MICROBIAL CONTAMINATION OF YOGURT SOLD AT THE UNIVERSITY OF BENIN, BENIN CITY

ABSTRACT

Yogurt is a fermented dairy product that undergoes bacterial fermentation of milk, and it is consumed throughout the world. Contamination of yoghurt exposes consumers to various health risks resulting from consumption of pathogens. In this study, microbial contamination of yogurt was evaluated. The bacterial isolates were tested and identified using morphological and biochemical methods and sugar fermentation test. The percentage distribution and frequency of the isolates were evaluated using statistical method. From the result obtained in this study, the bacterial colony ranged from 2.4843±2.00 (Log10 cfu/ml) to 2.60206±1.00 (Log10 cfu/ml) also the Log10 cfu/ml fungal count ranges from 1.954243±0.5 to 2.230449±2.00 (Log10 cfu/ml). Using standard cultural, morphological and biochemical characterization of bacteria, the isolates obtained were Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, Shigella sp. and Lactobacillus sp. and the fungal species obtained were Aspergillus niger, Mucor sp, Penicillium sp and Aspergillus fumiatus The isolates obtained were subjected to antibiotic test,based on the results. it shows that all isolates were resistant to some antibiotics namely colistin, erythromycin, tetracyclin, methronidazole and clindamycin, however they were susceptible to ciprofloxacin, augmentin and gentamicin. The resistivity of the bacterial isolates against antibiotics is a subject of concern to human health.