Captive wild birds as reservoirs of enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC)

Detection of EPEC and STEC strains isolated from children with diarrhea in Argentina

Rectal swabs (122) from pediatric patients were analyzed by polymerase chain reaction (PCR) for the detection of EPEC and STEC. STEC isolates were tested for the presence of stx1, stx2, eae, saa and ehxA. All eae-positive samples were tested for the presence of bfpA, and antigen O was determined using the agglutination test. Int1 and Int2 were detected to identify the presence of integrons class 1 and 2, respectively. Escherichia coli was detected in 68% of the samples, of which 18.8% were STEC (2.45%) and EPEC (16.3%). Serogroups STEC O145 and EPEC O130, O113 and O157 were observed, while three strains were non-typable. None of the EPEC strains carrying tbfpA and class 1 and 2 integrons was detected in any of the samples. The results obtained are important considering the virulence profiles found in the isolated EPEC and STEC strains and the serogroups associated with disease in humans.

Detection of pathogenic, heteropathogenic and hybrid Escherichia coli strains in psittacines from zoos and breeders in the state of Ceará, Brazil

The current study aimed to detect virulence, hetero-pathogenicity, and hybridization genes in Escherichia coli strains, previously isolated from cloacal swabs in commercial breeding psittacines and zoological collections, via multiplex PCR. A total of 68 strains of E. coli, previously isolated from psittacines in zoos and commercial breeding facilities in Ceará, Brazil, were assessed for the presence of the following genes and/or probes: eae, bfpA (EPEC - Enteropathogenic E. coli), CVD432 (EAEC - Enteroaggregative E. coli); LT gene and ST gene (ETEC - Enterotoxigenic E. coli); ipaH (EIEC - Enteroinvasive E. coli); stx1 and stx2 (STEC - Shiga toxin-producing E. coli); iroN, ompT, hlyF, iss, and iutA (APEC - Avian pathogenic E. coli). Of the 68 E. coli strains analyzed, 61 (98.7 %) were positive for the following genes and/or probes: Stx1 (61/98.7 %), ST gene (54/79.4 %), CVD432 (49/72 %), bfpA (44/64.7 %), eae (42/61.8 %), Stx2 (41/60.3 %), ipaH (34/50 %), LT gene (33/48.5 %), iroN (21/30.9 %), hlyF (11/6.2 %), iss (06/8.8 %) and iutA (06/8.8 %). The following diarrheagenic pathotypes were identified: 66 (97 %) from STEC, 49 (72 %) from EAEC, 35 (52 %) from EIEC, 25 (37 %) from ETEC, and one (1.5 %) from EPEC. Regarding hetero-pathogenicity, 50 (74 %) heterogeneous strains were identified. Positivity for APEC was seen in four (6 %) strains, all characterized as pathogenic hybrids. This study describes significant associations of virulence factors in E. coli strains DEC/DEC and DEC/APEC, which were isolated from psittacines and may be potentially harmful to One Health.

How to Improve Surveillance Program for Shiga Toxin-Producing E. coli (STEC): Gap Analysis and Pilot Study

Several pathotypes of enteric E. coli have been identified. The group represented by Shiga toxin-producing E. coli (STEC) is of particular interest. Raw milk and raw milk products are significant sources of STEC infection in humans; therefore, identifying pathogens at the herd level is crucial for public health. Most national surveillance programs focus solely on raw milk and raw milk cheeses that are ready for retail sale, neglecting the possibility of evaluating the source of contamination directly at the beginning of the dairy chain. To assess the viability of the application of new molecular methodologies to STEC identification in raw milk filters and in calf feces, we analyzed 290 samples from 18 different dairy herds, including 88 bulk tank milk (BTM), 104 raw milk filters (RMF), and 98 calf feces samples. In total 3.4% of BTM, 41.4% of RMF, and 73.4% of calves' feces were positive for stx, supporting our hypothesis that BTM is not a suitable matrix to assess the presence of STEC at herd level, underestimating it. Our conclusion is that the surveillance program needs critical and extensive improvements such as RMF and calves' feces analysis implementation to be more efficient in detecting and preventing STEC infections. The epidemiology of these infections and the characteristics of the pathogen clearly show how a One Health approach will be pivotal in improving our capabilities to control the spread of these infections.

Characterisation of typical enteropathogenic Escherichia coli (tEPEC) lineages and novel bfpA variants detected in Australian fruit bats (Pteropus poliocephalus)

Enteropathogenic Escherichia coli (EPEC) is an important cause of diarrhoeal disease in human infants. EPEC strains are defined by the presence of specific virulence factors including intimin (encoded by the eae gene) and bundle forming pili (Bfp). Bfp is encoded by the bfp operon and includes the bfpA gene for the major pilus subunit. By definition, Bfp are only present in typical EPEC (tEPEC), for which, humans are considered to be the only known natural host. This study detected tEPEC in faecal samples from a wild Australian fruit bat species, the grey-headed flying-fox (Pteropus poliocephalus). Whole genome sequencing of 61 E. coli isolates from flying-foxes revealed that 21.3 % (95%CI: 13 %-33 %) were tEPEC. Phylogenetic analyses showed flying-fox tEPEC shared evolutionary lineages with human EPEC, but were predominantly novel sequence types (9 of 13) and typically harboured novel bfpA variants (11 of 13). HEp-2 cell adhesion assays showed adherence to human-derived epithelial cells by all 13 flying-fox tEPEC, indicating that they all carried functional Bfp. Using an EPEC-specific duplex PCR, it was determined that tEPEC comprised 17.4 % (95%CI: 13 %-22 %) of 270 flying-fox E. coli isolates. Furthermore, a tEPEC-specific multiplex PCR detected the eae and bfpA virulence genes in 18.0 % (95%CI: 8.0 %-33.7 %) of 506 flying-fox faecal DNA samples, with occurrences ranging from 1.3 % to 87.0 % across five geographic areas sampled over a four-year period. The identification of six novel tEPEC sequence types and five novel bfpA variants suggests flying-foxes carry bat-specific tEPEC lineages. However, their close relationship with human EPEC and functional Bfp, indicates that flying-fox tEPEC have zoonotic potential and that dissemination of flying-fox tEPEC into urban environments may pose a public health risk. The consistent detection of tEPEC in flying-foxes over extensive geographical and temporal scales indicates that both wild grey-headed flying-foxes and humans should be regarded as natural tEPEC hosts.

Pathogenicity assessment of Shiga toxin-producing Escherichia coli strains isolated from wild birds in a major agricultural region in California

Shiga toxin-producing Escherichia coli (STEC) consists of diverse strains differing in genetic make-up and virulence potential. To better understand the pathogenicity potential of STEC carried by the wildlife, three STEC and one E. coli strains isolated from wild birds near a major agricultural region in California were selected for comparative pathogenomic analyses. Three American crow (Corvus brachyrhynchos) strains, RM9088, RM9513, and RM10410, belonging to phylogroup A with serotypes O109:H48, O9:H30, and O113:H4, respectively, and a red-winged blackbird (Agelaius phoeniceus) strain RM14516 in phylogroup D with serotype O17:H18, were examined. Shiga toxin genes were identified in RM9088 (stx1a), RM10410 (stx1a + stx2d), and RM14516 (stx2a). Unlike STEC O157:H7 strain EDL933, none of the avian STEC strains harbored the pathogenicity islands OI-122, OI-57, and the locus of enterocyte effacement, therefore the type III secretion system biogenesis genes and related effector genes were absent in the three avian STEC genomes. Interestingly, all avian STEC strains exhibited greater (RM9088 and RM14516) or comparable (RM10410) cytotoxicity levels compared with EDL933. Comparative pathogenomic analyses revealed that RM9088 harbored numerous genes encoding toxins, toxins delivery systems, and adherence factors, including heat-labile enterotoxin, serine protease autotransporter toxin Pic, type VI secretion systems, protein adhesin Paa, fimbrial adhesin K88, and colonization factor antigen I. RM9088 also harbored a 36-Kb high pathogenicity island, which is related to iron acquisition and pathogenicity in Yersinia spp. Strain RM14516 carried an acid fitness island like the one in EDL933, containing a nine gene cluster involved in iron acquisition. Genes encoding extracellular serine protease EspP, subtilase cytotoxin, F1C fimbriae, and inverse autotransporter adhesin IatC were only detected in RM14516, and genes encoding serine protease autotransporter EspI and P fimbriae were only identified in RM10410. Although all curli genes were present in avian STEC strains, production of curli fimbriae was only detected for RM9088 and RM14516. Consistently, strong, moderate, and little biofilms were observed for RM9088, RM14516, and RM10410, respectively. Our study revealed novel combinations of virulence factors in two avian strains, which exhibited high level of cytotoxicity and strong biofilm formation. Comparative pathogenomics is powerful in assessing pathogenicity and health risk of STEC strains.

Monitoring the genetic variation of some Escherichia coli strains in wild birds and cattle

To date, there is limited data about the genetic relationship of Escherichia coli between wild birds and cattle because these birds act as silent vectors for many zoonotic bacteria. This study aimed to elucidate the role of rooming wild birds in the vicinity of cattle farm in transmission of the same pathogenic E. coli variants, identifying their virulence, resistance traits and genetic similarities of fimH virulence gene. About 240 faecal/cloacal swabs were collected from both species and examined bacteriologically. Escherichia coli was yielded in 45.8% and 32.5%, respectively, of examined cattle and wild birds. The most prevalent detected E. coli serovar was O26. High tetracycline and chloramphenicol resistance were recorded; however, gentamycin and ciprofloxacin exhibited the highest sensitivity rates. Polymerase chain reaction (PCR) conserved genotypic resistance (tetA and blaCTX-M) and virulence attributes (fimH, stx1, eaeA and ompA) of E. coli isolates were discussed in detail. The fimH gene revealed 100% sequence similarity when comparing with different E. coli isolates globally and locally. Finally, a close genetic association of E. coli with both wild birds and cattle was detected, thus strengthening its role in the dissemination of the infection via environment. Prevention and conservative policy should be carried as E. coli constitute enormous significant zoonotic risks to livestock and animal workers. Also, further studies to the whole genome sequencing of fimH, other virulence and resistance genes of E. coli are recommended trying to limit the possibilities of co-infection and transfer among different species.Contribution: The current study recorded updated data about the critical infectious role of wild birds to livestock, including cattle farms in Egypt. It also delivered some recommendations for good hygienic practices in cattle farms which must be implemented for handling animal manure.

Prevalence and Implications of Shiga Toxin-Producing E. coli in Farm and Wild Ruminants

Shiga-toxin-producing Escherichia coli (STEC) is a food-borne pathogen that causes human gastrointestinal infections across the globe, leading to kidney failure or even death in severe cases. E. coli are commensal members of humans and animals' (cattle, bison, and pigs) guts, however, may acquire Shiga-toxin-encoded phages. This acquisition or colonization by STEC may lead to dysbiosis in the intestinal microbial community of the host. Wildlife and livestock animals can be asymptomatically colonized by STEC, leading to pathogen shedding and transmission. Furthermore, there has been a steady uptick in new STEC variants representing various serotypes. These, along with hybrids of other pathogenic E. coli (UPEC and ExPEC), are of serious concern, especially when they possess enhanced antimicrobial resistance, biofilm formation, etc. Recent studies have reported these in the livestock and food industry with minimal focus on wildlife. Disturbed natural habitats and changing climates are increasingly creating wildlife reservoirs of these pathogens, leading to a rise in zoonotic infections. Therefore, this review comprehensively surveyed studies on STEC prevalence in livestock and wildlife hosts. We further present important microbial and environmental factors contributing to STEC spread as well as infections. Finally, we delve into potential strategies for limiting STEC shedding and transmission.

