Salmonella and risk factors for the contamination of cattle carcass from abattoir of Mekelle City, Ethiopia

The objective of this study was to assess the incidence of Salmonella species and identify the risk factors for the presence of Salmonella and E.coli on cattle carcasses of Mekelle abattoir. A total of 96 swab samples were collected from hind limb, abdomen and neck of 32 randomly selected cattle and taken in an icebox to laboratory for microbial analysis. Analyses were done within 1 h of sample collection. Swab samples were homogenized by manually shaking with 10 ml of sterile peptone water and transferred to Selenite Cystine Broth prior for inoculation onto xylose-lysine deoxycholate agar. The plates were incubated under aerobic atmosphere at 37°C and examined after 24 h. The mean aerobic count of hind, abdomen and neck found were 2.40, 2.37 and 2.33 with overall mean of log CFU/100 cm2 2.37. Of the 32 oxen/cows included in the study, 4 (12.5%) of them were found positive for the presence of Salmonella. The occurrence of Salmonella in the neck was found to be higher compared to other parts of the carcass. Of the 96 swab samples, 18 swab samples from 6 cattle neither their hind limp and abdomen nor their neck was positive for the presence of E.coli. However, 19 hind limb, 18 of the abdomen and 18 of neck were found to be positive for the presence of E.coli. The bacteriological swab tests of the carcass parts also showed that the meat contained aerobic mesophilic bacteria and pathogenic microorganisms which show lack of hygienic condition and improper handling of the cattle before slaughtering.