K-State Research Team Explains Age-Old Iron Debate

A Kansas State University research team has resolved a 40-year-old debate on the role of iron acquisition in bacterial invasion of animal tissues.

The collaborative research -- led by Phillip Klebba, professor and head of the department of biochemistry -- clarifies how microorganisms colonize animal hosts and how scientists may block them from doing so. The findings suggest new approaches against bacterial disease and new strategies for antibiotic development.

The study -- in collaboration with Tyrrell Conway, director of the Microarray and Bioinformatics Core Facilities at the University of Oklahoma, and Salete M. Newton, Kansas State University research professor of biochemistry -- recently appeared in PLOS ONE. It shows how iron acquisition affects the ability of bacteria to colonize animals, which is the first stage of microbial disease.

"This paper establishes that iron uptake in the host is a crucial parameter in bacterial infection of animals," said Klebba, the senior author on the publication. "The paper explains why discrepancies exist about the role of iron, and it resolves them."

Iron plays a key role in metabolism, leading bacteria and animals to battle each other to obtain it. Klebba's team found that E. coli must acquire iron from the host to establish a foothold and colonize the gut -- a concept that was often debated by scientists.

"For years it was theorized that iron is a focal point of bacterial pathogenesis and infectious disease because animals constantly defend the iron in their bodies," Klebba said. "Animal proteins bind iron and prevent microorganisms from obtaining it. This is called nutritional immunity, and it's a strategy of the host defense system to minimize bacterial growth. But successful pathogens overcome nutritional immunity and get the iron."