Isolation and Molecular Characterization of Extended Spectrum Beta Lactamase Producing Escherichia coli from Milk

Milk plays a major role as a source of nutrition in the diet but contaminated milk can be a source of harmful bacteria. Escherichia coli is opportunistic pathogen and is responsible for a wide range of infections. The prevalence of pathogenic multi-drug resistant extended-spectrum β-lactamase (ESBL)-producing E. coli is increasing and becoming a global concern. A study was carried out to isolate ESBL producing E. coli from 150 milk samples from Anand and around villages. Total 94(62.66%) samples were found positive as E. coli by isolation on MacConkey and Eosin Methylene Blue agar which were confirmed by primary & biochemical tests including Gram’s staining. Antibiotic sensitivity test (ABST) was performed against 6 antibiotics and isolates found resistant to Aztrionem: 58(61%), Cefoxitin: 20(21%), Ceftriaxone: 56(59%), Ceftazidime: 62(65%), Cefpodoxime: 34(44.73%) & Ceftazidime + Clavulanic acid: 8(8.5%). A total 34(36.17%) ESBL producing E. coli were phenotypically confirmed by ABST and Epsilometer test. Genotypic confirmation of 34 isolates was done by PCR and isolates found positive for bla CTX M-3 gene: 18(52.94%), bla CTX M-9 gene 6(17.64%), bla SHV gene: 5(14.70%) and bla TEM gene: 5(14.70%). In summary, analyzed milk samples were found to have a health risk for consumers due to contamination by ESBL producing E. coli, their pathogenicity and treatment failure as a result of antibiotic resistance

Sugar-hydrolysing enzymes in gustatory mutants of Drosophila.

The distribution of the isozymes of α-glucosidase in different parts of Drosophila melanogaster was examined. Two of the eight glucosidase bands are associated with tarsi. The gustatory mutations in the genes gustB and gustC greatly reduce tarsal glucosidase activity, but the enzyme deficiency is not correlated with inability to taste sugars.