While completing a postdoctoral fellowship at the National Institutes of Health (NIH), Kiratisin noticed that standard methods used to identify members of the viridans group of streptococci did not always accurately distinguish between different species in this large group of bacteria, many of which cause endocarditis and other serious infections in humans. Moreover, more-sensitive molecular methods for identifying these organisms are not readily available outside of specialized laboratories. He hypothesized that identification of viridans group streptococci might be enhanced by using a technique known as housekeeping gene sequence analysis. Sequencing the glucose-6-phosphate dehydrogenase (gdh) and glucose kinase (gki) genes, he found, produced more accurate identification than either traditional biochemical techniques or sequence analysis of the 16S ribosomal DNA gene of these bacteria.
Kiratisin concluded that ghd/gki gene sequencing is a rapid and accurate means of identifying streptococcus species belonging to the mitis and sanguinis groups of viridans organisms. He also identified several reference strains of viridans group streptococci that had previously been misclassified. Clinical laboratories and physicians will both benefit from Kiratisin's innovative work; precise identification of viridans groups streptococci is particularly vital in treating infections caused by these organisms, some of which are resistant to antibiotics.
More recent research projects also have essential clinical implications. Kiratisin is now studying Burkholderia pseudomallei, a microbe causing melioidosis, an infectious disease endemic to southeast Asia and northern Australia. His work on this pathogen and the application of his gene sequence analysis technique will be of prime importance to clinical microbiology laboratories seeking to identify the disease quickly and accurately.
Kiratisin received his M.D. degree with honors at Mahidol University and his M.S. and Ph.D. degrees in microbiology and immunology from the University of Rochester Medical Center, Rochester, New York. He completed a postdoctoral fellowship in molecular genetics at Stanford University and, with the support of a Fogarty International Center scholarship, a second postdoctoral fellowship in clinical microbiology at the NIH Clinical Center.
The Dade MicroScan Young Investigator Award will be presented at the 104th General Meeting of the American Society for Microbiology (ASM), May 23–27, 2004, in New Orleans, Louisiana. ASM is the largest single life science society, composed of over 42,000 scientists, teachers, physicians, and health professionals. Its mission is to promote research and training in the microbiological sciences and to assist communication between scientists, policymakers, and the public to improve health, economic well-being, and the environment.