Antibiotic susceptibility and phage typing of methicillin-resistant Staphylococcus aureus clinical isolates from blood cultures of 692 patients in 15 Israeli hospitals.

Six hundred ninety-two clinical isolates of Staphylococcus aureus were collected from blood cultures of 692 patients in 15 Israeli hospitals over a two year period. Antibiotic sensitivity was tested by the standard disk diffusion technique. Of these isolates, 41.6% were methicillin-resistant (MRSA). All 288 MRSA isolates were sensitive to vancomycin and pristinomycin; 98.6% were sensitive to fucidine; 97.9% to imipenem; 79% to rifampicin; 63.6% to amikacin; 54.5% to augmentin; 36.4% to clindamycin; 12.6% to ciprofloxacin; 11.9% to cotrimoxazole and ofloxacin; 10.5% to gentamicin; 9.8% to erythromycin; and 8.4% to norfloxacin. Phage typing was determined by using the international set of phages. All the isolates that were sensitive to Group I phages, and 91.8% of those sensitive to Group II phages, were sensitive to methicillin. Of the isolates that were sensitive to Group III phages, 79.2% were methicillin-resistant and 72.4% of the latter were sensitive to phages 75/85. Of the isolates that were sensitive to Group III and miscellaneous phages, 50.7% were methicillin-resistant and 71% of the latter were sensitive to phages 75/85 as well.