Targeted next generation sequencing directly from sputum for comprehensive genetic information on drug resistant Mycobacterium tuberculosis.

Background: Timely drug resistance detection is essential to global tuberculosis management. Unfortunately, rapid molecular tests assess resistance to only a few drugs, with culture required for comprehensive susceptibility test results.

Methods: We evaluated targeted next generation sequencing (tNGS) for tuberculosis on 40 uncultured sputum samples.

Evaluation of pyrosequencing for extensive drug resistance-defining anti-tuberculosis drugs for use in public healthcare.

MGIT 960 drug susceptibility testing (DST) for Mycobacterium tuberculosis was compared for performance and speed with pyrosequencing (PSQ). Pulmonary samples (n = 100), from GeneXpert/MTB/Rifampicin-resistant patients receiving second-line treatment for 1-3 months, were subjected to DST and PSQ for seven drugs (isoniazid, rifampicin, kanamycin, amikacin, capreomycin, moxifloxacin, and ofloxacin). The mean time-to-result was 35 and two days for DST and PSQ, respectively.

Correlating rrs and eis promoter mutations in clinical isolates of Mycobacterium tuberculosis with phenotypic susceptibility levels to the second-line injectables.

Objective/background: The in vitro drug-susceptibility testing of Mycobacterium tuberculosis reports isolates as resistant or susceptible on the basis of single critical concentrations. It is evident that drug resistance in M. tuberculosis is quite heterogeneous, and involves low level, moderate level, and high level of drug-resistant phenotypes.

Defining multidrug-resistant tuberculosis: correlating GenoType MTBDRplus assay results with minimum inhibitory concentrations.

This study correlates MICs of rifampicin (RIF) and isoniazid (INH) with GenoType MTBDRplus assay results for drug-resistant Mycobacterium tuberculosis (MTB) clinical isolates. MICs of RIF and INH were established for 84 and 90 isolates, respectively, testing 7 concentrations of each drug. Genotypic resistance to each drug was determined by GenoType MTBDRplus assay with 50 representative mutations confirmed by pyrosequencing, with mutations in the rpoB gene associated with RIF resistance and mutations in the katG and/or inhA genes associated with INH resistance.

Correlating Minimum Inhibitory Concentrations of ofloxacin and moxifloxacin with gyrA mutations using the genotype MTBDRsl assay.

Objective: To correlate gyrA mutations found on the Genotype MTBDRsl assay in Mycobacterium tuberculosis (MTB) isolates with Minimum Inhibitory Concentrations (MICs) to the fluoroquinolones compounds ofloxacin (OFX) and moxifloxacin (MXF).

Methods: MICs for OFX and MXF were ascertained for 93 archived clinical MTB isolates that showed gyrA mutations at Ala90Val, Ser91Pro, Asp94Ala, Asn/Tyr, Gly and His. Thirty fluoroquinolones susceptible isolates as determined by presence of all wild-type gyrA bands on the Genotype MTBDRsl assay were also included.

Immunochromatographic assays for detection of Mycobacterium tuberculosis: what is the perfect time to test?

In this study, we aimed to correlate the analytical performance of SD BIOLINE TB Ag MPT64 Rapid Test kit (MPT64 assay) with the mycobacterial growth unit (GU) reported by the BACTEC MGIT 960 (MGIT 960) instrument. A total of 394 culture isolates reported positive by MGIT 960 were processed daily (until 'day 4') with the MPT64 assay until a positive MPT64 result was obtained and their GU values were noted daily before MPT64 testing. Based on this correlation of MPT64 positivity and corresponding GU values, a GU cut-off was determined.

Drug resistance patterns in 111 cases of drug-resistant tuberculosis spine.

Purpose: We report the largest study conducted till date of drug resistant tuberculosis in spine analyzing the drug susceptibility patterns in 111 cases of proven drug resistance.

Methods: An observed cross-sectional study was conducted. Six-hundred and eighty-six patients with positive cultures underwent sensitivity testing to 13 commonly used anti-tubercular drugs using BACTEC MGIT-960 system.

Clonal population of Mycobacterium tuberculosis strains reside within multiple lung cavities.

Background: Unsuccessful treatment outcomes among patients with multi-/extensively-drug resistant tuberculosis (TB) have hampered efforts involved in eradicating this disease. In order to better understand the etiology of this disease, we aimed to determine whether single or multiple strains of Mycobacterium tuberculosis (MTB) are localized within lung cavities of patients suffering from chronic progressive TB.

Methodology/findings: Multiple cavity isolates from lung of 5 patients who had undergone pulmonary resection surgery were analyzed on the basis of their drug susceptibility profile, and genotyped by spoligotyping and 24-loci MIRU-VNTR.

Can cord formation in BACTEC MGIT 960 medium be used as a presumptive method for identification of M. tuberculosis complex?

Background: Serpentine cord formation in BACTEC MGIT 960 medium was evaluated as a rapid method for the presumptive identification of M. tuberculosis complex (MTBC).

Material & Methods: Total 2527 samples were processed for AFB culture using MGIT 960 TB system over a period of three months.

Comparison of phenotypic and genotypic methods for pyrazinamide susceptibility testing.

Objectives: To evaluate Pyrazinamide (PZA) susceptibility results obtained by phenotypic MGIT 960 TB system against enzymatic Pyrazinamidase assay and genotypic pncA gene sequencing. To find the prevalence of infections caused by M. bovis in PZA resistant M.