International Journal of Vaccines and Vaccination Prevalence and serological detection of Enterohaemorrhagic Escherichia coli O157 serogroup in commercial cattle farms in Kaduna State, Nigeria Submit Manuscript | http://medcraveonline.com Volume 2 Issue 6 - 2016 1 Department of Veterinary Microbiology and Parasitology, University of Maiduguri, Nigeria 2 Department of Veterinary Pathology and Microbiology, Ahmadu Bello University, Zaria, Nigeria *Corresponding author: Musa JA, Department of Veterinary Microbiology and Parasitology, University of Maiduguri, Nigeria, Tel: +234 8030575355; +234 8025355408; Email: Received: August 07, 2016 | Published: October 18, 2016 Research Article Int J Vaccines Vaccin 2016, 2(6): 00053 Abstract Objectives: To determine the prevalence and to detect the presence of Escherichia coli O157 serogroup in commercial cattle farms in Kaduna State, Nigeria. Methods: A total of 240 faecal samples were obtained from eight randomly selected commercial cattle farms and then placed in tryptose soya broth (TSB). Thereafter, the faeces were inoculated onto sorbitol MacConkey agar (SMAC) to identify non-sorbitol fermenting (NSF) colonies, and then sub cultured onto eosin methylene blue agar (EMB). Escherichia coli O157 agglutination test for the identification of E. coli O157 antigen was carried out with O157 latex kit (Oxoid). This involved mixing the isolates with 2 ml of 0.85% saline solution separately, followed by the addition of test antigens to observe for agglutination. Results: Colonies on SMAC appeared phenotypically colourless and were presumptive for E. coli O157, while those on EMB gave the characteristic greenish metallic sheen for E. coli. Of the 240 faecal samples, E. coli colonies of seventy six (31.2%) were confirmed by Gram staining and biochemical testing using Indole, Methyl red, Voges Proskauer and Citrate (IMViC). Characterization of the E. coli isolates detected two O157 serogroups from two apparently healthy cattle. The prevalence of E. coli O157 was found to be 0.8%. Association between the serogroup and source of samples (farms) was significant (P<0.05). The study confirmed that cattle are important source of enterohaemorrhagic E. coli and may pose a risk to humans who come in contact with cattle faeces in areas of Kaduna State, Nigeria. Conclusion: Escherichia coli O157 serve as a threat to human health. The differences in the dynamics of disease may contribute to disparity in prevalences. Good hygienic measures on the farms are essential in limiting the transmission of E. coli to in-contact individuals. Keywords: Detection; Enterohaemorrhagic; E. coli O157; Serogroup; Prevalence; Cattle; Kaduna; Nigeria Introduction The term ‘Enterohaemorrhagic Escherichia coli’ (EHEC) was originally used to describe strains that cause haemorrhagic colitis (HC) and haemolytic-uraemic syndrome (HUS), express shiga-toxins (Stx), cause attaching and effacing (A/E) lesions on epithelial cells and possess large plasmid [1]. On the other hand, they are known as Shiga toxin-producing Escherichia coli (STEC); foodborne pathogens that are associated with human illnesses that could be life-threatening in nature [2]. They have emerged through the production of shiga toxins; stx 1 and stx 2 and other probable virulence factors such as intimin gene (eae) and enterohaemolysin (ehly) [3-4]. The major and the most essentially suggested cardinal feature of EHEC strains is the production of shiga toxins (stx1 and stx2), which comprise a family of structurally related cytotoxins with similar biological activity and distinct antigenic structures [1]. The colonization of the intestinal mucosa by most of the EHEC is associated with a mechanism that subverts the function of the epithelial cells. The effect of this interaction is the inducement of a characteristic “attaching and effacing” (A/E) lesion, a complex mechanism genetically controlled by a locus of large pathogenicity island (PAI) called the “locus of enterocyte effacement (LEE)”. Intimin mediates the intimate attachment of EHEC by binding to β1-integrins and to cell-surface localized nucleolin [5]. The EHEC can cause diarrhoea, HC and HUS in children less than five years of age, the elderly and the immunocompromised individuals [6,7]. Escherichia coli (E. coli) O157 was first associated with HC in humans in 1982 and was earlier isolated and reported in cattle with substantial evidence provided by serological studies that, E. coli O157:H7 is widely spread in cattle [8,9]. Escherichia coli O157 in human infections may either be waterborne, food borne or consumption of food and water contaminated by faeces of ruminants, direct contact with infected animals or human-to-human transmission [10]. In EU member states, data on STEC in cattle and beef products are poor. There has been low isolation rate for positive samples were 0.1 per cent for STEC O157 and low levels of microorganisms [11]. Enterohaemorrhagic E. coli is a diverse group of food borne zoonotic pathogens of which O157:H7 is a major public health concern and is reported as an emerging infectious agent [12,13].