UC scientist awarded for fungus study

Melanie Cushion, a professor in the University of Cincinnati's infectious disease division, recently received an award to help her continue her studies for another five years.

Cushion received the Research Career Scientist Award from the Department of Veterans Affairs Medical Center.

It is the highest award for non-clinician VA scientists. Cushion is only the third scientist from Cincinnati to receive the award in the last 20 years.

Cushion studies pneumocystis carinii, an ancient parasitic fungus that causes pneumonia in infants, the elderly and people who have weak immune systems.

The fungus received widespread attention when the AIDS epidemic took hold in the 1980s.

Pneumocystis has lived in people's lungs and killed humans since they split off from reptiles in the mammalian diversion, according to a press release.

"We all basically have it," Cushion said, "and one of the areas of research my laboratory is getting into is to understand this relationship better in terms of its colonization. It's very elusive."

The fungus isn't particularly harmful. It becomes a problem when a person's immune system is weakened by old age, radiation and sickness.

"Pneumocystis doesn't want to kill us," Cushion said. "Unlike a nasty organism like Ebola, which jumps species, something that pneumocystis doesn't do and hasn't been able to establish this balance with its host."

The fungus was first identified in 1912, but no one was able to grow enough of it needed for study, according to the press release.

A lot of the work went into collecting enough material. Cushion, along with her colleagues Jim Stringer, Scott Keely, George Smulian and Brad Slaven, have been able to determine the chemical arrangement of some of the host genome, some bacteria from immunosuppressed lung tissue and almost all of the pneumocystis genome using rat tissue.

"Before we started this project, only about 20 pneumocystis genes were known. We estimate now it's got about 4,000," Cushion said.

Regardless of all the research, problems still remain.

The researchers overcame a shortage of purified study material and had difficulty cloning some of the pneumocystis genome regions.

There is good news, according to Cushion.

The polymerase enzyme may keep making copies so that it becomes detectable to researchers, as long as they have the DNA sequence.

The fungus appears to be spreading to different subpopulations.

It's been found in underlying diseases like cancer and chronic obstructive pulmonary disorder.

The fungus may also be involved in sudden infant death syndrome, according to the press release.

The question is whether it's a "co-morbidity factor," contributing to the underlying chronic disease states, Cushion said.

One of her team's major goals is to use genetic analysis to find drug targets in pneumocystis, so new medications can be developed to treat it, Cushion said.

New medication is needed because the commonly used antibiotic, Bactrim, works well against pneumocystis when it comes to AIDS, but half the patients can't tolerate it.

Evidence shows that the organism is mutating genetically to resist the standard treatment, according to the press release.

"People thought we were crazy when we began the Pneumocystis Genome Project," Cushion said. "But genetic analysis is where the action is and that's the fun and interesting part of pneumocystis research."