Sheep as an important source of E. coli O157/O157:H7 in Turkey

Antimicrobial Resistance of Escherichia coli Isolates from Livestock and the Environment in Extensive Smallholder Livestock Production Systems in Ethiopia

The objective of this study was to characterize the distribution of antimicrobial resistance (AMR) of Escherichia coli (E. coli) isolated from livestock feces and soil in smallholder livestock systems. A cross-sectional study was carried out sampling 77 randomly selected households in four districts representing two agroecologies and production systems. E. coli was isolated and the susceptibility to 15 antimicrobials was assessed. Of 462 E. coli isolates tested, resistance to at least one antimicrobial was detected in 52% (43.7-60.8) of isolates from cattle fecal samples, 34% (95% CI, 26.2-41.8) from sheep samples, 58% (95% CI, 47.9-68.2) from goat samples and 53% (95% CI, 43.2-62.4) from soil samples. AMR patterns for E. coli from livestock and soil showed some similarities, with the highest prevalence of resistance detected against streptomycin (33%), followed by amoxycillin/clavulanate (23%) and tetracycline (8%). The odds of detecting E. coli resistance to ≥2 antimicrobials in livestock fecal samples were nearly three times (Odd Ratio-OR: 2.9; 95% CI, 1.72-5.17; p = 0.000) higher in lowland pastoral than in highland mixed crop-livestock production systems. These findings provide insights into the status of resistance in livestock and soil, and associated risk factors in low-resource settings in Ethiopia.

Antimicrobial drug resistance against Escherichia coli and its harmful effect on animal health

Multidrug resistance among pathogenic bacteria is imperilling the worth of antibiotic infection, which has become an emerging problem, which previously transformed the veterinary sciences. Since its discovery, many antibiotics have been effective in treating bacterial infections in animals. Escherichia coli, a bacterium, is one of the reservoirs of antibiotic resistance genes in a community. The current use of antibiotics and demographic factors usually increase multidrug resistance. Genetically, the continuous adoption of environmental changes by E. coli allows it to acquire many multidrug resistance. During the host's life, antimicrobial resistance rarely poses a threat to the E. coli strain and pressure, similar to that of a flexible animal lower intestine. In this review, we describe the E. coli antibiotic drug–resistance mechanism driving transmission, the causes of transmission and the harmful effects on animal health.

An Overview of Shiga-Toxin Producing Escherichia coli Carriage and Prevalence in the Ovine Meat Production Chain

Shiga-toxin producing Escherichia coli (STEC) are zoonotic foodborne pathogens that are capable of causing serious human illness. Ovine ruminants are recognized as an important source of STEC and a notable contributor to contamination within the food industry. This review examined the prevalence of STEC in the ovine food production chain from farm-to-fork, reporting carriage in sheep herds, during abattoir processing, and in raw and ready-to-eat meats and meat products. Factors affecting the prevalence of STEC, including seasonality and animal age, were also examined. A relative prevalence can be obtained by calculating the mean prevalence observed over multiple surveys, weighted by sample number. A relative mean prevalence was obtained for STEC O157 and all STEC serogroups at multiple points along the ovine production chain by using suitable published surveys. A relative mean prevalence (and range) for STEC O157 was calculated: for feces 4.4% (0.2-28.1%), fleece 7.6% (0.8-12.8%), carcass 2.1% (0.2-9.8%), and raw ovine meat 1.9% (0.2-6.3%). For all STEC independent of serotype, a relative mean prevalence was calculated: for feces 33.3% (0.9-90.0%), carcass 58.7% (2.0-81.6%), and raw ovine meat 15.4% (2.7-35.5%). The prevalence of STEC in ovine fleece was reported in only one earlier survey, which recorded a prevalence of 86.2%. Animal age was reported to affect shedding in many surveys, with younger animals typically reported as having a higher prevalence of the pathogen. The prevalence of STEC decreases significantly along the ovine production chain after the application of postharvest interventions. Ovine products pose a small risk of potential STEC contamination to the food supply chain.

