High prevalence of ESBLs in retail chicken meat despite reduced use of antimicrobials in chicken production, France

Environment, animals, and food as reservoirs of antibiotic-resistant bacteria for humans: One health or more?

Antimicrobial resistance (AMR) is a major public health challenge. For several years, AMR has been addressed through a One Health approach that links human health, animal health, and environmental quality. In this review, we discuss AMR in different reservoirs with a focus on the environment. Anthropogenic activities produce effluents (sewage, manure, and industrial wastes) that contaminate soils and aquatic environments with antibiotic-resistant bacteria (ARB), antibiotic-resistant genes (ARGs), and selective agents such as antibiotics, biocides, and heavy metals. Livestock treated with antibiotics can also contaminate food with ARB. In high-income countries (HICs), effective sanitation infrastructure and limited pharmaceutical industries result in more controlled discharges associated with human activities. Hence, studies using genome-based typing methods have revealed that, although rare inter-reservoir transmission events have been reported, human acquisition in HICs occurs primarily through person-to-person transmission. The situation is different in low- and middle-income countries (LMICs) where high population density, poorer sanitation and animal farming practices are more conducive to inter-reservoir transmissions. In addition, environmental bacteria can be a source of ARGs that, when transferred to pathogenic species under antibiotic selection pressure in environmental hotspots, produce new antibiotic-resistant strains that can potentially spread in the human community through human-to-human transmission. The keys to reducing AMR in the environment are (i) better treatment of human waste by improving wastewater treatment plants (WWTPs) in HICs and improving sanitation infrastructure in LMICs, (ii) reducing the use of antibiotics by humans and animals, (iii) prioritizing the use of less environmentally harmful antibiotics, and (iv) better control of pharmaceutical industry waste.

Comparison of IncK-blaCMY-2 Plasmids in Extended-Spectrum Cephalosporin-Resistant Escherichia coli Isolated from Poultry and Humans in Denmark, Finland, and Germany

Escherichia coli carrying IncK-blaCMY-2 plasmids mediating resistance to extended-spectrum cephalosporins (ESC) has been frequently described in food-producing animals and in humans. This study aimed to characterize IncK-blaCMY-2-positive ESC-resistant E. coli isolates from poultry production systems in Denmark, Finland, and Germany, as well as from Danish human blood infections, and further compare their plasmids. Whole-genome sequencing (Illumina) of all isolates (n = 46) confirmed the presence of the blaCMY-2 gene. Minimum inhibitory concentration (MIC) testing revealed a resistant phenotype to cefotaxime as well as resistance to ≥3 antibiotic classes. Conjugative transfer of the blaCMY-2 gene confirmed the resistance being on mobile plasmids. Pangenome analysis showed only one-third of the genes being in the core with the remainder being in the large accessory gene pool. Single nucleotide polymorphism (SNP) analysis on sequence type (ST) 429 and 1286 isolates showed between 0-60 and 13-90 SNP differences, respectively, indicating vertical transmission of closely related clones in the poultry production, including among Danish, Finnish, and German ST429 isolates. A comparison of 22 ST429 isolates from this study with 80 ST429 isolates in Enterobase revealed the widespread geographical occurrence of related isolates associated with poultry production. Long-read sequencing of a representative subset of isolates (n = 28) allowed further characterization and comparison of the IncK-blaCMY-2 plasmids with publicly available plasmid sequences. This analysis revealed the presence of highly similar plasmids in ESC-resistant E. coli from Denmark, Finland, and Germany pointing to the existence of common sources. Moreover, the analysis presented evidence of global plasmid transmission and evolution. Lastly, our results indicate that IncK-blaCMY-2 plasmids and their carriers had been circulating in the Danish production chain with an associated risk of spreading to humans, as exemplified by the similarity of the clinical ST429 isolate to poultry isolates. Its persistence may be driven by co-selection since most IncK-blaCMY-2 plasmids harbor resistance factors to drugs used in veterinary medicine.

[Development of antibiotic resistance in animals not receiving antibiotic therapy]

The fight against antibiotic resistance in the animal sector over the last ten years in France (Ecoantibio plans) has largely focused on reducing the veterinary use of antibiotics. However, antibiotic resistance in an animal is not necessarily due to antibiotic therapy, but can also result from the transmission of resistant bacteria or resistance plasmids. Several examples illustrate the importance of this transmission of antibiotic resistance in the animal world, which are detailed in this communication. Like in human medicine, this nosocomial transmission can be observed in veterinary care institutions, as well as in animal husbandry. It also explains the presence of antibiotic resistance on the surface of foodstuffs, which by definition are not treated with antibiotics. At the international level, countries that are very virtuous in their use of veterinary antibiotics can display high levels of antibiotic resistance through the importation of carrier animals. Finally, the presence of antibiotic resistance in wildlife is likewise explained by contamination and not by antibiotic treatment. All these situations demonstrate that, in addition to paying attention to antibiotic prescription, an equally important facet of the fight against antibiotic resistance is to control the transmission routes of resistant bacteria.

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 Transmission of Extended-Spectrum Cephalosporin (ESC) Resistance Genes in Escherichia coli Isolated from Poultry Production Systems and Slaughterhouses in Denmark

The emergence of extended-spectrum cephalosporin (ESC)-resistant Escherichia coli is a global concern. This study aimed to assess the prevalence and transmission of ESC-resistant E. coli in the Danish broiler production system. Samples from two vertically integrated Production Systems (1 and 2) and two slaughterhouses (A and B) were analyzed (n = 943) for the occurrence of ESC-resistant E. coli from 2015 to 2018. ESC-resistant E. coli isolates were whole-genome sequenced (WGS) for characterization of the multi-locus sequence type (MLST), antibiotic resistance genes, virulence genes, and plasmid replicon types. An ad hoc core genome (cg) MLST based on 2513 alleles was used to examine the genetic relatedness among isolates. The prevalence of ESC-resistant E. coli in the conventional Production System 1 was 2.7%, while in Production System 2 the prevalence was 26.7% and 56.5% for samples from the conventional and organic production, respectively. The overall prevalence of ESC-resistant E. coli in broiler thigh and fecal samples ranged from 19.3% in Slaughterhouse A to 22.4% in Slaughterhouse B. In total, 162 ESC-resistant E. coli were isolated and shown to belong to 16 different sequence types (STs). The most prevalent STs were ST2040 (n = 85) and ST429 (n = 22). Seven ESC resistance genes were detected: blaCMY-2 (n = 119), blaTEM-52B (n = 16), blaCTX-M-1 (n = 5), blaTEM-52C (n = 3), blaCTX-M-14 (n = 1), blaSHV-12 (n = 1), and up-regulation of ampC (n = 16), with an unknown resistance gene in one isolate (n = 1). The carriage of blaCMY-2 in 119 isolates was primarily associated with IncI1 (n = 87), and IncK plasmids (n = 31). Highly similar blaCMY-2 carrying E. coli isolates from ST429 were found in production systems as well as in slaughterhouses. In conclusion, findings from this study indicate that ESC-resistant E. coli are transferred vertically from farms in the production systems to slaughterhouses with the potential to enter the food supply.

Modeling of interventions for reducing external Enterobacteriaceae contamination of broiler carcasses during processing

This article presents a mathematical model for the Enterobacteriaceae count on the surface of broiler chicken during slaughter and how it may be affected by different processing technologies. The model is based on a model originally developed for Campylobacter and has been adapted for Enterobacteriaceae using a Bayesian updating approach and hitherto unpublished data gathered from German abattoirs. The slaughter process in the model consists of five stages: input, scalding, defeathering, evisceration, washing, and chilling. The impact of various processing technologies along the broiler processing line on the Enterobacteriaceae count on the carcasses' surface has been determined from literature data. The model is implemented in the software R and equipped with a graphical user interface which allows interactively to choose among different processing technologies for each stage along the processing line. Based on the choice of processing technologies the model estimates the Enterobacteriaceae count on the surface of each broiler chicken at each stage of processing. This result is then compared to a so-called baseline model which simulates a processing line with a fixed set of processing technologies. The model calculations showed how even very effective removal of bacteria on the exterior of the carcass in a previous step will be undone by the cross-contamination with leaked feces, if feces contain high concentrations of bacteria.

Detection and genetic characterization of blaESBL-carrying plasmids of cloacal Escherichia coli isolates from white stork nestlings (Ciconia ciconia) in Spain

OBJECTIVES

This study aimed to characterize Escherichia coli isolates from cloacal samples of white stork nestlings, with a special focus on extended-spectrum β-lactamases (ESBLs)-producing E. coli isolates and their plasmid content.

METHODS

Cloacal samples of 88 animals were seeded on MacConkey-agar and chromogenic-ESBL plates to recover E. coli and ESBL-producing E. coli. Antimicrobial susceptibility was screened using the disc diffusion method, and the genotypic characterization was performed by polymerase chain reaction (PCR) and subsequent sequencing. S1 nuclease Pulsed-Field-Gel-Electrophoresis (PFGE), Southern blotting, and conjugation essays were performed on ESBL-producing E. coli, as well as whole-genome sequencing by short- and long-reads. The four blaESBL-carrying plasmids were completely sequenced.

