Fecal Carriage of Extended-Spectrum β-Lactamases in Healthy Humans, Poultry, and Wild Birds in León, Nicaragua-A Shared Pool of blaCTX-M Genes and Possible Interspecies Clonal Spread of Extended-Spectrum β-Lactamases-Producing Escherichia coli

Anthropogenic contamination sources drive differences in antimicrobial-resistant Escherichia coli in three urban lakes

Antimicrobial resistance (AMR) is an ever-present threat to the treatment of infectious diseases. However, the potential relevance of this phenomenon in environmental reservoirs still raises many questions. Detection of antimicrobial-resistant bacteria in the environment is a critical aspect for understanding the prevalence of resistance outside of clinical settings, as detection in the environment indicates that resistance is likely already widespread. We isolated antimicrobial-resistant Escherichia coli from three urban waterbodies over a 15-month time series, determined their antimicrobial susceptibilities, investigated their population structure, and identified genetic determinants of resistance. We found that E. coli populations at each site were composed of different dominant phylotypes and showed distinct patterns of antimicrobial and multidrug resistance, despite close geographic proximity. Many strains that were genome-sequenced belonged to sequence types of international concern, particularly the ST131 clonal complex. We found widespread resistance to clinically important antimicrobials such as amoxicillin, cefotaxime, and ciprofloxacin, but found that all strains were susceptible to amikacin and the last-line antimicrobials meropenem and fosfomycin. Resistance was most often due to acquirable antimicrobial resistance genes, while chromosomal mutations in gyrA, parC, and parE conferred resistance to quinolones. Whole-genome analysis of a subset of strains further revealed the diversity of the population of E. coli present, with a wide array of AMR and virulence genes identified, many of which were present on the chromosome, including blaCTX-M. Finally, we determined that environmental persistence, transmission between sites, most likely mediated by wild birds, and transfer of mobile genetic elements likely contributed significantly to the patterns observed.IMPORTANCEA One Health perspective is crucial to understand the extent of antimicrobial resistance (AMR) globally, and investigation of AMR in the environment has been increasing in recent years. However, most studies have focused on waterways that are directly polluted by sewage, industrial manufacturing, or agricultural activities. Therefore, there remains a lack of knowledge about more natural, less overtly impacted environments. Through phenotypic and genotypic investigation of AMR in Escherichia coli, this study adds to our understanding of the extent and patterns of resistance in these types of environments, including over a time series, and showed that complex biotic and abiotic factors contribute to the patterns observed. Our study further emphasizes the importance of incorporating the surveillance of microbes in freshwater environments in order to better comprehend potential risks for both human and animal health and how the environment may serve as a sentinel for potential future clinical infections.

Zoonotic sources and the spread of antimicrobial resistance from the perspective of low and middle-income countries

BACKGROUND

Antimicrobial resistance is an increasing challenge in low and middle-income countries as it is widespread in these countries and is linked to an increased mortality. Apart from human and environmental factors, animal-related drivers of antimicrobial resistance in low- and middle-income countries have special features that differ from high-income countries. The aim of this narrative review is to address the zoonotic sources and the spread of antimicrobial resistance from the perspective of low- and middle-income countries.

MAIN BODY

Contamination with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli is highest in poultry (Africa: 8.9-60%, Asia: 53-93%) and there is a risk to import ESBL-producing E. coli through poultry meat in Africa. In aquacultures, the proportion of ESBL-producers among E. coli can be high (27%) but the overall low quality of published studies limit the general conclusion on the impact of aquacultures on human health. ESBL-producing E. coli colonization of wildlife is 1-9% in bats or 2.5-63% birds. Since most of them are migratory animals, they can disperse antimicrobial resistant bacteria over large distances. So-called 'filth flies' are a relevant vector not only of enteric pathogens but also of antimicrobial resistant bacteria in settings where sanitary systems are poor. In Africa, up to 72.5% of 'filth flies' are colonized with ESBL-producing E. coli, mostly conferred by CTX-M (24.4-100%). While methicillin-resistant Staphylococcus aureus plays a minor role in livestock in Africa, it is frequently found in South America in poultry (27%) or pork (37.5-56.5%) but less common in Asia (poultry: 3%, pork: 1-16%).

CONCLUSIONS

Interventions to contain the spread of AMR should be tailored to the needs of low- and middle-income countries. These comprise capacity building of diagnostic facilities, surveillance, infection prevention and control in small-scale farming.

Exploring broilers and native fowls of Andaman and Nicobar Islands as a source of β-lactamase-producing Enterobacteriaceae even with limited anthropogenic activities and docking-based identification of catalytic domains in novel β-lactamase variants

Objectives

The present study was conducted to detect the occurrence of β-lactamase and biofilm-producing Escherichia coli, Salmonella, and Klebsiella in broilers and native fowl reared in the Andaman and Nicobar Islands, India. The study also included molecular docking experiments to confirm the nature of the catalytic domains found in the β-lactamase variants obtained and to reveal the clonal relationship of the isolates with human clinical strains from the database.

Materials and methods

A total of 199 cloacal swabs were collected from five poultry breeds/varieties (broiler, Vanraja, Desi, Nicobari, and layer) in three districts of the Andaman and Nicobar Islands. E. coli, Salmonella enterica, and Klebsiella pneumoniae were isolated by standard techniques and confirmed by PCR. Phenotypical β-lactamase producers were identified by a double-disc test. The genes (bla _CTX, bla _SHV, bla _TEM , and bla _AmpC) were screened, and selected sequences of β-lactamase variants were submitted to DDBJ. Homology modeling, model validation, and active site identification of different β-lactamase variants were done by the SWISS-MODEL. Molecular docking was performed to identify the catalytic domains of the β-lactamase variants. The selected β-lactamase sequences were compared with the Indian ESBL sequences from human clinical strains in NCBI-GenBank.

