Cystic fibrosis and bacteria. Is there a link?

There are those holding on to the hope that C.F. will one day stand for “cure found”.

Steps in the right direction continue with a study from the University of British Columbia. The new research on bacteria that create considerable complications for people with cystic fibrosis indicates how it escalates in the lungs for extended periods and provides new avenues for possible treatment.

Corey Nislow, a professor in UBC’s faculty of pharmaceutical science, explained someone with cystic fibrosis has about one less teaspoon of water in the mucous in their lungs, making it much thicker.

“We wanted to know how the airway environment and the bacteria interact and evolve,” said Nislow.

This information, recently published in Genome Research, focused on Burkholderia cenocepacia, a bacteria that commonly live in the natural environment, but can also become a pathogen for people living with the disease.

A Burkholderia epidemic occurred in Canada and the United Kingdom in the 1990s, with hundreds of cases in British Columbia alone. The bacteria remains to be a major issue as it can be passed from one patient with cystic fibrosis to another; furthermore, a patient with an infection may be ineligible to receive a lung transplant.

Burkholderia is complex to treat, as it is a species of gram-negative bacteria, and contains an almost impenetrable extra membrane that can be resistant to antibiotics.

Nislow used samples of Burkholderia gathered from B.C. patients during the outbreak to examine the bacteria’s genetics and how they interact with the environment.

The researchers discovered the longer the bacteria lived in the host, the fewer toxic traits they retained. As well, the bacteria’s genome often became smaller over time, implying some of the strains were capable of adapting to the inside of the patient’s lungs.

“Burkholderia’s genomes are very malleable and many of the strains isolated from patients had streamlined their genomes and lived and survived with less DNA. Different strains can have three times more DNA than others,” stated the UBC article.

“We’ve identified a common set of core genes that are common to all patient samples,” said Nislow. “The next step is to identify drugs that are specific to those gene products.”

In more recent news about cystic fibrosis, researchers reported in the Annals of Internal Medicine that patients with the disease live a decade longer in Canada than in the United States.

After taking into account the differences of patients’ overall health, severity of the disease, and clinical factors, researchers from both countries discovered the median age for survival is 50.9 years in Canada and 40.6 years in the U.S., speculating the “significant survival gap” could be due to more transplants and universal healthcare.

“Although we cannot draw definitive causal inferences from these analyses, the observed differences raise the question of whether a disparity exists in access to therapeutic approaches or health care delivery such that hypotheses may be generated for further investigation,” concluded the authors.