title: Characterization of Bacteroides forsythus isolates.
abstract: Fifteen Bacteroides forsythus strains freshly isolated from patients with periodontitis were used together with three collection strains and one type strain for characterization of growth on various media; determination of enzymatic profiles, antibiotic susceptibility profiles, 16S rRNA ribotypes, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) outer membrane protein profiles, and pathogenicity; and gas chromatography analysis by using a wound chamber model in rabbits. All strains were stimulated by N-acetylmuramic acid, while one strain needed a further supplement such as yeast extract for optimal growth. All strains showed trypsin-like activity. While 10 different ribotypes were found, the SDS-PAGE profiles revealed similar patterns for all strains. All strains were sensitive to penicillin G (MICs, <0.5 microg/ml), ampicillin (MICs, <1.0 microg/ml), amoxicillin (MICs, <0.38 microg/ml), metronidazole (MICs, <0.005 microg/ml), tetracycline (MICs, <0.19 microg/ml), doxycycline (MICs, 0.05 microg/ml), erythromycin (MICs, <0.4 microg/ml), and clindamycin (MICs, <0.016 microg/ml), while they were less sensitive to ciprofloxacin (MICs, <4 microg/ml). B. forsythus did not cause abscess formation by monoinoculation. B. forsythus coinoculated with Fusobacterium nucleatum ATCC 10953 caused abscess formation in 75% of rabbits, while it caused abscess formation in 100% of rabbits when it was coinoculated with Porphyromonas gingivalis FDC 381. In the case of the latter combination, four of six rabbits died of sepsis after 6 to 7 days, and P. gingivalis and B. forsythus were recovered from the heart blood at a proportion of 10:1. B. forsythus strains were highly virulent and invasive in combination with P. gingivalis.
authors.affiliation: Department of Endodontology and Periodontology, Hiroshima University School of Dentistry, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Takemoto
authors.forename: H
authors.initials: H
authors.lastname: Kurihara
authors.forename: G
authors.initials: G
authors.lastname: Dahlen
mesh_terms: D000038:Abscess / Q000382:microbiology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001439:Bacteroides / Q000187:drug effects / Q000302:isolation & purification / Q000472:pathogenicity / Q000502:physiology; D001442:Bacteroides Infections / Q000382:microbiology*; D003470:Culture Media; D006801:Humans; D008826:Microbial Sensitivity Tests; D010518:Periodontitis / Q000382:microbiology*; D012329:RNA, Bacterial / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D011817:Rabbits
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S