Results

In total, 425 Enterobacteriaceae strains were isolated from the collected samples. Klebsiella pneumoniae (42.58%) was found to be the most prevalent, followed by Salmonella enterica (30.82%) and E. coli (26.58%). The phenotypical antibiogram of all 425 isolates showed the highest resistance against oxytetracycline (61-76%) and the lowest against gentamicin (15-20%). Phenotypical production of β-lactamase enzymes was observed in 141 (33.38%) isolates. The isolation rate of β-lactamase producing E. coli, Salmonella enterica, and Klebsiella pneumoniae was significantly higher (p < 0.05) in the birds reared in the South Andaman district (25.6, 17.5, and 18.7%, respectively) than in Nicobar (11.5, 7.6, 7.1%, respectively). Genotyping of the β-lactamase-producing isolates revealed the maximum possession of bla _TEM, followed by bla _SHV and bla _{CTX - M}. The nucleotide sequences were found to be similar with bla _{CTX - M-15}, bla _{SHV - 11}, bla _{SHV - 27}, bla _{SHV - 228}, bla _{TEM - 1}, and bla _AmpC in BLAST search. Distribution of studied biofilm-associated genes in Enterobacteriaceae strains from different varieties of the birds revealed that the layer birds had the maximum possession, followed by Vanraja, Desi, broilers, and Nicobari fowls. The phylogenetic analysis of selected sequences revealed a partial clonal relationship with human clinical strains of the Indian subcontinent. Molecular docking depicted the Gibbs free energy release for 10 different macromolecules (proteins) and ligand (antibiotic) complexes, ranging from -8.1 (SHV-27 + cefotaxime) to -7 (TEM-1 + cefotaxime) kcal/mol.

Conclusion and relevance

The study revealed β-lactamase variants circulating in the fowl population of the Andaman and Nicobar Islands (India), even in remote places with low anthropogenic activity. Most of the strains possessed bla _{TEM - 1}, followed by bla _{CTX - M-15}. Possession of bla _{SHV - 11}, bla _{SHV - 27}, and bla _{SHV - 228} in poultry Enterobacteriaceae strains was not reported earlier from any part of the world. The phylogenetic analysis revealed a partial clonal relationship of β-lactamase sequences with the human clinical strains isolated from the Indian subcontinent.

Faecal carriage of ESBL producing and colistin resistant Escherichia coli in avian species over a 2-year period (2017-2019) in Zimbabwe

Introduction

Extended spectrum beta-lactamase (ESBL) producing Escherichia coli have become widespread among food producing animals. These strains serve as a reservoir of antibiotic resistance genes (ARGs) and act as a possible source of infection to humans as transmission can occur by direct or indirect contact.

Methods

This study investigated the faecal carriage of ESBL producing and colistin resistant E. coli in poultry over a 2-year period (2017-2019) from Zimbabwe. A total of 21 ESBL positive isolates from poultry cloacal specimens were selected for whole genome sequencing from animal E. coli isolates bio-banked at the National Microbiology Reference laboratory using phenotypic susceptibility testing results from the National Escherichia coli Surveillance Program to provide representation of different geographical regions and year of isolation. Cloacal swabs were collected from 3000 broiler live birds from farm 1 and from farm 2, 40 backyard chickens and 10 ducks were sampled. Antimicrobial susceptibility and ESBL testing were performed as per Clinical Laboratory Standards Institute guidelines. Whole genome sequencing of ESBL producing isolates was used to determine sequence types (STs), ARGs, and phylogroups.

Results

Twenty-one of the included E. coli isolates were confirmed as ESBL producers. Three defined sequence type clonal complexes (CCs) were identified (ST10CC, ST155CC and ST23CC), with ST10CC associated with the most antibiotic resistant profile. The ESBL phenotype was linked to the presence of either cefotaximase-Munich-14 (CTX-M-14) or CTX-M-79. Plasmid mediated quinolone resistant determinants identified were qnrB19 and qnrS1 and one ST10CC isolate from farm 1 broiler chickens harbored a mobile colistin resistance gene (mcr-1). Phylogenetic groups most identified were B1, A and unknown.

Discussions

The avian ESBL producing E. coli belonged to a diverse group of strains. The detection of several ARGs highlights the importance of implementing enhanced control measures to limit the spread in animals, environment, and humans. This is the first report of mcr-1 in Zimbabwe, which further underscores the importance of the One Health approach to control the spread and development of AMR.

Antimicrobial Resistance Analysis of Escherichia coli Isolated from Pigeons in Qingdao, Shandong Province, China

With the development of the pigeon industry in Qingdao, more attention is paid to scientific breeding and precise treatment. This study isolated and identified Escherichia coli from pigeons in Qingdao to determine their susceptibility to 18 antibiotics. The PCR method was used to detect the prevalence of Extended-Spectrum β-Lactamase genes, carbapenem resistance genes, 16S rRNA methylase genes and plasmid-mediated colistin resistance genes in the isolates. The results showed that Escherichia coli isolated from pigeons in Qingdao were the most resistant to tetracycline, followed by ampicillin, conventional cyclosporines, quinolones, cephalosporins, and aminoglycosides. No isolates were found to be resistant to amikacin, meropenem, colistin, tigecycline, and fosfomycin. The resistance to some antibiotics (ampicillin, tetracycline, and florfenicol) and the muti-drug resistance of Escherichia coli from meat pigeons were both higher than those from homing and ornamental pigeons. A total of 24.8% of the isolates showed multi-drug resistance, especially triple-drug resistance. Two isolates were found to carry ESBLs resistance genes. Hopefully, this study will provide a certain scientific basis for the clinical medication of pigeon colibacillosis, helping to prevent antimicrobial resistance transmission of Escherichia coli among different host animals and humans and maintain public health safety in Qingdao.

