E-cigarette vapor containing nicotine failed to have an impact on the ability of Streptococcus pneumoniae strain TIGR4 to infect mouse models. Researchers at the University of Louisiana at Lafayette investigated whether e-cigarettes could increase the risk of pneumonia. As seen in previous studies with conventional cigarettes, cigarette smoke is a critical risk factor for pneumonia.
The researchers compared the effects on S. pneumoniae to strawberry-flavored e-cigarette vapor containing nicotine, the same vapor with no nicotine, cigarette smoke and a no cigarette-related control. The results found that nicotine-containing e-cigarette vapor induced major changes in gene expression of pneumococcus, affecting 264 genes. Nicotine free e-cigarette vapor altered expression of just 14 genes. Conventional cigarette smoke altered expression in 982 genes.
"Interestingly, neither nicotine-containing nor nicotine-free e-cigarette vapor altered the ability of pneumococci to cause lung infection in a mouse model of infection," said Dr. Kulkarni PhD, Assistant Professor of Immunology, University of Louisiana at Lafayette. “However, both nicotine-containing e-cigarette vapor and cigarette smoke caused moderate induction of biofilm formation" Dr. Kulkarni continued.
Their research is published in Applied and Environmental Microbiology.