Isolation and Identification of Gram-Positive and Gram-Negative Bacteria from Different Types of Cheese in Baghdad’s Local Markets

Abstract

The current study was undertaken to determine the occurrence of different types of bacteria in cheese samples. A total of 100 samples of white cheese were collected from different locally supermarkets. Plate Count Agar was used to determine the total Counts of the samples. Ten milliliters of the pre-enrichment, sample were incubated in Petri dishes from Violet Red Bile Agar (VRBA), Mannitol Salt agar, and Xylose Lysine Deoxycholate agar (XLD agar) mixing vigorously to ensure homogeneity. The agar was put upside-down in the laboratory incubator that was set to 37°C overnight. Plates with 20 to 300 colonies were counted using Manual Colony Counter with a 100mm magnifying glass. The results of current survey based on microbial plate counts showed that there are different types of bacteria present in different kinds of cheese samples. The most predominant bacterial species isolated from cheese were E. coli and Staphylococcus aureus in which a considerable number of contaminations with these bacteria were detected. The current study demonstrated a high number of bacterial isolates particularly E. coli and S. aureus in the cheese samples as a result of poor cheese manufacturing and storage conditions, inadequate refrigeration, and a lack of quality control measures throughout transportation.