants: A Narrative Review

Globalization in the 21st century has posed several challenges. In particular, the spread of multidrug-resistant bacterial strains, especially Gram-negative bacteria, which are prevalent in certain regions of the world, is one of the most critical issues. This raises concerns about the risks associated with the booming tourism industry and migratory flows. In fact, even transient colonization with multidrug-resistant strains can present significant challenges to individual, family, and public health. Understanding the epidemiology and mechanisms of resistance, associated risk factors and prevention policies is therefore essential to ensure that strategies are in place to limit the global spread of high-risk bacterial clones and thereby protect public health.

Extended-spectrum β-lactamase production and antimicrobial resistance among Enterobacteriaceae causing clinical infections in Africa: a systematic review and meta-analysis (2012-2020)

BACKGROUND

Worldwide, antimicrobial resistance (AMR) has grown to represent a serious threat to the diagnosis, management, and prevention of bacterial diseases. Due to their multidrug resistance attributes, the WHO has classified extended-spectrum-β-lactamase-producing Enterobacteriaceae (ESBL-PE)-associated infections as infections of critical significance, posing a serious risk to human health. Thus, the goal of this systematic review and meta-analysis was to assess the pooled prevalence of ESBL-PE and AMR among strains causing clinical infections in Africa.

METHODS

In this systematic review and meta-analysis, two investigators independently made an electronic search in Google Scholar and PubMed databases using related keywords and corresponding "MeSH." terms for the PubMed. The accessed studies were screened, assessed for eligibility, and critically evaluated as per the PRISMA guidelines. The prevalence and 95% confidence intervals (CI) for ESBL-PE in Africa were evaluated using a random-effects model of a meta-analysis. As a visual and statistical way assessment, the funnel plot and Egger's test were utilized to assess the risk of bias or publication bias, with a statistically significant level of bias being determined at p < 0.05.

RESULTS

Twenty-six studies were included in the meta-analysis. Among the included studies done in Africa, the overall pooled proportion of ESBL-PE was reported to be 28% (95% CI 25-31%). ESBL-PE prevalence differed by region, the pooled estimates for East and North Africa were 29% (95% CI 20-38%) and 19% (95% CI 6-33%), respectively. The greatest sub-group analysis of pooled estimates among bacterial isolates was found in Klebsiella. pneumoniae, at 73% (95% CI 62-85%), while Proteus mirabilis had the lowest, at 40% (95% CI 1-81%).

CONCLUSIONS

In Africa, ESBL-PE is noticeably prevalent. The included studies demonstrated a significant variation in ESBL-PE resistance among the countries. This illustrates the necessity of actively monitoring antimicrobial resistance in Africa to develop interventions aimed at halting the spread of ESBL-PE.

Development and evaluation of a sensitive approach for detection and recovery of third-generation cephalosporin- and carbapenem-resistant Enterobacterales from ready-to-eat frozen stone fruit

Antimicrobial resistance (AMR) is a global public health threat, but the role of foods in its dissemination is poorly understood. We examined the incidence of foodborne bacteria carrying AMR genes considered high-priority research targets by the World Health Organization. Frozen, ready-to-eat, avocado, coconut, mango, and peach (n = 161) were tested for bacteria encoding extended-spectrum β-lactamases (ESBLs) and carbapenemases. Over 600 presumptive-positive isolates were recovered and analyzed with a pooled sequencing (Pool-seq) strategy. Coconut samples exhibited the highest bacterial loads and prevalence/diversity of AMR genes. Isolates harbouring the β-lactamase genes blactx-m, blatem, and blashv, identified in 14 coconut and 2 mango samples, were further characterized by whole-genome sequencing and antimicrobial susceptibility testing. The most common gene was blactx-m-15, detected in 20 unique strains. Two carbapenemase-producing strains were isolated from coconut: Enterobacter roggenkampii encoding blandm-1 and Escherichia coli encoding blandm-5. Subsequent quantitative PCR (qPCR) analysis of enrichments for blactx-m/blandm indicated a potentially higher prevalence of these genes than observed by colony screening. This study presents a practical method for recovering ESBL- and carbapenemase-producing bacteria from foods. Mapping their distribution in food products is crucial to assessing the role of foods in the global spread of AMR and developing effective public health interventions.

Genetic characterization and clonal analysis of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae from canine and human origins

Introduction

Carbapenem-resistant Enterobacterales (CRE), particularly carbapenemase-producing Escherichia coli and Klebsiella pneumoniae, pose a significant global health challenge due to their resistance to last-resort antibiotics. This study investigates the genetic characteristics and clonal relationships of CRE isolated from canine and human clinical samples in Bangkok to understand potential interspecies transmission.

Methods

Fifty-two CRE isolates were collected from 477 clinical samples from dogs and humans at Chulalongkorn University between 2017-2021. Bacterial species were identified using MALDI-TOF, and antimicrobial resistance was confirmed through broth microdilution testing. Genetic analyses included plasmid replicon typing, multilocus sequence typing (MLST), whole genome sequencing (WGS), and pulsed-field gel electrophoresis (PFGE) to assess resistance genes and clonal relatedness.

Results

CRE isolates from both species exhibited genetic variability with high ARG counts, particularly in human isolates. MLST identified ST410 in most E. coli isolates from both dogs and humans, and IncFIA/IncFIB plasmids were predominant among blaNDM-positive isolates. PFGE patterns and SNP analysis showed no clonal relationship between canine and human isolates, suggesting independent acquisition pathways for CRE in the two hosts.

Discussion

The study highlights the absence of direct clonal transmission between canine and human isolates but reveals overlapping sequence types and plasmid types. The findings underscore the potential for interspecies transmission under certain conditions, emphasizing the importance of a One Health approach for monitoring CRE in both human and animal populations.

VirBR, a transcription regulator, promotes IncX3 plasmid transmission, and persistence of blaNDM-5 in zoonotic bacteria

IncX3 plasmids carrying the New Delhi metallo-β-lactamase-encoding gene, blaNDM-5, are rapidly spreading globally in both humans and animals. Given that carbapenems are listed on the WHO AWaRe watch group and are prohibited for use in animals, the drivers for the successful dissemination of Carbapenem-Resistant Enterobacterales (CRE) carrying blaNDM-5-IncX3 plasmids still remain unknown. We observe that E. coli carrying blaNDM-5-IncX3 can persist in chicken intestines either under the administration of amoxicillin, one of the largest veterinary β-lactams used in livestock, or without any antibiotic pressure. We therefore characterise the blaNDM-5-IncX3 plasmid and identify a transcription regulator, VirBR, that binds to the promoter of the regulator gene actX enhancing the transcription of Type IV secretion systems (T4SS); thereby, promoting conjugation of IncX3 plasmids, increasing pili adhesion capacity and enhancing the colonisation of blaNDM-5-IncX3 transconjugants in animal digestive tracts. Our mechanistic and in-vivo studies identify VirBR as a major factor in the successful spread of blaNDM-5-IncX3 across one-health AMR sectors. Furthermore, VirBR enhances the plasmid conjugation and T4SS expression by the presence of copper and zinc ions, thereby having profound ramifications on the use of universal animal feeds.