Multi-Drug Resistant Pathogenic Escherichia coli Isolated from Wild Birds, Chicken, and the Environment in Malaysia

Transmission of pathogenic microorganisms in the last decades has been considered a significant health hazard and pathogenic E. coli, particularly antibiotic-resistant strains, have long been identified as a zoonotic problem. This study aimed to investigate multidrug resistant pathogenic E. coli isolates from wild birds, chickens, and environment in selected Orang Asli and Malay villages in Peninsular Malaysia. The bacteriological culture-based technique, disc diffusion method, and multiplex Polymerase Chain Reaction (mPCR) assay was used to determine the occurrence of pathogenic E. coli strains in the several samples in the study. E. coli isolates showed a variety of multi-drug resistant (MDR) antibiotypes and Enteropathogenic E. coli (EPEC) and Enteroinvasive E. coli (EIEC) were the most predominantly identified pathogenic E. coli strains. The findings of this study demonstrated the significance of animal reservoirs and the environment as sources of pathogenic E. coli, resistant bacteria, and resistance genes. Hence, there is a need for adoption of a practical surveillance approach on MDR pathogens to control foodborne contamination.

Prevalence and Characterization of Shiga Toxin Producing Escherichia coli Isolated from Animal Feed in Croatia

A survey on prevalence and number of Shiga toxin-producing Escherichia (E.) coli (STEC) in animal feed was carried out over a period of nine years in the Republic of Croatia. A total of 1688 feed samples were collected from feed factories and poultry farms. Analysis included two standard procedures: sample enrichment and (a) immunomagnetic separation and plating on two selective media; or (b) plating on two selective media. Confirmation of STEC included morphological examination, biochemical tests, serotyping, and polymerase chain reaction. Morphological and biochemical characterization revealed 629 E. coli strains. Further serological screening method revealed 78 STEC and EPEC serotypes, while only 27 strains were confirmed as STEC with PCR. All positive samples (1.6%) originated from poultry farms and contained combination of virulence genes: eaeA, stx1, and/or stx2. Since the presence of stx (especially stx2) and eae are identified as risk factors for development of severe diseases in humans, results of this survey indicate that avian sources of STEC infections might be one of those "undefined sources" of human illnesses. Further research is necessary for evaluation of risks posed by contaminated feed, poultry, and environment.

Virulence Genes of Pathogenic Escherichia coli in Wild Red Foxes (Vulpes vulpes)

Simple Summary

Escherichia coli is a commensal of the intestinal tract of humans and animals, but some pathotypes can cause severe infections. Enteropathogenic E. coli (EPEC), Shiga toxin-producing E. coli (STEC), and enterohemorrhagic E. coli (EHEC) are the pathotypes most frequently involved in enteric disorders observed in people and domestic animals. Wildlife may harbor and excrete these pathotypes too, therefore, they may be source of infections for humans and domestic animals. Vulpes vulpes seem to be involved in the epidemiology of pathogenic E. coli strains, and thus they could be a relevant threat mainly when they invade human settlements in rural and urban areas.

Abstract

Different pathotypes of Escherichia coli can cause severe diseases in animals and humans. Wildlife may contribute to the circulation of pathogenic pathotypes, including enteropathogenic E. coli (EPEC), Shiga toxin-producing E. coli (STEC), and enterohemorrhagic E. coli (EHEC). This study analyzed 109 DNA samples previously extracted from fecal specimens collected from red foxes (Vulpes vulpes) to detect E. coli virulence genes eaeA, hlyA, stx1, and stx2, that characterize the EPEC, STEC, and EHEC strains. Thirty-one (28.4%) samples were positive for at least one investigated virulence gene: eaeA gene was detected in 21 (19.2%) samples, hlyA in 10 (9.1%), stx1 in 6 (5.5%), and stx2 in 4 (3.6%). Nine DNA samples resulted positive for two or three virulence genes: five (4.6%) samples were positive for eaeA and hlyA genes, two (1.8%) for eaeA and stx1, one (0.9%) for hlyA and stx1, one (0.9%) for eaeA, hlyA and stx2. Red foxes seem to be involved in the epidemiology of these infections and their role could be relevant because they may be source of pathogenic E. coli for other wild animals, as well as domestic animals and humans.

Antimicrobial Resistance of E. coli and Salmonella Isolated from Wild Birds in a Rehabilitation Center in Turkey

Wildlife plays a critical role as a reservoir for zoonosis especially pathogenic enteric bacteria. In this study we evaluated the presence of E. coli and Salmonella isolates from wild birds and determined their antimicrobial resistance. Intestine and fecal samples from 82 dead wild birds obtained from rehabilitation centre, were examined by microbiological analysis, antibiotic susceptibilities against of 18 antimicrobials and presence of tetracycline resistance genes by multiplex and singleplex PCR were investigated. A total of 51 E. coli were identified as well as Salmonella Kentucky and Salmonella Bisberg. A majority of the E. coli isolates were resistant to lincomysin (100%), penicilline (96.1%), kanamycin (80.4%), tetracycline (68.6%), and oxytetracycline (64.7%). All Salmonella serotypes were resistant to lincomycin, nalidixic acid and penicilline.In addition, 58.82% of E. coli isolates had phenotypic resistance to at least three or more antimicrobials. Our results indicated that the high frequency of tetracycline resistance (68.62%) due to the tet (A), tet (B), and tet (D) genes. This is the first report isolating S. Bisberg and determining antibiotic susceptibility of E.coli and Salmonella isolates from wild birds in Turkey. These results will help providing better understand of the dissemination of antibiotic resistancy in the environment, which can be used to potentially decrease spread through bird migration. Moreover, these results help assess the risk of spread of resistance from wild birds to humans.