Comparison of approaches for source attribution of ESBL-producing Escherichia coli in Germany

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia (E.) coli have been widely described as the cause of treatment failures in humans around the world. The origin of human infections with these microorganisms is discussed controversially and in most cases hard to identify. Since they pose a relevant risk to human health, it becomes crucial to understand their sources and the transmission pathways. In this study, we analyzed data from different studies in Germany and grouped ESBL-producing E. coli from different sources and human cases into subtypes based on their phenotypic and genotypic characteristics (ESBL-genotype, E. coli phylogenetic group and phenotypic antimicrobial resistance pattern). Then, a source attribution model was developed in order to attribute the human cases to the considered sources. The sources were from different animal species (cattle, pig, chicken, dog and horse) and also from patients with nosocomial infections. The human isolates were gathered from community cases which showed to be colonized with ESBL-producing E. coli. We used the attribution model first with only the animal sources (Approach A) and then additionally with the nosocomial infections (Approach B). We observed that all sources contributed to the human cases, nevertheless, isolates from nosocomial infections were more related to those from human cases than any of the other sources. We identified subtypes that were only detected in the considered animal species and others that were observed only in the human population. Some subtypes from the human cases could not be allocated to any of the sources from this study and were attributed to an unknown source. Our study emphasizes the importance of human-to-human transmission of ESBL-producing E. coli and the different role that pets, livestock and healthcare facilities may play in the transmission of these resistant bacteria. The developed source attribution model can be further used to monitor future trends. A One Health approach is necessary to develop source attribution models further to integrate also wildlife, environmental as well as food sources in addition to human and animal data.

Molecular Characterization of Clinically Relevant Extended-Spectrum β-Lactamases blaCTX-M-15-Producing Enterobacteriaceae Isolated from Free-Range Chicken from Households in Bangladesh

The study explored the potential colonization and characterization of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae in the gut of free-range poultry from the rural households in Bangladesh. From 48 households located in several rural regions (eastern, western, and southern) of Bangladesh, 180 poultry fecal samples were collected to isolate ESBL-producing Enterobacteriaceae. ESBL producers were characterized by susceptibility testing, conjugation experiment, conventional polymerase chain reactions (PCRs), and multilocus sequence typing (MLST) followed by sequencing. Total 23% (42/180) poultry were ESBL positive consisting of Escherichia coli (n = 41) and Klebsiella pneumoniae (n = 1). ESBL producers were resistant to Cefotaxime (CTX; 100%), Cefepime (100%), Amoxicillin-clavulanic acid (36%), Ciprofloxacin (31%), and Trimethoprim-sulfamethoxazole (24%), and 12% isolates were multidrug resistant. All ESBL producers were carrying bla_CTX-M-15-like genotype.Isolates were also carrying genes for quinolone resistance [qnrS1, aac(6')-Ib-cr], silver resistance (silE), and mercury resistance (merA). Isolates were negative for 025b-ST131 clone, mcr-1, and bla_OXA-48 gene. The repetitive element PCR revealed 15 different clones of E. coli and some of these clones were found to be common in 3 sampling locations. MLST analysis of E. coli revealed 9 different sequence types (STs); ST4, ST156, ST542, ST1140, ST1290, ST4628, ST5114, ST9768, and ST11317. ESBL producers were carrying transferable plasmids and 4 different plasmid replicon types; IncI1 (29%), IncY (7%), IncFIB (7%), and IncF1A (5%). The findings from the study confirmed that free-range poultry are potential ESBL carriers with coresistance to other antibiotic classes, metals, and biocides. This study confirms that free-range poultry in Bangladesh living close to humans without any direct antibiotic exposure could carry ESBL bacteria. Free-range poultry could be reservoir as well as a potential spreader of pathogenic E. coli and antibiotic- or biocide-resistant genes.

Genomically diverse carbapenem resistant Enterobacteriaceae from wild birds provide insight into global patterns of spatiotemporal dissemination

Carbapenem resistant Enterobacteriaceae (CRE) are a threat to public health globally, yet the role of the environment in the epidemiology of CRE remains elusive. Given that wild birds can acquire CRE, likely from foraging in anthropogenically impacted areas, and may aid in the maintenance and dissemination of CRE in the environment, a spatiotemporal comparison of isolates from different regions and timepoints may be useful for elucidating epidemiological information. Thus, we characterized the genomic diversity of CRE from fecal samples opportunistically collected from gulls (Larus spp.) inhabiting Alaska (USA), Chile, Spain, Turkey, and Ukraine and from black kites (Milvus migrans) sampled in Pakistan and assessed evidence for spatiotemporal patterns of dissemination. Within and among sampling locations, a high diversity of carbapenemases was found, including Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-beta-lactamase (NDM), oxacillinase (OXA), and Verona integron Metallo beta-lactamase (VIM). Although the majority of genomic comparisons among samples did not provide evidence for spatial dissemination, we did find strong evidence for dissemination among Alaska, Spain, and Turkey. We also found strong evidence for temporal dissemination among samples collected in Alaska and Pakistan, though the majority of CRE clones were transitory and were not repeatedly detected among locations where samples were collected longitudinally. Carbapenemase-producing hypervirulent K. pneumoniae was isolated from gulls in Spain and Ukraine and some isolates harbored antimicrobial resistance genes conferring resistance to up to 10 different antibiotic classes, including colistin. Our results are consistent with local acquisition of CRE by wild birds with spatial dissemination influenced by intermediary transmission routes, likely involving humans. Furthermore, our results support the premise that anthropogenically-associated wild birds may be good sentinels for understanding the burden of clinically-relevant antimicrobial resistance in the local human population.

