BACTERIOLOGICAL ANALYSIS OF MILK SOLD IN KATHMANDU AND ANTIBIOTIC SUSCEPTIBILITY PATTERN OF Staphylococcus species ISOLATED FROM MILK

Abstract

Milk is a rich source of nutrients. Milk –borne pathogenic bacteria pose a serious threat to human health. Staphylococcus aureus, Salmonella spp., Listeria monocytogenes with Escherichia coli and Campylobacter are the main microbial hazards associated with contaminated milk. Therefore, it can cause milk borne diseases like scarlet fever, Brucella, diphtheria typhoid etc. This study was conducted to assess and compare microbial quality of raw milk and pasteurized milk and also determine the antimicrobial susceptibility of Staphylococcus species isolated from milk sample consumed in Kathmandu. For this, 30 milk samples (15 raw milk and 15 pasteurized) were collected from different location of Kathmandu district. Total Plate Count and Total Staphylococcus Count for each sample were determined by pour plate technique. While for isolation of Staphylococcus species, samples were isolated by using selective media (MSA) and characterized by biochemical test. Antibiotic susceptibility testing of isolates was carried out by Kirby Bauer disk diffusion method. Total bacterial count of all raw milk samples were within the range while for TBC of pasteurized milk 93% were within the range. 17 Staphylococcus species were isolate from TSC. Among them 15 were identified as Staphylococcus aureus. 17 Staphylococcus species were 100% sensitive to Cotrimoxazole, Amikacin and Levofloxacin but resistant to Penicillin G (100%),Ceftriaxone (52.92%), Tetracycline (17.68%), Cefoxitin (23.58%), Ampicillin (76.82%) Ciprofloxacin (17.68%) and Chloramphenicol (11.79%). 3(17.68%) of Staphylococcus aureus isolated from raw milk samples showed multi-drug resistance and 4(23.58%) MRSA were detected. It is concluded that the milk produced by small scale farm from different places of Kathmandu district are not of quality and can be potential source of milk-borne infection. It is recommended that routine assessment of microbial quality of milk should be done for the safeguard of consumer health.