Rapid Identification Of Mycobacterium Species In Suspicious Joint Tuberculosis By PCR-reverse Cross-blot Hybridization Method

Joint tuberculosis etiological diagnosis is difficult, its early clinical manifestations and imaging tests are lack of specificity, serological tests only have diagnostic value, tuberculous granuloma-likechanges of Mycobacterium tuberculosis infection are not unique pathological manife stations, it also can be caused by non-tuberculous mycobacteria(NTM) infection; Therefore, the clinical diagnosis of suspected joint tuberculosis contains the cases of joint tuberculosis and non-tuberculous mycobacteria joint infections, it's need the further mycobacterial species identification before a final diagnosis. In recent years, the development of molecular biology technique is rapidly, it only needs a small amount of mycobacteria's DNA to figure the species out,with high sen sitivity; The differences between the orders of nucleotides in length of mycobacterial genes conserved sequences(such as the 16S rRNA gene, 16S?23S rRNA gene), can be used as a target gene in strain identification tests; Based on these characteristics of molecular biology techniques, it can be an effective means for suspected joint TB species identification.In this study, using culture strain identification method and PCR-reverse cross-blot hybridization method, depend on the clinical manifestations, serological tests, imaging tests and pathology diagnosis, to identify the strains of 35 cases of suspected joint TB cases and 35 cases of non-joint TB cases, in No.309 Hospital of PLA orthopedics, from December 2013 to October 2015.Culture strain identification method 4-6 weeks reporting results, from suspected joint tuberculosis group identified 8 cases of tuberculosis,one case of Mycobacterium bovis, non-joint TB group results are positive, the sensitivity 25.7%, specificity is 100%; PCR-reverse cross-blot hybridization method one day report, from joint tuberculosis group identified 18 cases of Mycobacterium tuberculosis complex, and 1 case of Mycobacterium gordonae, 1 case of Mycobacterium gilvum, non-joint tuberculosis group has 1 positive case of mycobacterium tuberculosis complex, through PCR-Direct Sequencing of joint tuberculosis 20 cases PCR-reverse cross-blot hybridization method consistent positive results with PCR-Direct Sequencing, One case of Mycobacterium tuberculosis complex in non-joint tuberculosis group detected by PCR-direct sequencing is not amplified nucleotide sequence, proved to be falsepositive, sensitivity 57.1%, specificity is 97.1%; the differences between both the positive rates of strain identification methods have statistically significant by using paired Kapha test(?~2 = 11.286, P = 0.01).PCR-reverse cross-blot hybridization method don't need to isolate mycobacterial strains from clinical specimens, the M. tuberculosis DNA can be extracted directly from the clinical specimens of suspected joint tuberculosis in testing, rapid identifying the species of bacteria, guiding orthopedic doctors correct diagnosis, rational drug use and does not require expensive laboratory equipment, suitable for using in primary hospitals.