Antimicrobial susceptibility test on streptococcus viridans in children's oral cavity

Shin, Sang Hun; Song, Jung Ho

Abstract

A large number of streptococci that do not fit readily into any of the established classification schemes have been relegated to a large heterogeneous group called the Streptococcus viridans, which are members of the normal flora of the mucous membranes of the body, including the oral cavity, the nasopharynx, and genitourinary tract. This group includes S. mitis, S. oralis, S. sanguis, S. salivarius, S. milleri, etc. Surveying on the literature, it has been reported that infective endocarditis, meningitis, rhabdomyolysis, cholangitis, appendicitis caused by Streptococcus viridans, which were the most important pathogen in children with malignant hematologic disease. Various antibiotics has been chosen for treatment or prophylaxis for these infections, but were generally lower antimicrobial susceptibilities because of an abuse of antibiotics and advent of resistant group. Therefore, surveillant culture must be performed to evaluate personal antimicrobial susceptibilities of intraoral microbes for proper antimicrobial choice for dental procedures. This study examined sampling from subgingival plaque of 60 chidren's microbes. The cultured bacterial isolates, Streptococcus viridans were examined 10 antimicrobial drugs with the Kirby-Bauer agar disk diffusion method. The used drugs were Penicillin, Ampicillin, Oxacillin, Cephalothin, Imipenem, Gentamicin, Erythromycin, Vancomycin, Ciprofloxacin, Clindamycin. The results were as follows: 1. Sampling Streptococcus viridans were S. mitis(65%), S. oralis(22%), S. sanguis(5%), S. intermedius(3%), S. salivarius(2%), S. acidominimus(2%), Unidentified streptococcus(2%). 2. The antimicrobial susceptibility of total Streptococcus viridans : Oxacillin< Erythromycin< Pencillin= Ciprofloxacin< Cephalothin< Ampicillin< Clindamycin< Gentamicin< Imipenem=Vancomycin. 3. The antimicrobial susceptibility of S. mitis : Oxacillin=Erythromycin< Ciprofloxacin< Cephalothin< Penicillin=Ampicillin< Gentamicin< Clidamycin< Imipenem=Vancomycin. 4. The antimicrobial susceptibility of S. oralis : Oxacillin< Erythromycin< Penicillin=Ciprofloxacin= Clindamycin< Cephalothin=Gentamicin< Ampicillin< Imipenem=Vancomycin. 5. There was no significant difference in the antimicrobial susceptibility among each Streptococcus viridans group.