Migratory Birds as Vehicle to Transmit Multi Drug Resistant Extended Spectrum β Lactamase Producing Escherichia fergusonii, an Emerging Zoonotic Pathogen

The acquisition of multi-drug resistance (MDR) genes by pathogenic bacterial bugs and their dispersal to different food webs has become a silent pandemic. The multiplied use of different antibacterial therapeutics during COVID-19 pandemic has accelerated the process among emerging pathogens. Wild migratory birds play an important role in the spread of MDR pathogens and MDR gene flow due to the consumption of contaminated food and water. Escherichia fergusonii is an emerging pathogen of family Enterobacteriaceae and commonly causes disease in human and animals. The present study focused on the isolation of E. fergusonii from blood, saliva, and intestine of selected migratory birds of the Hazara Division. The sensitivity of isolated strains was assessed against ten different antibiotics. The isolation frequency of E. fergusonii was 69%. In blood samples, a high rate of resistance was observed against ceftriaxone (80%) followed by ampicillin (76%) whereas, in oral and intestinal samples, ceftriaxone resistant strains were 56% and 57% while ampicillin resistance was 49% and 52% respectively. The overall ceftriaxone and ampicillin-resistant cases in all three sample sources were 71% and 65% respectively. In comparison to oral and intestinal samples, high numbers of ceftriaxone-resistant strains were isolated from the blood of mallard while ampicillin-resistant strains were observed in blood samples of cattle egrets. 16S rRNA-based confirmed strains of E. fergusonii were processed for detection of CTX-M and TEM-1 gene through Polymerase chain reaction (PCR) after DNA extraction. Hundred percent ceftriaxone resistant isolates possessed CTX-M and all ampicillin-resistant strains harbored TEM-1 genes. Amplified products were sequenced by using the Sanger sequencing method and the resulted sequences were checked for similarity in the nucleotide Database through the BLAST program. TEM-1 gene showed 99% and the CTX-M gene showed 98% similar sequences in the Database. The 16S rRNA sequence and nucleotide sequences for TEM-1 and CTX-M genes were submitted to Gene Bank with accession numbers LC521304, LC521306, LC521307 respectively. We posit to combat MDR gene flow among the bacterial pathogens across different geographical locations, regular surveillance of new zoonotic pathogens must be conducted.

Risk Factors for Positivity to Shiga Toxin-Producing Escherichia coli and Salmonella enterica in Backyard Production Systems Animals from Metropolitana Region, Chile: A Threat to Public Health?

In the Metropolitana region of Chile there are 3836 backyard production systems (BPS), characterized as small-scale systems. They act as a source of zoonotic pathogens, such as Salmonella enterica and Shiga toxin-producing Escherichia coli (STEC), whose prevalence in BPS has not been fully described. The objective of this study was to determine the positivity for both agents in BPS and to establish the risk factors related to their presence. In each BPS, an epidemiological survey was undertaken, and stool samples were collected to detect these pathogens via bacteriological culture and conventional PCR techniques. Subsequently, multivariable logistic regression models were applied to establish the risk factors associated with their presence. BPS positivity rates of 11.76% for STEC and 4.7% for S. enterica were observed. The systems showed poor welfare standards and a lack of biosecurity measures. The risk factor analysis concluded that the Gini-Simpson index (p = 0.030; OR = 1.717) and the presence of neighboring intensive poultry or swine production systems (p = 0.019; OR = 20.645) act as factors that increased the risk of positivity with respect to STEC. In the case of S. enterica, exchanging embryonated eggs (p = 0.021; OR = 39) and the presence of debeaked chickens (p = 0.001; OR = 156) were determined as factors that increased the risk of positivity for this agent. For positivity with respect to both pathogens, the Gini-Simpson index (p = 0.030; OR = 1.544) and being INDAP/PRODESAL users (p = 0.023; OR = 15.026) were determined as factors that increased the risk, whereas the type of confinement (p = 0.002; OR = 0.019) decreased it. Epidemiological surveillance of these neglected populations is lacking, highlighting the fact that STEC and S. enterica maintenance on BPS represents a potential threat to public health.

Two Paralogous Gb3/CD77 Synthases in Birds Show Different Preferences for Their Glycoprotein and Glycosphingolipid Substrates

Most glycosyltransferases show remarkable gross and fine substrate specificity, which is reflected in the old one enzyme-one linkage paradigm. While human Gb3/CD77 synthase is a glycosyltransferase that synthesizes the Galα1→4Gal moiety mainly on glycosphingolipids, its pigeon homolog prefers glycoproteins as acceptors. In this study, we characterized two Gb3/CD77 synthase paralogs found in pigeons (Columba livia). We evaluated their specificities in transfected human teratocarcinoma 2102Ep cells by flow cytofluorometry, Western blotting, high-performance thin-layer chromatography, mass spectrometry and metabolic labelling with 14C-galactose. We found that the previously described pigeon Gb3/CD77 synthase (called P) can use predominately glycoproteins as acceptors, while its paralog (called M), which we serendipitously discovered while conducting this study, efficiently synthesizes Galα1→4Gal caps on both glycoproteins and glycosphingolipids. These two paralogs may underlie the difference in expression profiles of Galα1→4Gal-terminated glycoconjugates between neoavians and mammals.