Detection of blaOXA-48 and mcr-1 Genes in Escherichia coli Isolates from Pigeon (Columba livia) in Algeria

The emergence and spread of β-lactams and colistin-resistant Escherichia coli in birds deserve a special concern worldwide. This study aimed to investigate the presence of β-lactams and colistin-resistant Escherichia coli strains isolated from the faeces of urban and rural pigeons in Batna, Algeria, and to characterise their molecular traits of resistance. Between March and April 2019, a total of 276 faecal droppings samples were collected in Batna, Algeria. Samples were subjected to selective isolation of β-lactams and colistin-resistant Escherichia coli. The representative colonies were then identified using Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry. Antimicrobial susceptibility testing was performed using the disc diffusion method. β-lactamases, as well as mcr genes, were screened for by PCR and confirmed by sequencing. Genetic relatedness of the mcr-positive E. coli strains was determined using multi-locus sequence typing analysis. Transferability features of carbapenemase genes were assessed by conjugation experiments. Overall, thirty-five E. coli isolates were obtained only from urban pigeon samples. All carbapenem-resistant isolates harboured the bla_OXA-48 gene as the only carbapenemase gene detected (n = 11), while bla_ESBL genes were detected in eighteen isolates. Out of the thirty-five isolates, four E. coli isolates were positive for the mcr-1 gene. The obtained mcr-1 positive E. coli isolates belonged to four STs, including ST1485, ST224, ST46, and a new ST. This study is the first to report the isolation of E. coli strains carrying the mcr-1 gene from pigeon faeces in Algeria and also the first to report the detection of bla_OXA-48-positive E. coli in pigeons. Close surveillance is, therefore, urgently needed to monitor the dissemination of bla_OXA-48 and mcr-1 producing E. coli strains in wildlife.

Long-term maintenance of multidrug-resistant Escherichia coli carried by vampire bats and shared with livestock in Peru

Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E. coli) have been reported in wildlife worldwide. Whether wildlife is a transient host of ESBL-E. coli or comprises an independently maintained reservoir is unknown. We investigated this question by longitudinally monitoring ESBL-E. coli in common vampire bats and nearby livestock in Peru. Among 388 bats from five vampire bat colonies collected over three years, ESBL-E. coli were detected at a low prevalence (10% in 2015, 4% in 2017 and 2018) compared to a high prevalence (48%) from 134 livestock sampled in 2017. All ESBL-E. coli were multidrug-resistant, and whole genome sequencing of 33 randomly selected ESBL-E. coli isolates (18 recovered from bats) detected 46 genes conferring resistance to antibiotics including third-generation cephalosporins (e.g., bla_CTX-M-55, bla_CTX-M-15, bla_CTX-M-65, bla_CTX-M-3, bla_CTX-M-14), aminoglycosides, fluoroquinolones, and colistin (mcr-1). The mcr-1 gene is reported for the first time on a wild bat in Latin America. ESBL-E. coli also carried 31 plasmid replicon types and 16 virulence genes. Twenty-three E. coli sequence types (STs) were detected, including STs involved in clinical infections worldwide (e.g., ST 167, ST 117, ST 10, ST 156 and ST 648). ESBL-E. coli with identical cgMLST (ST 167) were detected in the same bat roost in 2015 and 2017, and several ESBL-E. coli from different bat roosts clustered together in the cgMLST reconstruction, suggesting long-term maintenance of ESBL-E. coli within bats. Most antibiotic resistance and virulence genes were detected in E. coli from both host populations, while ESBL-E. coli ST 744 was found in a bat and a pig from the same locality, suggesting possible cross-species exchanges of genetic material and/or bacteria between bats and livestock. This study suggests that wild mammals can maintain multidrug-resistant bacteria and share them with livestock.

High Prevalence and Diversity Characteristics of blaNDM, mcr, and blaESBLs Harboring Multidrug-Resistant Escherichia coli From Chicken, Pig, and Cattle in China