First report on Cryptosporidium parvum, Escherichia coli K99, rotavirus and coronavirus in neonatal lambs from north-center region, Algeria

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The etiology of neonatal diarrhea is multifactorial and remains one of the biggest problems in ruminant livestock farming. This study represent the first report in Algeria on Cryptosporidium parvum, Escherichia coli K99, rotavirus and coronavirus in the etiology of neonatal diarrhea in lambs.

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Faecal samples from 559 neonatal lambs aged less than 30 days from 30 sheepfolds were screened with pathogen-specific antigen ELISA for C. parvum, E. coli K99, rotavirus, and coronavirus.

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The prevalence of C. parvum was the highest compared to other enteric pathogens.

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In various combinations, mixed infections were detected only with C. parvum.

The etiology of neonatal diarrhea is multifactorial and remains one of the greatest health problems in sheep livestock farming. Faecal samples from 559 neonatal lambs aged less than 30 days from 30 sheepfolds located in the north-center region of Algeria were screened with pathogen-specific antigen ELISA for Cryptosporidium parvum, Escherichia coli K99, rotavirus, and coronavirus. Of the 559 lambs, 312 (58.81 %), 155 (27.72 %), 72 (12.88 %) and 20 (3.57 %) were positives for C. parvum, E. coli K99, rotavirus and coronavirus antigens, respectively. The prevalence of C. parvum was the highest (p < 0.0001). C. parvum, E. coli K99, rotavirus and coronavirus were observed in 23 (76.66 %), 17 (56.66 %), 9 (30 %) and 3 (10 %) sheepfolds, respectively. Compared to age, the prevalence of C. parvum was highest during the second and third week of age (p < 0.001). In contrast, other pathogens were found to be more frequent in lambs aged ≤7 days (p < 0.001). The number of lambs with diarrhea was 280 (50.09 %) of which 280 (100 %), 127 (45.35 %), 52 (18.57 %) and 10 (3.57 %) were found to be infected with C. parvum, E. coli K99, rotavirus and coronavirus, respectively (p < 0.0001). In various combinations, mixed infections were detected only with C. parvum. This is the first report of C. parvum, E. coli K99, rotavirus, and coronavirus in ≤30-days old neonatal lambs in Algeria. Special attention should be given to the first colostrum feeding, hygiene of the farm, prevention and control measures for a better prevention of neonatal diarrhea in lambs.

Escherichia coli O157:H7: distribution, molecular characterization, antimicrobial resistance patterns and source of contamination of sheep and goat carcasses at an export abattoir, Mojdo, Ethiopia

BACKGROUND

Cattle have been identified as a major reservoir of E. coli O157:H7 for human infection; the ecology of the organism in sheep and goats is less understood. This study was carried out to determine prevalence, source of infection, antibiotic resistance and molecular characterization of Escherichia coli O157: H7 isolated from sheep and goat.

METHODS

Systematic random sampling was carried out at Modjo export abattoir, Ethiopia, from November 2012 to April 2013 to collect 408 samples from 72 sheep and 32 goats. Samples collected were skin swabs, fecal samples, intestinal mucosal swabs and the inside and outside part of carcasses as well as carcass in contacts such as workers hands, knife, hook and carcass washing water. Then, samples were processed following standard bacteriological procedures. Non-Sorbitol fermenting colonies were tested on latex agglutination test and the positives are subjected to PCR for detection of attaching and effacing genes (eaeA) and shiga toxin producing genes (stx1 and stx2). All E. coli O157:H7 isolates were checked for their susceptibility pattern towards 15 selected antibiotics.

RESULTS

E. coli O157:H7 were detected in only 20/408 samples (4.9%). Among these 20 positive samples, 70% (14/20), 25% (5/20) and 5% (1/20) were from sheep, goats and knife samples, respectively. No significant associations were found between carcasses and the assumed sources of contaminations. Of all the 20 isolates virulence genes were found in 10 (50%) of them; 3 (15%) with only the eaeA gene and 7(35%) expressing eaeA and stx2 genes. All the isolates were susceptible to Norfloxacin (NOR) (100%).