RESULTS

A total of 113 non-ESBL-producing E. coli isolates were collected on antibiotic-free MacConkey-agar, of which 27 (23.9%) showed a multidrug-resistance (MDR) phenotype, mainly associated with β-lactam-phenicol-sulfonamide resistance (blaTEM/cmlA/floR/sul1/sul2/sul3). Moreover, four white stork nestlings carried ESBL-producing E. coli (4.5%) with the following characteristics: blaSHV-12/ST38-D, blaSHV-12/ST58-B1, blaCTX-M-1/ST162-B1, and blaCTX-M-32/ST155-B1. Whole-genome sequencing followed by Southern blot hybridizations on S1-PFGE gels in ESBL-positive isolates proved that the blaCTX-M-1 gene and one of the blaSHV-12 genes were carried by IncI1/pST3 plasmids, while the second blaSHV-12 gene and the blaCTX-M-32 gene were located on IncF plasmids. The two blaSHV-12 genes and the two blaCTX-M genes had similar but non-identical close genetic environments, as all four genes were flanked by a variety of insertion sequences.

CONCLUSION

The role played by several genetic platforms in the mobility of ESBL genes allows for interchangeability on a remarkably small scale (gene-plasmid-clones), which may support the spread of ESBL genes.

Acquisition of a novel conjugative multidrug-resistant hypervirulent plasmid leads to hypervirulence in clinical carbapenem-resistant Klebsiella pneumoniae strains

The co-occurrence of plasmid-mediated multidrug resistance and hypervirulence in epidemic carbapenem-resistant Klebsiella pneumoniae has emerged as a global public health issue. In this study, an ST23 carbapenem-resistant hypervirulent K. pneumoniae (CR-HvKP) strain VH1-2 was identified from cucumber in China and harbored a novel hybrid plasmid pVH1-2-VIR. The plasmid pVH1-2-VIR carrying both virulence and multidrug-resistance (MDR) genes was likely generated through the recombination of a virulence plasmid and an IncFIIK conjugative MDR plasmid in clinical ST23 18622 isolated from a sputum sample. The plasmid pVH1-2-VIR exhibited the capacity for transfer to the clinical ST11 carbapenem-resistant K. pneumoniae (CRKP) strain via conjugation assay. Acquisition of pVH1-2-VIR plasmid directly converted a CRKP into CR-HvKP strain characterized by hypermucoviscosity, heightened virulence for Galleria mellonella larvae, and increased colonization ability in the mouse intestine. The emergence of such a hybrid plasmid may expedite the spread of CR-HvKP strains, posing a significant risk to human health.

Analysis of Retrospective Laboratory Data on the Burden of Bacterial Pathogens Isolated at the National Veterinary Research Institute Nigeria, 2018-2021

Farm animals harbour bacterial pathogens, which are often viewed as important indicators of animal health and determinants of food safety. To better understand the prevalence and inform treatment, we audited laboratory data at the Bacteriology Laboratory of the NVRI from 2018-2021. Antibiotics were classified into seven basic classes: quinolones, tetracyclines, beta-lactams, aminoglycosides, macrolides, nitrofuran, and cephalosporins. Trends were analysed using a generalised linear model with a log link function for the Poisson distribution, comparing proportions between years with an offset to account for the variability in the total number of organisms per year. Avian (73.18%) samples were higher than any other sample. The major isolates identified were Escherichia. coli, Salmonella spp., Klebsiella spp., Staphylococcus spp., Proteus spp., and Pseudomonas spp. We found that antimicrobial resistance to baseline antibiotics increased over the years. Of particular concern was the increasing resistance of Klebsiella spp. to cephalosporins, an important second-generation antibiotic. This finding underscores the importance of farm animals as reservoirs of pathogens harbouring antimicrobial resistance. Effective biosecurity, surveillance, and frugal use of antibiotics in farms are needed because the health of humans and animals is intricately connected.

Characterization of Extended Spectrum Cephalosporin-Resistant Escherichia coli Strains Isolated from Raw Poultry Carcasses in Catering Services in Northern Greece

Antimicrobial resistance is considered a topic of utmost interest under the concept of "One Health", having severe implications in both human and veterinary medicine. Among the antibiotic-resistant bacteria, gram-negative bacteria, especially those belonging to the order of Enterobacterales (such as Escherichia coli), hold a prominent position in terms of both virulence and possessing/disseminating antimicrobial resistance (AMR) traits. The aim of this study was to examine the presence of extended-spectrum β-lactamase producing E. coli isolates in raw poultry carcasses collected from a university club. Five hundred raw poultry skin samples were collected from the Aristotle University of Thessaloniki (AUTh) club in Thessaloniki, Greece. A total of 64% of the samples were positive for the presence of extended-spectrum β-lactamase (ESBL)-producing E. coli. The isolates were further examined for their susceptibility to selected antibiotics by the disc diffusion method and were characterized as true ESBL, as producing class C cephalosporinases (AmpC) or "of unknown etiology" by the combination disc test. The 86 of the 120 isolates (71.67%) were classified as true ESBL, 24 (20.00%) as AmpC, and 10 (8.33%) as "of unknown etiology". The isolates were screened for the occurrence of β-lactamase genes (blaTEM, blaCTX-M, blaSHV, and blaOXA). Thirty-six isolates (32 ESBL- and 4 AmpC-phenotype) harbored both blaTEM and blaCTX-M genes, twenty-two isolates (among which 19 ESBL-phenotype and 2 AmpC-phenotype) harbored blaCTX-M only, whereas twenty-six (14 ESBL- and 12 AmpC-phenotype) isolates harbored blaTEM alone. No isolate harboring blaSHV or blaOXA was detected. The results demonstrate the existence of E. coli isolates producing extended-spectrum β-lactamases in poultry carcasses from Greece, pausing a risk for antibiotic resistance transfer to humans.

Prevalence of the blaCTX-M and blaTEM genes among extended-spectrum beta lactamase-producing Escherichia coli isolated from broiler chickens in Indonesia

Introduction

Infections of humans and animals by multidrug resistant bacteria are increasing because of the inappropriate use of antibiotics. Disease management may be more challenging if Escherichia coli produce extended-spectrum beta-lactamase (ESBL), which could cause resistance to aztreonam and third-generation cephalosporins. This study was aimed at determining the prevalence of the blaCTX-M and blaTEM genes among ESBL-producing E. coli isolated from broiler chickens in Indonesia.

Material and Methods

A total of 115 broiler cloacal swab samples were obtained from 22 farms and studied for the presence of E. coli. The isolates were identified using approved standard methods and were purified on eosin methylene blue agar media. The E. coli isolates were subjected to sensitivity testing using beta-lactam antibiotics, and ESBL production was confirmed by a double-disc synergy test. The presence of the blaCTX-M and blaTEM genes was identified using a PCR.

Results

It was found that 99/115 (86.1%) of the isolated E. coli were resistant to beta-lactam antibiotics and 34/115 (29.6%) of them were phenotypically detected to be ESBL producers. Of the 34 isolates that were confirmed ESBL producers, 32/34 (94.1%) of them harboured the blaCTX-M and 13/34 (38.2%) the blaTEM genes. The blaCTX-M and blaTEM genes were detected together in 12/34 (35.3%) isolates.

Conclusion

This study discovered that broiler chickens are possible reservoirs of ESBL-producing E. coli that may infect humans. Thus, a committed public health education campaign is recommended in order to mitigate the potential threat to human health.

Molecular characterization of extended-spectrum β-lactamases-producing Enterobacteriaceae species in ground beef and chicken meat

The objectives of this study were i) to characterize extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) using pheno- and genotyping methods, ii) to evaluate the antimicrobial resistance pattern against 10 antibiotics, and iii) to investigate class 1 integron (intI1) in 80 Enterobacteriaceae isolates obtained from chicken meat (n = 40; 47 isolates) and ground beef (n = 40; 33 isolates) samples. Through the study, we found that 55 (68.7 %) of 80 Enterobacteriaceae isolates were capable of β-lactamase activity, and 38 (47.5 %) of them were multi-drug-resistant (MDR). The ground meat-origin isolates are 1.2 times more likely to produce imipenem resistance compared to chicken-meat-origin isolates (z = 2.1, p < 0.05, OR = 1.42). ESBL-E was found in 18 (22.5 %) of the isolates, 16.3 % of chicken meat and 6.3 % of ground beef origin. The bla genes were detected in 14 isolates [bla-_TEM (n = 10; 12.5 %); bla-_SHV (n = 4; 5.0 %); bla-_CTX-M (n = 0)], where the predominant species were Escherichia (E.) coli and Citrobacter braakii. The nine ESBL-E isolates were MDR. Twenty-eight (35.0 %) of 80 isolates were found to be resistant to at least one third-generation cephalosporin, and eight (28.6 %) of them were also ESBL-E. Eleven of 16 (48.5 %) carbapenem-resistant isolates were ESBL-E. The intI1 gene was found in 13 (16.3 %) isolates, five of which were ESBL-E, and four of which were MDR. Co-existing with bla-_TEM and the intI1 isolate was ESBL-E. coli, which was resistant to nine antibiotics. In conclusion, chicken meat and ground beef may pose a potential risk of containing ESBL-E, and bla genes which could be spread to the entire food chain.