Virulent-MDR-ESBL E. coli and Klebsiella pneumoniae report from North Sinai calves diarrhea and in vitro antimicrobial by Moringa oleifera

The health of calves has a significant impact on the production of cows and livestock. Some desert plants have pharmacological importance, as they can be used to reduce antibiotic resistance. Our hypothesis is designed to detect Virulent- Multidrug-Resistant and Extended- spectrum Beta- lactamase Enterobacteriaceae (Virulent-MDR-ESBL Enterobacteriaceae and to determine whether Moringa oleifera has antibacterial activity against the detected isolates. A total of 39 Enterobacteriaceae isolates from 28 diarrheic samples were collected from calves aged between 20 days and 20 months from 3 different flocks in North Sinai, Sahl-Eltina region, Egypt. E.coli 46% (18/39), O157 13% (5/39), Klebsiella pneumoniae 41% (16/39). MDR members accounted for 87%, while ESBL isolates accounted for 43%. The antibacterial activity is represented by microdilution. Minimum inhibition concentration (MIC) for the methanol extract of Moringa oleifera ranged from 2.5,5,10, and 25mg/ ml among E.coli isolates, and O157 was susceptible to (2.5mg/ ml), Klebsiella pneumoniae isolates were susceptible to (5-50mg/ ml). Analysis of the methanol extract revealed that ferulic acid was the dominant phenolic compound with a concentration of 29,832 parts per million (ppm). In silico docking study expected the active site of ferulic acid to act on the tyrosine bacterial enzyme through Pi-alkyl, Pi-anion, Carbon hydrogen bonds, and extra ionic attractive interactions with copper ions which can stabilize ferulic acid inside the targeted pocket Diverse virulent gene profiles were observed in E. coli. The Shiga toxin-producing Escherichia coli (STEC) was reported in 83% of the isolated E. coli, while the DNA gyrase (gyrA) was harbored in 100% of Klebsiella pneumoniae isolates. Various profiles of antibiotic resistance genes for both E. coli and Klebsiella pneumoniae isolates were distinguished. blaTEM genes were detected in 99% of E. coli and 100% of Klebsiella pneumoniae. Sequence analysis for E. coli strain DRC-North Sinai-Eg was placed in accession numbers (OP955786) for the Shiga toxin 2 gene (Stx2A), (OP997748) and (OP997749) for the Adhesion to host cell gene (Eae). For the hemolysine gene (hylA), the accession number was (OP946183). Klebsiella pneumoniae strain DRC-North Sinai-Eg was placed in (OP946180) for (gyrA). This study has proven the broad range of Moringa oliefera's antibacterial effects in vitro against the virulent-MDR- ESBL E. coli and Klebsiella pneumoniae isolated from North Sinai calves diarrhea. These are congruent with the disability effect on bacterial tyrosinase enzyme through docking study therefore, we recommend the usage of this desert plant as a prospective feed additive, we endorse this as an antibacterial new insight natural source and for the medication of considered pathogens with zoonotic impacts.

Antimicrobial resistance in Enterobacterales infections among children in sub-Saharan Africa: a systematic review and meta-analysis

Background

The burden of antimicrobial resistance (AMR) has been estimated to be the highest in sub-Saharan Africa (SSA). The current study estimated the proportion of drug-resistant Enterobacterales causing infections in SSA children.

Methods

We searched MEDLINE/PubMed, Embase and the Cochrane Library to identify retrospective and prospective studies published from 01/01/2005 to 01/06/2022 reporting AMR of Enterobacterales causing infections in sub-Saharan children (0-18 years old). Studies were excluded if they had unclear documentation of antimicrobial susceptibility testing methods or fewer than ten observations per bacteria. Data extraction and quality appraisal were conducted by two authors independently. The primary outcome was the proportion of Enterobacterales resistant to antibiotics commonly used in paediatrics. Proportions were combined across studies using mixed-effects logistic regression models per bacteria and per antibiotic. Between-study heterogeneity was assessed using the I2 statistic. The protocol was registered with PROSPERO (CRD42021260157).

Findings

After screening 1111 records, 122 relevant studies were included, providing data on more than 30,000 blood, urine and stool isolates. Escherichia coli and Klebsiella spp. were the predominant species, both presenting high proportions of resistance to third-generation cephalosporins, especially in blood cultures: 40.6% (95% CI: 27.7%-55%; I2: 85.7%, number of isolates (n): 1032) and 84.9% (72.8%-92.2%; I2: 94.1%, n: 2067), respectively. High proportions of resistance to other commonly used antibiotics were also observed. E. coli had high proportions of resistance, especially for ampicillin (92.5%; 95% CI: 76.4%-97.9%; I2: 89.8%, n: 888) and gentamicin (42.7%; 95% CI: 30%-56.5%; I2: 71.9%, n: 968). Gentamicin-resistant Klebsiella spp. were also frequently reported (77.6%; 95% CI: 65.5%-86.3%; I2: 91.6%, n: 1886).

Interpretation

High proportions of resistance to antibiotics commonly used for empirical treatment of infectious syndromes were found for Enterobacterales in sub-Saharan children. There is a critical need to better identify local patterns of AMR to inform and update clinical guidelines for better treatment outcomes.

Funding

No funding was received.

Evaluation of three protocols for direct susceptibility testing for gram negative-Enterobacteriaceae from patient samples in Uganda with SMS reporting

In Uganda, the challenge of generating and timely reporting essential antimicrobial resistance (AMR) data has led to overreliance on empirical antibiotic therapy, exacerbating the AMR crisis. To address this issue, this study aimed to adapt a one-step AMR testing protocol alongside an SMS (Short Message Service) result relay system (SRRS), with the potential to reduce the turnaround time for AMR testing and result communication from 4 days or more to 1 day in Ugandan clinical microbiology laboratories. Out of the 377 samples examined, 54 isolates were obtained. Notably, E. coli (61%) and K. pneumoniae (33%) were the most frequently identified, majority testing positive for ESBL. Evaluation of three AMR testing protocols revealed varying sensitivity and specificity, with Protocol A (ChromID ESBL-based) demonstrating high sensitivity (100%) but no calculable specificity, Protocol B (ceftazidime-based) showing high sensitivity (100%) and relatively low specificity (7.1%), and Protocol C (cefotaxime-based) exhibiting high sensitivity (97.8%) but no calculable specificity. ESBL positivity strongly correlated with resistance to specific antibiotics, including cefotaxime, ampicillin, and aztreonam (100%), cefuroxime (96%), ceftriaxone (93%), and trimethoprim sulfamethoxazole (87%). The potential of integrating an SRRS underscored the crucial role this could have in enabling efficient healthcare communication in AMR management. This study underscores the substantial potential of the tested protocols for accurately detecting ESBL production in clinical samples, potentially, providing a critical foundation for predicting and reporting AMR patterns. Although considerations related to specificity warrant careful assessment before widespread clinical adoption.

