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Bacteria in disguise cause problems for cystic fibrosis sufferers

Bacteria that cause infections in the lungs of cystic fibrosis patients avoid detection by changing their appearance according to Cardiff University researchers speaking today, Thursday 13 September 2001, at the bi-annual meeting of the Society for General Microbiology at the University of East Anglia.

"Pseudomonas aeruginosa bacteria, which cause life-threatening infections in 70% of cystic fibrosis (CF) patients, repeatedly adapt themselves during long-term infection. They produce large quantities of slime and change the structure of their cell wall to avoid detection and escape the lethal effects of antibiotics " says Dr Eshwar Mahenthiralingam of the School of Biosciences at Cardiff University, UK.

CF patients also face life-threatening infections caused by Burkholderia cepacia complex bacteria, which are extremely difficult to identify and control. B. cepacia complex bacteria account for approximately 6% of infections in CF patients nationally, although some treatment centres have many more infected patients. They are intrinsically resistant to many antibiotics and infections caused by these bugs are rarely cured.

"We have found that the B. cepacia complex is made up of at least seven closely related species, initially called genomovars I to VII, which cause infections of varying severity. Genomovar III appears to be the most pathogenic species isolated from CF patients 70% of all B. cepacia complex infections and it also has the ability to replace infections caused by other genomovars. If we can correctly identify which species is causing an infection then this will have implications for treatment." Says Dr Mahenthiralingam.

Dr Mahenthiralingam says, "Both P. aeruginosa and B. cepacia complex bacteria are highly resistant to antibiotics and by dissecting their biology we are learning new information about how bacteria resist killing by these therapies. This research will reduce the impact of hospital acquired infections on the health service and also greatly inform the CF community on the risks associated with infection by these bacterial species."


Society for General Microbiology. August 2001.