New research suggests that exposure to cigarette smoke could make some methicillin-resistant Staphylococcus aureus (MRSA) bacterial strains more resistant to antibiotics. The findings were published in the journal Scientific Reports.
Researchers from the University of Bath, Imperial College London and the University of Oxford in collaboration with Spanish researchers conducted a series of in vitro experiments to investigate the effects of cigarette smoke exposure on six reference strains of MRSA.
The strains showed variable responses to smoke exposure, but certain strains including those known to cause invasive infections exhibited increased resistance to the antibiotic rifampicin. Exposure to cigarette smoke was also found to increase their invasiveness and persistence. It is likely that resistance of these strains to other antibiotics may also be affected. The authors believe these changes could lead to the emergence of 'Small Colony Variants' that are highly adhesive, invasive and persistent colonies associated with chronic infections in smokers.
Previous studies believed the higher susceptibility of smokers to infection could be attributed to the detrimental effects of smoke on the immune system; however, this study indicates that cigarette smoke can also affect the DNA and characteristics of pathogenic microorganisms.