Abstract:

Objective To analyze the role of phenotypic drug sensitivity test(DST) and GeneXpert MTB/RIF in the diagnosis of drug-resistant spinal tuberculosis. Methods Data of 514 patients diagnosed as spinal tuberculosis in Beijing Chest Hospital, Capital Medical University from 2015-2018 were retrospectively investigated. Pus, granulation tissue and caseous necrotic tissue in the focus were obtained by puncture and surgery in all the patients, then tubercle bacillus among them were cultured by modified L?wenstein-Jensen medium without potato starch and phenotypic drug sensitive tests by concentration methods were carried out, and GeneXpert MTB/RIF test was performed at the same time. Results In 514 patients, 260 were males (50.6%),254 were females (49.4%), ranging from 1 to 86 years old with an average age of 46.2±18.7 years. There were 200 (38.9%) cases of lumbar tuberculosis, 186 (36.2%) cases of thoracic tuberculosis, 60 (11.7%) cases of lumbosacral tuberculosis,46 (8.9%) cases of thoracolumbar tuberculosis,14 (2.7%) cases of cervical tuberculosis and 8 (1.6%) cases of cervical and thoracic tuberculosis. The results of drug sensitivity test were obtained in 109 cases, the positive ratio was 21.2%, 25 bacterial strains were resistance to one and more drugs, the positive ratio was 4.9%, 9 of the positive culture strains were multidrug-resistance tuberculosis and extensively-resistant tuberculosis (XDR-TB) (8.3%). Three hundred and eighty-three cases (74.5%) were positive for GeneXpert MTB/RIF, of which 47 cases (9.1%) were tested rpoB mutation including that of 9 MDR-TB patients confirmed by DST. Conclusion The detection rate of drug-resistant Mycobacterium tuberculosis in spinal tuberculosis focus is low through DST, and drug-resistant cases can not be detected early. GeneXpert MTB/RIF method has a high value for the early diagnosis of drug-resistant spinal tuberculosis patients.

Key words: Tuberculosis, spine, Tuberculosis, multidrug-resistant, Microbial sensitivity tests, Comparative study