The objective of this study was to understand the diversity characteristics of ESBL-producing Escherichia coli (ESBL-EC) in chicken, pig, and cattle. A high prevalence of ESBL-EC (260/344) was observed in all food animals with prevalence rates of 78.6% (110/140) for chicken, 70.7% (58/82) for cattle, and 75.4% (92/122) for swine. However, the resistance rates presented significant differences in different animal origin ESBL-EC, where resistance to CTX, GEN, IMP, NEO, and OFL was the highest in chicken ESBL-EC, then in cattle, and the lowest in swine. Seriously, most ESBL-EC harbor multidrug resistance to antibiotics (MDR, ≥3 antibiotic categories), and the MDR rates of ESBL-EC were the highest in chicken (98.18%), followed by swine (93.48%), and the lowest in cow (58.62%), while the same trend also was observed in MDR of ≥5 antibiotic categories. This high prevalence and resistance can be partly interpreted by the high carriage rates of the β-lactamases CTX-M (n = 89), OXA (n = 59), SHV (n = 7), and TEM (n = 259). A significant difference of β-lactamase genes also presented in different animal species isolates, where the chicken origin ESBL-EC possessed higher carriage rates of almost all genes tested than cattle and swine. Notably, eight chicken origin ESBL-EC carried transferable plasmid-mediated bla_NDM-1 or bla_NDM-5, especially, of which four ESBL-EC also contained the colistin resistance gene mcr-1, as confirmed by genomic analysis. More interestingly, two deletion events with a 500-bp deletion in ΔISAba125 and a 180-bp deletion in dsbC were observed in three bla_NDM-5 IncX3 plasmids, which, as far as we know, is the first discovery. This showed the instability and horizontal transfer of bla_NDM genetic context, suggesting that bla_NDM is evolving to “pack light” to facilitate rapid and stable horizontal transfer. Sequence types (STs) and PFGE showed diversity patterns. The most prevalent STs were ST48 (n = 5), ST189 (n = 5), ST206 (n = 4), ST6396 (n = 3), ST10 (n = 3), and ST155 (n = 3), where ST48 ESBL-EC originated from three food animal species. The STs of all bla_NDM-positive ESBL-EC were attributed to three STs, namely, ST6396 (n = 2), ST206 (n = 2), and ST189 (n = 4), where ST189 was also the unique type for four mcr-1-carrying ESBL-EC. In conclusion, we suggest that the three animal species ESBL-EC show similar high prevalence, diversity in isolate lineages, and significant discrepancies in antibiotic resistance and resistance genes. This suggests that monitoring and anti-infection of different food animal origin ESBL-EC need different designs, which deserves more attention and further surveillance.

Isolation of Salmonella spp. from black spiny-tailed iguana (Ctenosaura similis) meat commercialised in markets of León city, Nicaragua

Background

The black spiny‐tailed iguana (Ctenosaura similis) is an endemic animal in Mesoamerica, whose meat is consumed by the local population.

Objectives

Because the black spiny‐tailed iguana may be potential reservoirs of pathogens, this study aimed to isolate and characterise Salmonella spp. in their meat commercialised in markets of the city of León, Nicaragua.

Methods

Thirteen specimens were analysed for the isolation of Salmonella spp., as well as their antimicrobial resistance patterns, including the presence of genes encoding extended‐spectrum β‐lactamases.

Results

Salmonella spp. isolates were found in eight out of 13 samples, with S. enterica serovar Enteritidis being found in six out of eight samples. Moreover, eight Salmonella spp. isolates were resistant to amoxicillin plus clavulanic acid and cephalexin, but sensitive to other tested antibiotics. The bla_SHV gene was detected in seven out of eight Salmonella spp. isolates, followed by the bla_TEM (two out of eight) and bla_CXT‐M (one out of eight) genes.

Conclusions

These findings represent an important contribution to the implementation of appropriate strategies to prevent foodborne diseases.

A high frequency of Salmonella was observed in Ctenosura similis meat in markets of the city of León. Salmonella enterica serovar Enteritidis was the most frequent. Moreover, high antimicrobial resistance to amoxicillin/clavulanic acid and cephalexin was observed coinciding with the presence of the bla_SHV gene.

Extended-Spectrum β-Lactam Resistant Klebsiella pneumoniae and Escherichia coli in Wild European Hedgehogs (Erinaceus europeus) Living in Populated Areas

Simple Summary

The alarming emergence of antimicrobial resistance (AMR) in human and veterinary medicine has activated awareness for monitoring the levels of AMR pollution in the environment and wildlife. European hedgehogs (Erinaceus europaeus) are common wild species habiting urban areas in Europe. In this study, the occurrence and distribution of extended-spectrum β-lactam (ESBL) resistant enterobacteria and AMR genes were assessed in wild European hedgehogs in Catalonia, NE Spain. The results showed that 36.8% of the animals were detected as carriers of β-lactamase/carbapenemase resistance genes, with a special occurrence of human nosocomial bacteria such as Klebsiella pneumoniae, Escherichia coli, and Citrobacter freundii. In addition, more than half of the enterobacteria presented a multidrug resistance (MDR) phenotype and 31% of the isolates had an extended XDR profile. No differences in the spatial distribution of animals with AMR genes were observed within the study region. The results of this study suggest that the close contact with human areas predispose the transmission of AMR genes to wild hedgehogs because they either inhabit and/or feed in an anthropogenic environment. In conclusion, hedgehogs could be good sentinels or bioindicators of AMR environmental pollution, especially in highly populated areas with high human activity.

