Phage types and drug susceptibility patterns of Staphylococcus aureus from two hospitals in northwest Ethiopia.

Fifty-eight Staphylococcus aureus strains from Gonder College of Medical Sciences Hospital, (43 isolates from patients and 15 from carriers) and 28 from Debre Tabor Hospital (14 each from patients and carriers), both in northwest Ethiopia, were phage typed in 1988. Eighty-one of the 86 strains were recognized by their phage types. A multiresistant strain of type 29 was frequent among Gonder patients'. This strain was also recovered from the hospital personnel. Other well known multiresistant strains of phage type NT/A994 and 85/A994 were identified among patients from Gonder and phage type 85/A994 was recovered from 5 patients and 4 carriers from Debre Tabor. These findings suggest cross-infection with virulent strains of Staphylococcus aureus in both hospitals. All 86 phage-typed strains were tested for susceptibility to 7 antibiotics. A high frequency of multiple resistance was observed. Double resistance to penicillin and tetracycline was frequent among patients strains from Gonder. Among strains of phage type 85/A994 multiresistance to penicillin, chloramphenicol, tetracycline, streptomycin, erythromycin and oxacillin was found. Strains of phage type 85/A994 and NT/A994 were resistant to mercury. No plasmid DNA was detected in one strain of 85/A994 investigated.