Infect Immun. 2017 Jul 31. pii: IAI.00434-17. doi: 10.1128/IAI.00434-17. [Epub ahead of print]

Streptococcus pneumoniae colonization is required to alter the nasal microbiota in cigarette smoke-exposed mice.

Shen P1, Whelan FJ2,3, Schenck LP2,3, McGrath JJC1, Vanderstocken G4, Bowdish DME3,4, Surette MG2,3,5,6, Stämpfli MR7,8.

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Smokers have nasal microbiota dysbiosis, with an increased frequency of colonizing bacterial pathogens. It is possible that cigarette smoke increases pathogen acquisition by perturbing the microbiota and decreasing colonization resistance. However, it is difficult to disentangle microbiota dysbiosis due to cigarette smoke exposure from microbiota changes caused by increased pathogen acquisition in human smokers. Utilizing an experimental mouse model, we investigated the impact of cigarette smoke on the nasal microbiota in the absence and presence of nasal pneumococcal colonization. We observed that cigarette smoke exposure alone did not alter nasal microbiota composition. Microbiota composition was also unchanged at 12 hours following low dose nasal pneumococcal inoculation, suggesting the ability of the microbiota to resist initial nasal pneumococcal acquisition was not impaired in smoke-exposed mice. However, nasal microbiota dysbiosis occurred as a consequence of established high dose nasal pneumococcal colonization at day 3 in smoke-exposed mice. Similar to clinical reports in human smokers, we observed an enrichment of potentially pathogenic bacterial genera such as Fusobacterium, Gemella, and Neisseria Our findings suggest that cigarette smoke exposure predisposes to pneumococcal colonization independent of changes to the nasal microbiota, and microbiota dysbiosis observed in smokers may occur as a consequence of established pathogen colonization.

Copyright © 2017 American Society for Microbiology.

PMID: 28760931 DOI: 10.1128/IAI.00434-17