While many smokers believe e-cigarettes to be a healthy and safer alternative to smoking, they appear to be just as dangerous as regular cigarettes, based on a new laboratory study.

In spite of being advertised as a healthy cigarette substitute, e-cigarettes increase the potency of life-threatening, drug-resistant bacteria and even decrease the human cells' ability to eliminate it. The vapor from e-cigarettes makes the methicillin-resistant Staphylococcus aureus (MRSA) superbug even more toxic.

A team of researchers from the University of California San Diego and VA San Diego Healthcare System tested how the e-cigarette vapor affected live MRSA and human epithelial cells. MRSA usually colonizes the nasopharynx where the epithelial cells and bacteria are constantly exposed to inhaled substances, including cigarette smoke and e-cigarette vapor.

The researchers grew MRSA in culture with concentrations of vapor similar to the amount found in the inhalers on the market. To conduct the experiment, they first tested the biochemical changes in the culture promoting pathogen virulence and introduced the alveolar macrophage-killing assays and epithelial cells.

The team found that the e-cigarette vapor fortified the bacteria. The bugs sensed danger when they were exposed to the e-cigarette vapor. They heightened their defense mechanisms immediately, making it harder to destroy them with antibiotics.

The research concludes that the strength of MRSA is increased by vapor from e-cigarettes, which induces the bacteria to produce a defense mechanism in acids within three hours after exposure. It raises the same mechanism against nitric oxide, which is one component of innate immunity response to infection.

"As health care professionals, we are always being asked by patients, 'Would this be better for me?' In the case of smoking e-cigarettes, I hated not having an answer. While the answer is not black and white, our study suggests a response: even if e-cigarettes may not be as bad as tobacco, they still have measurable detrimental effects on health," researcher Laura Crotty Alexander said.

The scientists said that the e-cigarette did not turn the bacteria as violent as the smoke from a regular cigarette. Prior research also says that MRSA resistance is boosted more by conventional cigarettes than electronic ones.