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

Abstract

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. Key words : Abattoir, antibiotic sensitivity, CT-SMAC, E. coli O157:H7, IMS, Latex agglutination, multiplex PCR.

Escherichia coli O157 : H7 from Food of Animal Origin in Arsi: Occurrence at Catering Establishments and Antimicrobial Susceptibility Profile

“…In Ethiopia, a country which ranks second after Nigeria in the health burden of zoonotic diseases in Africa [28], the epidemiology of food-borne pathogens especially that of pathogenic E. coli is not well studied. However, recently, there is an increasing trend of reporting the occurrence level of the organism in beef, dairy products, and fish [2,3,9,16,[29][30][31][32][33][34][35][36][37]. Besides this, current and detailed studies on the prevalence of antibiotic resistance and multidrug phenotypes of enterohemorrhagic E. coli O157 : H7 in foods of animal origin in different catering establishments are very limited in Ethiopia except for the report of [2,3,9] on beef at butcher shops and restaurants and raw milk and dairy products such as yogurt and cheese derived from raw milk at cafeterias, restaurants, open markets, and supermarkets in Central Ethiopia.…”

Review on Major Food-Borne Zoonotic Bacterial Pathogens

“…Most of E. coli are normal inhabitants of the gastrointestinal tract (lower ileum and large intestine) of animals and humans [23,131,132], while others are pathogenic to humans [133]. E. coli are of zoonotic in nature and constitute a public health hazard [134].…”

“…is strain is an important emerging food-borne pathogen of humans causing outbreaks worldwide [3,138]. Outbreaks have been reported from different countries of the world including the United States, Canada, Asia, Australia, Europe [23], and different African countries, stretching from South to East and West parts of the continent [131]. It has been indicated that an estimated 74,000 cases and 61 deaths annually are attributable to E. coli O157:H7 in the USA [17].…”

“…However, some strains can cause diseases [136]. Cattle are the major reservoirs of E. coli O157:H7 [3,8,131,133,139] followed by sheep and goats [137].…”

“…e role of small ruminants as a source of human infection through fecal shedding is being reported in a number of studies [131]. e organisms are also isolated from horses, dogs, and deer [3].…”