Identifying study on cross infection of tuberculosis by RAPD analysis

Objective: To investigate the identifying effect of RAPD on DNA fingerprinting of M．tuberculosis． Methods: Mult-i PCR was adapted to identify the strains from a mother and a daughter who were infected with tuberculosis at the same time and a brother and a sister who were infected one after another．RAPD was used for analyzing fingerprinting polymorphism of genomic DNA of these strains．Results: The four pathogenic strains were all belonged to M tuberculosis．No discrimination of DNA fingerprinting was found between the strain from the mother and the daughter and a obvious discrimination was found between the strains of the brother and the sister by RAPD ANALYSIS．It proved that the homogeneity of strains isolated from the mother and the daughter was good．The contagion was the same and it might be a cross infection between the mother and the daughter．the homogeneity of strains isolated from the brother and sister was poor，it can not be a cross infection． Conclusion: The study showed that RAPD could be used for epidemiological investigation of M tuberculosis，especially for indentifying cross infection．