Infectious Disease 2016: MRSA

Dr. Theodore Rosen

Smoking and treatment of methicillin-resistant Staphylococcus aureus (MRSA): apparently cigarette smoke isn’t deadly for all living creatures

Results from a recent study have shown that cigarette smoke may make MRSA more virualent. Researchers at the University of California in San Diego infected macrophages with MRSA that were grown normally or with exposure to cigarette smoke extract. While macrophages were equally able to take up the two bacterial populations, smoke-exposed MRSA were more resistant to killing by reactive oxygen species (i.e., the macrophage oxygen burst). In addition, the smoke-exposed MRSA were more resistant to killing by naturally produced antimicrobial peptides and more adherent to keratonocytes. Additional in vivo experiments in mice showed pneumonia resulting from that smoke-exposed MRSA pneumonia was associated with higher mortality (40% vs 10%) and increased bacterial burden compared to control MRSA-infected mice