Domestic cats constitute a natural reservoir of human enteropathogenic Escherichia coli types

Whole genome sequencing analysis of enteropathogenic Escherichia coli from human and companion animals in Korea

IMPORTANCE

This study is essential for comprehending the zoonotic transmission, antimicrobial resistance, and genetic diversity of enteropathogenic Escherichia coli (EPEC).

OBJECTIVE

To improve our understanding of EPEC, this study focused on analyzing and comparing the genomic characteristics of EPEC isolates from humans and companion animals in Korea.

METHODS

The whole genome of 26 EPEC isolates from patients with diarrhea and 20 EPEC isolates from companion animals in Korea were sequenced using the Illumina HiSeq X (Illumina, USA) and Oxford Nanopore MinION (Oxford Nanopore Technologies, UK) platforms.

RESULTS

Most isolates were atypical EPEC, and did not harbor the bfpA gene. The most prevalent virulence genes were found to be ompT (humans: 61.5%; companion animals: 60.0%) followed by lpfA (humans: 46.2%; companion animals: 60.0%). Although pan-genome analyses showed no apparent correlation among the origin of the strains, virulence profiles, and antimicrobial resistance profiles, isolates included in clade A obtained from both humans and companion animals exhibited high similarity. Additionally, all the isolates included in clade A encoded the ompT gene and did not encode the hlyE gene. The two isolates from companion animals harbored an incomplete bundle-forming pilus region encoding bfpA and bfpB. Moreover, the type IV secretion system-associated genes tra and trb were found in the bfpA-encoding isolates from humans.

CONCLUSIONS AND RELEVANCE

Whole-genome sequencing enabled a more accurate analysis of the phylogenetic structure of EPEC and provided better insights into the understanding of EPEC epidemiology and pathogenicity.

Domestic cats are potential reservoirs of multidrug-resistant human enteropathogenic E. coli strains in Bangladesh

Companion animals serve as our best friends, confidants, and family members. Thus, disease and antibiotic resistance gene transmission in pets and humans must be sought out. The study aimed to identify the common pathogenic Escherichia coli (E.coli) in pet cats and the antibiotic resistance patterns and resistant gene distribution. Samples (n = 210) were collected from different veterinary clinics in Bangladesh's cities of Mymensingh and Dhaka. Pathogenic E. coli was identified using conventional and molecular approaches. The disc diffusion method assessed the resistance profile against 12 antibiotics, and PCR was used to identify the beta-lactam resistance genes. The prevalence of the stx-1 gene was found to be 2.86%, whereas the rfbO157 prevalence was found to be 1.90% in cats. The stx-1 gene (n = 6) was 100% resistant to erythromycin and imipenem, whereas 100% sensitive to chloramphenicol. In turn, the rfbO157 gene (n = 4) exhibited 100% resistance to erythromycin, imipenem, cefixime, and azithromycin. In addtion, we identified genes that exhibit resistance to beta-lactam antibiotics (100% blaTEM, 40% blaCTX-M, 40% blaSHV2). This study found shiga-toxin producing and extended-spectrum beta-lactamase (ESBL) producing E. coli for the first time in pet cats of Bangladesh. Furthermore, the antimicrobial resistance (AMR) profile of the isolated strains refers to the occurrence of multidrug, which concerns cats and their owners. The existence of these genes in non-diarrheic pet animal isolates indicates that domestic pets may serve as a reservoir for human infection. Thus, one health strategy comprising animal and human health sectors, governments, together with stakeholders is needed to confront multidrug-resistant E. coli infections in Bangladesh.

