title: Gentamicin- and clindamycin-resistant Staphylococcus aureus.
abstract: From 1975 through 1978 isolates from 21 of 230 (9%) Staphylococcus aureus bacteremias were resistant to gentamicin and clindamycin. Gentamicin- and clindamycin-resistant S aureus (GCRS) accounted for 23% of all S aureus isolates from 1977 compared with 2 to 6% in the two years immediately preceding, and the year following 1977. When compared with patients with gentamicin- and clindamycin-sensitive S aureus (GCSS) from 1977, GCRS were more often isolated from patients who acquired their infections in the hospital, particularly in the intensive care unit. A significant association existed between prior or concurrent therapy with gentamicin and/or clindamycin and the isolation of GCRS. Infection with GCRS was associated with a 73% mortality rate versus 28% with GCSS. GCRS were susceptible to oxacillin, cephalothin, tetracycline, and vancomycin. GCRS were resistant to kanamycin and tobramycin but were susceptible to amikacin (median MIC of GCRS, 4.0 microgram/ml). Multiple bacteriophage types of S aureus were involved, and resistance appeared to be plasmid-mediated. A survey of antibiotic usage showed that in comparison to January 1977, a mikacin usage increased and gentamicin usage decreased in March 1979. Because of the popularity of the combination of clindamycin and gentamicin for therapy of life-threatening infections, clinicians should be aware of potential gentamicin- and clindamycin-resistance in S aureus.
mesh_terms: D002981:Clindamycin / Q000627:therapeutic use*; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination; D005260:Female; D005839:Gentamicins / Q000627:therapeutic use*; D006801:Humans; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D018805:Sepsis / Q000188:drug therapy; D013203:Staphylococcal Infections / Q000188:drug therapy*
chemical_list: D005839:Gentamicins; D002981:Clindamycin