Susceptibility of Hong Kong isolates of methicillin-resistant Staphylococcus aureus to antimicrobial agents

Publisher Website
Google Scholar
Abstract
Two hundred and sixty-six non-repHcate Hong Kong isolates of methicilnn-resistant Staphylococcus aureus were tested for their susceptibility to various anti-staphylococcal agents. Multiple resistance was common. More than 95% of patient isolates were resistant to both gcntamicin and tetracycline, 68% to erythromycin, 37% to chloramphenicol, 10% to trimethoprim 5% to rifampkin and 2% to fusidic acid. No isolate was resistant to all these agents, but nineteen different patterns of resistance were identified. Selected gentamicin-resistant isolates were tested against other aminoglycosides, and were sensitive to amikacin and netilmicin. The pattern of aminoglycoside resistance indicated that all isolates produced the aminogrycoside-modifying enzymes APH-(2″) and AAC-(6′)-I. All isolates were sensitive to vancomycin and tcicoplanin. A single strain was resistant to three of the five quinolones tested, but resistance to all the quinolones could be induced easily in vitro by exposure to increasing subinhibitory concentrations of norfloxacin in broth.