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.

Evaluation of Antimicrobial Resistance of Different Phylogroups of Escherichia coli Isolates from Feces of Breeding and Laying Hens

Animal and food sources are seen as a potential transmission pathway of multi-drug resistance (MDR) micro-organisms to humans. Escherichia. coli is frequently used as an indicator of fecal contamination in the food industry and known as a reservoir of antimicrobial resistance genes (ARGs). Microbial contamination as a major outcome for the poultry and egg industry and is a serious public health problem. In the present study we performed the quantification of β-glucoronidase positive E. coli in 60 fecal samples of breeding and laying hens collected in Portugal in 2019. Phylogenetic and pathotypic characterization, antimicrobial susceptibility, and detection of resistant extended-spectrum β-lactamase (ESBL) genes were assessed. The phylogenetic and pathogenic characterization and detection of ESBL genes were assessed by real-time PCR and antimicrobial susceptibility was evaluated using the disk diffusion method. Overall, E. coli quantification was 6.03 log CFU/g in breeding hens and 6.02 log CFU/g in laying hens. The most frequent phylogroups were B1. None of the isolates was classified as diarrheagenic E. coli (DEC). In total, 57% of the isolates showed MDR and 3.8% were positive for ESBL. Our study highlights that consumers may be exposed to MDR E. coli, presenting a major hazard to food safety and a risk to public health.

Comparative Analysis of Phylogenetic Relationships and Virulence Factor Characteristics between Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolates Derived from Clinical Sites and Chicken Farms

Antimicrobial resistance in bacteria is the most urgent global threat to public health, with extended-spectrum β-lactamase-producing Escherichia coli (ESBL-E. coli) being one of the most documented examples. Nonetheless, the ESBL-E. coli transmission relationship among clinical sites and chicken farms remains unclear. Here, 408 ESBL-E. coli strains were isolated from hospitals and chicken farms in Sichuan Province and Yunnan Province in 2021. We detected blaCTX-M genes in 337 (82.62%) ESBL-E. coli strains. Although the isolation rate, prevalent sequence type (ST) subtypes, and blaCTX-M gene subtypes of ESBL-E. coli varied based on regions and sources, a few strains of CTX-ESBL-E. coli derived from clinical sites and chicken farms in Sichuan Province displayed high genetic similarity. This indicates a risk of ESBL-E. coli transmission from chickens to humans. Moreover, we found that the high-risk clonal strains ST131 and ST1193 primarily carried blaCTX-M-27. This indicates that drug-resistant E. coli from animal and human sources should be monitored. As well, the overuse of β-lactam antibiotics should be avoided in poultry farms to ensure public health and build an effective regulatory mechanism of "farm to fork" under a One Health perspective. IMPORTANCE Bacterial drug resistance has become one of the most significant threats to human health worldwide, especially for extended-spectrum β-lactamase-producing E. coli (ESBL-E. coli). Timely and accurate epidemiological surveys can provide scientific guidance for the adoption of treatments in different regions and also reduce the formation of drug-resistant bacteria. Our study showed that the subtypes of ESBL-E. coli strains prevalent in different provinces are somewhat different, so it is necessary to individualize treatment regimens in different regions, and it is especially important to limit and reduce antibiotic use in poultry farming since chicken-derived ESBL-E. coli serves as an important reservoir of drug resistance genes and has the potential to spread to humans, thus posing a threat to human health. The use of antibiotics in poultry farming should be particularly limited and reduced.

Integrated surveillance of extended-spectrum beta-lactamase (ESBL)-producing Salmonella and Escherichia coli from humans and animal species raised for human consumption in Canada from 2012 to 2017

Resistance to beta-lactam antimicrobials caused by extended-spectrum beta-lactamase (ESBL)-producing organisms is a global health concern. The objectives of this study were to (1) summarise the prevalence of potential ESBL-producing Escherichia coli (ESBL-EC) and Salmonella spp. (ESBL-SA) isolates from agrifood and human sources in Canada from 2012 to 2017, and (2) describe the distribution of ESBL genotypes among these isolates. All data were obtained from the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). CIPARS analysed samples for the presence of ESBLs through phenotypic classification and identified beta-lactamase genes (bla_TEM, bla_SHV, bla_CTX, bla_OXA, bla_CMY-2) using polymerase chain reaction (PCR) and whole genome sequencing (WGS). The prevalence of PCR-confirmed ESBL-EC in agrifood samples ranged from 0.5% to 3% across the surveillance years, and was detected most frequently in samples from broiler chicken farms. The overall prevalence of PCR-confirmed ESBL-SA varied between 1% and 4% between 2012 and 2017, and was most frequently detected in clinical isolates from domestic cattle. The TEM-CMY2 gene combination was the most frequently detected genotype for both ESBL-EC and ESBL-SA. The data suggest that the prevalence of ESBL-EC and ESBL-SA in Canada was low (i.e. <5%), but ongoing surveillance is needed to detect emerging or changing trends.

Prevalence and Characterization of Extended-Spectrum β-Lactamase- and Carbapenemase-Producing Enterobacterales from Tunisian Seafood

Aquaculture is a rapidly expanding sector in which it is important to monitor the occurrence of multi-drug resistant (MDR) bacteria. The presence of extended-spectrum β-lactamase (ESBL-) or carbapenemase-producing Enterobacterales is a commonly used indicator of the resistance burden in a given sector. In this study, 641 pieces of farmed fish (sea bream and sea bass), as well as 1075 Mediterranean clams, were analyzed. All ESBL- and carbapenemase-producing Enterobacterales collected were whole-genome sequenced. The proportion of ESBL-producing Enterobacterales was 1.4% in fish and 1.6% in clams, carried by Escherichia coli (n = 23) and Klebsiella pneumoniae (n = 4). The ESBL phenotype was exclusively due to the presence of bla_CTX-M genes, the most frequent one being bla_CTX-M-15. The bla_CTX-M-1 gene was also identified in six E. coli, among which four were carried by IncI1/pST3 plasmids, possibly betraying an animal origin. Carbapenemases were absent in fish but identified in two K. pneumoniae isolates from clams (bla_NDM-1 and bla_OXA-48). Several sequence types (STs) identified were associated with human MDR clones such as E. coli ST131 and ST617, or K. pneumoniae ST307 and ST147. Our results might indicate that bacteria from hospital or farm effluents can reach the open sea and contaminate seafood and fish that are living or raised nearby. Therefore, monitoring the quality of water discharged to the sea and the presence of MDR bacteria in seafood is mandatory to ensure the quality of fishery products.

Raw Meat Contaminated with Cephalosporin-Resistant Enterobacterales as a Potential Source of Human Home Exposure to Multidrug-Resistant Bacteria

The prevalence of cephalosporine-resistant (3GC-R) strains among United States community-related research samples ranged from 5.6 to 10.8%, while, in the European countries, it was 1.2% to 10.1%. Several studies suggest that meat of animal origin could be one of the reservoirs of 3GC-R bacteria. Here, 86 raw meat samples (turkey, pork, chicken and beef) were collected randomly and verified for the presence of 3GC-R bacteria. The 3GC-R bacteria were isolated, identified and characterized phenotypically (antibiotic resistance, motility and biofilm) and genotypically (repetitive-sequence-based rep-PCR) to elucidate any correlations with principal component analysis (PCA). From 28 3GC-R positive samples, 41 strains were isolated, from which the majority belonged to Serratia fonticola (39%), followed by Escherichia coli (19.5%), Enterobacter cloacae (17.1%) and Klebsiella pneumoniae (14.6%). The isolates of E. coli and S. fonticola presented diverse profiles in rep-PCR. Generally, 3GC-R strains were more resistant to antibiotics used in veterinary medicine than in human medicine. PCA derived from antibiotic resistance, motility and biofilm formation of S. fonticola and E. coli strains showed that resistance to beta-lactams was separated from the resistance to other antibiotic classes. Moreover, for the S. fonticola, E. coli and En. cloacae, the type of meat can create a specific tendency towards antibiotic resistance and phenotypic characteristics for S. fonticola, while these relationships were not found for other tested species.

