Staph Bacteria Are Prolific Gene Swappers.(Brief Article)

2001 AUG 8 - (NewsRx.com & NewsRx.net) --

When some disease-causing bacteria encounter a new obstacle, they simply swap DNA with their relatives to acquire the genes needed to overcome it. And they do so quite readily, according to scientists at the U.S. National Institute of Allergy and Infectious Diseases (NIAID).

The research reveals how Staphylococcus aureus, the common "staph" bacterium responsible for several human infections, has repeatedly adapted to novel environments and conditions. The research offers new approaches to antibiotic and vaccine design, and answers long-standing questions about the origins of both diseases: toxic shock syndrome (TSS) and antibiotic-resistant infections.

"We have long wondered how TSS and methicillin-resistant staph strains took hold in the population," says study director James Musser, MD, PhD, a bacteria researcher from NIAID's Rocky Mountain Laboratories in Hamilton, Montana. "The debate among microbiologists has been, did isolated strains pick up new genes once and then spread through the population, or did the bacteria acquire the genes on multiple occasions? Our research clearly shows the second explanation is correct."

The discovery likely settles the debate, Musser explains, and raises a concern about how easily bacteria can become dangerous. S. aureus is a common microbe that often causes no illness. Some strains can cause diseases, however, including TSS, food poisoning, and impetigo. The bacteria can infect the skin, blood, urinary tract, and wounds, and are a common source of infections acquired in hospitals. Most people are unknowing S. aureus carriers, intermittently harboring the bacteria on their skin or in their nose and throat, even in the absence of illness.

Whether or not a particular S. aureus strain causes disease depends largely on its genes. Different strains can survive different environments, and Musser's team sought to learn how genes have been exchanged between strains. In the study ...