A gram-negative anaerobic nonmotile and asaccharolytic obligatory bacterium associated with dental infections particularly in subgingival plaques in humans.
Bacteroides gracilis has been isolated from subgingival plaque with periodontal pockets but not found in subgingival microbiota of healthy gingival sulci. It is also found in pulmonary infections, brain abscesses, peritonitis, wound infection, intra-abdominal abscesses and soft tissue abscesses.
Bacteroides gracilis in cultured media forms translucent small colonies which frequently overlooked in mixed cultures thus; selective media has been developed that contains formate, tryptic soy agar base, fumarate nitrate, teicoplanin and nalidixic acid.
Bacteroides gracilis is implicated in abdominal infection typically gangrenous or perforated appendicitis and basically isolated from polymicrobial infections yet its pathogenicity potential remains uncertain. It is susceptible to some antimicrobial agents including aztreonam, amoxicillin-clavulanic acid, cefotaten, chloramphenicol, colistin, ciprofloxacin, metronidazole and kanamycin yet it showed relatively high incidence of antibiotic resistance.
Species: Bacteroides gracilis
• Subgingival plaque