Comparative Characteristics and Pathogenic Potential of Escherichia coli Isolates Originating from Poultry Farms, Retail Meat, and Human Urinary Tract Infection

The pathogenicity of many bacterial strains is determined by the acquisition of virulence genes and depends on many factors. The aim of this study was to analyse the phylogenetic background, virulence patterns, and drug susceptibility of 132 E. coli isolates tested in the context of the ExPEC (Extraintestinal Pathogenic E. coli) pathotype and the correlation of these features with bacterial isolation source: food (retail meat), poultry farms (AFEC—Avian Faecal E. coli), and patients with UTI (urinary tract infection) symptoms. The drug-susceptibility results of tested E. coli isolates obtained indicate that the resistance profile—ampicillin/tetracycline/trimethoprim+sulfamethoxazole/ciprofloxacin (AMP/TE/SXT/CIP)—was most frequently observed. The multidrug resistance (MDR) phenotype was found in 31.8% of isolates from poultry farms, 36.8% of strains isolated from food, and 20% of clinical samples. The greatest similarity of virulence profiles applied to isolates derived from poultry farms and food. Most of the AFEC from poultry farms and food-derived isolates belonged to commensals from phylogroups A and B1, while among the isolates from patients with UTI symptoms, the most common was the B2 phylogroup. The collective analysis showed similarity of the three studied groups of E. coli isolates in terms of the presented patterns of antimicrobial resistance, while the virulence profiles of the isolates studied showed great diversity. The phylogroup analysis showed no similarity between the poultry/food isolates and the UTI isolates, which had significant pathogenic potential.

High Prevalence of Klebsiella pneumoniae in European Food Products: a Multicentric Study Comparing Culture and Molecular Detection Methods

The Klebsiella pneumoniae species complex (KpSC) is a leading cause of multidrug-resistant human infections. To better understand the potential contribution of food as a vehicle of KpSC, we conducted a multicentric study to define an optimal culture method for its recovery from food matrices and to characterize food isolates phenotypically and genotypically. Chicken meat (n = 160) and salad (n = 145) samples were collected in five European countries and screened for the presence of KpSC using culture-based and zur-khe intergenic region (ZKIR) quantitative PCR (qPCR) methods. Enrichment using buffered peptone water followed by streaking on Simmons citrate agar with inositol (44°C for 48 h) was defined as the most suitable selective culture method for KpSC recovery. A high prevalence of KpSC was found in chicken meat (60% and 52% by ZKIR qPCR and the culture approach, respectively) and salad (30% and 21%, respectively) samples. Genomic analyses revealed high genetic diversity with the dominance of phylogroups Kp1 (91%) and Kp3 (6%). A total of 82% of isolates presented a natural antimicrobial susceptibility phenotype and genotype, with only four CTX-M-15-producing isolates detected. Notably, identical genotypes were found across samples-same food type and same country (15 cases), different food types and same country (1), and same food type and two countries (1)-suggesting high rates of transmission of KpSC within the food sector. Our study provides a novel isolation strategy for KpSC from food matrices and reinforces the view of food as a potential source of KpSC colonization in humans. IMPORTANCE Bacteria of the Klebsiella pneumoniae species complex (KpSC) are ubiquitous, and K. pneumoniae is a leading cause of antibiotic-resistant infections in humans. Despite the urgent public health threat represented by K. pneumoniae, there is a lack of knowledge of the contribution of food sources to colonization and subsequent infection in humans. This is partly due to the absence of standardized methods for characterizing the presence of KpSC in food matrices. Our multicentric study provides and implements a novel isolation strategy for KpSC from food matrices and shows that KpSC members are highly prevalent in salads and chicken meat, reinforcing the view of food as a potential source of KpSC colonization in humans. Despite the large genetic diversity and the low levels of resistance detected, the occurrence of identical genotypes across samples suggests high rates of transmission of KpSC within the food sector, which need to be further explored to define possible control strategies.

Prevalence of poultry Escherichia coli isolates producing extended-spectrum beta-lactamases and their public health importance

Recently, different reports highlighted the problem with dissemination of Escherichia coli producing extended spectrum beta-lactamases (ESBL) in poultry farms in Europe. The high incidence of Escherichia coli among poultry in Europe harbouring blaCTX-M-1 and the occurrence of ESBL and AmpC-producing Escherichia coli in raw meat samples collected from slaughterhouses in Europe have been discussed. ESBL-producing Enterobacteriaceae can be transmitted along the broiler production chain. Plasmids responsible for ESBL production frequently carry genes coding resistance to other antimicrobial classes, such as fluoroquinolones, aminoglycosides, sulphonamides. Resistance to cephalosporins in Enterobacteriaceae is of special concern for public health, because these anti­microbial agents are critically important. The aim of this mini review was to describe the mechanisms of resistance and prevalence of ESBL-producing E. coli. It is important to investigate the spread of these bacteria among poultry, the role of farm birds as reservoir of E. coli and the risk for people.

Prevalence and Characterization of ESBL/AmpC Producing Escherichia coli from Fresh Meat in Portugal

The present study aimed to characterize the extended-spectrum β-lactamases and plasmid-mediated AmpC β-lactamases (ESBL/PMAβ) among Escherichia coli producers isolated from beef, pork, and poultry meat collected at retail, in Portugal. A total of 638 meat samples were collected and inoculated on selective medium for the search of E. coli resistant to 3rd generation cephalosporins. Isolates were characterized by antimicrobial susceptibility testing, molecular assays targeting ESBL/AmpC, plasmid-mediated quinolone resistance (PMQR), and plasmid-mediated colistin resistance (PMCR) encoding genes. The highest frequency of E. coli non-wild type to 3rd generation cephalosporins and fluoroquinolones was observed in broiler meat (30.3% and 93.3%, respectively). Overall, a diversity of acquired resistance mechanisms, were detected: bla_ESBL [bla_CTX-M-1 (n = 19), bla_CTX-M-15 (n = 4), bla_CTX-M-32 (n = 12), bla_CTX-M-55 (n = 8), bla_CTX-M-65 (n = 4), bla_CTX-M-27 (n = 2), bla_CTX-M-9 (n = 1), bla_CTX-M-14 (n = 11), bla_SHV-12 (n = 27), bla_TEM-52 (n = 1)], bla_PMAβ [bla_CMY-2 (n = 8)], PMQR [qnrB (n = 27), qnrS (n = 21) and aac(6')-Ib-type (n = 4)] and PMCR [mcr-1 (n = 8)]. Our study highlights that consumers may be exposed through the food chain to multidrug-resistant E. coli carrying diverse plasmid-mediated antimicrobial resistance genes, posing a great hazard to food safety and a public health risk.

Are There Effective Intervention Measures in Broiler Production against the ESBL/AmpC Producer Escherichia coli?

Extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase (AmpC) producing Enterobacteriaceae occur frequently in livestock animals and the subsequent stages of the meat production chain and are therefore considered a risk for human health. Strict biosecurity measures and optimal farm management should reduce or even prevent poultry flock colonization at farm level. This review summarizes and evaluates published information on the effectiveness of specific intervention measures and farm management factors aiming to reduce the occurrence and spread of ESBL/AmpC producing or commensal or pathogenic E. coli in broiler chicken farms. In this systematic literature review, a total of 643 publications were analyzed, and 14 studies with significant outcome about the effectiveness of specific measures against E. coli and ESBL/AmpC producing E. coli in broiler chicken farms were found. Different feed additives seem to have an impact on the occurrence of those microorganisms. The measures ‘cleaning and disinfection’ and ‘competitive exclusion’ showed strong effects in prevention in some studies. In summary, some intervention measures showed potential to protect against or eliminate ESBL/AmpC-producing, commensal or pathogenic E. coli at farm level. Due to the high variability in the outcome of the studies, more specific, detailed investigations are needed to assess the potential of the individual intervention measures.

An inventory of 44 qPCR assays using hydrolysis probes operating with a unique amplification condition for the detection and quantification of antibiotic resistance genes

Early antibiotic resistance determinants (ARDs) detection in humans or animals is crucial to counteract their propagation. The ARDs quantification is fundamental to understand the perturbation caused by disruptors, such as antibiotics, during therapies. Forty-three qPCRs on the most diffused ARDs and integrons among human and animal Enterobacterales, and one on the 16S rDNA for bacteria quantification, were developed. The qPCRs, using hydrolysis probes, operated with a unique amplification condition and were tested analytically and diagnostically performing 435 reactions on five positive and negative controls for each qPCR. Diagnostic sensitivity and specificity were confirmed by PCR and genome sequencing of control isolates, demonstrating 100% performance for all qPCRs. An easy and rapid discrimination method for the epidemiologically relevant bla_CTX-Ms is provided. This large, noncommercial qPCRs inventory could serve for precise quantification of ARDs, but also as a rapid screening tool for surveillance purposes, providing the basis for further high-throughput developments.

Potentially Pathogenic Multidrug-Resistant Escherichia coli in Lamb Meat

Extended-spectrum cephalosporin (ESC) resistance remains a threat since ESC are important antimicrobials used to treat infections in humans and animals. Escherichia coli is an important source of ESC-resistance genes, such as those encoding extended-spectrum β-lactamases (ESBLs). E. coli is a common commensal of lambs. Reports that contaminated food can be a source of ESC-resistant bacteria in humans and that ESBL-producing E. coli are found in sheep in Brazil led us to survey their presence in retail lamb meat. Twenty-five samples intended for human consumption were screened for ESC-resistant E. coli, and the isolates were characterized. IncI1-bla_CTX-M-8 and IncHI2-bla_CTX-M-2 were the main plasmids responsible for ESC resistance. The plasmids harbored common ESBL genes in Enterobacteriaceae from food-producing animals in Brazil. IncI1-bla_CTX-M-14 and IncF-bla_CTX-M-55 plasmids, associated with human infections, were also detected. Few CTX-M-producing E. coli have been clustered by typing methods, and some may be genetically pathogenic. The findings indicate the presence of diverse strains of E. coli, harboring important ESBL genes, in lamb meat in Brazil. Surveillance of ESC-resistant bacteria could reduce the spread of antimicrobial resistance through the food chain.