CONCLUSIONS

The presence of virulence genes shows E. coli O157:H7 is a potential source of human infection in Ethiopia.

Plasmid-Mediated Colistin Resistance in Escherichia coli O157:H7 Cattle and Sheep Isolates and Whole-Genome Sequence of a Colistin-Resistant Sorbitol Fermentative Escherichia coli O157:H7

The aims of this study were to investigate the plasmid-mediated colistin resistance genes (mcr-1, mcr-2, mcr-3, mcr-4, and mcr-5), phenotypic colistin resistance in Escherichia coli O157:H7⁺/H7^- strains isolated from cattle and sheep, and whole-genome sequence (WGS) analysis of colistin-resistant sorbitol fermentative E. coli O157:H7. According to the results, 5 of the 49 isolates were found to harbor mcr-2 and/or mcr-3 genes. Three isolates, including a sorbitol fermentative E. coli O157:H7, were found phenotypically resistant to colistin with a minimum inhibitory concentration value of 128 μg/mL. The genome of sorbitol fermentative E. coli O157:H7 did not show 100% similarity to any of the other genome sequences found in the universal genome database. It has also been determined that this isolate carried 62 different antimicrobial resistance genes. This is the first report of plasmid-mediated mcr-2 and mcr-3 genes carrying E. coli O157:H7 from cattle and sheep isolates and WGS of a colistin-resistant sorbitol fermentative E. coli O157:H7. Findings of this study indicate that cattle and sheep can be an important source of colistin resistance in E. coli O157:H7, and slaughterhouse wastewater might be a significant route for dissemination of the plasmid-mediated colistin genes. Therefore, the use of colistin in veterinary medicine should be restricted to reduce the development of resistance. Also it may be necessary to review the non-sorbitol fermentation-based isolation protocol for not missing the sorbitol fermentative E. coli O157:H7 in epidemiological studies.

Prevalence and pathogen load of Campylobacter spp., Salmonella enterica and Escherichia coli O157/O145 serogroup in sheep faeces collected at sale yards and in abattoir effluent in Western Australia

OBJECTIVE

Develop a multiplex quantitative PCR assay to investigate the prevalence and shedding of Escherichia coli O157/O145, Salmonella spp. and Campylobacter spp. in sheep at sale yards and abattoirs.

METHODS

A qPCR for E. coli O157/O145 was developed, validated and multiplexed with an existing qPCR for Campylobacter and Salmonella enterica. The absolute numbers of E. coli O157/O145, Campylobacter and Salmonella in control samples was determined using droplet digital PCR. These were then used as the controls in the multiplex qPCR on a total of 474 sheep faecal samples collected from two saleyards over a 4-month period (April-July 2014) and 96 effluent samples from an abattoir.

RESULTS

The mutiplex qPCR was specific with a sensitivity of 5 organisms/μL faecal DNA extract for Campylobacter, S. enterica and E. coli O157/O145. The overall prevalence of Campylobacter, S. enterica and E. coli O157/O145 in faecal samples was 5.7%, 3.6% and 8.4% and in effluent samples was 18.8%, 6.3% and 5.2%, respectively. The pathogen loads of Campylobacter, S. enterica and E. coli O157/O145 in faecal and effluent samples was also determined via mutiplex qPCR.

CONCLUSIONS

The overall prevalences of Campylobacter, S. enterica and E. coli O157/O145 were generally low (<6%), but point prevalences ranged considerably in healthy sheep (up to 26% for E. coli O157/O145). Further work to determine risk factors for shedding of bacterial organisms in meat sheep in the pre-slaughter period (on-farm, sale yards and lairage at abattoirs) could further reduce the risk of contamination of meat products.

