Faecal Carriage of Escherichia coli 0157:H7 Serotype by Free-Ranged and Confined Small Domestic Ruminants within Cross River State, Nigeria

Abstract

Background: The type of animal grazing method to be promulgated into the Federal Legal System has been an issue of controversy following incessant Farmers/Herdsmen clashes in Nigeria. The method to be adopted has to ensure a drastic reduction of common pathogens associated with the consumption of meat and its products notably Escherichia coli O157:H7. This pathogen has regularly been isolated from cattle by researchers while scanty information exists implicating small domestic ruminants especially in Cross River State, Niger Delta Region of Nigeria where ruminant meat is highly consumed. Similar studies on this pathogen associated with small domestic ruminants do not take into consideration all the different grazing methods practiced. Aim: This study was aimed at investigating the effects of two commonly used grazing methods (free-ranging and confined grazing) on the potentials of fecal carriage of Escherichia coli 0157:H7 by sheep and goats in different locations within Cross River State, Nigeria. Methodology: A total of 360 fresh recto-anal faecal swap samples each were collected from both confined (penned) and free- ranging goats and sheep within a 5-months sampling duration. Combined culture and serological methods such as growth on sorbitol macconkey agar supplemented with cefixime and tellurite (SMAC-CT), nonfluorescence of 4-Methylumbilliferyl- D-Glucoronide (E. coli-MUG) cultures under uv light at 650nm wavelength, serological identification using ELISA technique and H typing with standard E. coli H7 rabbit antisera were used in the isolation and identification of the pathogen.  Results: Among the various groups of domestic ruminants, free-ranged and confined sheep had highest overall prevalence of 31/180 (17.22%) and 12/180 ( 6.67%) respectively compared to free-ranged and confined goats with overall values of 19/180 ( 10.50%) and 9/180 (5.00%) respectively. Prevalence rates showed no significant difference (P = .05) between confined goats and sheep while significant difference (P =.05) was observed between the free-ranged groups. Also, the monthly values differed significantly at P = .05 between the free-ranged and confined groups. Conclusion: Confined grazing of ruminants in pens (ranching) significantly reduced the transmission of E. coli O157:H7 by goats and sheep which were highly implicated as possible vehicles within Cross River State, Nigeria.