Cigarette Smoke Makes MRSA Stronger

Stopping and controlling MRSA outbreaks is hard enough for hospitals and other healthcare facilities. That’s why it’s worth noting that new research finds cigarette smoke makes the bacterial strain more resistant to antibiotics.

MRSA, otherwise known as Methicillin-resistant Staphylococcus aureus, is a staph infection that is difficult to treat because it is resistant to a variety of antibiotics, according to the Centers For Disease Control and Prevention. Some strains of Staphylococcus aureus, such as MRSA, become more invasive and persistent when exposed to cigarette smoke, while others do not,  The University of Bath in England announced in a press release regarding its findings.

Past studies have suggested cigarette smokers are at increased risk of infection. However, Bath University’s research is unique in that it found that cigarette smoke can change the DNA and characteristics of pathogenic microbes, too.

In a series of lab-based experiments the researchers from Bath, working with colleagues from other universities, exposed six reference strains of the most important ‘superbug’ Methicillin- Resistant S. aureus (MRSA) clones to cigarette smoke.

The strains were known to cause conditions ranging from skin infections to pneumonia and endocarditis and were chosen for their clinical relevance and genetic diversity. Although not all responded to cigarette smoke in the same way, some, including those known to cause invasive infections, showed increased resistance to the antibiotic rifampicin and increased invasiveness and persistence. Resistance to other antibiotics is also likely to be affected.

The study links these changes to the emergence of small colony cariants (SCVs) – hardy sub-populations that are adapted to harsh conditions. SCVs have been linked to chronic infections in smokers in previous research.

“We wanted to study S. aureus because it’s so common in humans and it can cause a range of diseases, so we wanted to see what happened when we exposed it to smoke,” says Dr. Maisem Laabei of the University of Bath’s Department of Biology & Biochemistry.

The university’s study is published in the journal Scientific Reports. 

While MRSA is mostly an issue for healthcare, it can impact facilities in other industries. For example, MRSA was reported in several schools in Florida this past May, causing custodial staffs to clean and disinfect the schools according to CDC guidelines.