Escherichia coli, cattle and the propagation of disease

Several early models describing host–pathogen interaction have assumed that each individual host has approximately the same likelihood of becoming infected or of infecting others. More recently, a concept that has been increasingly emphasized in many studies is that for many infectious diseases, transmission is not homogeneous but highly skewed at the level of populations. In what became known as the ‘20/80 rule’, about 20% of the hosts in a population were found to contribute to about 80% of the transmission potential. These heterogeneities have been described for the interaction between many microorganisms and their human or animal hosts. Several epidemiological studies have reported transmission heterogeneities for Escherichia coli by cattle, a phenomenon with far-reaching agricultural, medical and public health implications. Focusing on E. coli as a case study, this paper will describe super-spreading and super-shedding by cattle, review the main factors that shape these transmission heterogeneities and examine the interface with human health. Escherichia coli super-shedding and super-spreading by cattle are shaped by microorganism-specific, cattle-specific and environmental factors. Understanding the factors that shape heterogeneities in E. coli dispersion by cattle and the implications for human health represent key components that are critical for targeted infection control initiatives.

Use of Bacteriophages to Control Escherichia coli O157:H7 in Domestic Ruminants, Meat Products, and Fruits and Vegetables

Escherichia coli O157:H7 is an important foodborne pathogen that causes severe bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Ruminant manure is a primary source of E. coli O157:H7 contaminating the environment and food sources. Therefore, effective interventions targeted at reducing the prevalence of fecal excretion of E. coli O157:H7 by cattle and sheep and the elimination of E. coli O157:H7 contamination of meat products as well as fruits and vegetables are required. Bacteriophages offer the prospect of sustainable alternative approaches against bacterial pathogens with the flexibility of being applied therapeutically or for biological control purposes. This article reviews the use of phages administered orally or rectally to ruminants and by spraying or immersion of fruits and vegetables as an antimicrobial strategy for controlling E. coli O157:H7. The few reports available demonstrate the potential of phage therapy to reduce E. coli O157:H7 carriage in cattle and sheep, and preparation of commercial phage products was recently launched into commercial markets. However, a better ecological understanding of the phage E. coli O157:H7 will improve antimicrobial effectiveness of phages for elimination of E. coli O157:H7 in vivo.

Dissemination of intestinal pathogens between lambs and puppies in sheep farms

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Rotavirus was detected in samples from lambs with diarrhoea.

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Salmonella enterica subsp. diarizonae was isolated in samples from lambs with diarrhoea.

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Antibiotic resistance was detected in >60% of Escherichia coli strains isolated in the study.

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Escherichia coli with identical antibacterial resistance were detected in lambs and puppies.

Objectives of the present work were (i) to confirm pathogens implicated in cases of diarrhoea in newborn and young lambs in sheep farms in Greece and (ii) to investigate a possible relation in dissemination of pathogens between lambs and dogs present in the farm. Work was carried out in 22 sheep farms, with (i) flock size over 150 animals, (ii) presence of clinical signs of diarrhoea in lambs in the flock and (iii) close and continuous contact and movement of shepherd dogs within the animal shed of each farm. Faecal sample collection from lambs was performed within 48 h of onset of clinical signs and prior to administration of any antimicrobial or antiparasitic medication to lambs. Faecal samples were also collected from puppies in the farm. In total, samples were collected from 126 lambs and 58 puppies. Samples were processed by using established techniques for isolation of bacteria, detection of viruses and observation of protozoan oocycts. Escherichia coli isolates obtained during the study, were tested for antimicrobial resistance against a variety of antimicrobial agents. In total, 236 bacterial isolates were recovered from faecal samples of lambs and 165 isolates from faecal samples of puppies. E. coli was the most frequently isolated microorganism: 104 isolates from lambs and 109 isolates from puppies were recovered. Other bacteria isolated were Enterobacter spp., Proteus spp., Klebsiella spp., (lambs and puppies), Clostridium perfringens, Citrobacter freundi, Salmonella enterica subsp. diarizonae (only lambs) and Streptococcus spp. (only puppies). Group A Rotavirus was detected in samples from lambs (2.5%) and Parvovirus in samples from puppies (5%). Cryptosporidium spp. oocysts were observed in samples from lambs and puppies. This is the first report of isolation of S. enterica subsp. diarizonae and of detection of Rotavirus from lambs in Greece. Rates of E. coli isolates from puppies resistant to antimicrobial agents were, in general, smaller than respective rates in isolates from lambs. Two pairs of isolates from the same farm (one from a lamb and one from a puppy) with identical patterns of resistance to antimicrobial agents were detected, which provides some evidence in support of a hypothesis that members of each pair might possibly have been spread from one animal species to the other.