Prevalence of Antibiotic-Resistant Escherichia coli Isolates from Local and Imported Retail Chicken Carcasses

ABSTRACT

The spread of antibiotic resistance among bacterial strains has been associated with consumption of food contaminated with both pathogenic and nonpathogenic bacteria. The objective of this study was to determine the prevalence of antibiotic resistant Escherichia coli isolates in local and imported retail raw chicken meat in Qatar. A total of 270 locally produced (chilled) and imported (chilled or frozen) whole chicken carcasses were obtained from three Hypermarket stores in Qatar. The 216 E. coli isolates recovered from the chicken samples were subjected to antibiotic susceptibility testing with the disk diffusion method. Extended-spectrum β-lactamase (ESBL) production was evaluated with the double disk synergy test. Isolates harboring colistin resistance were identified with a multiplex PCR assay and DNA sequencing. Nearly 89% (192) of the 216 isolates were resistant to at least one of the 18 antibiotics tested. Isolates from local and imported chicken carcasses had relatively higher resistance to sulfamethoxazole (62% of isolates), tetracycline (59.7%), ampicillin and trimethoprim (52.3% each), ciprofloxacin (47.7%), cephalothin (45.4%), and colistin (31.9%). Less resistance was found to amoxicillin-clavulanic acid (6%), ceftriaxone (5.1%), nitrofurantoin (4.2%), piperacillin-tazobactam (4.2%), cefepime (2.3%), meropenem (1.4%), ertapenem (0.9%), and amikacin (0.9%). Nine isolates (4.2%) were ESBL producers, and 137 (63.4%) were multidrug resistant. The percentages of multidrug-resistant, ESBL-producing, and colistin resistant isolates were significantly higher among isolates from local chilled than from imported chilled and frozen chicken samples. Our findings indicate the high prevalence of antibiotic-resistant E. coli in chicken meat sold at retail in Qatar.

HIGHLIGHTS

Escherichia coli as Commensal and Pathogenic Bacteria Among Food-Producing Animals: Health Implications of Extended Spectrum β-lactamase (ESBL) Production

Simple Summary

This revision is about the problem of Escherichia coli as a commensal and pathogenic bacterium among food-producing animals and health implications. Escherichia coli may play an important ecological role and can be used as a bioindicator of antimicrobial resistance. All animal species used for food production, as well as humans, carry E. coli in their intestinal tract; plus, the genetic flexibility and adaptability of this bacteria to constantly changing environments allows it to acquire a great number of antimicrobial resistance mechanisms. The majority of E. coli strains are commensals inhabiting the intestinal tract of humans and warm-blooded animals and rarely causes diseases. However, E. coli also remains as one of the most frequent causes of several common bacterial infections in humans and animals. All over the word, antibiotic resistance is commonly detected among commensal bacteria from food-producing animals, raising important questions on the potential impact of antibiotic use in animals and the possible transmission of these resistant bacteria to humans through the food chain. The use, in food-producing animals, of antibiotics that are critically important in human medicine has been implicated in the emergence of new forms of resistant bacteria, including new strains of multidrug-resistant foodborne bacteria, such as extended spectrum β-lactamase (ESBL)-producing E. coli.

Abstract

Escherichia coli are facultative, anaerobic Gram-negative rods with many facets. Within resistant bacterial populations, they play an important ecological role and can be used as a bioindicator of antimicrobial resistance. All animal species used for food production, as well as humans, carry E. coli in their intestinal tracts; plus, the genetic flexibility and adaptability of this bacteria to constantly changing environments allows it to acquire a great number of antimicrobial resistance mechanisms. Thus, the prevalence of antimicrobial resistance in these commensal bacteria (or others, such as enterococci) can be a good indicator for the selective pressure caused by the use of antimicrobial agents, providing an early warning of the emergence of antimicrobial resistance in pathogens. As many as 90% of E. coli strains are commensals inhabiting the intestinal tracts of humans and warm-blooded animals. As a commensal, it lives in a mutually beneficial association with its hosts and rarely causes diseases. However, E. coli also remains as one of the most frequent causes of several common bacterial infections in humans and animals. In humans, it is the prominent cause of enteritis, community- and hospital-acquired urinary tract infection (UTI), septicemia, postsurgical peritonitis, and other clinical infections, such as neonatal meningitis, while, in farm animals, it is more prominently associated with diarrhea. On a global scale, E. coli can be considered the most important human pathogen, causing severe infection along with other major bacterial foodborne agents, such as Salmonella spp. and Campylobacter. Thus, the importance of resistance in E. coli, typically considered a benign commensal, should not be underestimated.

Dissemination of antibiotic resistance genes (ARGs) via integrons in Escherichia coli: A risk to human health

With the induction of various emerging environmental contaminants such as antibiotic resistance genes (ARGs), environment is considered as a key indicator for the spread of antimicrobial resistance (AMR). As such, the ARGs mediated environmental pollution raises a significant public health concern worldwide. Among various genetic mechanisms that are involved in the dissemination of ARGs, integrons play a vital role in the dissemination of ARGs. Integrons are mobile genetic elements that can capture and spread ARGs among environmental settings via transmissible plasmids and transposons. Most of the ARGs are found in Gram-negative bacteria and are primarily studied for their potential role in antibiotic resistance in clinical settings. As one of the most common microorganisms, Escherichia coli (E. coli) is widely studied as an indicator carrying drug-resistant genes, so this article aims to provide an in-depth study on the spread of ARGs via integrons associated with E. coli outside clinical settings and highlight their potential role as environmental contaminants. It also focuses on multiple but related aspects that do facilitate environmental pollution, i.e. ARGs from animal sources, water treatment plants situated at or near animal farms, agriculture fields, wild birds and animals. We believe that this updated study with summarized text, will facilitate the readers to understand the primary mechanisms as well as a variety of factors involved in the transmission and spread of ARGs among animals, humans, and the environment.

Efficacy of six disinfection methods against extended-spectrum beta-lactamase (ESBL) producing E. coli on eggshells in vitro

The presence of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli on poultry products is an important issue for veterinary and human health due to the zoonotic infection risk for producers and consumers. The present study focuses on testing the efficacy of six different disinfection methods on eggshell samples, aiming to reduce ESBL producing E. coli contamination on the hatching egg. Sterile eggshell cutouts were artificially contaminated with 10⁸ cfu/ml CTX-M-1 producing E. coli and used as a carrier model to analyze the efficacy of six disinfection methods. The contaminated samples were separated into two groups; 1) contaminated and disinfected, 2) contaminated and non-disinfected. Six independent disinfection protocols were performed following product specifications and protocols. Each eggshell sample was separately crushed, and the total viable bacterial count was calculated to determine the disinfection efficacy. Five out of six tested methods (formaldehyde gassing, hydrogen peroxide + alcohol spray, essential oils spray, peracetic acid foam, and low energetic electron radiation) demonstrated a reduction or completely eliminated the initial ESBL producing E. coli contamination. One method (essential oils as cold fog) only partly reached the expected efficacy threshold (reduction of >10² cfu/ml) and the result differed significantly when compared to the reference method i.e. formaldehyde gassing.

Extended Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae from Broiler Liver in the Center of Algeria, with Detection of CTX-M-55 and B2/ST131-CTX-M-15 in Escherichia coli

This study aimed to determine the prevalence and diversity of extended-spectrum β-lactamase (ESBL)-producing and multidrug-resistant (MDR) Escherichia coli and Klebsiella pneumoniae isolates from 136 broiler livers randomly purchased in 136 retail markets in Djelfa (Algeria). Isolation was performed on Hektoen agar and bacterial identification was carried out by API20E system and Maldi-TOF-MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry). Antimicrobial susceptibility was tested by the disk diffusion and agar dilution methods. Detection of ESBLs and other resistance and integron genes, phylogenetic grouping, and molecular typing was performed by PCR and sequencing. Seventy-eight isolates (one per positive sample) were recovered: 73 E. coli and 5 K. pneumoniae. Among E. coli, 86.3% of isolates were MDR. ESBL activity was revealed in eight E. coli and five K. pneumoniae isolates (rates of 5.9% and 3.7% in analyzed samples, respectively). ESBL genes detected among E. coli were as follows (number of isolates): bla_CTX-M-15 (3), bla_CTX-M-1 (3), bla_CTX-M-55 (1), and bla_SHV-12 (1); all ESBL-producing K. pneumoniae isolates carried the bla_CTX-M-15 gene. ESBL-producing E. coli isolates were assigned to lineages (phylogroup/sequence type and number of isolates in parenthesis): A/ST48 (1), B1/ST6448 (1), B1/ST5087 (3), B1/ST23 (1), and B2/ST131 (two bla_CTX-M-15 E. coli isolates). K. pneumoniae isolates were ascribed to sequence types ST2010 and ST3483. Regarding the 65 non-ESBL E. coli isolates, the most observed resistance genes were as follows: tet(A) (75%), bla_TEM (57.1%), and sul2 (43.5%). Class1 integrons were revealed in seven non-ESBL E. coli isolates (10.7%) and two gene-cassette arrays were identified: dfrA1 and aadA1+dfrA1. Our study provides evidence that broiler-derived food from Center of Algeria constitutes a source of ESBL and/or MDR-producing Enterobacteriaceae, with detection of relevant ESBL genes and epidemic clones.