Use of MALDI-TOF for identification and surveillance of gram-negative bacteria in captive wild psittacines

Microbiological studies of the sanitary and health status of psittacine birds that will be reintroduced is important in evaluating whether these animals act as carriers of pathogenic agents to other animals and humans. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a faster and more accurate method to identify bacteria than conventional microbiology methods. The aim of this study was to evaluate the health status of psittacines housed in captivity, by assessment of Gram-negative bacteria from fecal microbiota through MALDI- TOF MS identification. The results indicate high frequency of Gram-negative bacteria in feces (96.5%), especially from the Enterobacteriaceae family (88.7%). The most prevalent bacteria were Escherichia coli (39.0%), Proteus vulgaris (12.2%), Klebsiella spp. (12.1%) and Raoultella ornithinolytica (8.7%). Proteus hauseri, Citrobacter spp., Morganella morgannii, Providencia rettgeri, Enterobacter spp. and Escherichia hermannii were isolated with lower frequency. . All these agents are potentially pathogenic for parrots and can cause systemic infections in other animals and humans. These findings reinforce that MALDI- TOF MS proved to be a rapid and accurate method of identification of the microorganism and evaluation of the health status of psittacines, providing relevant data to assist decision-making regarding the sanitary protocols in wildlife centers, and possible future reintroduction of wild birds.

Characterization of multidrug-resistant avian pathogenic Escherichia coli: an outbreak in canaries

The canary (Serinus canaria) is appreciated for its beautiful song, colors, and docile temperament and drives a lucrative business. However, diseases caused by avian pathogenic Escherichia coli (APEC) compromise the health of canaries, and the inadequate antimicrobial treatment can lead to the emergence of resistant strains. This study aimed to characterize 21 isolates of E. coli obtained from canaries infected with colibacillosis during an outbreak in northern Paraná State, Brazil. APEC and diarrheagenic E. coli (DEC) virulence genes were screened for by polymerase chain reaction (PCR). All isolates were positive for the hlyF, iss, and ompT genes, which are characteristic of APEC. The iroN gene was found in 95.2% of isolates, and none had the iutA gene. The ipaH gene, characteristic of enteroinvasive E. coli (EIEC), was found in 71.4% of isolates, all belonging to the phylogenetic group B1. High genetic similarity (>95%) was found using enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). The isolates belonged to serotypes O117:H4 (71.4%) and O1:H20 (23.8%). This is the first report of a clonal colibacillosis outbreak in canaries caused by APEC. All isolates were resistant to ampicillin, nalidixic acid, ciprofloxacin, enrofloxacin, norfloxacin, and tetracycline. The high rate of multidrug resistance in our study shows the importance of avoiding the inadequate antibiotic treatment. We suggest that further studies should be conducted to contribute to the understanding of colibacillosis in canaries since the health of animals is linked to human and environmental health, as defined by the concept of One Health.

A One Health Perspective for Defining and Deciphering Escherichia coli Pathogenic Potential in Multiple Hosts

E. coli is one of the most common species of bacteria colonizing humans and animals. The singularity of E. coli 's genus and species underestimates its multifaceted nature, which is represented by different strains, each with different combinations of distinct virulence factors. In fact, several E. coli pathotypes, or hybrid strains, may be associated with both subclinical infection and a range of clinical conditions, including enteric, urinary, and systemic infections. E. coli may also express DNA-damaging toxins that could impact cancer development. This review summarizes the different E. coli pathotypes in the context of their history, hosts, clinical signs, epidemiology, and control. The pathotypic characterization of E. coli in the context of disease in different animals, including humans, provides comparative and One Health perspectives that will guide future clinical and research investigations of E. coli infections.

Whole-Genome Phylogenetic Analysis Reveals a Wide Diversity of Non-O157 STEC Isolated From Ground Beef and Cattle Feces

Shiga toxin-producing Escherichia coli (STEC) causes foodborne outbreaks that can lead to complications such as hemolytic uremic syndrome. Their main reservoir is cattle, and ground beef has been frequently associated with disease and outbreaks. In this study, we attempted to understand the genetic relationship among STEC isolated in Chile from different sources, their relationship to STEC from the rest of the world, and to identify molecular markers of Chilean STEC. We sequenced 62 STEC isolated in Chile using MiSeq Illumina. In silico typing was determined using tools of the Center Genomic Epidemiology, Denmark University (CGE/DTU). Genomes of our local STEC collection were compared with 113 STEC isolated worldwide through a core genome MLST (cgMLST) approach, and we also searched for distinct genes to be used as molecular markers of Chilean isolates. Genomes in our local collection were grouped based on serogroup and sequence type, and clusters were formed within local STEC. In the worldwide STEC analysis, Chilean STEC did not cluster with genomes of the rest of the world suggesting that they are not phylogenetically related to previously described STEC. The pangenome of our STEC collection was 11,650 genes, but we did not identify distinct molecular markers of local STEC. Our results showed that there may be local emerging STEC with unique features, nevertheless, no molecular markers were detected. Therefore, there might be elements such as a syntenic organization that might explain differential clustering detected between local and worldwide STEC.

Antimicrobial Usage Factors and Resistance Profiles of Shiga Toxin-Producing Escherichia coli in Backyard Production Systems From Central Chile

Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen and important cause of foodborne disease worldwide. Many animal species in backyard production systems (BPS) harbor STEC, systems characterized by low biosecurity and technification. No information is reported on STEC circulation, antimicrobial resistance (AMR) and potential drivers of antimicrobial usage in Chilean BPS, increasing the risk of maintenance and transmission of zoonotic pathogens and AMR generation. Thus, the aim of this study was to characterize phenotypic and genotypic AMR and to study the epidemiology of STEC isolated in BPS from Metropolitana region, Chile. A total of 85 BPS were sampled. Minimal inhibitory concentration and whole genome sequencing was assessed in 10 STEC strain isolated from BPS. All strains were cephalexin-resistant (100%, n = 10), and five strains were resistant to chloramphenicol (50%). The most frequent serotype was O113:H21 (40%), followed by O76:H19 (40%), O91:H14 (10%), and O130:H11 (10%). The stx1 type was detected in all isolated strains, while stx2 was only detected in two strains. The Stx subtype most frequently detected was stx1c (80%), followed by stx1a (20%), stx2b (10%), and stx2d (10%). All strains harbored chromosomal bla_AmpC. Principal component analysis shows that BPS size, number of cattle, pet and horse, and elevation act as driver of antimicrobial usage. Logistic multivariable regression shows that recognition of diseases in animals (p = 0.038; OR = 9.382; 95% CI: 1.138–77.345), neighboring poultry and/or swine BPS (p = 0.006; OR = 10.564; 95% CI: 1.996–55.894), visit of Veterinary Officials (p = 0.010; OR = 76.178; 95% CI: 2.860–2029.315) and close contact between animal species in the BPS (p = 0.021; OR = 9.030; 95% CI: 1.385–58.888) increase significantly the risk of antimicrobial use in BPS. This is the first evidence of STEC strains circulating in BPS in Chile, exhibiting phenotypic AMR, representing a threat for animal and public health. Additionally, we identified factors acting as drivers for antimicrobial usage in BPS, highlighting the importance of integration of these populations into surveillance and education programs to tackle the potential development of antimicrobial resistance and therefore the risk for ecosystemic health.

Antimicrobial resistance in Escherichia coli isolates from frugivorous (Eidolon helvum) and insectivorous (Nycteris hispida) bats in Southeast Nigeria, with detection of CTX-M-15 producing isolates

Thirty-five Escherichia coli isolates obtained from the liver, spleen and intestines of 180 frugivorous and insectivorous bats were investigated for antimicrobial resistance phenotypes/genotypes, prevalence of Extended-Spectrum beta-lactamase (ESBL) production, virulence gene detection and molecular typing. Eight (22.9 %) of the isolates were multidrug resistant (MDR). Two isolates were cefotaxime-resistant, ESBL-producers and harbored the bla_CTX-M-15 gene; they belonged to ST10184-D and ST2178-B1 lineages. tet(A) gene was detected in all tetracycline-resistant isolates while int1 (n = 8) and bla_TEM (n = 7) genes were also found. Thirty-three of the E. coli isolates were assigned to seven phylogenetic groups, with B1 (45.7 %) being predominant. Three isolates were enteropathogenic E. coli (EPEC) pathovars, containing the eae gene (with the variants gamma and iota), and lacking stx1/stx2 genes. Bats in Nigeria are possible reservoirs of potentially pathogenic MDR E. coli isolates which may be important in the ecology of antimicrobial resistance at the human-livestock-wildlife-environment interfaces. The study reinforces the importance of including wildlife in national antimicrobial resistance monitoring programmes.

Molecular Screening of Salmonella sp. from fecal sample of Sparrows (Passer domesticus) in Yogyakarta, Indonesia

Wild birds is one of the reservoir agent of some of various zoonotic diseases. The study was aim to see the potential of sparrow as the reservoir agent of Salmonella sp. using polymerase chain reaction (PCR) method. We detected the invA gene of Salmonella sp. from faecal sample of sparrows (Passer domesticus) in local area of Yogyakarta, Indonesia. A total of 30 faecal dropping samples were collected from sparrows. DNA was extracted from the faecal samples, then amplified by PCR for the target genes. The amplicons were electrophorized to see the visualization of DNA on the agarose gel. The result showed the prevalence of the positive result of Salmonella sp. was 3,3%. The study indicated that sparrows can spread zoonotic pathogens and this necessitates monitoring for the epidemiologic status of these pathogens among birds, also applying the appropriate intervention measures to prevent the transmission of zoonotic diseasesfrom birds to humans.

Occurrence of KPC-Producing Escherichia coli in Psittaciformes Rescued from Trafficking in Paraíba, Brazil

The emergence and spread of antimicrobial resistance pose a threat to public health globally. Antibiotic-resistant bacteria and genes can disseminate among environments, animals and humans. Therefore, investigation into potential reservoirs of multidrug-resistant bacteria is of great importance to the understanding of putative transmission routes of resistant bacteria and resistance genes. This study aimed to report the occurrence of Escherichia coli harboring the Klebsiella pneumoniae carbapenemase-producing gene (bla_KPC) in Psittaciformes rescued from wildlife trafficking in Paraíba State, Brazil. Cloacal swabs were collected from thirty birds and cultured by conventional microbiology using MacConkey and serum tryptone glucose glycerol (STGG) media supplemented with selective antimicrobials. E. coli isolates (n = 43) were identified by phenotypic tests and confirmed by MALDI-TOF. Antimicrobial susceptibility profiles were determined by means of Kirby–Bauer test. All isolates were further screened for extended-spectrum beta-lactamase (ESBL) production, and putative genes encoding ESBL were investigated by PCR. Additionally, bla_KPC-harboring strains were genotyped by REP-PCR. A total of 43 E. coli phenotypically resistant isolates were recovered. The highest resistance rate was observed against ciprofloxacin. Among the resistance genes, only bla_KPC was found in seven different birds from three species. According to the genotyping, these seven isolates belonged to four different strains. To date, this is the first report on the occurrence of KPC-E. coli in Psittaciformes rescued from trafficking in Northeastern Brazil. Due to the high clinical importance of KPC-E. coli, our findings suggest that wild animals in captivity at wildlife rescue centers can play a role as reservoirs of bacteria that are resistance to Critically Important antimicrobials in human medicine.

