Bacteroides fragilis is a gram-negative, pleomorphic anaerobe responsible for variety of anaerobic infections including peritonitis.
Actinomyces is a heterogeneous group of gram-positive, pleomorphic bacilli responsible for the disease actinomycosis.
Commensal in the large intestine of humans and is responsible for the disease, gas gangrene.
Gram positive, obligate anaerobe, looks like drum-stick shaped and causes tetanus.
Gram positive, anaerobic rod which produces powerful neurotoxin "botulinum toxin".