Genomic epidemiology of carbapenemase-producing Gram-negative bacteria at the human-animal-environment interface in Djibouti city, Djibouti

The emergence of carbapenem resistance is a major public health threat in sub-Saharan Africa but remains poorly understood, particularly at the human-animal-environment interface. This study provides the first One Health-based study on the epidemiology of Carbapenemase-Producing Gram-Negative Bacteria (CP-GNB) in Djibouti City, Djibouti, East Africa. In total, 800 community urine samples and 500 hospital specimens from humans, 270 livestock fecal samples, 60 fish samples, and 20 water samples were collected and tested for carbapenem resistance. The overall estimated CP-GNB prevalence was 1.9 % (32/1650 samples) and specifically concerned 0.3 % of community urine samples, 2.8 % of clinical specimens, 2.6 % of livestock fecal samples, 11.7 % of fish samples, and 10 % of water samples. The 32 CP-GNB included 19 Escherichia coli, seven Acinetobacter baumannii, five Klebsiella pneumoniae, and one Proteus mirabilis isolate. Short-read (Illumina) and long-read (Nanopore) genome sequencing revealed that carbapenem resistance was mainly associated with chromosomal carriage of blaNDM-1, blaOXA-23, blaOXA-48, blaOXA-66, and blaOXA-69 in A. baumannii, and with plasmid carriage in Enterobacterales (blaNDM-1 and blaOXA-181 in E. coli, blaNDM-1, blaNDM-5 and blaOXA-48 in K. pneumoniae, and blaNDM-1 in P. mirabilis). Moreover, 17/32 CP-GNB isolates belonged to three epidemic clones: (1) A. baumannii sequence type (ST) 1697,2535 that showed a distribution pattern consistent with intra- and inter-hospital dissemination; (2) E. coli ST10 that circulated at the human-animal-environment interface; and (3) K. pneumoniae ST147 that circulated at the human-environment interface. Horizontal exchanges probably contributed to carbapenem resistance dissemination in the city, especially the blaOXA-181-carrying ColKP3-IncX3 hybrid plasmid that was found in E. coli isolates belonging to different STs. Our study highlights that despite a relatively low CP-GNB prevalence in Djibouti City, plasmids harboring carbapenem resistance circulate in humans, animals and environment. Our findings stress the need to implement preventive and control measures for reducing the circulation of this potentially emerging public health threat.

Phenotypic and genotypic characterization of multidrug resistant and extended-spectrum β-lactamase-producing Enterobacterales isolated from clinical samples in the western region in Cameroon

BACKGROUND

The 2017 World Health Organization (WHO) report has listed extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) as critical pathogens for public health and requiring urgently new antibiotics. The aim of this study was to characterize phenotypically and genotypically ESBL-E isolated among clinical samples in Dschang, Cameroon.

METHODS

A cross-sectional study was conducted during a four-month periods from February to May 2022 in the two biggest hospitals of Dschang. Clinical samples were collected and cultured on Eosin Methylene Blue agar. Suspected growing colonies were biochemically identified using the Enterosystem Kit 18R. Antimicrobial susceptibility testing (AST) was done using the Kirby Bauer disc diffusion method and interpretated according to the CA-SFM recommendations. ESBL phenotypes were double screened using CHROMagar™ ESBL and double disk synergy test (DDST). The detection of resistance genes was performed using conventional and multiplex PCR methods. Results were analyzed with SPSS (version 21) and a p-value < 0.05 was considered statistically significant.

RESULTS

A total of 152 Enterobacterales were isolated among 597 clinical samples including urine, blood, cervico-vaginal, urethral swabs and wound samples. The overall prevalence of ESBL-Enterobacterales was 29.61% (45/152). The most represented ESBL species were Escherichia coli (n = 23; 51.11%), Klebsiella pneumoniae (n = 8; 17.78%) and Citrobacter freundii (n = 6; 13.33%).

CONCLUSION

This study reveals the high burden of ESBL-E among clinical samples in the regional hospital in Dschang with the most common species being E. coli and K. pneumoniae. It confirmed the high occurrence of blaCTX-M and blaTEM among ESBL-E. The study suggests that implementing antimicrobial stewardship program and real-time surveillance of antimicrobial resistance are needed in the Western region of Cameroon. Moreover, the implementation of infection prevention and control measures (IPC) is essential to curb the dissemination of these bacteria from community to hospital settings. Implementation of national action plan to fight against antimicrobial resistance at the local levels is urgently needed.

Prevalence and Antimicrobial Resistance of Escherichia coli Isolates from Chicken Meat in Romania

The current study was conducted in order to analyze the prevalence of Escherichia coli (E. coli) in samples of chicken meat (100 chicken meat samples), as well as to evaluate the antimicrobial susceptibility of these isolates. A total of 30 samples were positive for E. coli among the collected chicken samples. Most isolates proved to be highly resistant to tetracycline (80%), ampicillin (80%), sulfamethoxazole (73.33%), chloramphenicol (70%) and nalidixic acid (60%). Strong resistance to ciprofloxacin (56.66%), trimethoprim (50%), cefotaxime (46.66%), ceftazidime (43.33%) and gentamicin (40%) was also observed. Notably, one E. coli strain also proved to be resistant to colistin. The antimicrobial resistance determinants detected among the E. coli isolates recovered in our study were consistent with their resistance phenotypes. Most of the isolates harbored the tetA (53.33%), tetB (46.66%), blaTEM (36.66%) and sul1 (26.66%) genes, but also aadA1 (23.33%), blaCTX (16.66%), blaOXA (16.66%), qnrA (16.66%) and aac (10%). In conclusion, to the best of our knowledge, this is among the first studies analyzing the prevalence and antimicrobial resistance of E. coli strains isolated from chicken meat in Romania and probably the first study reporting colistin resistance in E. coli isolates recovered from food sources in our country.