Biofilm-forming antimicrobial-resistant pathogenic Escherichia coli: A one health challenge in Northeast India

This study aimed to investigate the prevalence of Shiga toxin-producing Escherichia coli (STEC), Enteropathogenic E. coli (EPEC), and Enterotoxigenic E. coli (ETEC) in common food animals (cattle, goats, and pigs) reared by tribal communities and smallholder farmers in Northeast India. The isolates were characterized for the presence of virulence genes, extended-spectrum beta-lactamases (ESBL) production, antimicrobial resistance, and biofilm production, and the results were statistically interpreted. In pathotyping 141 E. coli isolates, 10 (7.09%, 95% CI: 3.45%-12.66%) were identified as STEC, 2 (1.42%, 95% CI: 0.17%-5.03%) as atypical-EPEC, and 1 (0.71%, 95% CI: 0.02%-3.89%) as typical-EPEC. None of the isolates were classified as ETEC. Additionally, using the phenotypic combination disc method (ceftazidime with and without clavulanic acid), six isolates (46.1%, 95% CI: 19.22%-74.87%) were determined to be ESBL producers. Among the STEC/EPEC strains, eleven (84.6%, 95% CI: 54.55%-98.08%) and one (7.7%, 95% CI: 0.19%-36.03%) strains were capable of producing strong or moderate biofilms, respectively. PFGE analysis revealed indistinguishable patterns for certain isolates, suggesting clonal relationships. These findings highlight the potential role of food animals reared by tribal communities and smallholder farmers as reservoirs of virulent biofilm-forming E. coli pathotypes, with implications for food contamination and zoonotic infections. Therefore, monitoring these pathogens in food animals is crucial for optimizing public health through one health strategy.

Epidemiology of companion animal AMR in the United States of America: filling a gap in the one health approach

Introduction

Antimicrobial resistance (AMR) is a global health concern that affects all aspects of the One Health Triad, including human, animal, and environmental health. Companion animals, such as cats and dogs, may contribute to the spread of AMR through their close contact with humans and the frequent prescription of antimicrobials. However, research on AMR in companion animals is limited, and there are few surveillance measures in place to monitor the spread of resistant pathogens in the United States.

Methods

This study aims to explore the practicality of using data from commercial laboratory antimicrobial susceptibility testing (AST) services for epidemiological analyses of AMR in companion animals in the United States.

Results

The study analyzed 25,147,300 individual AST results from cats and dogs submitted to a large commercial diagnostic laboratory in the United States between 2019 and 2021, and found that resistance to certain antimicrobials was common in both E. coli and S. pseudintermedius strains.

Conclusion

There has been a paucity of information regarding AMR in companion animals in comparison to human, environmental and other animal species. Commercial AST datasets may prove beneficial in providing more representation to companion animals within the One Health framework for AMR.

Vector-borne and other pathogens of potential relevance disseminated by relocated cats

Large populations of unowned cats constitute an animal welfare, ecological, societal and public health issue worldwide. Their relocation and homing are currently carried out in many parts of the world with the intention of relieving suffering and social problems, while contributing to ethical and humane population control in these cat populations. An understanding of an individual cat’s lifestyle and disease status by veterinary team professionals and those working with cat charities can help to prevent severe cat stress and the spread of feline pathogens, especially vector-borne pathogens, which can be overlooked in cats. In this article, we discuss the issue of relocation and homing of unowned cats from a global perspective. We also review zoonotic and non-zoonotic infectious agents of cats and give a list of practical recommendations for veterinary team professionals dealing with homing cats. Finally, we present a consensus statement consolidated at the 15th Symposium of the Companion Vector-Borne Diseases (CVBD) World Forum in 2020, ultimately to help veterinary team professionals understand the problem and the role they have in helping to prevent and manage vector-borne and other pathogens in relocated cats.