Antimicrobial resistance genes in bacteria from animal-based foods

Antimicrobial resistance is a worldwide public health threat. Farm animals are important sources of bacteria containing antimicrobial resistance genes (ARGs). Although the use of antimicrobials in aquaculture and livestock has been reduced in several countries, these compounds are still routinely applied in animal production, and contribute to ARGs emergence and spread among bacteria. ARGs are transmitted to humans mainly through the consumption of products of animal origin (PAO). Bacteria can present intrinsic resistance, and once antimicrobials are administered, this resistance may be selected and multiply. The exchange of genetic material is another mechanism used by bacteria to acquire resistance. Some of the main ARGs found in bacteria present in PAO are the bla, mcr-1, cfr and tet genes, which are directly associated to antibiotic resistance in the human clinic.

Preliminary study: Health and performance assessment in broiler chicks following application of six different hatching egg disinfection protocols

As part of a Germany-wide project that evaluates strategies for the reduction of multi-resistant bacteria along the poultry production chain, the impact of different hatching egg disinfectants on hatchability and health of the broiler chicks was evaluated. Animal trials were conducted with extended-spectrum beta-lactamase- (ESBL) producing Escherichia (E.) coli contaminated hatching eggs and six disinfection protocols that used formaldehyde, hydrogen peroxide, low-energy electron irradiation, peracetic acid and an essential oil preparation. Each protocol was tested on a group of 50 chicks. Equally sized positive and negative control groups were carried along for each trial. Hatchability, mortality and body weight were recorded as performance parameters. During necropsy of half of the animals in each group on day 7 and 14 respectively, macroscopic abnormalities, body weight, weights of liver and gut convolute were recorded and a range of tissue samples for histological examination were collected as part of the health assessment. A decrease in hatchability was recorded for spray application of essential oils. Body weight development was overall comparable, in several groups even superior, to the Ross308 performance objectives, but a reduced performance was seen in the hydrogen peroxide group. Histologically, lymphoid follicles were regularly seen in all sampled organs and no consistent differences were observed between contaminated and non-contaminated groups. Significances were infrequently and inconsistently seen. In conclusion, remarkable findings were a decrease in hatchability caused by the essential oils spray application and a reduced body weight development in the hydrogen peroxide group. Therefore, the essential oils preparation as spray application was deemed inappropriate in practice, while the application of hydrogen peroxide was considered in need of further research. The other trial results indicate that the tested hatching egg disinfectants present a possible alternative to formaldehyde.

ESKAPE Bacteria and Extended-Spectrum-β-Lactamase-Producing Escherichia coli Isolated from Wastewater and Process Water from German Poultry Slaughterhouses

The wastewater of livestock slaughterhouses is considered a source of antimicrobial-resistant bacteria with clinical relevance and may thus be important for their dissemination into the environment. To get an overview of their occurrence and characteristics, we investigated process water (n = 50) from delivery and unclean areas as well as wastewater (n = 32) from the in-house wastewater treatment plants (WWTPs) of two German poultry slaughterhouses (slaughterhouses S1 and S2). The samples were screened for ESKAPE bacteria (Enterococcus spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) and Escherichia coli Their antimicrobial resistance phenotypes and the presence of extended-spectrum-β-lactamase (ESBL), carbapenemase, and mobilizable colistin resistance genes were determined. Selected ESKAPE bacteria were epidemiologically classified using different molecular typing techniques. At least one of the target species was detected in 87.5% (n = 28/32) of the wastewater samples and 86.0% (n = 43/50) of the process water samples. The vast majority of the recovered isolates (94.9%, n = 448/472) was represented by E. coli (39.4%), the A. calcoaceticus-A. baumannii (ACB) complex (32.4%), S. aureus (12.3%), and K. pneumoniae (10.8%), which were widely distributed in the delivery and unclean areas of the individual slaughterhouses, including their wastewater effluents. Enterobacter spp., Enterococcus spp., and P. aeruginosa were less abundant and made up 5.1% of the isolates. Phenotypic and genotypic analyses revealed that the recovered isolates exhibited diverse resistance phenotypes and β-lactamase genes. In conclusion, wastewater effluents from the investigated poultry slaughterhouses exhibited clinically relevant bacteria (E. coli, methicillin-resistant S. aureus, K. pneumoniae, and species of the ACB and Enterobacter cloacae complexes) that contribute to the dissemination of clinically relevant resistances (i.e., blaCTX-M or blaSHV and mcr-1) in the environment.IMPORTANCE Bacteria from livestock may be opportunistic pathogens and carriers of clinically relevant resistance genes, as many antimicrobials are used in both veterinary and human medicine. They may be released into the environment from wastewater treatment plants (WWTPs), which are influenced by wastewater from slaughterhouses, thereby endangering public health. Moreover, process water that accumulates during the slaughtering of poultry is an important reservoir for livestock-associated multidrug-resistant bacteria and may serve as a vector of transmission to occupationally exposed slaughterhouse employees. Mitigation solutions aimed at the reduction of the bacterial discharge into the production water circuit as well as interventions against their further transmission and dissemination need to be elaborated. Furthermore, the efficacy of in-house WWTPs needs to be questioned. Reliable data on the occurrence and diversity of clinically relevant bacteria within the slaughtering production chain and in the WWTP effluents in Germany will help to assess their impact on public and environmental health.

Translating 'big data': better understanding of host-pathogen interactions to control bacterial foodborne pathogens in poultry

Recent technological advances has led to the generation, storage, and sharing of colossal sets of information ('big data'), and the expansion of 'omics' in science. To date, genomics/metagenomics, transcriptomics, proteomics, and metabolomics are arguably the most ground breaking approaches in food and public safety. Here we review some of the recent studies of foodborne pathogens (Campylobacter spp., Salmonella spp., and Escherichia coli) in poultry using big data. Genomic/metagenomic approaches have reveal the importance of the gut microbiota in health and disease. They have also been used to identify, monitor, and understand the epidemiology of antibiotic-resistance mechanisms and provide concrete evidence about the role of poultry in human infections. Transcriptomics studies have increased our understanding of the pathophysiology and immunopathology of foodborne pathogens in poultry and have led to the identification of host-resistance mechanisms. Proteomic/metabolomic approaches have aided in identifying biomarkers and the rapid detection of low levels of foodborne pathogens. Overall, 'omics' approaches complement each other and may provide, at least in part, a solution to our current food-safety issues by facilitating the development of new rapid diagnostics, therapeutic drugs, and vaccines to control foodborne pathogens in poultry. However, at this time most 'omics' approaches still remain underutilized due to their high cost and the high level of technical skills required.

Whole genome sequence analysis of antimicrobial resistance genes, multilocus sequence types and plasmid sequences in ESBL/AmpC Escherichia coli isolated from broiler caecum and meat

Plasmid-encoded extended-spectrum β-lactamase and AmpC gene-carrying Escherichia coli (ESBL/AmpC E. coli) is an increasing cause of human infections worldwide. Increasing carbapenem and colistin resistance further complicate treatment of these infections. The aim of this study was to assess the occurrence of ESBL/AmpC E. coli in different broiler flocks and farms, as well as in broiler meat, in a country with no antimicrobial usage in broiler production. An additional goal was to assess the genetic characteristics of ESBL/AmpC E. coli isolates by using whole genome sequencing (WGS). Altogether 520 caecal swabs and 85 vacuum-packed broiler meat samples were investigated at the slaughterhouse level. WGS of the bacterial isolates revealed acquired antimicrobial resistance (AMR) genes, multilocus sequence types (MLST) and plasmid sequences. ESBL/AmpC E. coli was identified in 92 (18%) of the caecum and 27 (32%) of the meat samples. ESBL/AmpC E. coli-carrying birds derived from six (33%) out of 18 farms. Of the two bla_ESBL/AmpC genes detected by PCR, bla_CMY-2 (96%) was predominant over bla_CTX-M-1 (4%). Furthermore, WGS revealed an additional AMR gene sul2. Carbapenemase, colistin, and other AMR genes were not detected from the isolates of either the caecal or meat samples. Altogether seven MLSTs (ST101, ST117, ST212, ST351, ST373, ST1594 and an unknown ST) and a variety of different plasmid sequences (IncB/O/K/Z, IncI1, IncFII, IncII, IncFIB, IncFIC, IncX1 and an additional set of Col-plasmids) were detected. This is the first study on genomic epidemiology of ESBL/AmpC E. coli on broiler farms and flocks with no antimicrobial usage, by using WGS analysis. Results show that ESBL/AmpC E. coli occurrence is common both in the caecum and in the packaged meat. However, compared to other European countries, the occurrence is low and the presence of AMR genes other than bla_CMY-2 and bla_CTX-M-1 is rare. More studies are needed to understand the ESBL/AmpC E. coli occurrence in broiler production to prevent the meat from contamination during slaughter and processing, thereby also preventing zoonotic transmission of ESBL/AmpC E. coli. Additionally, more studies are needed to understand the ecology and fitness cost of Enterobacteriaceae plasmids in animal production in order to prevent their acquisition of plasmid-encoded antimicrobial resistance genes such as carbapenem and colistin resistance genes, as this would pose a great hazard to food safety.