Abstract

Wildlife has been suggested to be a good sentinel of environmental health because of its close interaction with human populations, domestic animals, and natural ecosystems. The alarming emergence of antimicrobial resistance (AMR) in human and veterinary medicine has activated/triggered the awareness of monitoring the levels of AMR pollution in wildlife. European hedgehogs (Erinaceus europaeus) are common wild species habiting urban areas in Europe. However, there are few studies conducted in hedgehogs as reservoirs of AMR bacteria or genes. The aim of this study was to assess the occurrence and distribution of ESBL, AmpC, and carbapenem-resistant enterobacteria and AMR genes in wild European hedgehogs in Catalonia, a densely populated region of NE Spain. A total of 115 hedgehogs admitted at the Wildlife Rehabilitation Center of Torreferrussa were studied. To our knowledge, this is the first description of β-lactam resistant enterobacteria in wild hedgehogs. Interestingly, 36.8% (42/114) of the animals were detected as carriers of β-lactamase/carbapenemase resistance genes. Klebsiella spp. (59.6%), and specifically K. pneumoniae (84.6%), were the bacteria with the highest proportion of resistance genes, followed by E. coli (34.6%) and C. freundii (5.8%). The most frequently detected genetic variants were blaCTX-M-15 (19.3%), blaSHV-28 (10.5%), blaCMY-1 (9.7%), blaCMY-2 (8.8%), and blaOXA-48 (1.7%). In addition, 52% (27/52) of the isolates presented a multidrug resistance (MDR) phenotype and 31% had an extended drug resistance (XDR) profile. No clustering of animals with AMR genes within the study region was shown in the spatial analysis, nor differences in the proportion of positive animals among regions, were detected. The results of this study suggest that wild European hedgehogs could be good sentinels of AMR environmental pollution, especially in areas with a high human population density, because they either inhabit and/or feed in an anthropogenic environment. In conclusion, it is crucial to raise awareness of the strong interconnection between habitats and compartments, and therefore this implies that AMR issues must be tackled under the One Health approach.

ESBL-Producing Escherichia coli Carrying CTX-M Genes Circulating among Livestock, Dogs, and Wild Mammals in Small-Scale Farms of Central Chile

Antibiotic-resistant bacteria of critical importance for global health such as extended-spectrum beta-lactamases-producing (ESBL)-Escherichia coli have been detected in livestock, dogs, and wildlife worldwide. However, the dynamics of ESBL-E. coli between these animals remains poorly understood, particularly in small-scale farms of low and middle-income countries where contact between species can be frequent. We compared the prevalence of fecal carriage of ESBL-E. coli among 332 livestock (207 cows, 15 pigs, 60 horses, 40 sheep, 6 goats, 4 chickens), 82 dogs, and wildlife including 131 European rabbits, 30 rodents, and 12 Andean foxes sharing territory in peri-urban localities of central Chile. The prevalence was lower in livestock (3.0%) and wildlife (0.5%) compared to dogs (24%). Among 47 ESBL-E. coli isolates recovered, CTX-M-group 1 was the main ESBL genotype identified, followed by CTX-M-groups 2, 9, 8, and 25. ERIC-PCR showed no cluster of E. coli clones by either host species nor locality. To our knowledge, this is the first report of ESBL-E. coli among sheep, cattle, dogs, and rodents of Chile, confirming their fecal carriage among domestic and wild animals in small-scale farms. The high prevalence of ESBL-E. coli in dogs encourages further investigation on their role as potential reservoirs of this bacteria in agricultural settings.

Community-Acquired Antimicrobial Resistant Enterobacteriaceae in Central America: A One Health Systematic Review

Community-acquired antimicrobial resistant Enterobacteriaceae (CA-ARE) are an increasingly important issue around the world. Characterizing the distribution of regionally specific patterns of resistance is important to contextualize and develop locally relevant interventions. This systematic review adopts a One Health framework considering the health of humans, animals, and the environment to describe CA-ARE in Central America. Twenty studies were identified that focused on antimicrobial resistance (AMR) in Enterobacteriaceae. Studies on CA-ARE in Central America characterized resistance from diverse sources, including humans (n = 12), animals (n = 4), the environment (n = 2), and combinations of these categories (n = 2). A limited number of studies assessed prevalence of clinically important AMR, including carbapenem resistance (n = 3), third generation cephalosporin resistance (n = 7), colistin resistance (n = 2), extended spectrum beta-lactamase (ESBL) production (n = 4), or multidrug resistance (n = 4). This review highlights significant gaps in our current understanding of CA-ARE in Central America, most notably a general dearth of research, which requires increased investment and research on CA-ARE as well as AMR more broadly.

MOLECULAR CHARACTERIZATION OF FECAL ESCHERICHIA COLI ISOLATED FROM ZOO ANIMALS

Accredited zoos and animal parks play an important role in animal health research and conservation, providing important insights on matters of public health including zoonotic infectious diseases and antimicrobial resistance (AMR). The emergence and spread of AMR is a complex phenomenon that jeopardizes human and animal health and also threatens the long-term survival of endangered species. The presence of β-lactamases in clinical isolates is particularly significant as they can jeopardize the efficacy of critically important antimicrobials. Although the presence of β-lactamases and extended-spectrum β-lactamases (ESBLs) producing Enterobacteriaceae in zoo animals has been reported, data are not available for northern European countries. In addition, few data are available on phylogenetic grouping of Escherichia coli isolated from zoo animals that can provide additional information on the host-bacterium relationship and on the pathogenicity of isolates. This study aimed to characterize fecal E. coli isolated from 33 healthy zoo animals from 22 species in Ireland, using conventional and molecular microbiological methods. All E. coli isolates were ampicillin resistant, but combined resistance to amoxicillin and clavulanic acid was not detected. Three E. coli isolates sampled from one Amur tiger, one Bornean orangutan, and one Southern white rhino were multidrug resistant, and blaTEM was detected in E. coli recovered from the Amur tiger and the Bornean orangutan. Other β-lactamases, including ESBLs and AmpCs and plasmid-mediated mcr-1 and mcr-2, were not detected. Overall, E. coli isolates investigated were susceptible to the majority of the antimicrobials tested, and only two animals shed E. coli carrying β-lactamase-encoding genes. The majority of isolates belonged to phylogenetic group B1. The screening of the AMR phenotype and genotype of zoo animal E. coli provides useful data that is relevant to antimicrobial stewardship in the zoo veterinary services and relevant to the bank of knowledge needed for tackling AMR.

