In vitroantimicrobial activity of ampicillin, panipenem, and ofloxacin against oral Streptococci adherent to solid phase

We investigated the antimicrobial activity of ampicillin, panipenem, and ofloxacin against oral Streptococci, which were isolated from odontogenic infections, adherent to solid phase. The minimum inhibitory concentration (MICAD) and minimum bactericidal concentration (MBCAD) for 10 oral Streptococci (S. mitis, 2 strains ; S. sanguis, 5 ; S. salivarius, 1 ; S. mutans, 1 ; S. oxalis, 1) that were adhered to the bottom of multi-well plastic tissue culture plates, were determined. The results were as follows : MICAD, 0.025*12.5li g/mL, and MBCAD, 200•`>400ƒÊg/mL, for ampicillin ; MICAD, <0.025-0.025ƒÊg/mL, and MBCAD, 12.5 •`> 400ƒÊg/mL, for panipenem ; and MICAD, <0.025-1.56ƒÊg/mL, and MBCAD, 50•`> 400ƒÊg/mL, for ofloxacin. From the results above, it is clear that oral Streptococci can show a much higher MBCAD than MICAD when adhering to solid phase, although there are some differences according to the antibiotics and strains studied.