Investigation of miRNA and cytokine expressions in latent tuberculosis infection and active tuberculosis.

BACKGROUND: In tuberculsosis (TB), miRNA has been used as a biomarker to distinguish between healthy individuals and TB patients. The aim of this study was to investigate (i) the association of the miRNA and cytokine expression levels, the course of tuberculosis infection, clinical forms and response to treatment, and (ii) the effects of genotypic features of bacteria on the course of tuberculosis and the relationship between miRNA and cytokine expressions and bacterial genotypes. METHODS: A total of 200 cases (100: culture positive active tuberculosis, 50: quantiferon positive latent tuberculosis infection and 50: quantiferon negative healthy controls) were included in the study. For the tuberculosis group at the time of admission and after treatment, for the latent tuberculosis infection and healthy control groups at the time of admission, miRNA and cytokine expressions were determined. Genotyping of M.tuberculosis isolates was performed by spoligotyping method. RESULTS: While, in the comparison of miRNA expressions between the pretreatment patient group and the healthy control group, there was a statistically significant decrease in the expression of miR-454-3p, miR-15a-5p, miR-590-5p, miR-381, and miR-449a in the Pulmonary TB group, there was no significant change in miRNA expression in extrapulmonary TB patients. When the cytokine expressions of the patient group and the healthy control group were compared before treatment, the expressions of all cytokines in the patient group decreased. However, the only cytokine that showed a significantly lower expression was IL12A in PTB patients. DISCUSSION: There is no significant relationship between the clinical course of the disease, cytokine and miRNA expression, and the genotype of the bacteria.

Evaluation of antimicrobial susceptibilities of non-tuberculous mycobacteria against linezolid and tigecycline.

Mycobacterial susceptibility testing is important for the management of nontuberculous mycobacteria (NTM) infections. The aim of the study is to determine the susceptibilities of tigecycline (TGC) and linezolid (LZD) against NTM. The study was carried out using stocks of NTM strains in the tuberculosis department of the microbiology laboratory. It was designed a retrospective study. LZD and TGC sensitivities of study isolates were analyzed by microdilution. Forty NTM isolates have been studied. LZD and TGC sensitivities varied according to the NTM type. It is concluded that each isolate should be individually evaluated due to variable susceptibilities to LZD and TGC.

Five Years' Evaluation of the BD ProbeTec System for the Direct Molecular Detection of Mycobacterium tuberculosis Complex in Respiratory and Nonrespiratory Clinical Samples.

In this study, Mycobacterium tuberculosis complex was detected by BD ProbeTec ET system in 4716 respiratory and 167 nonrespiratory samples [mostly (98%) smear negative). Sensitivity, specificity, positive and negative predictive values were 81.8%, 98.3, 85.1 and 97.9 for respiratory and 100%, 96.2, 64.7 and 100, for nonrespiratory samples, respectively. Among 149 (3.1%) ProbeTec DTB positive and culture negative samples, 72 (65 respiratory and seven nonrespiratory) (48.3%) were recovered from the patients who were evaluated as having TB infection. The system has been found as useful in early diagnosis of tuberculosis infection in association with the clinical, radiological and histopathological findings.

The role of the tissue culture in granulomatous mediastinal lymphadenitis: tuberculosis or not.

AIM: To evaluate the role of the tissue culture via mediastinoscopic biopsy in granulomatous mediastinal lymphadenitis. METHODS: The dossier data of 92 cases with mediastinal lymphadenitis showing granulomatous lymphadenitis features by cervical mediastinoscopy and whose clinical, radiological and bacteriological definitive diagnosis is tuberculosis and sarcoidosis were examined retrospectively. The rate of the positive tissue culture of mediastynoscopic biopsy in the diagnosis of granulomatous lymphadenitis was calculated. RESULTS: There were 65 (71%) females and 27 (29%) males. The mean age of the patients was 42.5 (range 15-75) years. Non necrotizing granulomatous lymphadenitis was detected in 58 (63 %) cases while necrotizing granulomatous lymphadenitis was seen in 34 (37%) cases. There were 29 cases diagnosed with tuberculosis. Acid resistant bacilli culture positive rate was 38% (in 11 cases). There were 21 (62%) cases of necrotizing granulomatous lymphadenitis and eight (14%) cases of non-necrotizing granulomatous lymphadenitis diagnosed with tuberculosis. Culture positivity was identified in two (25%) of eight cases whose differential diagnosis could not be made histopathologically as tuberculosis/sarcoidosis. CONCLUSIONS: In addition to clinical, radiological and histopathological diagnosis, the study aims to highlight the importance of tissue culture in definitive diagnosis, especially undetermined incidents.