Production of aminoglycoside inactivating enzymes by pseudomonas aeruginosa

ABSTRACT

Thirty strains of Pseudomonas aeruginosa were isolated from urinary tract infections, burns and osteomyelitis [10 strains from each clinical source]. The aminoglycoside resistance patterns [markers] were determined by the disc agar diffusion technique using the aminoglycoside antibiotic discs [micro g/disc]; amikacin [Am,30], gentamicin [Gm. 10], kanamycin [Km. 30], tobramycin [Nn, 10], streptomycin [Sm. 10], and neomycin [Nm. 30]. The crude enzymes obtained by sonication of the cells of the isolated strains of Pseudomonas aeruginosa largely inactivated the used aminoglycosides in the presence of adenosine triphosphate [ATP] or acetyl Co-A as cofactors. The three inactivation mechanisms were detected, kanamycin phosphotransferase and streptomycin adenyltransferase were predominant among 90% or more of the strains, however, gentamicin adenyltransferase was limited. There were only two acetylating enzymes; kanamycin acetyltransferase [produced by 60% of the tested strains] and gentamicin acetyltransferase which was produced by only 11 strains [36.7%]. The aminoglycoside resistance pattern was correlated to some extent, with the production of the aminoglycoside inactivating enzymes