A technique commonly used to measure atmospheric gasses may help doctors more easily detect which cystic fibrosis patients are harboring dangerous pulmonary infections. Researchers have found that the breath of patients with the disease contains relatively high levels of a bacterial gas, which may correlate with the severity of complications.
Cystic fibrosis patients develop an unusually thick and sticky mucous in their lungs, creating an ideal environment for the growth of the Pseudomonas aeruginosa bacterium (ScienceNow, 28 March 2002). Although generally harmless in healthy individuals, the bacterium grows rapidly in those with cystic fibrosis and can lead to breathing problems and death. Currently, doctors look for P. aeruginosa in phlegm; however, some individuals and children under the age of 10 have trouble with the strenuous coughing needed to obtain adequate samples.
Looking for a better way to detect the bacterium early, pediatrician Dan Cooper and chemist Donald Blake of the University of California, Irvine, teamed up with UC Irvine atmospheric chemist Sherwood Rowland, who first discovered the damaging effects of CFCs in the ozone layer. The team wondered if they could use methods similar to those employed to analyze atmospheric gases to measure trace amounts of bacterial gasses in an individual's breath. To do this, Cooper and colleagues collected breath samples from 23 cystic fibrosis patients and 20 patients without the disease using a mouthpiece and small, stainless steel canister.
The researchers quantified the samples on a sensitive gas analytical system, which can detect hundreds of chemicals in exhaled breath. The concentration of carbonyl sulfide gas (OCS), a common bacterial byproduct, was on average 2 times higher in cystic fibrosis patients than in healthy individuals, the team reports online this week in Proceedings of the National Academy of Sciences. "There [was also] a clear relationship between increased OCS concentration and poor pulmonary function," says Cooper.
If doctors can use this new method to detect and treat the bacteria before they become resistant to antibiotics, it could save lives and increase the quality of life of cystic fibrosis patients, says Brian Morrissey, the director of the Adult Cystic Fibrosis Clinic at the University of California, Davis. He cautions, however, that the study should be repeated in a larger group to determine whether the method will work for the population as a whole.