MedicalResearch.com Interview with:
Ying Kong Ph.D.
Assistant Professor
University of Tennessee Health Science Center
Department of Microbiology, Immunology, and Biochemistry
Memphis, TN 38163
MedicalResearch.com: What is the background for this study?
Response: Tuberculosis (TB) is a public health concern worldwide, with high morbidity and mortality. The causative agent of TB, M. tuberculosis, grows very slowly in culture. For research of TB, we need to quantitate bacterial numbers in order to evaluate drug and vaccine efficacy or to identify bacterial genes that are critical for survival in hosts or causing disease.
M. tuberculosis divides every ~20 hours, which is much slower than other bacteria such as E. coli and Salmonella typhimurium, which divide every 20 minutes. Conventionally, quantitation of M. tuberculosis needs to spread M. tuberculosis on agar plates and wait for four weeks to obtain visible colonies, and then to count colony forming units. For the fast-growing bacteria, it takes only 18 hours to obtain visible colonies on agar plates. We and other groups have developed fluorescent protein labeled M. tuberculosis strains in order to quantitate M. tuberculosis in real time by measuring fluorescence. In this way, we are able to estimate bacterial number right after fluorescence measurement, which only takes a few minutes. However, this technology is not a diagnostic tool for clinical use, because the M. tuberculosis strains that we used were recombinant strains transformed with fluorescent protein genes. Another imaging technology that we have developed, REF, is for diagnosis purpose, which has been described in details in our other papers (Xie H, et al. Rapid point-of-care detection of the tuberculosis pathogen using a BlaC-specific fluorogenic probe. Nat Chem. 2012 Oct;4(10):802-9. Cheng Y, et al. Fluorogenic probes with substitutions at the 2 and 7 positions of cephalosporin are highly BlaC-specific for rapid Mycobacterium tuberculosis detection. Angew Chem Int Ed Engl. 2014 Aug 25;53(35):9360-4.).
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