Epidemiology and molecular characterization of multi drug-resistant Escherichia coli isolated from cow milk

Abstract

xii ABSTRACT In communities and healthcare settings, Escherichia coli is developing antimicrobial resistance (AMR), which is a growing public health crisis. A recent high-profile report estimates that, by 2050, the rise in AMR will cause 10 million deaths each year unless a global response is ordered to the problem. Due to its relatively dense population with extremely unhygienic sanitary facilities and food and water sources, Bangladesh is more likely to suffer from infection than other countries around the world. Raw meat, leafy green vegetables, or fish are most frequently linked to bacterial infections. Milk also acts as a vector for transmitting pathogenic microbes. For this reason, this study focused on molecular characterization of multi drug resistant Escherichia coli isolated from cow milk. To conduct this study milk samples were collected from 18 different farms of Chattogram Metropolitan Area. E. coli, enriched culture was streaked on MacConkey agar medium followed by Eosin Methylene Blue (EMB) agar plates and incubated for 24 hours at 37°C in each state. The isolates were then inoculated onto blood agar and incubated for 24 hours at 37°C. After that, blood agar colonies were used to conduct CS tests to find out the samples that are resistant to specific antibiotics and then to extract DNA for PCR to identify the resistant genes. Among 450 milk samples, we found 134 positive isolates for E. coli which describes a prevalence of 29.77%. Highest number of E. coli isolates were resistant to Ampicillin (69%), Cephalothin (69%), Cephalexin (69%), Amoxicillin + Clavulinic Acid (69%) and lowest number of E. coli isolates were resistant to Colistin sulfate (0%). The study was designed using a one-health approach to demonstrate the identification, molecular characterization along with the antimicrobial sensitivity pattern evaluation of multidrug-resistant E. coli to determine the status of drug sensitivity and resistance pattern of the E. coli isolates from milk samples in Bangladesh and the outcomes indicate that the AMR is increasing in an alarming rate and can cause health threat. Before it manifests in large-scale medical emergencies, it is necessary to identify risks and appropriate mitigation strategies based on scientific evidence and knowledge.