A Growing Threat

Beyda's Publication on Risk Factors, Outcomes of Emerging Drug-resistant Fungal Infection Among 'Top 10 Papers in Mycology' at International Infectious Diseases Conference

UH College of Pharmacy's Nicholas Beyda, Pharm.D., BCPS, research assistant professor, was recognized at one of the world's premier meetings of the infectious disease community for his study identifying the risk factors and treatment outcomes associated with an emerging drug-resistant fungal infection.

Beyda's paper on the fungus Candida glabrata and its resistant mutant strains was honored among the "Top 10 Papers in Mycology" at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy Sept. 5-9 in Washington, D.C. The paper was published online May 2014 and in the hardcopy September 2014 issue of the Infectious Disease Society of America's peer-reviewed journal Clinical Infectious Diseases.

"Bloodstream infections due to Candida species are associated with significant mortality, morbidity and increased healthcare costs," Beyda said. "In the past, one of the major players in fungal infections was Candida albicans, which was usually treated with a class of antifungals called azoles. However, partly due to the widespread use of these drugs, C. glabrata is becoming one of the 'new kids on the block' among fungal infections, particularly among the elderly and immunosuppressed." 

The most common treatment for Candida species infections is a relatively new class of antifungal agents called echinocandins, which effectively kills the fungus by inhibiting an enzyme that forms a vital part of the fungal cell wall.

"However, we're starting to see the development of resistant strains of C. glabrata, most notably with FKS gene mutations, which encodes for resistance to the echinocandins," Beyda said. "In our study, we wanted to determine how prevalent these mutations were in patients with C. glabrata infections as well as identify any risk factors associated with developing a resistant strain and the treatment outcomes."

Biobanked isolates from 72 patients with C. glabrata bloodstream infections admitted to a Houston hospital over a three-year period were included in the study. Thirteen isolates (18%) were identified as having the FKS mutation, which Beyda said was high but comparable to recently published studies from Duke and the University of Pittsburgh.  

"When we further evaluated the charts for those with the FKS mutation, we identified a significant association of the mutation with previous exposure to echinocandins, which -- along with an underlying gastrointestinal disorder -- was significantly associated with echinocandin treatment failure," Beyda said.   

Beyda's coauthors on the paper, entitled "FKS mutant Candida glabrata: risk factors and outcomes in patients with candidemia," were current/former UHCOP lab members Julie John, Abdullah Kilic, and Mohammad J. Alam; Baylor St. Luke's Medical Center Director of Clinical Microbiology Todd M. Lasco, Ph.D.; and UHCOP Professor Kevin W. Garey, Pharm.D., M.S.