Analysis of neomycin, kanamycin, tobramycin and amikacin resistance mechanisms in gentamicin-resistant isolates of Enterobacteriaceae.
Twenty-four gentamicin-resistant isolates of Enterobacteriaceae, obtained from the clinical laboratories of three health centres in Nablus, Palestine, were tested for susceptibility to neomycin, kanamycin, tobramycin and amikacin. Resistance rates were 29.2% for neomycin, 58.3% for kanamycin, 45.8% for tobramycin and 8.3% for amikacin. Fourteen (58.3%) isolates were noted to be multiresistant, i.e., resistant to gentamicin and two or more other aminoglycosides; resistance to gentamicin, kanamycin and tobramycin was the most common pattern of multiple resistance. This pattern implies the involvement of adenyltransferase ANT(")-I activity. Plasmid profiles and curing experiments suggested a plasmid localisation of gentamicin, neomycin, kanamycin and tobramycin resistance genes. However, a chromosomal location is proposed for plasmid-deficient strains. Cross-resistance in two isolates to all aminoglycosides tested suggested membrane impermeability to aminoglycosides as the mechanism of resistance.
Adwan
K
K
Department of Biological Sciences, An-Najah National University, Nablus, Palestine.
Abu-Hasan
N
N
Al-Asmar
H
H
D000583:Amikacin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000032:analysis; D004352:Drug Resistance, Microbial / Q000235:genetics; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000235:genetics; D004996:Ethidium / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000494:pharmacology; D005839:Gentamicins / Q000494:pharmacology; D006801:Humans; D007613:Kanamycin Resistance / Q000235:genetics; D008826:Microbial Sensitivity Tests; D009355:Neomycin / Q000494:pharmacology; D011815:R Factors / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D014031:Tobramycin / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D005456:Fluorescent Dyes; D005839:Gentamicins; D000583:Amikacin; D004996:Ethidium; D009355:Neomycin; D014031:Tobramycin