Plasmid Profile of Multi-Drug Resistant Escherichia coli and Serratia marcescens Isolated from Surface Water in Ado Ekiti, Ekiti State, Nigeria

Abstract

This study examined the isolated bacteria from Elemi Stream in Ado Ekiti, Ekiti State, Nigeria for their microbial density, antibiotic resistance and plasmid profile. Pour plating was used to do the total bacterial and coliform counts, disc diffusion to evaluate the susceptibility of the isolated microorganisms, the alkaline lysis method to determine the plasmid profiles of the isolates, and agar gel electrophoresis to determine the coliform counts. The average total bacterial counts in sample A of the Elemi stream were 8.6 x 10³ CFU/mL and the average total coliform counts were 8.4 x 10³ CFU/mL, whereas the average total bacterial counts in sample B were 9.6 x 10³ CFU/mL and 8.9 x 10³ CFU/mL, respectively. The found isolates, together with their percentage distributions, include Escherichia coli (65.5%), Enterobacter aerogenes (13.8%), Serratia marcescens, and Staphylococcus aureus (10.3%). Augmentin demonstrated the highest level of resistance among the isolates, in contrast to Nitrofurantoin. Antibiotic resistance in various forms was discovered in Serratia marcescens and Escherichia coli. With molecular test, analysis revealed that the isolates with plasmid DNA had the gene encoding for antibiotic resistance, whereas the isolates without plasmids carried the gene encoding for antibiotic resistance on chromosomal DNA. The existence of multi-drug resistance plasmid-mediated bacteria in surface water is of great public health concern.