[Growth of Staphylococcus aureus Cowan I in the presence of subbactericidal concentrations of povidone-iodine].

Staphylococcus aureus, strain Cowan I, is cultivated in the presence of povidone iodine (PVP.I) at the concentration of 0, 640, 960 micrograms/ml; growth curves points are platted (OD 640 mm) at 0, 1, 2.50, 3, 4.50, 7 and 24 hours. Growth curves in the presence of povidone alone as well as in the standard without antiseptic are similar and reproducible. A bacteriostatic effect is observed with 640 micrograms/ml PVP.I concentration compared to an incomplete bactericidal effect with 960 micrograms/ml concentration. Proteinee A detected by conditioned hemagglutination method is present in the centrifugation pellet of the standard and only in the supernatant of the test samples during the early phases of the growth. Production of alpha-ribitol-teichoic acid detected by counterimmunoelectrophoresis is not significantly different in the standard and in the presence of antiseptic. Biochemical characteristics studied by Api Staph gallery are identical for the control strain and the strain grown in the presence of PVP.I. Observed by scanning and transmission electronic microscope the bacterial cells do not present structural modification during growth with PVP.I.