Genomic characterization of enteropathogenic Escherichia coli (EPEC) of avian origin and rabbit ileal loop response; a pet macaw (Ara chloropterus) as a possible zoonotic reservoir

Enteropathogenic Escherichia coli (EPEC) constitutes one of the main causes of mortality in children in low- to medium-income countries. Diverse animal species have been linked as reservoirs, including birds. The aim of this study was to describe the genomic and phylogenetic features of an EPEC recovered from a pet macaw and further characterizing the macro and microscopic lesion in a rabbit ileal loop experimental model. The isolate was whole-genome sequenced (WGS) obtaining its genotypic and phenotypic in silico characteristics and inoculated in a rabbit experimental model with subsequently evaluating the strain's pathogenicity by scanning electron microscopy (SEM) and histopathology. The isolate was characterized as O109:H21-B1-ST40 typical EPEC, harboring several virulence factors of diarrheagenic E. coli. The macaw EPEC genome was located in a monophyletic clade of human and animal ST40 EPEC sequences. In vivo inoculation demonstrated severe hemorrhage with SEM and histopathological analysis confirming these lesions to be associated with intra-epithelial lymphocytes. Therefore, the isolate not only shared several genotypic and phylogenetic similarities with EPEC that affects humans and animals, but was able to induce severe tissue injury in a mammal model. These findings highlight the underrated role of pet birds as zoonotic reservoirs and the diversity in virulence factors being unraveled by new WGS studies.

Antimicrobial susceptibility and detection of virulence-associated genes of Escherichia coli and Salmonella spp. isolated from domestic pigeons (Columba livia) in Brazil

Overpopulation of domestic pigeons is considered to be one of the major problems of urban centers, as these birds are responsible for the dissemination of relevant pathogens to animal and human health. The aim of this study was to detect potentially pathogenic Escherichia coli and Salmonella spp. in domestic pigeons captured in areas near silos used for grain and feed storage, analyzing the antimicrobial sensitivity and the presence of virulence-associated genes. We evaluated 41 pigeons. From each bird, cecal contents and a pool of viscera (heart, spleen, and liver) were collected. Fifty strains of E. coli and three strains of S. Typhimurium were isolated. The antimicrobial susceptibility assay showed that 2% of the isolates of E. coli were resistant to chloramphenicol and the combination of sulfamethoxazole + trimethoprim and 4% to tetracycline, doxycycline, and sulfonamide. The three S. Typhimurium strains were sensitive to all antimicrobials tested. The pathogenicity profile demonstrated that no E. coli isolates showed a STEC compatible profile. Regarding the APEC pathotype, all genes were observed in 8% of E. coli, 6% had only the iss gene and 4% presented ompT, hlyF, and iutA genes. invA, hilA, avrA, and lpfA genes were detected in 100% of Salmonella isolates. The sitC and pefA genes were only present in one strain and the remaining genes were detected in two. In conclusion, it was found that pigeons living in the vicinity of silos are carriers of important pathogens, and control measures should be taken to minimize animal and human health risks.

Captive Green Iguana Carries Diarrheagenic Escherichia coli Pathotypes

The green iguana appears to be a carrier for bacteria causing gastrointestinal infections in humans. The presence of diarrheagenic E. coli (DEC) pathotypes, however, has not been studied in this reptile. The aim of the current work was to investigate the prevalence of DEC in the intestines of 240 captive green iguanas, their phylogenetic groups, and the antibiotic susceptibility profile. E. coli strains were isolated from 41.7% (N = 100/240) of the intestinal content of green iguanas. DEC strains was identified in 25.9% of the screened population and were detected in the majority (62%, p = 0.009) of those reptiles carrying E. coli strains. Among DEC strains, STEC strains carrying the stx1 gene were the most prevalent pathotype isolated (38.7%), followed by EAEC and ETEC (27.4% each). Genetic markers of DEC strains belonging to the EHEC pathotype were not detected. More than a half of DEC strains were classified into the Clade I-II phylogroup (64.5%), followed by the phylogroup A (14.5%). The antibiotic susceptibility method demonstrated that a high proportion of DEC strains were resistance, or non-susceptible, to carbenicillin, amikacin, and ampicillin. We conclude that the green iguana kept in captivity is a carrier of DEC strains bearing resistance to first-line antibiotics, including penicillins. Given the increase presence of the green iguana in Latin American households, these reptiles represent a potential source of transmission to susceptible humans and therefore a potential source of gastrointestinal disease.

Shiga toxin-producing Escherichia coli in the animal reservoir and food in Brazil

Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathotype associated with human gastrointestinal disease that may progress to severe complications. Ruminants, especially cattle, are the main reservoirs of STEC contaminating the environment and foods of animal or vegetable origin. Besides Shiga toxin, other virulence factors are involved in STEC virulence. O157:H7 remains the most frequent serotype associated with disease. In Brazil, the prevalence of STEC reaches values as high as 90% in cattle and 20% in meat products which may impact the Brazilian food export trade. However, only few reports are related to human disease. The stx1 gene prevails in cattle, whereas the stx2 gene is more frequent in food. Several STEC serotypes have been isolated from cattle and food in Brazil, including the O157:H7, O111:NT, NT:H19 as well as O26 and O103 serogroups. O113: H21 STEC strains are frequent in ruminants and foods but with no report in human disease. The virulence profile of Brazilian STEC strains from cattle and food suggests a pathogenic potential to humans, although some differences with clinical strains have been detected. Further studies, employing recent and more discriminative techniques are in need to better clarify their virulence potential.

Shiga-Toxin Producing Escherichia Coli in Brazil: A Systematic Review

Shiga-toxin producing E. coli (STEC) can cause serious illnesses, including hemorrhagic colitis and hemolytic uremic syndrome. This is the first systematic review of STEC in Brazil, and will report the main serogroups detected in animals, food products and foodborne diseases. Data were obtained from online databases accessed in January 2019. Papers were selected from each database using the Mesh term entries. Although no human disease outbreaks in Brazil related to STEC has been reported, the presence of several serogroups such as O157 and O111 has been verified in animals, food, and humans. Moreover, other serogroups monitored by international federal agencies and involved in outbreak cases worldwide were detected, and other unusual strains were involved in some isolated individual cases of foodborne disease, such as serotype O118:H16 and serogroup O165. The epidemiological data presented herein indicates the presence of several pathogenic serogroups, including O157:H7, O26, O103, and O111, which have been linked to disease outbreaks worldwide. As available data are concentrated in the Sao Paulo state and almost completely lacking in outlying regions, epidemiological monitoring in Brazil for STEC needs to be expanded and food safety standards for this pathogen should be aligned to that of the food safety standards of international bodies.