Graphical Abstract

Companion Animals as Potential Reservoirs of Antibiotic Resistant Diarrheagenic Escherichia coli in Shandong, China

Antibiotic resistance genes of Escherichia coli (E. coli) from companion animals were still poorly understood. Here, we investigated the extended-spectrum β-lactamases (ESBLs) resistance genes of E. coli from companion animals in Shandong, China. A total of 79 isolates (80.6%) were recovered from 98 healthy or diarrheal companion animals in 2021, among which ESBLs-producing isolates accounted for 43.0% (34/79), and more than half of ESBL E. coli (ESBL-EC) strains (n = 19) were isolated from healthy companion animals. Diarrheagenic E. coli isolates (45.6%, n = 36) were represented by enterotoxigenic (ETEC) (32.9%), enteropathogenic (EPEC) (10.1%) and enteroinvasive (EIEC) (2.6%), 20 isolates of which were from healthy pets. Among tested antibiotics, resistance to tetracycline (64.6%) was the most commonly observed, followed by doxycycline (59.5%) and ampicillin (53.2%). Notably, all isolates were susceptible to meropenem. The multidrug-resistant (MDR) rate was 49.4%, 20 isolates of which were ESBLs producers; moreover, 23.4%, 16.4% of ESBL-EC strains were resistant to 5 or more, 7 or more antibiotics, respectively. Among the 5 β-lactamase resistance genes, the most frequent gene was bla_CTX-M (60.76%), followed by bla_SHV (40.51%). The plasmid-mediated quinolone resistance (PMQR) gene aac(6')-Ib-cr was detected in 35 isolates. Additionally, ESBL-associated genes (i.e., bla_CTX-M, bla_SHV) were found in 76.5% ESBL-EC strains, with six isolates carrying bla_CTX-M and bla_SHV. The marker gene of high-pathogenicity island gene irp2 (encoding iron capture systems) was the most frequency virulence gene. Our results showed that ESBL-EC were widespread in healthy or diarrhea companion animals, especially healthy pets, which may be a potential reservoir of antibiotic resistance, therefore, enhancing a risk to public and animal health.

Prevalence, co-infection and seasonality of fecal enteropathogens from diarrheic cats in the Republic of Korea (2016-2019): a retrospective study

Background

Diarrhea is one of the most common clinical symptoms in cats and can be caused by infectious pathogens and investigation of the prevalence, co-infection and seasonality of enteropathogens are not well-established in diarrheic cats.

Results

Fecal samples of 1620 diarrheic cats were collected and enteropathogens were detected using real-time PCR. We retrospectively investigated the clinical features, total/seasonal prevalence, and infection patterns of enteropathogens. The positive infection rate was 82.59%. Bacterial, viral, and protozoal infections accounted for 49.3, 37.57, and 13.13% of cases, respectively. Feline enteric coronavirus (FECV) was the most common pathogen (29.37%), followed by Clostridium (C.) perfringens, Campylobacter (C.) coli, feline parvovirus, and Tritrichomonas foetus. The seasonality of enteropathogens was observed with peaks as follows: bacterial infections peaked in October, viral infections peaked in November, and protozoal infections peaked in August. Viral and protozoal infections showed differences in prevalence according to patient age. In the infection patterns, the ratios of single infections, mixed infections, and co-infections were 35.72, 9.87, and 54.41%, respectively. FECV was predominant in single infections. The most common patterns of multiple infections were C. perfringens and C. coli in mixed infections and C. perfringens and FECV in co-infections.

Conclusions

Infection patterns differed according to the enteropathogen species, seasonality, and age distribution in cats. The results of this study might be helpful to understand in clinical characteristics of feline infectious diarrhea. In addition, continued monitoring of feline enteropathogens is required.

Antimicrobial Susceptibility Profiles of Escherichia Coli Isolates from Diarrheic Dogs in Maiduguri, Borno State, Nigeria

Diarrhea caused by multidrug-resistant Escherichia coli (E. coli) is an important and common problem in companion animals, especially dogs. Moreover, these dogs may serve as a reservoir of pathogenic strains of E. coli that may cause enteric and extra-intestinal infections in humans and other animals. This study was conducted to investigate the antibiotic susceptibility pattern of E. coli isolates from diarrheic dogs in Maiduguri Metropolis, Borno State, Nigeria. In fecal samples of 200 dogs with diarrhea, 147 E. coli strains (73.5%) were isolated and characterized by the standard bacteriological techniques (culture, biochemical tests, and antimicrobial susceptibility testing). Out of the 147 positive isolates, 45, 50, and 52 were from Elkanemi Park, Magaram, and Sabon gari wards respectively. The isolates show 100% resistance to chloramphenicol, cefuroxime, and ceftriaxone, 96.6% to amoxicillin, and 95.9% to gentamicin, while all (100%) were susceptible to ciprofloxacin. All the isolates showed multiple antimicrobial resistance. The result of the current study showed that dogs in Maiduguri are important reservoirs of multidrug-resistant E. coli. Therefore, it is important to adopt and apply guidelines for the correct use of antimicrobials in small animal practice to reduce the emergence of multidrug resistance among E. coli in companion animals.

