ABSTRACT
Pseudomonas aeruginosa [P. aeruginosa] is a Gram-negative pathogen associated with pneumonia, bronchitis, and chronic colonization of the respiratory tract. It easily affected by the environmental inhalant pollutants that may change its virulence and alter the host innate immunity against it. In this study, we aimed to establish the effect of cigarette smoke and electronic nicotine delivery device vapor on the virulence of P. aeruginosa. Bacteria were grown in control media, different concentrations of cigarette smoke exposed media, and range of doses of nicotine vapor exposed media. The growth ability of bacteria, pH change, and the pigment production capability were monitored for each culture. Sensitivities of P. aeruginosa to the reactive oxygen species and to killing by purified human polymorphonuclear neutrophils were established as well as their ability to change their surface charge and their susceptibility to antimicrobial peptides. Smoke exposed P. aeruginosa showed inhibition in their growth in a dose-dependent manner and inhibition of the pyocyanin production whilst the nicotine vapor did not affect their growth kinetics but increased the pigment production dose dependently too. When treated with H2O2, smoke and vapor exposed bacteria had significantly higher survival rates than the control. Where both smoke and vapor exposed cells grew significantly in the presence of human neutrophils while control bacteria were killed, exposure to 75% cigarette smoke showed the higher survival rate. Moreover, cigarette smoke was found to increase P. aeruginosa resistance to the antimicrobial peptides. Consequently, cigarette smoke and electronic nicotine vapor were found to boost P. aeruginosa pathogenesis and virulenc