A Molecular Investigation of Extended Spectrum Beta-Lactamase genes in Escherichia coli and Klebsiella spp. in raw cow Milk

Abstract

Objective: Raw milk is an important source of nutrients. Therefore, today, there is a great demand for raw milk consumption. The positive side of milk consumption on growth and development cannot be ignored, but unfortunately, pathogens in raw milk are always potential public health risks for transmission pathogens. Bacteria such as Enterobacteriaceae in normal flora can cause serious problems due to their extended-spectrum beta-lactamase (ESBL) production. These bacteria and their resistance genes have been reported in raw milk. In this matter, the aim of the study is to determine the status of blaCTX-M-1, blaCTX-M-2, blaTEM, and blaSHV genes responsible for the production of ESBL enzyme in Escherichia coli and Klebsiella spp. strains to identify risk factors in raw milk consumption and to gain an understanding of the epidemiology of these resistant strains. 
 Materials and methods: A total of different 50 raw milk samples were collected and subjected to phenotypic microbiological analysis and Real-time PCR targeting blaCTX-M-1, blaCTX-M-2, blaTEM, and blaSHV genes. In the phenotypic analyses, suspicious isolates were identified by classical microbiological methods and antibiotic resistance profiles were revealed. 
 Results: These results indicated that raw milk is a potential reservoir for ESBL producing E. Coli, Klebsiella spp. strains are obviously significant. And It was determined that CTX-M based ESBL genes are predominant in ESBL production. The present study revealed that raw milk is epidemiologically involved in the transmission of ESBL genes. Raw milk could be distributed to ESBL genes widely with which is consumed in Şanlı Urfa.