Prevalence and characterization of ESBL-producing Escherichia coli in healthy pregnant women and hospital environments in Benin: an approach based on Tricycle

Introduction

Extended-Spectrum Beta-Lactamase (ESBL)-producing Enterobacterales are recognized as significant pathogens due to their resistance to multiple antibiotics. This study aimed to determine the prevalence of ESBL-producing Escherichia coli (E. coli) in different settings, including healthy pregnant women, the food chain, and the environment of tertiary hospitals in Benin.

Methods

Samples were collected from various sources, including fecal samples from healthy pregnant women, food samples from hospital canteens, and hospital effluents from four tertiary hospitals in southern Benin. Fecal samples were plated on MacConkey agar supplemented with cefotaxime (4 μg/mL), while food and water samples were plated on Tryptone Bile X agar supplemented with cefotaxime (4 μg/mL). Urea indole tests were used for preliminary identification of E. coli colonies, followed by confirmation of ESBL production using the double disk synergy technique. Antibiotic susceptibility testing of ESBL-producing E. coli strains was conducted using the disk diffusion method on MH agar. Polymerase Chain Reaction (PCR) was used to investigate the presence of ESBL-encoding genes.

Results

Among the 296 fecal samples collected from four tertiary hospitals, ESBL-producing E. coli was isolated from 22.30% (66) of the samples. All E. coli isolates from hospital effluents exhibited ESBL production, while ESBL-producing E. coli was not detected in food and drinking water samples. The analysis of variable associations showed no significant associations (p > 0.05) for the studied factors. Antibiotic susceptibility testing revealed high resistance rates among the ESBL-Ec isolates against several tested antibiotics, including amoxicillin, aztreonam, ceftriaxone, ciprofloxacin, and trimethoprim-sulfamethoxazole. However, most isolates remained susceptible to ertapenem, amoxicillin-clavulanate, and imipenem. The most prevalent ESBL-encoding genes were blaTEM (37.50%), blaOXA-1 (19.44%), and blaSHV (11.11%), while a smaller proportion of isolates carried blaCTXM-1/blaCTXM-15 (5.55%) and blaCTXM-9.

Discussion

This study provides insights into the prevalence of ESBL-producing E. coli carriage in the feces of healthy pregnant women in southern Benin. Additionally, it highlights hospital wastewater as a potential reservoir of ESBL-producing bacteria in the environment. The detection of ESBL-producing E. coli in hospital effluents raises concerns about the dissemination of antibiotic resistance genes into the environment. The high resistance rates observed among ESBL-Ec isolates against commonly used antibiotics emphasize the urgent need for antimicrobial stewardship and infection control measures. The identification of prevalent ESBL-encoding genes contributes to understanding the genetic basis of ESBL resistance in the studied population. Further research is warranted to explore the mechanisms of transmission and potential interventions to mitigate the spread of ESBL-producing Enterobacterales.

Molecular epidemiology of antimicrobial resistance in central africa: A systematic review

Background

In Central Africa, it is difficult to tackle antibiotic resistance, because of a lack of data and information on bacterial resistance, due to the low number of studies carried out in the field. To fill this gap, we carried out a systematic review of the various studies, and devised a molecular epidemiology of antimicrobial resistance from humans, animals and the environmental samples.

Method

A systematic search of all publications from 2005 to 2020 on bacterial resistance in Central Africa (Gabon, Cameroon, Democratic Republic of Congo, Central African Republic, Chad, Republic of Congo, Equatorial Guinea, São Tomé and Príncipe, Angola) was performed on Pubmed, Google scholar and African Journals Online (AJOL). All circulating resistance genes, prevalence and genetic carriers of these resistances were collected. The study area was limited to the nine countries of Central Africa.

Results

A total of 517 studies were identified through a literature search, and 60 studies carried out in eight countries were included. Among all articles included, 43 articles were from humans. Our study revealed not only the circulation of beta-lactamase and carbapenemase genes, but also several other types of resistance genes. To finish, we noticed that some studies reported mobile genetic elements such as integrons, transposons, and plasmids.

Conclusion

The scarcity of data poses difficulties in the implementation of effective strategies against antibiotic resistance, which requires a health policy in a 'One Health' approach.

Isolation and genotypic characterization of extended-spectrum beta-lactamase-producing Escherichia coli O157:H7 and Aeromonas hydrophila from selected freshwater sources in Southwest Nigeria

The proliferation of antibiotic-resistant bacteria and antimicrobial resistance is a pressing public health challenge because of their possible transfer to humans via contact with polluted water sources. In this study, three freshwater resources were assessed for important physicochemical characteristics as well as heterotrophic and coliform bacteria and as potential reservoirs for extended-spectrum beta-lactamase (ESBL) strains. The physicochemical characteristics ranged from 7.0 to 8.3; 25 to 30 °C, 0.4 to 93 mg/L, 0.53 to 8.80 mg/L and 53 to 240 mg/L for pH, temperature, dissolved oxygen (DO), biological oxygen demand (BOD₅) and total dissolved solids, respectively. The physicochemical characteristics mostly align with guidelines except for the DO and BOD₅ in some instances. Seventy-six (76) Aeromonas hydrophila and 65 Escherichia coli O157: H7 isolates were identified by preliminary biochemical analysis and PCR from the three sites. Among these, A. hydrophila displayed higher frequencies of antimicrobial resistance, with all 76 (100%) isolates completely resistant to cefuroxime and cefotaxime and with MARI ≥ 0.61. The test isolates showed more than 80% resistance against five of the ten test antimicrobials, with resistance against cefixime, a cephalosporin antibiotic being the highest at 95% (134/141). The frequency of the detection of the resistance genes in the A. hydrophila isolates generally ranged between 0% (bla_SHV) and 26.3% (bla_CTX-M), while the frequency of detection among the E. coli O157:H7 isolates ranged between 4.6% (bla_CTX-M) and 58.4% (bla_TEM). Our findings indicate that the distribution of antibiotic-resistant bacteria with diverse ESBL-producing capabilities and virulence genes in freshwater sources potentially threatens public health and the environment.