Comparative Genomics of Atypical Enteropathogenic Escherichia coli from Kittens and Children Identifies Bacterial Factors Associated with Virulence in Kittens

Typical enteropathogenic Escherichia coli (tEPEC) is a leading cause of diarrhea and associated death in children worldwide. Atypical EPEC (aEPEC) lacks the plasmid encoding bundle-forming pili and is considered less virulent, but the molecular mechanism of virulence is poorly understood. We recently identified kittens as a host for aEPEC where intestinal epithelial colonization was associated with diarrheal disease and death. The purposes of this study were to (i) determine the genomic similarity between kitten aEPEC and human aEPEC isolates and (ii) identify genotypic or phenotypic traits associated with virulence in kitten aEPEC. We observed no differences between kitten and human aEPEC in core genome content or gene cluster sequence identities, and no distinguishing genomic content was observed between aEPEC isolates from kittens with nonclinical colonization (NC) versus those with lethal infection (LI). Variation in adherence patterns and ability to aggregate actin in cultured cells mirrored descriptions of human aEPEC. The aEPEC isolated from kittens with LI were significantly more motile than isolates from kittens with NC. Kittens may serve as a reservoir for aEPEC that is indistinguishable from human aEPEC isolates and may provide a needed comparative animal model for the study of aEPEC pathogenesis. Motility seems to be an important factor in pathogenesis of LI associated with aEPEC in kittens.

Catching a glimpse of the bacterial gut community of companion animals: a canine and feline perspective

Dogs and cats have gained a special position in human society by becoming our principal companion animals. In this context, efforts to ensure their health and welfare have increased exponentially, with in recent times a growing interest in assessing the impact of the gut microbiota on canine and feline health. Recent technological advances have generated new tools to not only examine the intestinal microbial composition of dogs and cats, but also to scrutinize the genetic repertoire and associated metabolic functions of this microbial community. The application of high-throughput sequencing techniques to canine and feline faecal samples revealed similarities in their bacterial composition, with Fusobacteria, Firmicutes and Bacteroidetes as the most prevalent and abundant phyla, followed by Proteobacteria and Actinobacteria. Although key bacterial members were consistently present in their gut microbiota, the taxonomic composition and the metabolic repertoire of the intestinal microbial population may be influenced by several factors, including diet, age and anthropogenic aspects, as well as intestinal dysbiosis. The current review aims to provide a comprehensive overview of the multitude of factors which play a role in the modulation of the canine and feline gut microbiota and that of their human owners with whom they share the same environment.

Pet dogs potential transmitters of pathogenic Escherichia coli with resistance to antimicrobials

Escherichia coli strains are part of the normal biota of humans and animals; however, several clinical reports have implicated E. coli as the etiological agent of diarrhea in humans and companion animals. Thus, the aim of the present study was to know if companion dogs in the city of San Luis Potosi are colonized with virulent potentially harmful E. coli strains. Rectal swabs from 30 dogs, 13 with and 17 without diarrhea were analyzed. Phylogenetic and virulence genes analysis was performed to the E. coli isolates. Additionally, the Kirby-Bauer test was used to analyze the sensitivity to 32 different antimicrobials from 14 families. Eighty-five isolates were identified as E. coli and detected in 97% of healthy and diarrheic dog samples. E. coli isolates from healthy dogs carried several virulence genes, in contrast with those from diarrheic animals that presented only eaeA. In healthy dogs, phylogenetic analysis showed that 57% and 43% of E. coli isolates belonged to commensal (A and B1) and virulent (B2 and D) groups respectively. Meanwhile, diarrheic dogs showed that 69% of the isolates were identified as virulent B2 and D phylogroups. Moreover, E. coli resistant to β-lactams, aminoglycosides, tetracycline, quinolones, and folate inhibitors were detected in both groups of dogs. The presence of E. coli with eaeA virulence gene in diarrheic dogs, suggest that these strains are associated with the animal´s condition. Finally, major attention must be drawn to the careful handling of dogs because of their capability to harbor and disseminate virulent E. coli strains.

