Abstract

This study was conducted on randomly selected 150 samples of soft cheese (Ayib)collected from five vendors of open market places at Jimma town and its surrounding districts: Dedo, Seka, Serbo and Yebu markets to determine microbial quality. Samples were taken three times from the same vendors at different market days with sterile screw cap bottles while categorized into two: leselasa (soft) and derake (dried) soft cheeses.Samples were collected following standard procedures and then cultured on plates of aerobic plate count (APC) agar, violet red bile lactose agar (VRBL agar) and violet red bile glucose agar (VRBG agar) for aerobic mesophilic bacteria, coliforms and Enterobacteriaceae count, respectively. Bacterial identification was done by culturing on selective medium and biochemical test using Bergey’s Manual of Systematic Bacteriology Identification flow chart. The mean count of coliforms, Enterobacteriaceae and aerobic mesophilic bacteria count were 5.709, 6.504 and 8.844 cfu/g, respectively. Significant difference (P<0.05) was observed between places in all microbial count parameters and between categories in coliforms and Enterobacteriaceae count. The dominant bacterial pathogens isolated from Ayib samples in decreasing order were E. coli  (20.67%),Staphylococcus aureus (18.00%), Vibrio spp. (12.67%) and Vibrio parahemolyticus  (12.00%); and also Pseudomonas aeruginosa, Salmonella spp., Staphylococci spp.,Shigella flexneri, and Proteus mirabilis. The high bacteria count, and isolates of different species of pathogenic suggested higher risk of public health and hence the need for improved hygienic practice at all levels during milk production and processing.  

Key words: Ayib, aerobic mesophilic bacteria, coliforms, cottage cheese, Enterobacteriaceae, Jimma.