Comparative molecular profiling of antimicrobial resistance and phylogenetic characterization of multidrug-resistant Escherichia coli isolated from meat sources in 2009 and 2021 in Japan

The global spread of antimicrobial resistance (AMR) is alarming. Escherichia coli is a Gram-negative bacterium that causes healthcare-associated infections and is a major threat to public health. Currently, no comprehensive antimicrobial surveillance of multidrug-resistant E. coli of diverse phylogroups along the meat value chain has been implemented in Higashihiroshima, Japan. Therefore, by employing the One Health approach, 1183 bacterial isolates, including 303 recovered from meat samples in 2009, were screened for the presence of antimicrobial resistance determinants using multiplex PCR and DNA sequencing techniques. Seventy-seven non-duplicate E. coli isolates that harbored AMR genes were subjected to antimicrobial susceptibility testing and the detection of integrons. Phylogenetic characterization, which has not been previously investigated, was used to assign E. coli to one of the eight phylogroups. Twenty-six out of 33 (78.8%) and 34 out of 44 (77.3%) E. coli isolates from 2009 and 2021 exhibited multidrug resistance (MDR) phenotypes, respectively. The most common clinical resistance was observed against ampicillin, tetracycline, kanamycin, sulfamethoxazole/trimethoprim, cefotaxime, and chloramphenicol. Overall, 22.1% (17/77) of the E. coli isolates carried extended-spectrum β-lactamase (ESBL)-encoding genes and showed the ESBL-resistant phenotypes. For the two isolation years, AmpC/ESBL prevalence decreased from 42.4% in 2009 to 20.5% in 2021. The identified AMR genes included bla_CTX-M-1, bla_CTX-M-2, bla_CTX-M-14, bla_CTX-M-15, and bla_SHV-12 (ESBL-types); bla_SHV-1, bla_TEM-1, bla_TEM-135, and bla_TEM-176 (narrow-spectrum types); bla_CMY-4, bla_ADC-32, bla_ADC-216, bla_ACT-48, and bla_ACT-51 (AmpC types); and integrons. All E. coli isolates were negative for carbapenemase-encoding genes, whereas one isolate from 2009 carried mcr-5.1 allele. Approximately 52% of E. coli isolates identified in 2009 were assigned to phylogroup A compared to the 20.5% in 2021. Notably, the highest proportions of E. coli phylogroups exhibiting MDR were groups A, B1, and F, suggesting that members of these groups are mostly associated with drug resistance. This study highlights the role of meat as a significant reservoir of MDR E. coli and potential source for transmission of AMR genes. Our findings emphasize the importance of continuous monitoring to track the changes in the spread of antimicrobial resistance in the food chain.

High prevalence of blaCTX-M-15 type extended-spectrum beta-lactamases in Gambian hooded vultures (Necrosyrtes monachus): A threatened species with substantial human interaction

One hundred fecal samples from hooded vultures in the Gambia (Banjul area) were investigated for the presence of bacteria with extended-spectrum cephalosporin- (ESBL/AmpC), carbapenemases, and colistin resistance. No Enterobacteriales carrying carbapenemases or resistance against colistin were detected. Fifty-four ESBL-producing Escherichia coli and five ESBL-producing Klebsiella pneumoniae isolates were identified in 52 of the samples, of which 52 E. coli and 4 K. pneumoniae yielded passed sequencing results. Fifty of the E. coli had ESBL phenotype and genotype harboring blaCTX-M genes, of which 88.5% (n = 46) were the blaCTX-M-15 gene, commonly found on the African continent. Furthermore, the genetic context around blaCTX-M-15 was similar between isolates, being colocalized with ISKpn19. In contrast, cgMLST analysis of the E. coli harboring ESBL genes revealed a genetic distribution over a large fraction of the currently known existing E. coli populations in the Gambia. Hooded vultures in the Gambia thus have a high ESBL E. coli-prevalence (>50%) with low diversity regarding key resistance genes. Furthermore, given the urban presence and frequent interactions between hooded vultures and humans, data from this study implies hooded vultures as potential vectors contributing to the further dissemination of antibiotic-resistance genes.

Impact of antibiotic intake on the incidence of extended-spectrum β-lactamase-producing Enterobacterales in sub-Saharan Africa: results from a community-based longitudinal study

OBJECTIVES

The global prevalence of intestinal extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE) is approximately 17% in communities, with significant variations among regions. This longitudinal study aimed to assess the impact of antibiotic intake on the incidence of intestinal ESBL-PE in Ghanaian pharmacy customers outside of hospitals.

METHODS

Screening for ESBL-PE was performed in four independent pharmacies in Kumasi, Ghana, using rectal swabs and an ESBL-PE-selective medium. Pharmacy customers purchasing antibiotics were recruited, and those buying non-antibiotic drugs served as controls. Participants who were negative for ESBL-PE provided follow-up swabs for up to 28 days.

RESULTS

At baseline, 302 (75%) of 404 participants were colonized with ESBL-PE. Sixty-three participants who were negative for ESBL-PE at baseline received per-protocol follow-up, including 28 individuals who took antibiotics and 35 controls. The cumulative proportions of ESBL-PE in the antibiotics and control groups were 71% (20/28) and 54% (19/35) at the first follow-up (p 0.258), 86% (24/28) and 80% (28/35) at the second follow-up (p 0.741) and 86% (24/28) and 94% (33/35) at the third follow-up (p 0.393), respectively.

DISCUSSION

The rate of intestinal ESBL-PE carriage among pharmacy customers outside of hospitals was higher than expected at baseline and further increased during the 28 days of follow-up, irrespective of antibiotic intake. This alarming finding needs to be considered in the antibiotic treatment of outpatients and emphasizes the urgent need for improved prevention strategies, development of new antibiotic drugs and potential future elimination strategies. Further longitudinal studies on ESBL-PE in African communities, also outside of pharmacy settings, are required.

Metagenomic Analysis of the Abundance and Composition of Antibiotic Resistance Genes in Hospital Wastewater in Benin, Burkina Faso, and Finland

Antibiotic resistance is a global threat to human health, with the most severe effect in low- and middle-income countries. We explored the presence of antibiotic resistance genes (ARGs) in the hospital wastewater (HWW) of nine hospitals in Benin and Burkina Faso, two low-income countries in West Africa, with shotgun metagenomic sequencing. For comparison, we also studied six hospitals in Finland. The highest sum of the relative abundance of ARGs in the 68 HWW samples was detected in Benin and the lowest in Finland. HWW resistomes and mobilomes in Benin and Burkina Faso resembled each other more than those in Finland. Many carbapenemase genes were detected at various abundances, especially in HWW from Burkina Faso and Finland. The bla_GES genes, the most widespread carbapenemase gene in the Beninese HWW, were also found in water intended for hand washing and in a puddle at a hospital yard in Benin. mcr genes were detected in the HWW of all three countries, with mcr-5 being the most common mcr gene. These and other mcr genes were observed in very high relative abundances, even in treated wastewater in Burkina Faso and a street gutter in Benin. The results highlight the importance of wastewater treatment, with particular attention to HWW. IMPORTANCE The global emergence and increased spread of antibiotic resistance threaten the effectiveness of antibiotics and, thus, the health of the entire population. Therefore, understanding the resistomes in different geographical locations is crucial in the global fight against the antibiotic resistance crisis. However, this information is scarce in many low- and middle-income countries (LMICs), such as those in West Africa. In this study, we describe the resistomes of hospital wastewater in Benin and Burkina Faso and, as a comparison, Finland. Our results help to understand the hitherto unrevealed resistance in Beninese and Burkinabe hospitals. Furthermore, the results emphasize the importance of wastewater management infrastructure design to minimize exposure events between humans, HWW, and the environment, preventing the circulation of resistant bacteria and ARGs between humans (hospitals and community) and the environment.

