Bacteriological Quality and the Antibiogram of Isolates from Raw Cow Milk Produced in Ibadan Metropolis Oyo State, Nigeria
Abstract
This study aimed at evaluating the bacteriological quality as well as the antibiogram (antibiotic sensitivity profile) of organisms isolated from raw cow milk produced in Ibadan metropolis. Raw cow milk samples were collected from University of Ibadan Research farm, Bodija, Sabo and Akinyele cow settlement ibadan. Bacterial counts, isolation and phenotypic identification of bacterial isolated from the assessed raw cow milk were determined using standard procedures. Antibiotic sensitivity tests was carried out by disc diffusion method. The total bacterial counts and total coliform counts ranged between 0.9×106 to 4.5×106 CFU/ml and 0.4×106 to 4.2×106 CFU/ml, respectively. Fourty-two (42) bacterial isolates were identiifield as Staphylococcus aureus (16), Escherichia coli (8), Salmonella typhimurium (6), Shigella dysentriae (6), Enterobacter aerogenes (4) and Serretia marcescens (2). Based on the antibiogram, S. aureus, E. coli , S. typhi and S. dysentriae had 100% resistance to Tetracycline, Gentamycin and Nitrofurantoin while Serratia marcescens strains had 100% susceptibility to all the antibiotic except Nitrofurantoin which had 50% susceptibility and Tetracycline which had 100% resistance. All of the E.coli isolates were resistance to tetracycline. The raw cow milk samples analysed exceeded the WHO microbiological standard of 1.0×105 CFU/mL and 3.0×101 CFU/mL for total bacteria count and coliform count for raw milk respectively. The antibiogram studies revealed that some bacteria isolates were resistant to most of the antibiotics used. This may pose a high risk of milk borne illnesses among consumers and put them at risk of being infected with antibiotic resistant strains of pathogenic bacteria. There is utmost need for an awareness program with a follow up mechanism to educate dairy farmers and handlers on hygienic production practices and discourage the indiscriminate use of antibotics to have a wholesome milk
Keywords: Antibiogram, Bacteriological quality, Cowmilk, Bacterial isolates, Pathogens