Bacteria found in major cigarette brands. It’s not enough that smoking causes all manner of cardiopulmonary complications, or that more than 3,000 chemicals and heavy metals have been identified as additives. Now comes evidence that tobacco particles extracted from cigarettes contain markers for hundreds of known bacteria. Lung infections in some smokers may be caused by germs on shredded tobacco, rather than the act of smoking itself. According to a report by Janet Raloff in Science News , Amy Sapkota and a team of researchers at the University of Maryland screened tobacco flakes from cigarettes for bacterial DNA using known markers. In an online paper for Environmental Health Perspectives , the scientists explored the bacterial metagenomics of cigarettes using standard cloning and sequencing processes. The team provided evidence for the presence of Campylobacter (a cause of food poisoning), E. coli, several Staphylococcus varieties, as well as a number of bacteria, such as Clostridium, which is directly associated with pneumonia and other infections . Fifteen different classes of bacteria in all, with no significant variation from one cigarette brand to another.