Diversity of enterobacterales in sediments of lagoons with fish farming activity and analysis of antibiotic resistance

The use of antibiotics in fish production can induce bacterial populations to develop resistance to multiple antibiotics and transfer antibiotic resistance genes to other bacteria, including clinically relevant bacteria. This study evaluated the diversity of Enterobacterales in sediment from lagoons with fish farming activity and analyzed antibiotic resistance in the central region of Peru. Sediment samples were collected from four fish-active ponds and transported to the laboratory for analysis. Bacterial diversity was analyzed using DNA sequencing and antibiotic resistance was tested using the disk diffusion method. The results showed variability of bacterial diversity in the ponds with fish farming activity. Simpson's index indicated that the Habascocha lagoon is the most diverse in bacterial species of the order Enterobacterales (0.8), but the least dominant. The Shannon-Wiener index revealed that it is the most diverse (2.93) and the Margalef index revealed that species richness in this lagoon is high (5.72). Similarity percentage analysis (SIMPER) allowed the identification of the main Enterobacterales with the highest percentage contribution in the frequencies of individuals. In general, the Enterobacterales species isolated showed multi-resistance to the antibiotics used and Escherichia coli was the most resistant.

Emergence of plasmid-mediated colistin resistance mcr-3.5 gene in Citrobacter amalonaticus and Citrobacter sedlakii isolated from healthy individual in Thailand

Citrobacter spp. are Gram-negative bacteria commonly found in environments and intestinal tracts of humans and animals. They are generally susceptible to third-generation cephalosporins, carbapenems and colistin. However, several antibiotic resistant genes have been increasingly reported in Citrobacter spp., which leads to the postulation that Citrobacter spp. could potentially be a reservoir for spreading of antimicrobial resistant genes. In this study, we characterized two colistin-resistant Citrobacter spp. isolated from the feces of a healthy individual in Thailand. Based on MALDI-TOF and ribosomal multilocus sequence typing, both strains were identified as Citrobacter sedlakii and Citrobacter amalonaticus. Genomic analysis and S1-nuclease pulsed field gel electrophoresis/DNA hybridization revealed that Citrobacter sedlakii and Citrobacter amalonaticus harbored mcr-3.5 gene on pSY_CS01 and pSY_CA01 plasmids, respectively. Both plasmids belonged to IncFII(pCoo) replicon type, contained the same genetic context (Tn3-IS1-ΔTnAs2-mcr-3.5-dgkA-IS91) and exhibited high transferring frequencies ranging from 1.03×10-4 - 4.6×10-4 CFU/recipient cell Escherichia coli J53. Colistin-MICs of transconjugants increased ≥ 16-fold suggesting that mcr-3.5 on these plasmids can be expressed in other species. However, beside mcr, other major antimicrobial resistant determinants in multidrug resistant Enterobacterales were not found in these two isolates. These findings indicate that mcr gene continued to evolve in the absence of antibiotics selective pressure. Our results also support the hypothesis that Citrobacter could be a reservoir for spreading of antimicrobial resistant genes. To the best of our knowledge, this is the first report that discovered human-derived Citrobacter spp. that harbored mcr but no other major antimicrobial resistant determinants. Also, this is the first report that described the presence of mcr gene in C. sedlakii and mcr-3 in C. amalonaticus.

ESBL and carbapenemase-producing Enterobacteriaceae in infectious pleural effusions: current epidemiology at Hôpital du Mali

Background

Antimicrobial resistance (AMR) is a global health concern, with extended-spectrum β-lactamases (ESBLs) and carbapenemases being major contributors. Pleural infection (PI) is a severe condition in West Africa, complicated by AMR. This study aimed to investigate the prevalence and molecular characteristics of ESBL and carbapenemase-producing enterobacteria in pleural effusions in Mali.

Materials and methods

Pleural fluid samples from 526 patients with pleuritis were analyzed. Enterobacterial species were isolated and identified, and the prevalence of resistance genes (blaOXA-48, blaNDM-1, blaKPC, blaTEM, blaSHV) and virulence factors was determined.

Results

Among the patients, 110 were diagnosed with enterobacterial pleuritis. Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis were the main pathogens identified. Resistance to β-lactams and cephalosporins was high, while carbapenems showed good activity. ESBL production was detected in 33.6% of isolates, with blaTEM being the most common gene. Carbapenemase gene (blaNDM-1) was found in three isolates.

Conclusion

The study highlights the high prevalence of multidrug-resistant bacteria and the need for appropriate antibiotic selection based on local resistance patterns. Understanding the molecular characteristics of resistance is crucial for optimizing patient care and developing effective therapeutic strategies. Further research is needed to monitor and control AMR in PIs in Mali.

Antimicrobial resistance, Extended-Spectrum β-Lactamase production and virulence genes in Salmonella enterica and Escherichia coli isolates from estuarine environment

The impact of antimicrobial resistance (AMR) on global public health has been widely documented. AMR in the environment poses a serious threat to both human and animal health but is frequently overlooked. This study aimed to characterize the association between phenotype and genotype of AMR, virulence genes and Extended-Spectrum β-Lactamase (ESBL) production from estuarine environment. The Salmonella (n = 126) and E. coli (n = 409) were isolated from oysters and estuarine water in Thailand. The isolates of Salmonella (96.9%) and E. coli (91.4%) showed resistance to at least one antimicrobial agent. Multidrug resistance (MDR) was 40.1% of Salmonella and 23.0% of E. coli. Resistance to sulfamethoxazole was most common in Salmonella (95.2%) and E. coli (77.8%). The common resistance genes found in Salmonella were sul3 (14.3%), followed by blaTEM (11.9%), and cmlA (11.9%), while most E. coli were blaTEM (31.5%) and tetA (25.4%). The ESBL production was detected in Salmonella (1.6%, n = 2) of which one isolate was positive to blaTEM-1. Eight E. coli isolates (2.0%) were ESBL producers, of which three isolates carried blaCTX-M-55 and one isolate was blaTEM-1. Predominant virulence genes identified in Salmonella were invA (77.0%), stn (77.0%), and fimA (69.0%), while those in E. coli isolates were stx1 (17.8%), lt (11.7%), and stx2 (1.2%). Logistic regression models showed the statistical association between resistance phenotype, virulence genes and ESBL production (p < 0.05). The findings highlighted that estuarine environment were potential hotspots of resistance. One Health should be implemented to prevent AMR bacteria spreading.