Novel Hybrid of Typical Enteropathogenic Escherichia coli and Shiga-Toxin-Producing E. coli (tEPEC/STEC) Emerging From Pet Birds

Exotic psittacine birds have been implicated as reservoir of diarrheagenic Escherichia coli (E. coli), including enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC). Here, we present a genotypic and phenotypic characterization of typical EPEC/STEC hybrid strains isolated from exotic psittacine birds. The strains were positive for eae, bfpA, and stx2f genes, belong to serotype O137:H6 and ST2678. Two strains were subject to whole genome sequencing, confirming the presence of the virulence factors of both E. coli pathotypes. Phenotypical in vitro tests confirmed their ability to adhere to HeLa cells and cause cytotoxicity to Vero cells. The rabbit ileal loop assays showed the attaching and effacing lesion, in addition to inflammatory process and overproduction of intestinal mucus. This is the first report of hybrid typical EPEC/STEC (O137:H6/ST2678) strains isolated from companion psittacine birds and the results suggest zoonotic risks.

Recent Advances in Shiga Toxin-Producing Escherichia coli Research in Latin America

Pathogenic Escherichia coli are known to be a common cause of diarrheal disease and a frequently occurring bacterial infection in children and adults in Latin America. Despite the effort to combat diarrheal infections, the south of the American continent remains a hot spot for infections and sequelae associated with the acquisition of one category of pathogenic E. coli, the Shiga toxin-producing E. coli (STEC). This review will focus on an overview of the prevalence of different STEC serotypes in human, animals and food products, focusing on recent reports from Latin America outlining the recent research progress achieved in this region to combat disease and endemicity in affected countries and to improve understanding on emerging serotypes and their virulence factors. Furthermore, this review will highlight the progress done in vaccine development and treatment and will also discuss the effort of the Latin American investigators to respond to the thread of STEC infections by establishing a multidisciplinary network of experts that are addressing STEC-associated animal, human and environmental health issues, while trying to reduce human disease. Regardless of the significant scientific contributions to understand and combat STEC infections worldwide, many significant challenges still exist and this review has focus in the Latin American efforts as an example of what can be accomplished when multiple groups have a common goal.

Survey on pathogenic Escherichia coli and Salmonella spp. in captive cockatiels (Nymphicus hollandicus)

We surveyed healthy captive cockatiels (Nymphicus hollandicus) for Escherichia coli and Salmonella spp. Cloacal swabs were collected from 94 cockatiels kept in commercial breeders, private residencies and pet shops in the cities of São Paulo/SP and Niterói/RJ (Brazil). Three strains of E. coli from each individual were tested for the presence of ExPEC-, APEC- and DEC-related genes. We evaluated the bla_TEM, bla_SHV, bla_OXA, bla_CMY, bla_CTX-M, tetA, tetB, aadA, aphA, strAB, sul1, sul2, sul3, qnrA, qnrD, qnrB, qnrS, oqxAB, aac (6)'-Ib-cr, qepA resistance genes and markers for plasmid incompatibility groups. Salmonella spp. was not detected. E. coli was isolated in 10% of the animals (9/94). Four APEC genes (ironN, ompT, iss and hlyF) were detected in two strains (2/27-7%), and iss (1/27-4%) in one isolate. The highest resistance rates were observed with amoxicillin (22/27-82%), ampicillin (21/27-79%), streptomycin (18/27-67%), tetracycline (11/27-41%). Multiresistance was verified in 59% (16/27) of the isolates. We detected strAB, bla_TEM, tetA, tetB, aadA, aphaA, sul1, sul2, sul3 resistance genes and plasmid Inc groups in 20 (74%) of the strains. E. coli isolated from these cockatiels are of epidemiological importance, since these pets could transmit pathogenic and multiresistant microorganisms to humans and other animals.

Identification of Atypical Enteropathogenic Escherichia coli O98 from Golden Snub-Nosed Monkeys with Diarrhea in China

Fecal samples (n = 76) were collected from 38 snub-nosed monkeys (Rhinopithecus roxellana) in Shennongjia National Nature Reserve (China) and examined for the presence of enteropathogenic Escherichia coli (EPEC). The 56 samples originated from 30 free-ranging monkeys on the reserve and 20 samples from 8 captive monkeys that were previously rescued and kept at the research center. Eight diarrhea samples were collected from four of the eight captive monkeys (two samples from each monkey), and two EPEC strains (2.6%) (95% confidence interval 0.3–9.2%) were isolated from two fecal samples from two diarrheic monkeys. Both strains belonged to serotype O98 and phylogenetic group D (TspE4C2⁺, ChuA⁺). The virulence gene detection identified these strains as an atypical EPEC (aEPEC) (bfpB^–, stx1^–, and stx2^–) with the subtype eae⁺, escV⁺, and intiminβ⁺. These strains were highly sensitive to all the antibiotics tested. The lethal dose 50% of the two isolates in Kunming mice was 7.40 × 10⁸ CFU/0.2 mL and 2.40 × 10⁸ CFU/0.2 mL, respectively, indicating low virulence. Based on the report that this serotype had been isolated from some other non-human animals and humans with diarrhea, the first identification of aEPEC O98 strains and their drug resistance profile in R. roxellana is of ecological significance for disease control in this endangered species.