RESUMO
Staphylococcus aureus is a bacterium which has shown variations, as to susceptibility, to antimicrobial agents. By the plate dilution method, response to 12 different antibiotics is studied in 609 strains isolated from children admitted, or who attended the outpatient clinic of the Hospital Infantil de México, between 1973 and 1974. Ninety per cent or over, of all strains, were sensitive to eight of the antibiotics. The most effective were: gentamicin, (99.8%), cephalothin and cloxacillin (99%). Lesser sensitivity was found to penicillin (28.7%), ampicillin (33.5%) and tetracycline (49%). In general, resistance was greater in cases of surgical wounds and abscesses, and lesser in respiratory infections (pharyngeal exudates and bronchoaspirations). All strains isolated from purulent ophthalmias showed resistance to penicillin and 91%, to ampicillin.