Antimicrobial, Multi-Drug and Colistin Resistance in Enterobacteriaceae in Healthy Pigs in the Greater Accra Region of Ghana, 2022: A Cross-Sectional Study

There is little published information on antimicrobial resistance (AMR) in animals in Ghana. We determined the prevalence and factors associated with AMR, multi-drug resistance (MDR-resistance to ≥3 antimicrobial classes) and colistin resistance in Enterobacteriaceae in healthy pigs in Accra, Ghana. Rectal swabs obtained from the pigs on 20 farms from January to March 2022, were examined for Escherichia coli, Enterobacter spp. and Klebsiella pneumoniae. AMR was determined using standard microbiological techniques and the mcr-1 gene detected through molecular analysis. Enterobacteriaceae were isolated from 197 of 200 pigs: these comprised 195 E. coli isolates, 38 Enterobacter spp. and 3 K. pneumoniae, either singly or combined. Over 60% of E. coli were resistant to tetracycline, with 27% and 34% being resistant to amoxicillin/clavulanic acid and ampicillin, respectively; 23% of E. coli and 5% of Enterobacter spp. exhibited MDR phenotypes. Phenotypic colistin resistance was found in 8% of E. coli and Enterobacter spp., with the mcr-1 gene detected in half. Our study findings should be incorporated into on-going AMR, MDR and colistin resistance surveillance programs in Ghana. We further advocate for tailored-specific education for pig farmers on animal antimicrobial use and for strengthened regulatory policy on antimicrobial usage and monitoring in the animal production industry.

Prevalence of Multidrug-Resistant CTX-M Extended Spectrum Beta-Lactamase-Producing Escherichia coli From Different Bovine Faeces in China

CTX-M extended spectrum beta-lactamase-producing Escherichia coli cause severe health hazards in livestock breeding. To date, little is known about antibiotic resistance differences among bacterial isolates from yaks, cows, and beef cattle; therefore, the aims of this study were to analyse the prevalence of CTX-M-producing E. coli in yak, beef cattle, and dairy cattle feces from different provinces in China. A total of 790 fecal samples from yaks, beef cattle, and dairy cows were used. Among all the samples, 523 non duplicate E. coli isolates were identified, and 29.6% of samples harbored CTX-M producers. The results showed that these E. coli strains harbored 15 clusters of CTX-M genes: CTX-M-79, CTX-M-55, CTX-M-15, CTX-M-14, CTX-M-28, CTX-M-179, CTX-M-65, CTX-M-24, CTX-M-27, CTX-M-102, CTX-M-105, CTX-M-173, CTX-M-238, CTX-M-196, and CTX-M-10. The dominant resistance genes were CTX-M-15, CTX-M-14, and CTX-M-55. Moreover, the distribution of CTX-M genes was related to geographical region. Based on the above findings, we reasoned that bovines are potential reservoirs of antibiotic resistance, and this problem should be given adequate attention.

Prevalence and Molecular Characterization of Extended-Spectrum β-Lactamases and AmpC β-lactamase-Producing Enterobacteriaceae among Human, Cattle, and Poultry

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are a universal public health alarm frequently identified among humans, animals, and poultry. Livestock and poultry production are a possible source of multidrug-resistant microorganisms, including ESBL-producing Enterobacteriaceae, which confer antimicrobial resistance to different β-lactam antimicrobial agents. From January to May 2020, a cross-sectional study was carried out in three dairy cattle farms and four poultry farms in different districts of northern Egypt to assess the prevalence of ESBLs, AmpC beta-lactamase-producing E. coli and Klebsiella in livestock, poultry, and human contacts, and to investigate the genetic relatedness of the recovered isolates. In total, 140 samples were collected, including human fecal samples (n = 20) of workers with intimate livestock contact, cattle rectal swabs (n = 34), milk (n = 14), milking machine swabs (n = 8), rations (n = 2), and water (n = 2) from different cattle farms, as well as cloacal swabs (n = 45), rations (n = 5), water (n = 5) and litter (n = 5) from poultry farms. The specimens were investigated for ESBL-producing E. coli and Klebsiella using HiCrome ESBL media agar. The agar disk diffusion method characterized the isolated strains for their phenotypic antimicrobial susceptibility. The prevalence of ESBL-producing Enterobacteriaceae was 30.0%, 20.0%, and 25.0% in humans, cattle, and poultry, respectively. Further genotypic characterization was performed using conventional and multiplex PCR assays for the molecular identification of ESBL and AmpC genes. The majority of the ESBL-producing Enterobacteriaceae showed a multi-drug resistant phenotype. Additionally, bla_SHV was the predominant ESBL genotype (n = 31; 93.94%), and was mainly identified in humans (n = 6), cattle (n = 11), and poultry (14); its existence in various reservoirs is a concern, and highlights the necessity of the development of definite control strategies to limit the abuse of antimicrobial agents.

Occurrence and Characteristics of ESBL- and Carbapenemase- Producing Escherichia coli from Wild and Feral Birds in Greece

Wild and feral birds are known to be involved in the maintenance and dissemination of clinically-important antimicrobial-resistant pathogens, such as extended-spectrum β-lactamase (ESBL) and carbapenemase-producing Enterobacteriaceae. The aim of our study was to evaluate the presence of ESBL- and carbapenemase-producing Escherichia coli among wild and feral birds from Greece and to describe their antimicrobial resistance characteristics. In this context, fecal samples of 362 birds were collected and cultured. Subsequently, the antimicrobial resistance pheno- and geno-type of all the obtained E. coli isolates were determined. A total of 12 multidrug-resistant (MDR), ESBL-producing E. coli were recovered from eight different wild bird species. Eleven of these isolates carried a blaCTX-M-1 group gene alone or in combination with blaTEM and one carried only blaTEM. AmpC, fluoroquinolone, trimethoprim/sulfamethoxazole, aminoglycoside and macrolide resistance genes were also detected. Additionally, one carbapenemase-producing E. coli was identified, harboring blaNDM along with a combination of additional resistance genes. This report describes the occurrence of ESBL- and carbapenemase-producing E. coli among wild avian species in Greece, emphasizing the importance of incorporating wild birds in the assessment of AMR circulation in non-clinical settings.

