The team includes Dr. Jen Koehl, former PhD student; Dr. Arunachalam Muthaiyan, Post Doctoral Fellow; and Professors R.K. Jayaswal and Brian Wilkinson. Their research was recognized by ASM News, the news magazine of the American Society for Microbiology, as one of the six major articles in microbiology published in November in the primary research journals of the society. “Being recognized by ASM News is a significant achievement because there are thousands of biologists working in the world and ASM News is one of the most widely read journals in the field. The article brings the work being produced at ISU to the attention of a huge professional audience, bringing recognition and prestige to university,” explained Biological Sciences Chair H. Tak Cheung. “In addition, ASM News recognizing this work is a reflection of the impact this research has on the theoretical level, as well its possibility for practical applications.” 

Staphylococcus aureus causes a variety of pus-forming infections and toxinoses in humans. It causes superficial skin lesions such as boils, styes, and pimples; more serious infections such as pneumonia, meningitis, and urinary tract infections; and deep-seated infections, such as osteomyelitis (invasion of bone). The bacterium is a major cause of hospital acquired infection of surgical wounds and infections associated with indwelling medical devices. It also causes food poisoning, toxic shock syndrome, and scalded skin syndrome (analogous to scarlet fever).

By the early 1990s, the pathogenic bacterium Staphylococcus aureus had become resistant to all available antibiotics, with the exception of vancomycin. This led to an increased use of vancomycin by physicians, and by 1997 the first vancomycin-resistant strain was reported.  PhD graduate Dr. Jen Koehl, now a faculty member at Saint Vincent College in her home state of Pennsylvania, studied the bacteria for her dissertation, of which the paper recognized by the ASM is a part. “Cell Wall Composition and Decreased Autolytic Activity and Lysostaphin Susceptibility of Glycopeptide-intermediate Staphylococcus aureus” was originally published in Antimicrobial Agents and Chemotherapy, the top journal in this area. The study reports investigations into the mechanism of vancomycin resistance. The authors show that the cells autolytic enzymes, which have the capacity to dissolve the bacterium, are downregulated in vancomycin-resistant strains. This helps the bacteria tolerate vancomycin. The ultimate goal for scientists is the development of novel strategies and agents for treating resistant infections.

“First of all, it is very gratifying for all involved that our work has been recognized in this way,” Wilkinson explained. “The research is a significant insight into the mechanism of vancomycin resistance in these strains. We plan to probe how autolysis is down regulated at the molecular level. Boosting of autolysis may well combat vancomycin resistance.”   

Information for this story was taken from Todar's Online Textbook of Bacteriology, “Staphylococcus.” © 2004 Kenneth Todar University of Wisconsin-Madison Department of Bacteriology.