Staphylococcus infections used to be associated with hospitalization, recent surgery, and residence in long-term-care facilities. But now, the infections are striking healthy individuals locally and nationally. The experts aren’t sure why.
Complicating the rise of infection is the organism’s growing resistance to antibiotic treatment — considered to be one of the most urgent priorities in public health. Many infectious disease experts believe the spread of staphylococcus is a public health crisis and new solutions must be found soon.
Antibiotic resistance is responsible for increasing deaths and severity of disease, and rising health care costs. Some physicians also fear a return to the pre-antibiotic era when there were no medications to fight off infection when living or dying depended on how strong the person was in fighting off an infection.
The University of Nebraska Medical Center recently formed a research group focused on the problem of staphylococcus infections. Members include: Paul Fey, Ph.D., Ken Bayles, Ph.D., Steven Hinrichs, M.D., Paul Dunman, Ph.D. and Mark Rupp, M.D., all of UNMC, as well as Greg Somerville, Ph.D., of the University of Nebraska-Lincoln; and Creighton University’s Richard Goering, Ph.D.
“We want to build our microbiology research capacity,” said Dr. Fey, an associate professor in the UNMC Department of Pathology/Microbiology, and associate director of the clinical microbiology laboratory and Nebraska Public Health Laboratory. “We decided to recruit faculty with interests within the staphylococci field since this problem is of national importance.
“We’re taking a systematic approach to studying staphylococci. Each investigator has his own niche, and our goal is to collaborate on large grants, projects, etc,” he said. Dr. Fey’s research will focus on staph’s clinical epidemiology – how the bacteria avoid detection and treatment.
The group of seven microbiologists and infectious disease researchers will study methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis. The group will pool their expertise and new technology to better understand and exploit their knowledge of the bacteria, in order to prevent and ultimately develop better antibiotics.
“Staph will be one of our biggest health challenges in the next five years. If the existing antibiotic drugs don’t work, we’ll be in significant trouble. We’ll have more people dying of infection,” said Dr. Hinrichs, UNMC professor of pathology and microbiology.
Antibiotic resistance is the result of microbes changing in ways that reduce or eliminate the effectiveness of drugs, chemicals, or other agents, to cure or prevent infections.
“We have seen the power of building multidisciplinary groups at other research institutions and realized it could be a strong recruiting tool for UNMC,” Dr. Hinrichs said. “Scientists are usually very excited about the possibility of working with others who have complimentary technology.
“We believe one of the best ways to compete with powerhouse institutions that have programs build on one individual with an international reputation is to build highly interactive programs with scientists who want to work together.”
Dr. Hinrichs said the team recently recruited Drs. Dunman and Bayles, recognized internationally as experts in staph.
UNMC and its hospital partner, The Nebraska Medical Center, have a special interest in infectious diseases because of its cancer and organ transplantation patients, a population susceptible to a variety of infections caused by weakened immune systems. A person with one infection is at risk for complication if they acquire other infections.
Staph, which is commonly present on the skin or in the nose of healthy people, is the cause of some of the most common causes of minor skin infections in the United States. Risk factors for MRSA infections include recent hospitalization or surgery, residence in a long-term-care facility or injecting-drug use. Staph infections can cause serious infections such as surgical wound infections, bloodstream infections and pneumonia. Severe infections can cause death.
Currently, about 50 to 60 percent of staph infections are resistant to multiple kinds of antibiotics, making staph much more difficult to treat. Not only are hospital-acquired MRSA infections on the rise, but so are MRSA infections in those living in the community. Physicians are baffled about how it has developed in community settings.
Over the past decade, health care surveillance officials have seen a remarkable increase in resistance among important community- and hospital-acquired pathogens, such as penicillin-resistant Streptococcus pneumoniae, vancomycin-resistant enterococci and MRSA.
According to a paper published in April in the New England Journal of Medicine, community-associated MRSA infections are now a common and serious problem. In the study, the Centers for Disease Control and Prevention (CDC) concluded the infection usually involves the skin, especially among children, and hospitalization is common.
Dr. Rupp said history has shown that bacteria are very successful at developing mechanisms of resistance and appears it’s only a matter of time before Staphylococci become resistant to any antibiotic thrown at them.
“Within a few years of developing simple penicillins, staph made an enzyme that broke down penicillin. In the 50s, antistaphylococcal pencillins were made, but within a few years, the organism developed a resistance to them as well,” Dr. Rupp said. “Staph has developed resistance to every antibiotic developed.”
Dr. Rupp said the group’s goal is to understand the mechanism of resistance and how the bacteria spread in order to better exploit the organism and develop better antibiotics. In addition, he said health professionals are working hard to use antibiotics more prudently to preserve their value.
“I think this may become a public health crisis,” Dr. Rupp said. “We’ll see more and more antibiotic resistance. There needs to be incentives to study it and come up with new solutions before we reach a crisis level. Here is a group that is being proactive. I fear we may run out of antibiotics to treat this organism in the next five to 10 years, so it is vitally important to anticipate this potential calamity.”
“They (bacteria) have a very plastic genome,” Dr. Rupp said. “The whole life cycle lasts 30 to 60 minutes. It’s not accurate in replicating its DNA like higher life forms. This is Darwinian evolution at a very, very fast pace.
“As has been said, when you grow up every 30 minutes, you get smart pretty fast. It takes thousands, if not millions of years, for humans to evolve and react to the environment. Bacteria, which can develop resistant traits in as short a time as a few days, are the most successful life form around. They will be here long after humans are gone,” he said.
MRSA is one example of an evolving bacterium.
“It’s no longer a pathogen associated exclusively with the health care environment. It’s striking healthy individuals,” Dr. Rupp said. “The big fear is we’re returning to the pre-antibiotic era – a time like the 1920s when all you had to offer someone with an infection was surgical drainage and supportive care. There was little you could do. Some people are calling this the beginning of the post-antibiotic age.”