Characteristics of gentamicin resistance in nosocomial infections.
Characteristics of gentamicin resistance were studied in gram-negative bacilli from 50 consecutive patients with nosocomial infection, during a time when gentamicin resistance had recently become prevalent at Medical University Hospital. Burns, decubitus ulcers, and cystic fibrosis were common precipitating factors for acquisition of gentamicin-resistant organisms. Pseudomonas aeruginosa accounted for 76% and Enterobacteriaceae for 24% of isolates. There was high prevalence of cross-resistance to amikacin (61%) and tobramycin (58%). Of the P aeruginosa strains 36% possessed plasmids which were rapidly detected by agarose gel electrophoresis. None of the isolates transferred gentamicin resistance. Representative isolates failed to elaborate aminoglycoside-modifying enzymes or to take up labelled amikacin. Multiple immunotypes of P aeruginosa were identified. These data suggest that a nonplasmid mediated resistance mechanism such as impermeability was responsible for the emergence of gentamicin resistance.
D000583:Amikacin / Q000494:pharmacology; D003428:Cross Infection / Q000188:drug therapy*; D003429:Cross Reactions; D004352:Drug Resistance, Microbial; D004587:Electrophoresis, Agar Gel; D004755:Enterobacteriaceae / Q000187:drug effects / Q000235:genetics; D005839:Gentamicins / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000235:genetics; D014031:Tobramycin / Q000494:pharmacology
D005839:Gentamicins; D000583:Amikacin; D014031:Tobramycin