Characterization and Public Health Insights of the New Delhi Metallo-β-Lactamase-Producing Enterobacterales from Laying Hens in China

The New Delhi metallo-β-lactamase (NDM) is a major element for the rapid expansion of the carbapenem-resistant Enterobacterales, which poses a great challenge to public health security. NDM-producing Enterobacterales strains (50 Escherichia coli, 40 Klebsiella pneumoniae, and 5 Enterobacter cloacae) were isolated from laying hens in China for the surveillance of antibiotic-resistant pathogens, and all were found to be multi-drug resistant bacteria. The genomic analysis of these NDM-positive bacteria revealed the ST167, ST617, and ST410 of the fifteen ST-type E. coli clones and ST37 of the four ST-type K. pneumoniae clones to be the same types as the human-derived strains. Among them, some new clone types were also found. Most of the bla_NDM genes (bla_NDM-1 or bla_NDM-5) were on the IncX3 plasmids (n = 80) and were distributed in E. coli, K. pneumoniae, and E. cloacae, while the remaining bla_NDM-5 genes were harbored in the E. coli ST167 with IncFII plasmids (n = 15). The typeⅠ1 of the eight IncX3 plasmid subtypes was consistent with the human-derived pNDM5_020001 plasmid (accession no. CP032424). In addition, these two plasmids did not affect the growth of the host bacteria and could be reproduced stably without antibiotics. Our study revealed the high genetic propensity of the NDM-positive Enterobacterales from the laying hens and human commensal Enterobacterales, suggesting the potentially enormous risk of its transmission to humans.

Genetic characterization of ESBL/pAmpC-producing Escherichia coli isolated from forest, urban park and cereal culture soils

Little is known about the role of forestland and non-fertilized agriculture soils as reservoirs of extended-spectrum beta-lactamase (ESBL) and plasmid-borne AmpC (pAmpC)-producing Escherichia coli isolates. Thus, in the present study, 210 soil samples from various origins (forest of Oued Zen (Ain Drahem), non-agriculture soils from different park gardens in Tunis City, cereal culture soils and home gardens) were investigated to characterize cefotaxime-resistant E. coli isolates. A total of 22 ESBL/pAmpC-producing E. coli were collected, and all harbored variants of the blaCTX-M gene (15 blaCTX-M-1, 5 blaCTX-M-55 and 2 blaCTX-M-15). A total of seven and two isolates harbored also blaEBC and blaDHA-like genes, respectively. Resistances to tetracycline, sulfonamides and fluoroquinolones were encoded by tetA (n = 4)/tetB (n = 12), sul1 (n = 17)/sul2 (n = 19) and aac(6')-Ib-cr (n = 2)/qnrA (n = 1)/qnrS (n = 1) genes, respectively. A total of seven isolates were able to transfer by conjugation cefotaxime-resistance in association or not with other resistance markers. PFGE showed that ten and two isolates were clonally related (pulsotypes P1 and P2). The 10 P1 isolates had been collected from forestland, cereal culture soils and an urban park garden in Tunis City, arguing for a large spread of clonal strains. Our findings highlight the occurrence of ESBL/pAmpC-E. coli isolates in soils under limited anthropogenic activities and the predominance of CTX-M enzymes that are largely disseminated in E. coli from humans and animals in Tunisia.

Outbreak of CTX-M-15 Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae ST394 in a French Intensive Care Unit Dedicated to COVID-19

Infections caused by extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) are constantly rising worldwide and are often reported as causative agent of outbreaks in intensive care units (ICUs). During the first wave of the COVID-19 pandemic, bacterial cross-transmission was thought unlikely to occur due to the reinforcement of hygiene measures and prevention control. However, we report here an ESBL-producing K. pneumoniae (ST394) isolate responsible for a nosocomial outbreak in an ICU dedicated to COVID-19 patients.

Comparative genomic characterization of multidrug-resistant Citrobacter spp. strains in Fennec fox imported to China

BACKGROUND

To investigate the antimicrobial profiles and genomic characteristics of MDR-Citrobacter spp. strains isolated from Fennec fox imported from Sudan to China.

METHODS

Four Citrobacter spp. strains were isolated from stool samples. Individual fresh stool samples were collected and subsequently diluted in phosphate buffered saline as described previously. The diluted fecal samples were plated on MacConkey agar supplemented with 1 mg/l cefotaxime and incubated for 20 h at 37 °C. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) was used for identification. Antimicrobial susceptibility testing was performed using the broth microdilution method. Whole-genome sequencing was performed on an Illumina Novaseq-6000 platform. Acquired antimicrobial resistance genes and plasmid replicons were detected using ResFinder 4.1 and PlasmidFinder 1.3, respectively. Comparative genomic analysis of 277 Citrobacter genomes was also performed.

RESULTS

Isolate FF141 was identified as Citrobacter cronae while isolate FF371, isolate FF414, and isolate FF423 were identified as Citrobacter braakii. Of these, three C. braakii isolates were further confirmed to be extended-spectrum β-lactamases (ESBL)-producer. All isolates are all multidrug resistance (MDR) with resistance to multiple antimicrobials. Plasmid of pKPC-CAV1321 belong to incompatibility (Inc) group. Comparative genomics analysis of Citrobacter isolates generated a large core-genome. Genetic diversity was observed in our bacterial collection, which clustered into five main clades. Human, environmental and animal Citrobacter isolates were distributed into five clusters.

CONCLUSIONS

To our knowledge, this is the first investigation of MDR-Citrobacter from Fennec Fox. Our phenotypic and genomic data further underscore the threat of increased ESBL prevalence in wildlife and emphasize that increased effort should be committed to monitoring the potentially rapid dissemination of ESBL-producers with one health perspective.

Insects, Rodents, and Pets as Reservoirs, Vectors, and Sentinels of Antimicrobial Resistance

This paper reviews the occurrence of antimicrobial resistance (AMR) in insects, rodents, and pets. Insects (e.g., houseflies, cockroaches), rodents (rats, mice), and pets (dogs, cats) act as reservoirs of AMR for first-line and last-resort antimicrobial agents. AMR proliferates in insects, rodents, and pets, and their skin and gut systems. Subsequently, insects, rodents, and pets act as vectors that disseminate AMR to humans via direct contact, human food contamination, and horizontal gene transfer. Thus, insects, rodents, and pets might act as sentinels or bioindicators of AMR. Human health risks are discussed, including those unique to low-income countries. Current evidence on human health risks is largely inferential and based on qualitative data, but comprehensive statistics based on quantitative microbial risk assessment (QMRA) are still lacking. Hence, tracing human health risks of AMR to insects, rodents, and pets, remains a challenge. To safeguard human health, mitigation measures are proposed, based on the one-health approach. Future research should include human health risk analysis using QMRA, and the application of in-silico techniques, genomics, network analysis, and ’big data’ analytical tools to understand the role of household insects, rodents, and pets in the persistence, circulation, and health risks of AMR.