First Microbiological and Molecular Identification of Rhodococcus equi in Feces of Nondiarrheic Cats

Rhodococcus equi is responsible for infections in multiple-host animals. In humans, the prevalence of rhodococcus has increased worldwide and represents an emergent risk. R. equi is a soil-borne opportunistic bacterium isolated from feces of a wide variety of domestic species, except cats; thus, there is no known potential risk of its transmission from humans. Here, the mono- and cooccurrence of Rhodococcus equi and other bacteria and selected virulence markers were investigated in feces of nondiarrheic cats from urban (n=100) and rural (n=100) areas. Seven (7/200=3.5%) R. equi isolates were recovered in ceftazidime, novobiocin, and cycloheximide (CAZ-NB) selective media, exclusively of cats from three distinct farms (p=0.01), and these cats had a history of contact with horses and their environment (p=0.0002). None of the R. equi isolates harbored hosted-adapted plasmid types associated with virulence (pVAPA, pVAPB, and pVAPN). One hundred seventy-five E. coli isolates were identified, and 23 atypical enteropathogenic E. coli (aEPEC), 1 STEC (Shiga-toxin producing E. coli), and 1 EAEC (enteroaggregative E. coli) were detected. Eighty-six C. perfringens type A isolates were identified, and beta-2 and enterotoxin were detected in 21 and 1 isolates, respectively. Five C. difficile isolates were identified, one of which was toxigenic and ribotype 106. The main cooccurring isolates in cats from urban areas were E. coli and C. perfringens A (26/100=26%), E. coli and C. perfringens type A cpb2⁺ (8/100=8%), and aEPEC (eae+/escN+) and C. perfringens type A (5/100=5%). In cats from farms, the main cooccurring isolates were E. coli and C. perfringens type A (21/100=21%), E. coli and C. perfringens type A cpb₂⁺ 8/100=8%), and E. coli and R. equi (4/100=4%). We identified, for the first time, R. equi in nondiarrheic cats, a finding that represents a public health issue because rhodococcus has been reported in both immunosuppressed and immunocompetent humans, particularly people living with HIV/AIDS.

Where Did They Come from-Multi-Drug Resistant Pathogenic Escherichia coli in a Cemetery Environment?

Human burial in cemeteries facilitates the decomposition of corpses without posing a public health danger. However, the role of cemeteries as potential environmental reservoirs of drug-resistant pathogens has not been studied. Thus, we investigated cemeteries as potential environmental reservoirs of multi-drug resistant (MDR) pathogenic Escherichia coli. E. coli isolates were obtained from water samples (collected from surface water bodies and boreholes in three cemeteries) after isolation using the Colilert^® 18 system. Pathogenic potentials of the isolates were investigated using real-time polymerase chain reactions targeting seven virulence genes (VGs) pertaining to six E. coli pathotypes. The resistance of isolates to eight antibiotics was tested using the Kirby–Bauer disc diffusion method. The mean E. coli concentrations varied from <1 most probable number (MPN)/100 mL to 2419.6 MPN/100 mL with 48% of 100 isolates being positive for at least one of the VGs tested. Furthermore, 87% of the isolates were resistant to at least one of the antibiotics tested, while 72% of the isolates displayed multi-drug resistance. Half of the MDR isolates harboured a VG. These results suggest that cemeteries are potential reservoirs of MDR pathogenic E. coli, originating from surrounding informal settlements, which could contaminate groundwater if the cemeteries are in areas with shallow aquifers.

