Polymerase chain reaction based detection of Mycobacterium tuberculosis complex in lupus vulgaris: a case report.

Lupus vulgaris (LV), the commonest of all forms of cutaneous tuberculosis, can affect the earlobes. Authors present a 20-year-old male patient with LV of the left earlobe initially misdiagnosed as pyoderma and treated superfluously with antibiotics at different intervals over the last 4 years in another hospital. Mycobacteria could not be seen or isolated by stained smears or conventional or radiometric culture methods from the skin biopsy specimens. Suspected clinical diagnosis of our patient was LV. This was supported by positive polymerase chain reaction assay and histological findings. The lesion was treated successfully with anti-tuberculosis chemotherapy, further confirming the diagnosis of LV.

Evaluation of a new automated, rapid, colorimetric culture system using solid medium for laboratory diagnosis of tuberculosis and determination of anti-tuberculosis drug susceptibility.

SETTING: Department of Microbiology and Clinical Microbiology, Gulhane Military Medical Academy, Ankara, Turkey, a tertiary referral hospital in a region endemic for tuberculosis. OBJECTIVE: To evaluate the performance of the Dio-TK Culture System (CS), a new, rapid, automated colorimetric culture system. DESIGN: Dio-TK CS results were compared with routinely used Löwenstein Jensen (LJ) medium and Bactec 460 TB. RESULTS: In this study, 449 specimens, mostly sputum samples obtained from 348 patients, were evaluated. Mycobacteria were isolated from 31 (6.9%), 23 (5.1%), 18 (4.0%) and 21 (4.7%) of the specimens using Bactec 12B, LJ, Dio-TK Medium and Dio-TK SLC (selective), respectively. The mean time to detection of growth of 13 isolates by Bactec 12B, Dio-TK Medium, Dio-TK SLC and LJ medium was respectively 8.9, 15.1, 17.0 and 26.1 days. CONCLUSION: Dio-TK may be a practical and rapid culture system for daily use. However, the manufacturer should improve the system to minimise the effects of manipulation errors. Comparative studies with a larger number of isolates are needed to standardise drug concentrations used in anti-tuberculosis drug susceptibility testing.

Evaluation of FASTPlaqueTB-RIF for determination of rifampicin resistance in Mycobacterium tuberculosis complex isolates.

SETTING: The Microbiology and Clinical Microbiology Department, Gulhane Military Medical Academy, Ankara, Turkey, a tertiary referral hospital in a region endemic for tuberculosis. OBJECTIVE: To evaluate rifampicin resistance of Mycobacterium tuberculosis complex strains using FASTPlaqueTB-RIF, a rapid and novel bacteriophage-based susceptibility technique. DESIGN: Results of isolates tested with the BACTEC 460 TB system were compared with FASTPlaqueTB-RIF. RESULTS: Susceptibility to rifampicin of M. tuberculosis complex isolates was tested for 88 isolates using FASTPlaqueTB-RIF. Sixty-seven isolates were susceptible and 21 were resistant to rifampicin using the BACTEC 460 TB system. Overall accuracy for FASTPlaqueTB-RIF was 94.3% (95%CI 87.3-97.5) for the detection of rifampicin susceptibility. The sensitivity and specificity of FASTPlaqueTB-RIF were respectively 100.0% (95%CI 84.5-100) and 92.5% (95%CI 83.6-96.7). CONCLUSION: This study demonstrates that FASTPlaqueTB-RlFM is a rapid and inexpensive test which has a good correlation with the BACTEC 460 TB system.