PCR Analysis of Resistant Bacteria Strains Isolated from River Sokoto, Northwestern Nigeria

Abstract

Thirteen resistant bacteria strains from River Sokoto namely Salmonella typhi, Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus faecalis, Bacillus subtilis, Enterobacter cloacae, Klebsiella oxytoca, Staphylococcus saprophyticus, Providencia rettgeri, Klebsiella pneumonae and Enterobacter aerogenes recovered on Mueller-Hinton agar by disc diffusion method were subjected to PCR (Polymerase chain reaction) analysis to determine their antibiotic resistance genes. Forward and reverse copies of five primers (TEM, spvC, SHV, aacC3 and qnrS) were used in the PCR analysis. Aminoglycoside resistance genes (aacC3) were detected in the majority of the isolates such as E. coli, Shigella flexneri, Enterobacter cloacae, Staphylococcus saprophytica and Enterobacter aerogenes with plasmid numbers ranging from 1 to 4 and molecular weights ranging from 185 bp to >10,200 bp. Virulence resistance genes (spvC) were detected in Salmonella typhi on two plasmids with molecular weights of 571 bp and >10,200 bp while quinolones resistance genes were detected on plasmid numbers ranging from 1 to 3 and molecular weights ranging from 400 bp to 1000 bp in Staphylococcus aureus, Streptococcus faecalis, Bacillus subtilis and Providencia rettgeri. Three different resistance genes namely β-lactam (bla TEM ), virulence (spvC) and quinolones (qnrS) on 6 plasmids with molecular weights ranging from 428 bp to 1,200 bp were found in Pseudomonas aeruginosa while two resistance genes (aacC3 and qnrS) on 2 plasmids with molecular weights of 185bp and 428bp were detected in Klebsiella pneumoneae. Non-specific resistance genes alongside with specific resistance genes were however detected in the majority of the isolates. The study revealed that the resistance genes exhibited by resistant bacteria isolates from River Sokoto were mainly virulence, aminoglycoside and quinolones resistant genes. The scientists are therefore challenged on the need for development of new antibiotics to combat the infections caused by these resistant strains.