Studies on Prevalence of Coliform Bacteria with Special Reference to Shiga-toxigenic Escherichia coli (STEC) in Market Milk and Milk Products
Loading...
Date
2019
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
SKUAST Kashmir
Abstract
The present study was carried out to determine hygienic quality of milk and milk products, with special reference to coliform and E. coli count. Prevalence of E. coli including STEC was also determined by detecting virulent Shiga toxigenic (stx1 and stx2) genes in the isolated strain. Antibiotic resistance pattern of the STEC isolates were studied against a panel of antibiotics. The mean coliform counts for raw milk, packaged, milk, paneer, dahi, kulfi and rasmlie were 4.680±0.164 log10 cfu /ml, 2.403±0.299 log10 cfu/ml, 2.771±0.230 log10 cfu/g, 3.614±0.247 log10 cfu/g, 3.615±0.247 log10 cfu/g and 3.911±0.215 log10 cfu/g. In present study, 80% raw milk, 26% packaged milk, 44% paneer, 36% dahi, 50% kulfi and 54% of rasmalaie samples had coliform count above permissible limits. The mean E. coli count of raw milk, packaged milk, paneer, dahi, kulfi and rasmalie were 3.48±0.15 log10 cfu/ml, 2.19±0.34 log10 cfu/ml, 2.05±0.32 log10 cfu/g , 2.43±0.37 log10 cfu/g, 2.69±0.25 log10 cfu/g and 3.10±0.23 log10 cfu/g respectively. The overall prevalence of E. coli was found to be 24.3% with highest (62.0 %) in raw milk and lowest (10.0%) in dahi. The overall prevalence of STEC from milk and milk products was found to be 3.6%. A total of eight (08) isolates were found positive for stx1 gene, two (02) for stx2 gene and one (01) for both stx1and stx2 genes. However, isolates recovered from packaged milk and dahi did not carry either stx1 or stx2 genes. All the E. coli isolates including STEC were found complete (100%) resistant to ampicillin and sensitive (100%) to cefuroxime. The present study thus confirmed the presence of coliform organisms including STEC in raw milk and their products indicating a potential hazard. Emergence of multi drug resistant STEC strains as observed in current study also possess threat to public health.
Description
MVSc Thesis submitted to SKUAST Kashmir
Keywords
Coliform bacteria, STEC, Multidrug resistance, Milk and Milk products, Veterinary Public Health, Veterinary Sciences and Animal Husbandry