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in cattle production - a threat around the world

Food producing animal is a global challenge in terms of antimicrobial resistance spread. Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are relevant opportunistic pathogens that may spread in many ecological niches of the One Health approach as human, animal and environment due to intestinal selection of antimicrobial resistant commensals in food production animals. Cattle production is a relevant ecological niche for selection of commensal bacteria with antimicrobial resistance from microbiota. Enterobacteriaceae show importance in terms of circulation of resistant-bacteria and antimicrobial resistance genes via food chain creating a resistance reservoir, setting up a threat for colonization of humans and consequent health risk. ESBL-producing Enterobacteriaceae are a threat in terms of human health responsible for life threatening outbreaks and silent enteric colonization of community populations namely the elder population. Food associated colonization is a risk difficult to handle and control. In a time of globalization of food trading, population intestinal colonization is a mirror of food production and in that sense this work aims to make a picture of ESBL-producing Enterobacteriaceae in animal production for food over the world in order to make some light in this reality of selection of resistant threats in food producing animal.

Prevalence of extended-spectrum β-lactamases in the local farm environment and livestock: challenges to mitigate antimicrobial resistance

The effectiveness of antibiotics has been challenged by the increasing frequency of antimicrobial resistance (AR), which has emerged as a major threat to global health. Despite the negative impact of AR on health, there are few effective strategies for reducing AR in food-producing animals. Of the antimicrobial resistant microorganisms (ARMs), extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriaceae are an emerging global threat due to their increasing prevalence in livestock, even in animals raised without antibiotics. Many reviews are available for the positive selection of AR associated with antibiotic use in livestock, but less attention has been given to how other factors including soil, water, manure, wildlife, and farm workers, are associated with the emergence of ESBL-producing bacteria. Understanding of antibiotic resistance genes and bacteria transfer at the interfaces of livestock and other potential reservoirs will provide insights for the development of mitigation strategies for AR.

High prevalence and diversity of extended-spectrum β-lactamase and emergence of OXA-48 producing Enterobacterales in wildlife in Catalonia

Most of the studies focused on antimicrobial resistance (AMR) performed in wildlife describe Escherichia coli as the principal indicator of the selective pressure. In the present study, several species of Enterobacterales with a large panel of cephalosporin resistant (CR) genes have been isolated from wildlife in Catalonia. A total of 307 wild animals were examined to determine the prevalence of CR enterobacteria, AMR phenotypes and the presence of common carbapenem and CR genes. The overall prevalence of CR-phenotype was 13% (40/307): 17.3% in wild mammals (18/104) and 11.5% in wild birds (22/191) (p<0.01). Hedgehogs showed the highest prevalence (13.5% of 104) of the mammal specimens, and raptors the highest in bird specimen (7.3% of 191). Although CR E. coli was the most frequently isolated (45%), other CR- Enterobacterales like Klebsiella pneumoniae (20%), Citrobacter freundii (15%), Enterobacter cloacae (5%), Proteus mirabilis (5%), Providencia spp (5%) and Serratia marcescens (2.5%) were also isolated. A high diversity of CR genes was identified among the isolates, with 50% yielding blaCMY-2, 23% blaSHV-12, 20% blaCMY-1 and 18% blaCTX-M-15. Additionally, resistance to carbapenems associated to OXA-48 gene was found. Most of the CR isolates, principally K. pneumoniae and C. freundii, were multi-resistant with co-resistance to fluoroquinolones, tetracycline, sulphonamides and aminoglycosides. This study reports high prevalence of Enterobacterales harbouring a variety of CR genes and OXA-48 mediated-carbapenem resistance, all of them frequently associated to nosocomial human infections, for the first time in wild mammals and wild birds. Implementation of control measures to reduce the impact of anthropogenic pressure in the environment is urgently needed.

Global Extraintestinal Pathogenic Escherichia coli (ExPEC) Lineages

Extraintestinal pathogenic Escherichia coli (ExPEC) strains are responsible for a majority of human extraintestinal infections globally, resulting in enormous direct medical and social costs. ExPEC strains are comprised of many lineages, but only a subset is responsible for the vast majority of infections. Few systematic surveillance systems exist for ExPEC. To address this gap, we systematically reviewed and meta-analyzed 217 studies (1995 to 2018) that performed multilocus sequence typing or whole-genome sequencing to genotype E. coli recovered from extraintestinal infections or the gut. Twenty major ExPEC sequence types (STs) accounted for 85% of E. coli isolates from the included studies. ST131 was the most common ST from 2000 onwards, covering all geographic regions. Antimicrobial resistance-based isolate study inclusion criteria likely led to an overestimation and underestimation of some lineages. European and North American studies showed similar distributions of ExPEC STs, but Asian and African studies diverged. Epidemiology and population dynamics of ExPEC are complex; summary proportion for some STs varied over time (e.g., ST95), while other STs were constant (e.g., ST10). Persistence, adaptation, and predominance in the intestinal reservoir may drive ExPEC success. Systematic, unbiased tracking of predominant ExPEC lineages will direct research toward better treatment and prevention strategies for extraintestinal infections.

