MANHATTAN, Kan. -- Antibiotic-resistant bacteria are becoming a growing problem around the world, and are a particular worry in hospital-acquired infections.
"In U.S. hospitals today there are reported to be upward of 2.5 million infections annually for people who came to a hospital to be treated for one thing, but before they are sent home they've acquired a secondary infection," said Lynn Hancock, assistant professor in the Division of Biology at Kansas State University.
Hancock was awarded nearly $1.5 million for the next five years from the National Institutes of Health, Institute of Allergy and Infectious Diseases, to investigate the antibiotic resistance of enterococci, a type of bacteria commonly found in hospitals.
Hancock said 10 to 12 percent of hospital-acquired infections, called nosocomial infections, are from enterococcus. Although not as severe or as numerous as the more commonly known staph infection, doctors are running out of therapeutic options for enterococcal infections.
"Some are resistant to just about every antibiotic we can throw at them and we are going to reach an era that many doctors and scientists think will be similar to the pre-antibiotic era, when we didn't have any way to really treat an infection," Hancock said. "Sadly, we don't do an adequate job of reporting the cause of death from infection; in many cases it is simply reported as complications from surgery."
On paper the numbers seem impersonal. However, Hancock has young children and has become fully aware of the possibility that they will grow up in a world that is teeming with antibiotic-resistant bacteria.
"As a father with young kids you worry about what they might get exposed to at school," Hancock said. "Not just enterococci but many other bacteria are evolving resistance to antibiotics, and if the most suitable antibiotic is not working anymore, it just prolongs the process of trying to overcome the infection."
Although enterococci are naturally found in the intestinal tract, outside the intestinal walls they can cause endocarditis, meningitis or bladder, prostate and urinary-tract infections, Hancock said. Routine hospital procedures also can facilitate the transmission of bacteria from patient to patient.
Under normal circumstances these infections could be eliminated by using antibiotics. Enterococci, however, like many other types of bacteria, have developed the ability to form 3-D tower-like structures called biofilms, Hancock said. The formation of the biofilm enables the bacterial cells to cluster together, resisting both antibiotic penetration and the host's immune system.
"The biofilm creates a lifestyle that really enhances survival of the bacteria, both within the patient and out in the environment, even on common medical devices such as catheters and stents," Hancock said.
Hancock's initial investigations have shown that within the community of bacteria certain cells are targeted for death using specific signals. Once the cell dies, the DNA from that dead cell is used as a matrix for the rest of the community, as bacterial cells assemble to form the biofilms.
"The focus of our research is to better understand what factors the bacteria use to structure themselves into communities like biofilms. The hope is that if we can identify the important factors that mediate the biofilm process, we can therapeutically target and disrupt these structures," Hancock said. "For example, if we could disrupt the signaling between bacterial cells, then they'll never be able to communicate to form and establish a biofilm."
The grant from the National Institutes of Health will give Hancock the resources for salaries, supplies and equipment that are necessary to carry out his research. He hopes that in the coming years the findings in his lab will lead to additional treatment options to allow clinicians to cure infections caused by a highly antibiotic-resistant bacterium.
|Contact: Lynn Hancock|
Kansas State University