Metagenomic insights into the roles of Proteobacteria in the gastrointestinal microbiomes of healthy dogs and cats

Interests in the impact of the gastrointestinal microbiota on health and wellbeing have extended from humans to that of companion animals. While relatively fewer studies to date have examined canine and feline gut microbiomes, analysis of the metagenomic DNA from fecal communities using next‐generation sequencing technologies have provided insights into the microbes that are present, their function, and potential to contribute to overall host nutrition and health. As carnivores, healthy dogs and cats possess fecal microbiomes that reflect the generally higher concentrations of protein and fat in their diets, relative to omnivores and herbivores. The phyla Firmicutes and Bacteroidetes are highly abundant, and Fusobacteria, Actinobacteria, and Proteobacteria also feature prominently. Proteobacteria is the most diverse bacterial phylum and commonly features in the fecal microbiota of healthy dogs and cats, although its reputation is often sullied as its members include a number of well‐known opportunistic pathogens, such as Escherichia coli, Salmonella, and Campylobacter, which may impact the health of the host and its owner. Furthermore, in other host species, high abundances of Proteobacteria have been associated with dysbiosis in hosts with metabolic or inflammatory disorders. In this review, we seek to gain further insight into the prevalence and roles of the Proteobacteria within the gastrointestinal microbiomes of healthy dogs and cats. We draw upon the growing number of metagenomic DNA sequence‐based studies which now allow us take a culture‐independent approach to examine the functions that this more minor, yet important, group contribute to normal microbiome function.

The fecal microbiomes of healthy dogs and cats often include Proteobacteria at varying abundances. This phylum can have a sullied reputation as it contains a number of well‐known pathogenic members. We explored the functions of the Proteobacteria in fecal shotgun metagenome datasets from healthy dogs and cats. The Proteobacteria appeared to be enriched for functions that are consistent with a role in helping to maintain the anaerobic environment of the gut for normal microbiome function.

Characterization of four Escherichia albertii isolates collected from animals living in Antarctica and Patagonia

Escherichia albertii is a recently discovered species with a limited number of well characterized strains. The aim of this study was to characterize four of the E. albertii strains, which were among 41 identified Escherichia strains isolated from the feces of living animals on James Ross Island, Antarctica, and Isla Magdalena, Patagonia. Sequencing of 16S rDNA, automated ribotyping, and rep-PCR were used to identify the four E. albertii isolates. Phylogenetic analyses based on multi-locus sequence typing showed these isolates to be genetically most similar to the members of E. albertii phylogroup G3. These isolates encoded several virulence factors including those, which are characteristic of E. albertii (cytolethal distending toxin and intimin) as well as bacteriocin determinants that typically have a very low prevalence in E. coli strains (D, E7). Moreover, E. albertii protein extracts caused cell cycle arrest in human cell line A375, probably because of cytolethal distending toxin activity.

Association of Atypical Enteropathogenic Escherichia coli with Diarrhea and Related Mortality in Kittens

Diarrhea is responsible for the death of approximately 900,000 children per year worldwide. In children, typical enteropathogenic Escherichia coli (EPEC) is a common cause of diarrhea and is associated with a higher hazard of death. Typical EPEC infection is rare in animals and poorly reproduced in experimental animal models. In contrast, atypical EPEC (aEPEC) infection is common in both children and animals, but its role in diarrhea is uncertain. Mortality in kittens is often attributed to diarrhea, and we previously identified enteroadherent EPEC in the intestines of deceased kittens. The purpose of this study was to determine the prevalence and type of EPEC in kittens and whether infection was associated with diarrhea, diarrhea-related mortality, gastrointestinal pathology, or other risk factors. Kittens with and without diarrhea were obtained from two shelter facilities and determined to shed atypical EPEC at a culture-based prevalence of 18%. In contrast, quantitative PCR detected the presence of the gene for intimin (eae) in feces from 42% of kittens. aEPEC was isolated from kittens with and without diarrhea. However, kittens with diarrhea harbored significantly larger quantities of aEPEC than kittens without diarrhea. Kittens with aEPEC had a significantly greater severity of small intestinal and colonic lesions and were significantly more likely to have required subcutaneous fluid administration. These findings identify aEPEC to be prevalent in kittens and a significant primary or contributing cause of intestinal inflammation, diarrhea, dehydration, and associated mortality in kittens.