High Genetic Diversity of Enterobacteriaceae Clones and Plasmids Disseminating Resistance to Extended-Spectrum Cephalosporins and Colistin in Healthy Chicken in Tunisia

Enterobacteriaceae resistant to extended-spectrum cephalosporins (ESC-R) are listed as "priority pathogens" by the World Health Organization, and the Agri-food sector has regularly been pointed out as a potential source of ESC-R for humans through food consumption and animal handling. Chicken industry and chicken meat have recurrently been under specific scrutiny due to the high proportions of ESC-R reported worldwide in this sector. In Tunisia, recent studies suggested that the plasmidic AmpC bla_CMY-2 gene may have emerged in chicken. We thus collected 258 cloacal swabs from five different farms and selected ESC-R isolates to determine the current ESC-R prevalence and epidemiology. All five farms were ESC-R positive with proportions ranging from 4% to 67.3%. bla_CTX-M-1/IncI1/ST3 was the dominant gene/plasmid association in chicken, but several other CTX-M genes and plasmid backgrounds were shown to spread ESC-R. Surprisingly, the CMY-2 enzyme was only identified in one isolate. In addition, we also reported the sporadic presence of the mcr-1 gene carried by an IncHI2 plasmid. Our data suggest that the high diversity of Enterobacteriaceae clones and plasmids circulating in healthy chicken in Tunisia maintains a high ESC-R proportion in flocks and constitutes a major source of ESC-R determinants further disseminating in the food chain.

High incidence of multidrug-resistant Escherichia coli coharboring mcr-1 and bla CTX-M-15 recovered from pigs

PURPOSE

The coexistence of mobile colistin (COL)-resistant gene mcr-1 with extended-spectrum beta-lactamase (ESBL) gene in Escherichia coli has become a serious threat globally. The aim of this study was to investigate the increasing resistance to COL and in particular its coexistence with ESBL-producing E. coli recovered from pig farms in China.

MATERIALS AND METHODS

E. coli were isolated from 14 pig farms in Jiangsu China. Susceptibility testing was identified by micro-dilution method. PCR assay and nucleotide sequencing were used to detect COL-resistant genes, mcr-1 to -5, as well as ESBL genes, bla CTX-M, bla SHV and bla TEM. Conjugation experiment, plasmid replicon typing of the multidrug resistance (MDR), S1-PFGE and DNA southern hybridization were performed to study the transferability of these genes.

RESULTS

Overall, 275 E. coli isolates were recovered from a total of 432 cloacal and nasal swabs. More than 90% of the isolates were MDR, of which 70.18% were resistant to COL. Of these 275 isolates, mcr-1 was identified as the most predominant gene carried by 71.63% (197/275) of isolates, 39.59% (78/197) of the isolates were harboring both mcr-1 and ESBL genes (bla CTX-M, bla SHV and bla TEM). ESBL genotyping showed that bla CTX-M was the most predominant ESBL (68.49%) followed by bla SHV (16.4%) and bla TEM (15%). Sequencing revealed that the most common variants of bla CTX-M identified were, bla CTX-M-15 (69%), bla CTX-M-55 (29%) and bla CTX-M-1 (1.8%). IncHI2, IncFIB, IncFIC, IncN and IncX4 were found to be the most common Inc-types found both in donors and in transconjugants and were associated with the transfer of the mcr-1 and ESBL encoding genes. Six strains carried a total of five different plasmids: approximately 97-, 130-, 160-, 227- and 242-kb plasmids.

CONCLUSION

The coexistence of the mcr-1- and bla CTX-M-15-carrying isolates displaying high MDR, recovered from E. coli of pig origin, is a major concern for both humans and veterinary medicine.

Prevalence and distribution of blaCTX-M, blaSHV, blaTEM genes in extended- spectrum β- lactamase- producing E. coli isolates from broiler farms in the Philippines

BACKGROUND

Antimicrobial resistance is a worldwide problem causing serious health threats. Escherichia coli is one of the most important bacteria that causes resistance problem. These bacteria produce an enzyme called extended-spectrum β-lactamase (ESBL) that allows it to become resistant to a wide variety of penicillins and cephalosporins. Currently, no information or published studies on ESBL-producing E.coli in broilers are available in the Philippines. This cross-sectional study was conducted to determine the prevalence and distribution of extended-spectrum β-lactamase (ESBL)-encoding genes, blaCTX-M, blaSHV, and blaTEM, among E. coli isolates from broiler farms in Luzon, Philippines.

RESULTS

Results showed a farm prevalence of 66. 67%. A total of 69 (44.23%) ESBL-producing E. coli were isolated from boot swabs and cloacal swab samples from broiler farms. All major blaCTX-M groups except blaCTX-M-25 group were identified in the isolates. The most prevalent group was blaCTX-M-1, 72.46% (CI: 60.38-82.54%), followed by blaCTX-M-2, blaCTX-M-9 group and blaCTX-M-8. The blaTEM and blaSHV genes were identified in 57.97 and 27.54% of isolates, respectively. The blaCTX-M and blaTEM were the most common gene combinations (33.33%). Coexistence of blaCTX-M types was observed in 50 (73.53%) isolates.

CONCLUSION

This study shows the high prevalence, diversity of patterns and coexistence of ESBL genes in the E. coli isolates from cloacal and boot swabs from broiler farms which pose risks of possible transmission to the environment, other animals and human.

Dissemination of Multidrug-Resistant Commensal Escherichia coli in Feedlot Lambs in Southeastern Brazil

Antimicrobial resistance (AR) is a public health issue since it limits the choices to treat infections by Escherichia coli in humans and animals. In Brazil, the ovine meat market has grown in recent years, but studies about AR in sheep are still scarce. Thus, this study aims to investigate the presence of AR in E. coli isolated from lambs during feedlot. To this end, feces from 112 lambs with 2 months of age, after weaning, were collected on the first day of the animals in the feedlot (day 0), and on the last day before slaughtering (day 42). Isolates were selected in MacConkey agar supplemented with 4 mg/L of ceftiofur and identified by biochemical methods. Isolates were submitted to an antimicrobial susceptibility test by disc-diffusion and PCR to investigate genes for phylogenetic group, virulence determinants and resistance to the several antimicrobial classes tested. The genetic localization of the bla genes detected was elucidated by S1-PFGE followed by Southern blot-hybridizations. The isolates were typed by XbaI-PFGE and MLST methods. Seventy-eight E. coli were isolated from 8/112 (7.1%) animals on day 0, and from 55/112 (49.1%) animals on day 42. Since only fimH was present in almost all E. coli (97.4%) as a virulence gene, and also 88.5% belonged to phylogroups B1 or A, we consider that isolates represent intestinal commensal bacteria. The dendrogram separated the 78 non-virulent isolates in seven clusters, two of which comprised 50 E. coli belonging to ST/CC 1727/446 or ST 3994 recovered on day 42 commonly harboring the genotype bla CMY -2-aac(3)-IIa -tetA-sul1-sul2-floR-cmlA. Special attention should be given to the presence of bla CTX-M-15, a worldwide gene spread, and bla CTX-M-14, a hitherto undetected gene in Enterobacteriaceae from food-producing animals in Brazil. Importantly, E. coli lineages and plasmids carrying bla genes detected here have already been reported as sources of infection in humans either from animals, food, or the environment, which raises public health concerns. Hence, two types of commensal E. coli carrying important AR genes clearly prevailed during feedlot, but lambs are also reservoirs of bacteria carrying important AR genes such as bla CTX-M-14 and bla CTX-M-15, mostly related to antimicrobial treatment failure.

