Culture proven extra pulmonary tuberculosis: drug susceptibility and genetic profile analysis

Abstract

Tuberculosis is seen generally in the lungs. Besides, all organs in the body can be affected by tuberculosis. Diagnosis of extra pulmonary tuberculosis (EPTB) is more difficult than pulmonary tuberculosis (PTB). Although, the isolation of Mycobacterium tuberculosis is gold standard of diagnosis of EPTB, the rate of bacteriologic isolation is low especially in EPTB. If M. tuberculosis is detected, it gives some information about the epidemiological features of the disease and drug susceptibility. In this study, extra pulmonary samples isolated M. tuberculosis in mycobacteriology laboratory were evaluated between 2009-2016. The identification of the genotype of isolated bacteria and drug sensitivity tests were conducted. Spoligotyping was accomplished using a standard technique as described previously. During the study period, M. tuberculosis were cultured in 171 extra pulmonary samples of 165 patients (75 male, 90 female, mean age: 53.35 ± 19.92). Initial direct microscopically examination was revealed M. tuberculosis in 44 patients. There were more than one extra pulmonary organ involvement in six patients. The most common EPTB forms were lymph node TB in 60 patients, pleural tuberculosis in 32 patients and bone tuberculosis in 25 patients. Immunosuppression was detected in 44 (%26.6) patients. Among these, seven patients were infected with HIV. In 21 of 175 samples, drug resistance was detected. Rifampicin resistance in 7 samples, high level isoniazid resistance in 11 samples and rifampicin plus isoniazid resistance (multiply drug resistance) in 6 samples were demonstrated. One hundred thirty-five clinical isolates were cultured from tuberculosis patient's different samples, of which the genetic profile was determined by using Spoligotyping. The major Spoligotypes were T (n= 62; 45.9%), LAM7-TUR (ST41) (n= 11; 8.1%) and H1 (n= 9; 6%) genotypes. The most common EPTB form was lymph node tuberculosis in culture proven patients. In these patients group, multiply drug resistance rate was low (3.6%). Spoligotypes T (45.9%) was detected as most common genetic profile.