Microbial and Parasitic Contamination of Fresh Raw Vegetable Samples and Detection of the BlaTEM and BlaCTX-M Genes from E. coli Isolates

Abstract

A total of 100 fresh-raw vegetable samples were collected from the Kathmandu, Lalitpur and Bhaktapur districts of Nepal to evaluate microbial and parasitic contamination, presence of Extended Spectrum Beta Lactamase (ESBL)-producing Escherichia coli and detect the blaTEM and blaCTX-M genes among the Escherichia coli isolates. This study revealed that the prevalence of Giardia cysts was highest (100%) and Hookworm and Entamoeba coli were lowest (1% each). Coliforms were isolated from every raw vegetable sample. A total of 178 bacterial isolates were isolated among which 57 isolates were identified as E. coli, out of which 33 were Multi-drug resistant (MDR) isolates. The high rate of resistance was found towards amoxicillin/clavulanate, tetracycline and cotrimoxazole. The 10 E. coli isolates tested positive in an ESBL screening, out of which 4 were confirmed as ESBL producers by a combined disc test. Out of these 4 confirmed ESBL E. coli, one was found to carry both the blaTEM gene and blaCTX-M genes by the Polymerase Chain Reaction (PCR) technique. One isolate has only the blaTEM gene, while other isolate harboured only blaCTX-M genes.