Detection of Verocytotoxigenic <i>Escherichia coli</i> O157 Serotype in Dairy Products in Abuja, Nigeria

Abstract

Ruminants are recognized as healthy carriers of Verocytotoxigenic Escherichia Coli (VTEC) organisms and as such most dairy products may provide these bacteria with favourable conditions for their growth. A cross sectional study was conducted to detect the occurrence of VTEC O157 in dairy products in the Federal Capital Territory, Abuja, Nigeria. Raw milk, Nunu and yoghurt were analyzed using standard cultural and biochemical procedures to isolate typical E. coli. Isolated E. coli samples were sub-cultured into plates of sorbitol MacConkey and Cefixime Tellurite-Sorbitol MacConkey agar. Isolates that are sorbitol negative were further characterized using commercially procured latex agglutination test kits. A total of 367 samples were analyzed out of which 3 tested positive for VTEC O157 (108 of raw milk -1 (0.93%); 127 of Nunu -2 (1.57%) and 132 of yoghurt -none). There was no significant association (p > 0.05) between season and infection with VTEC O157 in dairy products. Dairy products remained a potential vehicle for VTEC O157 infection.

Sorbitol non-fermenting Escherichia coli and E. coli O157: prevalence and antimicrobial resistance profile of strains in slaughtered food animals in Southeast Nigeria

“…However, no E. coli O157 was detected among SN-F E. coli isolates from chickens in Jos Plateau State, Northcentral Nigeria [17]. The absence of E. coli O157 in cattle in this study contrasts previous reports in cattle/dairy products sampled in Northcentral Nigeria in which phenotypic E. coli O157 prevalence ranged from 0.43-67.5% [13,19,20,28] and in Southsouth Nigeria where 6.94-28% E. coli O157 prevalence rate was reported [18,29]. In Southwestern Nigeria, phenotypic E. coli O157 prevalence rate reported in cattle/beef ranged from 3.9-28% [23,30].…”

Detection of Verocytotoxin-Producing Escherichia Coli in Raw and Fermented (Nono) Milk in Sokoto Metropolis, Sokoto State, Nigeria.

“…This study confirmed the presence of VTEC in raw and fermented milk in Sokoto metropolis. The prevalence of VTEC in raw milk from this study is higher than 0.9% and 2.0% found in Abuja (Enem et al, 2015) and Ogun State (Ivbade et al 2014) respectively. And lower than the 9.4% reported in Sokoto (Yakubu et al 2018).…”

“…Cattle are known to be the major reservoirs of the organism and can actively shed the organism in faeces without manifestation of clinical signs (Leedom, 2006;Neher et al, 2015);Thus, there is high tendency of milk contamination following unsanitary collection from disease animals or herds with carrier of the organism. Predominance of stx2 (94.4%) in this study is related to the studies conducted in Ogun State Nigeria, India and Switzerland, where frequency of stx2 was more against other gene (Stephan et al, 2008;Vendramin et al, 2014;Enem et al, 2015). Higher frequencies of stx2 positive isolate can be of a public health concern as the strains that express stx2 were most likely associated with HUS in human (Enabulele & Nwankiti, 2016).…”

“…N=Z2p(1-q) /d2 (Thrushfield; 2007) Where, N=Sample Z= the standard normal deviate corresponding to a two-sided level of significant of 5% (1.96) p=Expected prevalence q= 1-prevalence d= is the desired level of precision (usually at 5% for single proportion) = 0.05 Based on previous prevalence of 9.6% for fermented milk (Ivbade et al 2014) and 7.3% for raw milk (Enem et al, 2015); the estimated sample size for fermented milk was 134 samples and for raw milk was 104 samples.…”

“…Non ruminant animals such as pig and pigeons are also reported to becomes reservoirs of VTEC, and these may harbour and shed VTEC while asymptomatic (Ateba & Bezuidenhout., 2008). Raw milk can be contaminated with animal faeces and become good source of human infection if consumed without proper pasteurization (Enem et al, 2015). However, people are vulnerable to HUS after direct contact with faeces or consumption of animal products that are contaminated such as meat, milk and milk products (Lupindu et al, 2018).…”