Phylogrouping and Antibiogram of Escherichia coli from river water sample

Abstract

Water borne diseases like diarrheal infection caused by E. coli is a serious threat to public health. However, in Nepal there are no clear data on characterization of these E. coli based on their virulence or antimicrobial resistance. And phylogrouping will help to track the microbial source and help us understand the route of transmission. Also, antibiotic resistant profile will help to design a better treatment regime for the patients. Therefore, this study aims to characterize the diarrheagenic E. coli that are prevalent in the water sources and gauge their transmission potential to humans. For this E. coli was isolated and identified from water sample following the conventional culture techniques and enumerated by standard membrane filtration method. Further antibiotic susceptibility was determined by disc diffusion method towards different classes of antibiotics that are used in clinical settings following the procedure recommended by CLSI. Further, gene detection was done by PCR using specific primers for phylogroup. The result was then analyzed using SPSS and WHONET software. Descriptive analysis as well as inferential analysis was done to fulfill the objective of the study. The result revealed a high occurrence of thermotolerant E. coli of phylogroup B1 (58.2%) in Bagmati river which is commensal in nature and originates from either human or animals. Also, isolates conferring resistance to multiple antibiotics (n= 6) were detected along with high priority isolates (n=11). Thus, circulation of such high risk isolates in aquatic settings of Nepal is concerning so a comprehensive study of such isolates should be done at genomic level so that to better understand their transmission potential and intervene their transmission.