The role of wildlife (wild birds) in the global transmission of antimicrobial resistance genes

Antimicrobial resistance is an urgent global health challenge in human and veterinary medicine. Wild animals are not directly exposed to clinically relevant antibiotics; however, antibacterial resistance in wild animals has been increasingly reported worldwide in parallel to the situation in human and veterinary medicine. This underlies the complexity of bacterial resistance in wild animals and the possible interspecies transmission between humans, domestic animals, the environment, and wildlife. This review summarizes the current data on expanded-spectrum β-lactamase (ESBL), AmpC β-lactamase, carbapenemase, and colistin resistance genes in Enterobacteriaceae isolates of wildlife origin. The aim of this review is to better understand the important role of wild animals as reservoirs and vectors in the global dissemination of crucial clinical antibacterial resistance. In this regard, continued surveillance is urgently needed worldwide.

Transmission routes of ESBL/pAmpC producing bacteria in the broiler production pyramid, a literature review

Plasmid mediated Extended Spectrum Beta-Lactamase and AmpC Beta-Lactamase (ESBL/pAmpC) producing bacteria are resistant to beta-lactam antimicrobials and are widespread in humans, the environment and animals. Animals, especially broilers, are an important reservoir of ESBL/pAmpC producing bacteria. To control ESBL/pAmpC prevalence in broilers, transmission within the entire broiler production pyramid should be considered. This study, including 103 articles originating from two electronic databases, searched for evidence for possible routes of transmission of ESBL/pAmpC producing bacteria in the broiler production pyramid. Possible routes of transmission were categorised as 1) vertical between generations, 2) at hatcheries, 3) horizontal on farm, and 4) horizontal between farms and via the environment of farms. This review presents indications for transmission of ESBL/pAmpC producing bacteria for each of these routes. However, the lack of quantitative results in the literature did not allow an estimation of the relative contribution or magnitude of the different routes. Future research should be specifically targeted towards such information as it is crucial to guide reduction strategies for the spread of ESBL/pAmpC producing bacteria in the broiler production chain.

Extended-spectrum beta-lactamase-producing Escherichia coli in common vampire bats Desmodus rotundus and livestock in Peru

Antibiotic resistance mediated by bacterial production of extended-spectrum beta-lactamase (ESBL) is a global threat to public health. ESBL resistance is most commonly hospital-acquired; however, infections acquired outside of hospital settings have raised concerns over the role of livestock and wildlife in the zoonotic spread of ESBL-producing bacteria. Only limited data are available on the circulation of ESBL-producing bacteria in animals. Here, we report ESBL-producing Escherichia coli in wild common vampire bats Desmodus rotundus and livestock near Lima, Peru. Molecular analyses revealed that most of this resistance resulted from the expression of bla_CTX-M-15 genes carried by plasmids, which are disseminating worldwide in hospital settings and have also been observed in healthy children of Peru. Multilocus sequence typing showed a diverse pool of E. coli strains carrying this resistance that were not always host species-specific, suggesting sharing of strains between species or infection from a common source. This study shows widespread ESBL resistance in wild and domestic animals, supporting animal communities as a potential source of resistance. Future work is needed to elucidate the role of bats in the dissemination of antibiotic-resistant strains of public health importance and to understand the origin of the observed resistance.

Prevalence of CTX-M-Producing Klebsiella spp. in Broiler, Kuroiler, and Indigenous Poultry in West Bengal State, India

This study was undertaken to detect the prevalence of CTX-M-producing Klebsiella spp. in healthy broiler, indigenous, and kuroiler birds reared in West Bengal (India) during November 2014-February 2015. In addition to CTX-M gene, the study was also conducted to reveal the occurrence of other β-lactamase and class I integron genes in Klebsiella spp. isolates along with their clonal relationship. A total of 321 cloacal swabs from healthy broiler, indigenous, and kuroiler birds were collected from different places of West Bengal, India. Klebsiella spp. isolation rate varies among different types of poultry birds (43.8-72.3%). In total, 33 (10.7%) Klebsiella spp. isolates were detected phenotypically as CTX-M producers and all the isolates possessed bla_CTX-M in polymerase chain reaction. Whereas 17 (51.5%) and 16 (48.5%) Klebsiella spp. isolates possessed bla_SHV, and bla_TEM with bla_CTX-M, respectively. None of the CTX-M-producing Klebsiella spp. isolates in this study possessed class I integron gene. Randomly amplified polymorphic DNA-based phylogenetic tree revealed the presence of clonal relationship among the CTX-M-producing Klebsiella spp. isolates, recovered from broilers and indigenous birds. This study identified broilers and indigenous game birds as a potential reservoir of CTX-M-producing Klebsiella spp., which could be transmitted to the human food chain directly or indirectly.

Rapid and Specific Detection of the Escherichia coli Sequence Type 648 Complex within Phylogroup F

The Escherichia coli sequence type 648 complex (STc648) is an emerging lineage within phylogroup F-formerly included within phylogroup D-that is associated with multidrug resistance. Here, we designed and validated a novel multiplex PCR-based assay for STc648 that took advantage of (i) four distinctive single-nucleotide polymorphisms in icd allele 96 and gyrB allele 87, two of the multilocus sequence typing alleles that define ST648; and (ii) the typical absence within STc648 of uidA, an E. coli-specific gene encoding β-glucuronidase. Within a diverse 212-strain validation set that included 109 STs other than STc648, from phylogroups A, B1, B2, C, D, E, and F, the assay exhibited 100% sensitivity (95% confidence interval [CI], 82% to 100%) and specificity (95% CI, 98% to 100%). It functioned similarly well in two distant laboratories that used boiled lysates or DNAzol-purified DNA as the template DNA. Thus, this novel multiplex PCR-based assay should enable any laboratory equipped for diagnostic PCR to rapidly, accurately, and economically screen E. coli isolates for membership in STc648.