Antimicrobial Usages and Antimicrobial Resistance in Commensal Escherichia coli From Veal Calves in France: Evolution During the Fattening Process

Extended-Spectrum-Cephalosporin (ESC)-resistant Enterobacteriaceae have widely spread in all settings worldwide. In animals, Extended-Spectrum Beta-Lactamase (ESBL) producers have been frequently identified in veal calves. The objectives of this study were to investigate the trends in the ESBL load and antimicrobial resistance (AMR) proportions, and antimicrobial usages (AMU) in veal calves during the fattening process. Ten fattening farms were selected and 50 animals per farm were sampled. AMR was assessed in bacteria from the dominant flora (collected on non-selective MacConckey agar) and in ESBL/AmpC-carrying bacteria from the subdominant flora (selected on ChromID ESBL selective plates) upon arrival and 5-6 months later before slaughter. The number and types of treatments during fattening were also collected. Rates of ESBL-producing E. coli from the subdominant flora significantly decreased in all farms (arrival: 67.7%; departure: 20.4%) whereas rates of multidrug-resistant E. coli from the dominant flora have significantly increased (arrival: 60.2%; departure: 67.2%; p = 0.025). CTX-M-1 was the most frequently identified ESBL enzyme (arrival: 59.3%; departure: 52.0%). The plasmid-mediated mcr-1 gene was also identified occasionally. In parallel, levels of resistances to non-critically important antimicrobials were already high upon arrival but have still further increased over time until slaughter. Our study also highlighted that if only ESBL-producing isolates were monitored, it might have led to a partial (and partly false) picture of AMR rates globally decreasing during the fattening period. The mean number of antimicrobial treatments per calf (NTPC) was 8.75 but no association between AMU and AMR was evidenced. Most ESBL producers were clonally unrelated suggesting multiple sources and not cross-contaminations among calves during transportation. Feeding milk containing antimicrobial residues to veal calves is hypothesized to explain the high ESBL loads in animals at the entrance on farms.

Characterization of cefotaxime resistant Escherichia coli isolated from broiler farms in Ecuador

Antimicrobial resistance (AR) is a worldwide concern. Up to a 160% increase in antibiotic usage in food animals is expected in Latin American countries. The poultry industry is an increasingly important segment of food production and contributor to AR. The objective of this study was to evaluate the prevalence, AR patterns and the characterization of relevant resistance genes in Extended Spectrum β-lactamases (ESBL) and AmpC-producing E. coli from large poultry farms in Ecuador. Sampling was performed from June 2013 to July 2014 in 6 slaughterhouses that slaughter broilers from 115 farms totaling 384 flocks. Each sample of collected caeca was streaked onto TBX agar supplemented with cefotaxime (3 mg/l). In total, 176 isolates were analyzed for AR patterns by the disk diffusion method and for blaCTX-M, blaTEM, blaCMY, blaSHV, blaKPC, and mcr-1 by PCR and sequencing. ESBL and AmpC E. coli were found in 362 flocks (94.3%) from 112 farms (97.4%). We found that 98.3% of the cefotaxime-resistant isolates were multi-resistant to antibiotics. Low resistance was observed for ertapenem and nitrofurantoin. The most prevalent ESBL genes were the ones belonging to the blaCTX-M group (90.9%), specifically the blaCTX-M-65, blaCTX-M-55 and blaCTX-M-3 alleles. Most of the AmpC strains presented the blaCMY-2 gene. Three isolates showed the mcr-1 gene. Poultry production systems represent a hotspot for AR in Ecuador, possibly mediated by the extensive use of antibiotics. Monitoring this sector in national and regional plans of AR surveillance should therefore be considered.

Intestinal colonization and acute immune response in commercial turkeys following inoculation with Campylobacter jejuni constructs encoding antibiotic-resistance markers

Consumption of contaminated poultry products is one of the main sources of human campylobacteriosis, of which Campylobacter jejuni subsp. jejuni (C. jejuni) is responsible for approximately 90% of the cases. At slaughter, the ceca of commercial chickens and turkeys are the main anatomical site where C. jejuni asymptomatically colonizes. We have previously colonized commercial turkey poults with different isolates of C. jejuni and evaluated different media to best enumerate Campylobacter from intestinal samples, but the host-response is unknown in turkeys. Enumeration of Campylobacter (colony forming units (cfu)/gram of intestinal contents) can be challenging, and can be confounded if animals are colonized with multiple species of Campylobacter. In order to precisely enumerate the C. jejuni isolate used to experimentally colonize turkeys, constructs of C. jejuni (NCTC 11,168) were tagged with different antibiotic resistance markers at the CmeF locus (chloramphenicol (CjCm) or kanamycin (CjK)). We sought to examine the kinetics of intestinal colonization using the antibiotic resistant constructs, and characterize the immune response in cecal tissue of turkeys. In vitro analysis of the tagged antibiotic-resistant constructs demonstrated no changes in motility, morphology, or adherence and invasion of INT-407 cells compared to the parent isolate NCTC 11,168. Two animal experiments were completed to evaluate intestinal colonization by the constructs. In experiment 1, three-week old poults were colonized after oral gavage for 14 days, and CjCm and CjK cfu were recovered from cecal, but not ileal contents. In experiment 2, nine-week old poults were orally inoculated with CjCm, and the abundance of CjCm cfu/g of cecal contents significantly decreased beyond 14 days after inoculation. Significant lesions were detected in CjCm colonized poults at day 2 post-colonization. Using immunohistochemistry, Campylobacter antigen was detected in between cecal villi by day 7 of CjCm colonized poults. Quantitative RT-PCR of CjCm-colonized cecal tissue demonstrated significant down-regulation of IL-1β, IL-10 and IL-13 mRNA, and significant up-regulation of IL-6, IL-8, IL-17 A, IL-22 and IFNγ mRNA on day 2, and for some on day 7 post-colonization. All differentially expressed genes were similar to mock-infected poults by day 14. These data suggest that C. jejuni induced a brief inflammatory response in the cecum of poults that quickly resolved. Results from this study provide valuable insight into host-response and persistent colonization of the turkey cecum. These findings will help to develop and test strategies to promote food safety in commercial turkeys.

Antimicrobial Resistance in Escherichia coli

Multidrug resistance in Escherichia coli has become a worrying issue that is increasingly observed in human but also in veterinary medicine worldwide. E. coli is intrinsically susceptible to almost all clinically relevant antimicrobial agents, but this bacterial species has a great capacity to accumulate resistance genes, mostly through horizontal gene transfer. The most problematic mechanisms in E. coli correspond to the acquisition of genes coding for extended-spectrum β-lactamases (conferring resistance to broad-spectrum cephalosporins), carbapenemases (conferring resistance to carbapenems), 16S rRNA methylases (conferring pan-resistance to aminoglycosides), plasmid-mediated quinolone resistance (PMQR) genes (conferring resistance to [fluoro]quinolones), and mcr genes (conferring resistance to polymyxins). Although the spread of carbapenemase genes has been mainly recognized in the human sector but poorly recognized in animals, colistin resistance in E. coli seems rather to be related to the use of colistin in veterinary medicine on a global scale. For the other resistance traits, their cross-transfer between the human and animal sectors still remains controversial even though genomic investigations indicate that extended-spectrum β-lactamase producers encountered in animals are distinct from those affecting humans. In addition, E. coli of animal origin often also show resistances to other-mostly older-antimicrobial agents, including tetracyclines, phenicols, sulfonamides, trimethoprim, and fosfomycin. Plasmids, especially multiresistance plasmids, but also other mobile genetic elements, such as transposons and gene cassettes in class 1 and class 2 integrons, seem to play a major role in the dissemination of resistance genes. Of note, coselection and persistence of resistances to critically important antimicrobial agents in human medicine also occurs through the massive use of antimicrobial agents in veterinary medicine, such as tetracyclines or sulfonamides, as long as all those determinants are located on the same genetic elements.

Association between excreta management and incidence of extended-spectrum β-lactamase-producing Enterobacteriaceae: role of healthcare workers' knowledge and practices

BACKGROUND

The spread of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) in healthcare environments has become a major public health threat in recent years.

AIM

To assess how healthcare workers (HCWs) manage excreta and the possible association with the incidence of ESBL-PE.

METHODS

Eight hundred HCWs and 74 nurse-supervisors were questioned through two self-report questionnaires in order to assess their knowledge and practices, and to determine the equipment utilized for excreta management in 74 healthcare departments. Performance on equipment utilized, knowledge and practices were scored as good (score of 1), intermediate (score of 2) or poor (score of 3) on the basis of pre-established thresholds. Linear regression was performed to evaluate the association between HCWs' knowledge/practices and the incidence of ESBL-PE.

FINDINGS

Six hundred and eighty-eight HCWs (86%) and all nurse-supervisors participated in the survey. The proportions of respondents scoring 1, 2 and 3 were: 14.8%, 71.6% and 17.6% for equipment; 30.1%, 40.6 % and 29.3% for knowledge; and 2.0%, 71.9% and 26.1% for practices, respectively. The single regression mathematic model highlighted that poor practices (score of 3) among HCWs was significantly associated with increased incidence of ESBL-PE (P = 0.002).

CONCLUSIONS

A positive correlation was found between HCWs' practices for managing excreta and the incidence of ESBL-PE, especially in surgical units. There is an urgent need for development of public health efforts to enhance knowledge and practices of HCWs to better control the spread of multi-drug-resistant bacteria, and these should be integrated within infection control programmes.