Investigation of enteropathogenic Escherichia coli and Shiga toxin-producingEscherichia coli associated with hemolytic uremic syndrome in İzmir Province, Turkey

BACKGROUND/AIM

The purpose of this study was to investigate Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) strains originating from diarrheagenic patients.

MATERIALS AND METHODS

A total of 102 patients with diarrhea between October 2012 and January 2013 were enrolled in this study. Multiplex and standard polymerase chain reactions were performed to detect and distinguish STEC and EPEC strains. O serotyping of EPEC was carried out by monovalent antisera. The O and H serotyping of STEC strains was performed at the Refik Saydam Institute, Ankara.

RESULTS

A total of 5 (3.42%) strains were identified as STEC, and 3 strains (2.05%) were atypical EPEC. One of the STEC serotypes was O157:H7 carrying VT1, Stx1A, and escv genes. The other STEC strain was identified as O174:H21, which is associated with hemolytic uremic syndrome and consists of VT2 and Stx2A genes. One of the EPEC and three of the STEC serotypes were nontypeable. The serotypes of the atypical EPEC strains were identified as O114 and O26.

CONCLUSION

To the best of our knowledge, this is the first report of O174:H21 from the İzmir region that was shown to be a Shiga toxin-producing non-O157 serotype of STEC.

Antimicrobial and disinfectant resistance of Escherichia coli isolated from giant pandas

AIMS

The study aims to demonstrate the antimicrobial and disinfectant resistance phenotypes and genotypes of Escherichia coli isolates obtained from giant pandas (Ailuropoda melanoleuca).

METHODS AND RESULTS

Antimicrobial testing was performed according to the standard disk diffusion method. The minimal inhibitory concentrations (MICs) of disinfectants were determined using the agar dilution method. All isolates were screened for the presence of antimicrobial and disinfectant resistance genes and further analysed for genetic relatedness by pulse-field gel electrophoresis (PFGE). Results showed that 46·6% of the isolates were resistant to at least one antimicrobial. Escherichia coli isolates showed resistance to fewer antimicrobials as panda age increased. Among antimicrobial-resistant E. coli isolates, the antimicrobial resistance genes blaCTX-M (88·2%) and sul1 (92·3%) were most prevalent. The disinfectant resistance genes emrE, ydgE/ydgF, mdfA and sugE(c) were commonly present (68·2-98·9%), whereas qac and sugE(p) were relatively less prevalent (0-21·3%). The frequencies of resistance genes tended to be higher in E. coli isolated in December than in July, and PFGE profiles were also more diverse in isolates in December. The qacEΔ1 and sugE(p) genes were higher in adolescent pandas than in any other age groups. PFGE revealed that antimicrobial resistance correlated well with sampling time and habitat.

CONCLUSIONS

This study demonstrated that antimicrobial and disinfectant resistance was common in giant panda-derived E. coli, and the antimicrobial resistance was associated with sampling time and habitat. Escherichia coli could serve as a critical vector in spreading disinfectant and antimicrobial resistance.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study that demonstrated the phenotypic and genetic characterizations of antimicrobial and disinfectant resistance in E. coli isolates from more than 60 giant pandas. Frequent transfer of pandas to other cages may lead to the dissemination of antimicrobial resistance. The study highlights the need for regularly monitoring the antimicrobial and disinfectant resistance in bacteria from giant pandas.