Anaerobic Gram‐positive bacilli of clinical relevance in human infections are divided into two distinct groups: sporeforming Gram‐positive anaerobic bacilli, including
Clostridium sensu stricto
and allied genera, and a group of asporogenic, anaerobic Gram‐positive bacilli (Grampositive rods (GPRs)). Many of these anaerobic GPRs are part of the normal microbiota of the oral cavity, gastrointestinal tract, genitourinary tract, and skin. They can, however, be associated with skin and soft tissue infections, periodontitis and other oral infections, pulmonary infections (usually in combination with other aerobes and anaerobes), genitourinary tract infections, and, in the case of
Cutibacterium acnes
, infected CSF shunts, prosthetic joint infections, and endophthalmitis. Many of the nonsporeformers are aerotolerant and are often resistant to metronidazole, an antimicrobial agent that is usually effective against most other anaerobes.