Scientists discover how hospital bacteria becomes superbug

An international team of scientists led by Monash University researchers has determined how a common hospital bacterium becomes a deadly superbug that kills increasing numbers of hospital patients worldwide.
The microorganism, Clostridum difficult, accounts for $3.2 billion each year in health care costs in the United States. Team leader Dr. Dena Lyras and lead author Dr. Glen Carter have linked a naturally occurring mutation in the bacteria to severe and debilitating diarrhea in hospital patients undergoing antibiotics therapy.
The antibiotics destroy the "good" bacteria in the gut, allowing the "bad" bacterium to colonize the colon, which then causes bowel infections that are difficult to treat.
"This mutation effectively wipes out an inbuilt disease regulator, called anti-sigma factor TcdC, producing hypervirulent strains of C. difficile that are resistant to antibiotics and which have been found to circulate in Canada, the US, UK, Europe and Australia," Lyras said.
The results of the research suggests that bacterial strains carrying this mutation have the potential produce more of the harmful toxins that cause disease in susceptible individuals, such as patients aged 65 years or over.
"As we now have a better understanding of these strains, we can design new strategies to prevent, control and treat these infections," Carter said.