Virulent gene profile and antibiotic susceptibility pattern of Shiga toxin-producing Escherichia coli (STEC) from cattle and camels in Maiduguri, North-Eastern Nigeria

Prevalence and distribution of Shiga toxin-producing Escherichia coli (STEC) serogroups from the faecal samples of cattle and camels slaughter in Maiduguri abattoir and their antibiotic resistance profile of the isolates were determined. The highest prevalence (24%) was recorded in the month of September and more STEC isolates came from cattle than the camels. There was significant (P < 0.05) seasonal trend in the prevalence of STEC among cattle and camel with more cases recorded during the wet season. Although, the study did not demonstrate significant influence of sex from the various sources. The serogroups recorded in this study were O157, O26, O91, O103 and O111. There was no significant difference (P < 0.05) between the detection rates of serogroups. The serogroup O26 was significantly (P < 0.05) the most observed serogroup in both camels and cattle. None of the STEC isolates tested positive for the O45 serogroup. PCR assays shows that 50 (63.3%) of the 86 STEC isolates carried the stx2 gene, 34 (43%) possessed the stx1 gene, and 14 (16.3%) carried both stx1 and stx2 genes. Other genes detected include eae and ehlyA. The antimicrobial resistance among the STEC O157 and non-O157 isolates from cattle and camels in Maiduguri abattoir were very high and the STEC isolates were resistant to at least one or more of the antimicrobial agents tested. There was also multidrug resistance with the most frequent occurring patterns been ampicillin/nalidixic acid and tetracycline/trimethoprim. However, all the 79 isolates were sensitive to chloramphenicol, ceftazidime and ceftriaxone; therefore, these drugs could be drugs of choice in the treatment of STEC infections.