Evaluation of mycobacterium tuberculosis complex isolates which isolated between year 2013 and 2018 at zonguldak Bülent Ecevit University Health Application and Research Center

Aim: In this study, it was aimed to evaluate the Mycobacterium tuberculosis isolates obtained from the patients' specimens sent to the laboratory with the pre-diagnosis of tuberculosis between January 2013 and February 2018. Method: Patients' information was obtained from registry and hospital information operating system. Microscopic evaluation of all specimens was performed with Erlich-Zielh-Neelsen, specimens were cultured with Löwenstein Jensen and BACTEC MGIT 960 system, tested by BACTEC MGIT 960 for sensitivity to four basic drugs and PCR test was performed with TB AMPLICOR (Roche Diagnostics) system. Data were entered into SPSS 19.0 program and descriptive evaluations were made. Results: Among the mentioned dates, 7842 patient specimens (72.7% lung, 15.4% sterile body fluid, 6.1% tissue and 5.7% urine) were examined. 2.7% of the specimens were positive with EZN staining. Of the 380 culture positive specimens, 90 (23.7%) were found to be female patients and 290 (76.3%) were male. Culture positivity was found to be statistically significantly higher in male patients and in patients 65 years and older (p <0.001). Tuberculosis positivity was 5.9% in lung specimens, 1% in sterile body fluid specimens, 5.1% in tissue specimens and 0.7% in urine specimens. The rate of positivity was found to be 4.8% by both culture methods, and it was determined that there was a statistically significant decrease in positive culture rates between 2013-2018. Seven patients who were found to be negative with LJ were positive with MGIT 960 culture method. Contamination rates were found to be 1.9% and 2.4% for LJ and MGIT 960, respectively. Five of the 303 specimens with the PCR test request were positive and all of them were grown in culture. Nine specimens with negative PCR were identified positive for culture and tuberculosis was reported. STR, EMB, INH and RIF resistances were determined as 9.5%, 1.5%, 15.9% and 1.1% respectively. 8 isolates were found to be resistant to STR + INH, 3 isolates RIF + INH, 1 isolate RIF + STR, 1 isolate STR + EMB, 4 isolates EMB + INH and 1 isolate INH + RIF + STR. Results: There was a statistically significant decrease in positive culture rates between 2013-2018. Culture positivity was found to be statistically significantly higher in male patients and in patients 65 years and older. The highest resistance rate was found against isoniazide. Three isolates (0.7%) were found to be multidrug resistant (INH + RIF). Keywords: Mycobacterium tuberculosis, Löwenstein Jensen, MGIT 960, drug susceptibility testing