High-level gentamicin resistance in Enterococcus: microbiology, genetic basis, and epidemiology.
Antibiotic resistance is an ever-increasing problem in enterococci. These bacteria are remarkable in their ability to acquire and disseminate antibiotic resistance genes by a variety of routes. Since first described in 1979, high-level resistance to gentamicin (MIC, greater than 2,000 micrograms/mL) has spread worldwide and has been responsible for serious infections. Resistance is plasmid-mediated and due to aminoglycoside-modifying enzymes. High-level gentamicin resistance indicates that there will be no synergistic bactericidal activity with penicillin-gentamicin combinations. The epidemiology of nosocomial enterococcal infections is remarkably similar to that of nosocomial infections caused by methicillin-resistant staphylococci and by multidrug-resistant gram-negative bacilli. The most likely way these resistant bacteria are spread among hospital patients is via transient carriage on the hands of hospital personnel. Patient-to-patient and interhospital transmission of strains has been reported recently. However, clonal dissemination is not the cause of the increased frequency of resistant strains, since gentamicin resistance appears in a variety of different conjugative and nonconjugative plasmids in Enterococcus.
Patterson
J E
JE
Department of Medicine and Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut.
Zervos
M J
MJ
D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology* / Q000517:prevention & control; D004352:Drug Resistance, Microbial / Q000235:genetics; D013293:Enterococcus faecalis / Q000187:drug effects*; D005839:Gentamicins / Q000494:pharmacology*; D006801:Humans; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology* / Q000517:prevention & control; D013291:Streptococcus / Q000187:drug effects* / Q000235:genetics
D005839:Gentamicins