Is the term anti-anaerobic still relevant?

For decades, the term anti-anaerobic has been commonly used to refer to antibiotics exhibiting activity against anaerobic bacteria, also designated as anaerobes. This term is used in various situations ranging from infections associated with well-identified pathogens like Clostridioides difficile, or Fusobacterium necrophorum in Lemierre's syndrome, that require specific antibiotic treatments to polymicrobial infections generally resulting from the decreased permeability of anatomical barriers (e.g., intestinal translocation and stercoral peritonitis) or infectious secondary localizations (e.g., brain abscess and infectious pleurisy). In these cases, the causal bacteria generally remain unidentified and the antimicrobial treatment is empirical. However, major progress in the knowledge of human bacterial microbiotas in the last 10 years has shown how diverse are the species involved in these communities. Here, we sought to reappraise the concept of anti-anaerobic spectrum in the light of recent advances in the microbiota field. We first highlight that the term anaerobic itself does not represent the tremendous diversity of the bacteria it spans, and then we stress that the antibiotic susceptibility profiles for most anaerobic bacteria remain unaddressed. Furthermore, we provide examples challenging the relevance of the anti-anaerobic spectrum from a clinical and ecological perspective. (C) 2020 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.

Automated summary

The article discusses the use of antibiotics against anaerobic bacteria and reevaluates the concept of anti-anaerobic spectrum in light of developments in the microbiota field. By highlighting the diversity of anaerobic bacteria species and the lack of antibiotic susceptibility profiles for many anaerobic bacteria, the relevance of the anti-anaerobic spectrum is challenged from clinical and ecological perspectives.