Several studies investigated the effects of exposure to direct and indirect smoking on the oro-pharyngeal colonization with potential pathogenic bacteria and aerobic and anaerobic organisms that can interfere with their growth. The potential pathogens included Streptococcus pneumoniae, Hamophillus influenzae, Staphylococcus aureus , and Streptococcus pyogenes. Bacteria with interference capability of potential respiratory pathogens include alpha- hemolytic streptococci, non-hemolytic streptococci, and Prevotella and Peptostreptococcus spp.
The flora of smokers contained less aerobic and anaerobic organisms with interfering capability and more potential pathogens as compared with non-smokers. The high number of pathogens and the low number of interfering organisms found in the nasopharynx of smokers revert to normal levels after complete cessation of smoking.
A high recovery rate of potential pathogens and low number of interfering organisms were observed in otitis media prone (OMP) children. This was not related to their parents smoking habits. The flora of smoking parents contains more potential pathogens that are similar to the one recovered from their OMP children, and less interfering organisms as compared to non-smoking parents.
Parents that smoked were more often colonized by potential pathogens than parents that did not smoke. The flora of healthy children of smoking parents contained high number of potential pathogens similar to the one found in their parents and OMP children. Concordance with pathogens in the parent was high among the OMP children of smoking parents but this was not observed in OMP children of non-smoking parents. A higher recovery rate of potential pathogenic organisms was observed in OMP children of both smoking and non-smoking parents, as compared to healthy children whose parents were non-smoking. Since smoking parents harbor more potential pathogens and less interfering organisms they may serve as a source of pathogens that can colonize and/or infect their children.