Antimicrobial Susceptibility Pattern of Enteric Bacteria from Fresh cow milk and handlers in Zaria Metropolis, Kaduna State Nigeria

Abstract

A bacteriological examination of raw cow milk for the isolation of enteric based bacteria was conducted on milking cows and their handlers from selected farms in four Local Governments in Zaria, Kaduna State. The aim of the study was to check the quality of the raw cow’s milk and also verify the rate of contaminations of the raw cow’s milk from external sources which are regarded as environmental pathogens during and after milking processes. A total of 105 samples; 42 raw milks from lactating cows, 42 swabs from cow teat, 16 swabs from herd handlers and 5 samples from water used in the cleaning process were obtained. The raw milk samples were screened using a Methylene dye reagent to check its microbial load before analysis began, the total bacteria count (TBC) and total coliform count (TCC) were analyzed using the standard cultural methods. The isolates were identified using the standard biochemical procedure and Microgen TM System (GN-ID A+B Kit). Results revealed that one hundred and two (102) bacteria consisting of Seventy-six (76) Polymicrobial and twenty-six (26) single cultures were recovered as positive culture while three (3) had no growth. The mean TBC and TCC of raw milk observed in this study were 2.56 ± 0.40 x104cfu/ml and 1.06 ± 0.16 x104cfu/ml respectively. Acinetobacter iwoffi and other members of Enterobacteriaceae isolates were resistant to tetracycline (68.75%), erythromycin (71.74%) and metronidazole (100%), while high susceptibility was observed to gentamicin (94.34%) and chloramphenicol (80.85%). High bacterial contaminations including Multidrug-resistant bacteria were observed in this study, contaminations were majorly from improper pre and post dipping processes and the use of non-portable water