Occurrence of aminoglycoside-modifying enzymes genes (aac(6′)-I and ant(2′′)-I) in clinical isolates of Pseudomonas aeruginosa from Southwest Nigeria

Background: Enzymatic modification of aminoglycosides is the primary mechanism of resistance by Pseudomonas aeruginosa . Obejectives: We investigated the occurrence and mechanism of aminoglycosides resistance in P. aeruginosa isolates from hospitals in SouthWest Nigeria. Methods: A total of 54 consecutive, non-duplicate clinical isolates of P. aeruginosa were studied for the presence of aminoglycosides -modifying enzymes (AMEs) by PCR amplification and sequencing of genes encoding AMEs. Results and Conclusion: Two types of AME genes [aac (6′) - I and ant (2′′) - I] were found in 12 isolates out of 54. Seven strains harboured one or more types of enzymes of which aac (6′) - I was the most frequently found gene (10/54 isolates, 18.5%). None of the isolates investigated in this study were positive for aph, aac (3) and aac (6′′) - II genes. Prevalence of P. aeruginosa producing AME genes in this study may suggest aminoglycosides use in Nigeria. This study highlights need for functional antimicrobial surveillance system in Nigeria.