Bacteroides fragilis

Laboratory diagnosis

• Gram-negative pleomorphic

• anaerobic

• Non-sporing

Features

• lipopolysaccharide (LPS) lacks endotoxin activity

Colonises

• GI tract

Diseases

• Intra-abdominal infections

• Skin and soft-tissue infections

• Bacteraemia

• Gynaecological infections (inc abscesses)

• Respiratory tract infections

• Brain abscess

Treatment

• metronidazole

• piperaciliin

• imipenem

• co-amoxiclav

• clindamycin

• chloramphenicol

Resistance

• beta-lactamase produced

• ampicillin

• most cephalosporins

• gentamicin

• some resistance to clindamycin