Escherichia coli diseases in Latin America-a 'One Health' multidisciplinary approach

The emergence and evolution of pathogenic Escherichia coli strains associated with animal and human infections continues being a topic of active investigation in recent years. Latin America has responded to this thread establishing the Latin American Coalition for Escherichia coli Research (LACER), a multidisciplinary group of scientists applying principles of the One Health initiative. LACER is integrating animal, human and environmental health for the mutual benefit of all, while reducing the impact of human disease. Here, I depict the usefulness of this approach by providing three examples from several priority areas in E. coli research and comparing them to the activities performed by LACER, which are enhancing collaborative efforts in biomedical research and providing a translational platform to connect with epidemiological studies and public health policy makers. The manuscript concludes with a brief historical description regarding the establishment of LACER, emphasizing the importance of collaboration between health professionals of different international organizations and not only across one specific country, to effectively combat current and future E. coli infections. The benefits of utilizing 'One Health' concepts in the establishment of LACER should encourage other professionals studying zoonotic or environmentally acquired human infections to implement effective international collaborations to combat common problems.

The Escherichia coli Serogroup O1 and O2 Lipopolysaccharides Are Encoded by Multiple O-antigen Gene Clusters

Escherichia coli strains belonging to serogroups O1 and O2 are frequently associated with human infections, especially extra-intestinal infections such as bloodstream infections or urinary tract infections. These strains can be associated with a large array of flagellar antigens. Because of their frequency and clinical importance, a reliable detection of E. coli O1 and O2 strains and also the frequently associated K1 capsule is important for diagnosis and source attribution of E. coli infections in humans and animals. By sequencing the O-antigen clusters of various O1 and O2 strains we showed that the serogroups O1 and O2 are encoded by different sets of O-antigen encoding genes and identified potentially new O-groups. We developed qPCR-assays to detect the various O1 and O2 variants and the K1-encoding gene. These qPCR assays proved to be 100% sensitive and 100% specific and could be valuable tools for the investigations of zoonotic and food-borne infection of humans with O1 and O2 extra-intestinal (ExPEC) or Shiga toxin-producing E. coli (STEC) strains.

Evaluating the occurrence of Escherichia albertii in chicken carcass rinses by PCR, Vitek analysis, and sequencing of the rpoB gene

Escherichia albertii is a recently described species that has been associated with gastroenteritis in humans and with healthy and ill birds. Most recently, it has been identified as the causative agent in a food-borne outbreak in Japan. The distribution and clinical importance of E. albertii are not well studied because its importance is unclear. Culture methods for clinical isolation frequently miss E. albertii or incorrectly identify it as Shigella spp., Escherichia coli, or Hafnia alvei. This study was designed to determine if E. albertii could be recovered from chicken carcass rinses collected at slaughter during a 1-year period from November 2009 until October 2010. Colonies were isolated from chicken carcass rinses and tested by PCR for the presence or absence of clpX, lysP, mdh, intimin (eae), Shiga toxins 1 and 2 (stx1, stx2, and stx2f), heat-stable enterotoxin A (staA), and cytolethal distending toxins 1 and 2 (cdtB) genes. Sixty-five isolates were analyzed by sequencing a section of the rpoB gene. Analysis of the rpoB gene sequences revealed 14 fixed differences between E. albertii and other, closely related organisms. The fixed differences found in the rpoB gene could aid in future discrimination of E. albertii from closely related bacteria.

