Comparison of PCR and ELISA on Rapid Diagnois of Tuberculosis
Li Xiaoming;Wu Xueqong;Zhang Dunrong;Li Guoli;Zhang Xiaogang and Wang Wei (Laboratory of Microbiology and Immunology, Hei Shanhu Hospital and Medical Center, Beijing100091)
An assay of amplincation for a 245hp segment derived from the repetitive DNA IS986 specific for Mycobacterium tuberculosis complex was developed by using Polymerase chain reaction(PCR),and a sandwich enzyme linked immunosorbant assay (ELISA) was developed by usingmonoclonal antibody TB15-C3 that recognized specific antigenic determinant of Mycobacterium tuberculosis. Ten strains of acid-fast mycobacteria and 2 strains of non-mycobacteria were tested.Thespecific PCR product was obtained only from Mycobacterium tuberculosis complex. Besides M. tuberculosis and BCG, M. avium and M.scrofulaceum was POsitive by ELISA analysis. The sensitivity ofdetection of M.tuberculosis genomic DNA and bacteria suspension by PCR was lpg or 13 viable bacteria cells respeCtively.The sensitivity of detection of PPD by ELISA was 15 ng / ml. They were usedto detect M.tuberculosis DNA and specific antigenic determinant in 96 clinical specimens from patients with tuberculosis. It was shown that the positivity rate of PCR was higher than that ofconventional acid-fast stain(P0.05) and was not remarkably higher than that of culturgtechniques (P 0.05).The POsitivity rate of ELISA for detection of speCific antigenic detendnant w4smuch higher than that of conventional acid--fast stain, culture techniques and PCR(P0.01).The falsePOsitly rate of ELISA was not remerkably higher than that of PCR (P0.05).Our resultS suggest thatPCR and ELISA may be speCieic, sensitive and rapid techniques for ti.,e diagnosis of tuberculosis.