Comparative in-vitro activity of fourteen antibiotics against clinical isolates of enterococci.
The in-vitro antibacterial activities of fourteen antimicrobial agents, including ampicillin, amikacin, Augmentin, ceftazidime, cefotaxime, ceftriaxone, ciprofloxacin, erythromycin, gentamicin, penicillin G, piperacillin, rifampicin, streptomycin and vancomycin, were compared against 195 enterococcal strains isolated from clinical specimens received at the King Abdulaziz University Hospital in Saudi Arabia. The antibacterial susceptibility was determined by the minimal inhibitory concentration (MIC) using an agar dilution method. Ampicillin, Augmentin and vancomycin exhibited the greatest activity, inhibiting 90% of the tested strains (MIC90) at 2 micrograms/ml, followed by penicillin G and piperacillin with MIC90 of 4 micrograms/ml. Erythromycin, third generation cephalosporins, aminoglycosides and rifampicin, on the other hand, had poor activity against enterococci with MIC90s well above the obtainable serum concentrations. The clinical implications of resistance to aminoglycosides and the alternative antimicrobial therapy in serious enterococcal infections are discussed in the text.
Abd-Elalim Eltahawy
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AT
Microbiology Department, King Abdulaziz University Hospital, Jeddah, Saudi Arabia.
Fouad Khalaf
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RM
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D006801:Humans; D008826:Microbial Sensitivity Tests; D013291:Streptococcus / Q000187:drug effects*; D001618:beta-Lactamases / Q000032:analysis
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases