[Identification of the Mycobacterium tuberculosis complex by detecting recombinant secretory protein MPT64].
OBJECTIVE
To identify the Mycobacterium tuberculosis complex by detecting the secretory protein MPT64.


METHODS
The gene mpt64 was amplified by polymerase chain reaction (PCR) from the genome of Mycobacterium tuberculosis H(37)Rv strain and cloned into expression vector. Immune sera from rabbits by recombinant proteins MPT64, were used to make enzyme-labeled antibodies and coated antibodies. A double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was established to detect the secretory protein MPT64 of the culture supernatants in Mycobacterium strains. Results of ELISA were compared to those of the gene mpt64 amplified by PCR.


RESULTS
A recombinant vector was constructed. The minimum detectable concentration of MPT64 was 0.01 mg/L. A total of 27 reference strains and 170 clinical isolate strains were evaluated. PCR for Mycobacterium tuberculosis reference strain, Mycobacterium bovis reference strain and Mycobacterium africanum reference strain was positive, but that for other reference stains was negative, consistent with the results of ELISA. In the 170 clinical isolate stains, the positive result of PCR and ELISA was 98.2% (111/113) and 97.3% (110/113) respectively, while the specificity of PCR and ELISA was both 100%, no positive result in non-tuberculosis mycobacterium strains.


CONCLUSIONS
Identification of the Mycobacterium tuberculosis complex by detecting secretory protein MPT64 is rapid, sensitive, and specific, which can be used routinely in clinical laboratories.
Liu
Zhong-hua
ZH
Tuberculosis Key Laboratory of Shanghai, Shanghai Pulmonary Hospital, Affiliated to Tongji University, Shanghai, China.
Qin
Lian-hua
LH
Feng
Yong-hong
YH
Bi
Ai-xiao
AX
Yang
Hua
H
Ding
Yuan-sheng
YS
Cui
Zhen-ling
ZL
Jin
Rui-liang
RL
Zheng
Rui-juan
RJ
Hu
Zhong-yi
ZY
D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial; D005822:Genetic Vectors; D006801:Humans; D008297:Male; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism*; D016133:Polymerase Chain Reaction / Q000379:methods; D011817:Rabbits; D012680:Sensitivity and Specificity
D000942:Antigens, Bacterial; C510537:MPT64 protein, Mycobacterium tuberculosis