Public Release: 

Slimy Bacteria Common Cause Of Chronic Infections

Montana State University

BOZEMAN, MT--Bacterial slime is the culprit behind many nagging infections that plague children and adults, say scientists from Montana State University-Bozeman and the University of Iowa in a paper that will be published May 21, 1999 in the journal Science.

Ear infections, periodontitis and cystic fibrosis pneumonia are just a few examples of the infections that involve sticky communities of bacteria called biofilms. Lingering infections can also occur when a person has sutures, contact lenses, urinary catheters, intrauterine devices (IUDs), mechanical heart valves, penile prostheses, and a variety of other implanted devices or procedures.

The researchers explain the relationship between biofilms and infections in a review paper titled, "Bacterial Biofilms: A Common Cause of Persistent Infections." William Costerton, director of MSU's Center for Biofilm Engineering (CBE), is the lead author. Co-authors are Philip Stewart of the CBE and Pete Greenberg of the University of Iowa.

"We have made mild inroads into the medical area since '92," Costerton said. "We are chipping away at our image of bacteria."

Recent advances in understanding the genetic and molecular makeup of biofilms may help find ways to control related infections, the article says.

Science is a weekly journal that publishes scientific news, as well as the most significant breakthroughs in global research. It is the world's largest circulation journal for a general science audience.

"Having a paper accepted that you submitted is rare," Costerton commented. "But then to be invited to write a review for them is a world recognition. I think it's wonderful."

Science is an ideal forum since it covers the "whole spectrum of science, medicine and engineering," he added.

The biofilm article reviews much of the work that has become familiar to followers of the CBE. It tells how bacteria attach to surfaces and, when there's a quorum of cells, form biofilms. It explains the communication that goes on between cells as they create microscopic communities complete with canals, towers and even balloons. It describes how bacteria know when to come together and when to disperse.

The paper goes on to discuss the environmental and medical problems that can result from biofilms. Cystic fibrosis is about the best example of a persistent infection that involves slime, said Costerton, who has seen it close-up for more than 30 years. Costerton and Greenberg each have a child with cystic fibrosis, a disorder that produces abnormally thick mucus in the lungs.

The Science article also explains why it's so difficult to fight biofilm infections. Biofilms, for a variety of reasons, resist the antibiotic artillery that's lodged against them. One theory is that some of the cells grow so slowly - or are so starved - that they don't pass along the antibiotics. Another idea is that some of the cells set up barriers to block penetration.

The future of biofilm research will see the continued dissection of biofilms on a molecular and genetic level, the article says.

"Our modern view of biofilm infections leads to the realization that their effective control will require a concerted effort to develop therapeutic agents that target the biofilm phenotype and community signaling based agents that prevent the formation, or promote the detachment, of biofilms," the article concludes. The techniques are now available to undertake such efforts.


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