title: Patient factors contributing to the emergence of gentamicin-resistant Serratia marcescens.
abstract: One hundred forty nosocomial Serratia marcescens infections (including 76 cases of bacteremia) were identified by prospective surveillance from 1975 through 1977 and retrospective chart review from 1968 through 1974. Thirty-four cases (24 per cent) involved gentamicin-resistant strains. All gentamicin-resistant strains appeared after 1974. Ninety per cent of the patients had undergone surgery, and 88 per cent had received prior antimicrobial therapy. The emergence of gentamicin-resistant S. marcescens paralleled the increase in usage of gentamicin. Prior use of gentamicin for more than two days in an individual patient was a significant risk factor (P = 0.0002) for being infected with a Serratia that was gentamicin-resistant. Other factors which separated gentamicin-resistant Serratia infections from gentamicin-sensitive Serratia infections were (1) urinary site of infection (P = 0.0005), (2) urinary catheter (P = 0.002), (3) endotracheal tube or tracheotomy (P = 0.03) and (4) increasing duration of hospitalization (P less than 0.05). Thirty-three of 34 (97 per cent) patients with gentamicin-resistant strains had urinary catheters. Specific measures to control infection were effective in decreasing the incidence of infections caused by gentamicin-resistant Serratia.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002140:California; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000209:etiology* / Q000382:microbiology; D004352:Drug Resistance, Microbial; D004756:Enterobacteriaceae Infections / Q000209:etiology* / Q000382:microbiology; D005260:Female; D005839:Gentamicins / Q000627:therapeutic use*; D006801:Humans; D007223:Infant; D007441:Intubation, Gastrointestinal / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D018805:Sepsis / Q000209:etiology* / Q000382:microbiology; D012706:Serratia marcescens / Q000187:drug effects*; D014546:Urinary Catheterization / Q000009:adverse effects; D014552:Urinary Tract Infections / Q000209:etiology* / Q000382:microbiology
chemical_list: D005839:Gentamicins