Detection of diarrheagenic Escherichia coli strains isolated from dogs and cats in Brazil

Escherichia coli are gut microbiota bacteria that can cause disease in some humans and other animals, including dogs and cats that humans often keep as pets. Diarrheagenic E. coli (DEC) strains are classified into six categories: enteropathogenic (EPEC), enterotoxigenic (ETEC), Shiga toxin-producing (STEC), enteroinvasive (EIEC), enteroaggregative (EAEC), and diffuse-adhering E. coli (DAEC). In this study 144 and 163 E. coli colonies were isolated from the fecal samples of 50 dogs and 50 cats, respectively, with and without diarrhea from a Veterinary Hospital (clinical isolates). The virulence factors were determined using multiplex Polymerase Chain Reaction. Adherence assays, antibacterial susceptibility and serotyping (somatic or flagellar antigens) were performed on DEC isolates. We found 25 (17.4%) and 4 (2.5%) DEC strains isolated from dogs and cats, respectively. Only the EPEC and EAEC pathotypes were found in both animals. Meanwhile, genes from other pathotypes (STEC, EIEC, and ETEC) were not found in these clinical isolates. All of the DEC strains showed mannose-resistant adherence to HEp-2 and HeLa cells, and aggregative adherence was predominant in these isolates. Multiresistant strains to antimicrobials were found in most DEC strains including usual and unusual antimicrobials in veterinary practices. The serotypes of these DEC isolates were variable. The ONT serotype was predominant in these isolates. Some serotypes found in our study were described to human DEC. Here, we demonstrate that pets carry virulent DEC genes, which are mainly strains of EPECs and EAECs. The presence of these virulence factors in isolates from animals without diarrhea suggests that pets can act as a reservoir for human infection.

Molecular detection of enteropathogenic Escherichia coli in asymptomatic captive psittacines

Psittaciformes are one of the most endangered groups of birds, and several Brazilian species are classified between vulnerable and critically endangered. It is thus necessary to identify agents that cause infections in captive wild animals and to assess the risks posed thereof and to design interventions to minimize the possibility of disease outbreaks, leading to the conservation of endangered species. The purpose of this study was to identify enteropathogenic Escherichia coli (EPEC) cloacal isolates from asymptomatic psittacines in captivity and evaluate the distribution of the EPEC pathotype. Cloacal swabs were obtained from 46 asymptomatic birds, and resulting isolates were tested by polymerase chain reaction (PCR) for the presence of the attaching and effacing gene (eae) and bundle-forming pilus structural gene (bfpA) of EPEC. Samples from several species were tested, and three samples were found to be positive for the eae and bfpA genes and characterized as typical EPEC. This is the first report of this pathotype in asymptomatic psittacines. Although certain E. coli strains are more pathogenic than others, various factors should be considered when determining the potential of E. coli isolates to cause disease in captive psittacines. Birds that are positive for the EPEC (typical) strain could be zoonotic sources of infection, and may have acquired these strains through contact with humans or domestic animals. These findings may also be valuable for the long-term management of endangered species ex situ as one EPEC sample was isolated from a Red-tailed Amazon (Amazona brasiliensis).

Clonal relationship among atypical enteropathogenic Escherichia coli strains isolated from different animal species and humans

Forty-nine typical and atypical enteropathogenic Escherichia coli (EPEC) strains belonging to different serotypes and isolated from humans, pets (cats and dogs), farm animals (bovines, sheep, and rabbits), and wild animals (monkeys) were investigated for virulence markers and clonal similarity by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The virulence markers analyzed revealed that atypical EPEC strains isolated from animals have the potential to cause diarrhea in humans. A close clonal relationship between human and animal isolates was found by MLST and PFGE. These results indicate that these animals act as atypical EPEC reservoirs and may represent sources of infection for humans. Since humans also act as a reservoir of atypical EPEC strains, the cycle of mutual infection of atypical EPEC between animals and humans, mainly pets and their owners, cannot be ruled out since the transmission dynamics between the reservoirs are not yet clearly understood.