[Study on DNA fingerprinting of Mycobacterium tuberculosis strains isolated in Southern Chinese army by IS6110-restriction fragment length polymorphism].

Objective: To study the correlation between DNA fingerprinting of Mycobacterium tuberculosis (MTB) stains isolated from the Chinese army in the south and from local residents, and to investigate the molecular epidemiological characteristics of tuberculosis (TB) in the army, for the sake of TB prevention in the army.

Methods: MTB DNA was digested with restriction endonuclease PvuII and electrophoresed in agarose gel, after Southern Blotting, the membrane was hybridized with a 245 bp fragment of IS6110 which labeled [alpha(32)P]-dCTP as probe. Finally, a restriction fragment length polymorphism (RFLP) patterns was shown, and analyzed logestic with epidemiological data from the patients.

Results: A total number of 185 TB strains were detected and the IS6110 copy numbers ranged from 1 - 22. No significant difference was found in the IS6110 copy numbers between patients from army and local patients. IS6110 copy numbers of TB strains in army patients were centered in 6 - 20, however, with 7 - 20 copies in local TB patients. The TB strains were dispersed into 8 groups and the majority of TB strains in both army and local patients was centered in groups I, II, III. The distribution of DNA fingerprint for drug resistance TB strains was significantly different from those for sensitive strains. No different distribution of among groups was found regarding BCG history.

Conclusions: The genetics of TB stains were roughly the same between the army patients and local ones, but there was a strong correlation in the gene levels. Data suggested that a close connection should be considered on TB prevention and treatment for TB patients in the army and local residents.