Recombinant M. Tuberculosis Rv0192A Antigen [His, GST]

Tuberculosis (TB) is a deadly infection and caused 1.4 million deaths in 2018. Assessing the geographic distribution of major lineages of Mycobacterium tuberculosis can contribute greatly to TB control. Mycobacterial interspersed repetitive unit variable number tandem repeat (MIRU-VNTR) typing is commonly used to differentiate various lineages of M. tuberculosis. A total of 2747 clinical specimens were collected consecutively from October 2018 through June 2019. Clinical isolates were identified as M. tuberculosis using standard biochemical tests. The standard 15-locus MIRU-VNTR typing was used for the genotyping of clinical isolates. Drug susceptibility testing was performed using the conventional proportion method. From the collected specimens, 100 were culture positive for M. tuberculosis. Using MIRU-VNTR, 99 different patterns were detected among the 100 isolates. They were distributed in one cluster comprising two strains and 98 unique patterns. Most of our isolates were similar to New-1 and Delhi/CAS strains. Of the M. tuberculosis isolates, 83 (83.0%) were pan-susceptible and 17 (17.0%) were resistant to at least one drug. Our study showed that MIRU-VNTR is a useful method for studying the genetic diversity of M. tuberculosis isolates in different regional settings and will help the health authorities to construct a preventive programme for TB. (C) 2020 The Author(s). Published by Elsevier Ltd.

Longitudinal studies regarding the reproducibility of Interferon-gamma release assay (IGRA) T-SPOT.TBfor the diagnosis ofMycobacterium tuberculosis(M. tb) infection in serial testing are limited. We retrospectively analysed results of serially tested subjects in a medical laboratory in Germany over a time period of 14 years. From October 2004 to December 2018, a total of 5440 subjects were identified with a second T-SPOT.TBtest after a median time interval of 258 days (interquartile range [IQR] 62-665). Consistently negative (n = 4520) or positive results (n = 682) were observed in 5202 (95.6%) subjects, indicating a high degree of concordance in serial testing (kappa = 0.83). Test conversions occurred in 101 of 4621 (2.2%) subjects with initially negative tests. Of 819 subjects with initially positive test results, 137 (16.7%) had a test reversion which was associated with low spot numbers of the first test. Of 529 subjects retested within 1 year, only 60 (11.3%) displayed a test reversion. In subjects retested after more than 1 year, 77 of 290 (26.6%) tests reverted. This significantly higher rate of test reversions after more than 1 year was age-dependent and only observed in subjects above the age of 40 years. In the medical laboratory, the T-SPOT.TBtest demonstrates a high reproducibility in serial testing.