Early detection of Pre-XDR TB with line probe assay in a high TB burden country

Background: Worldwide, tuberculosis (TB) is one of the top 10 causes of death. Drug resistant tuberculosis has lately become a major public health problem that threatens progress made in Tuberculosis (TB) care and control worldwide. The aim of this study was to determine the prevalence of Pre-extensive drug resistant TB among MDR TB in North Central of Nigeria. Methods: This study was conducted from October, 2018 to August, 2019 with 150 samples. In Nigeria, guidelines for DR-TB as recommended by WHO is followed. All the samples from the patients who gave their consent were transported to a zonal reference TB laboratory (ZRL). Results: Mean age was 38.6 ± 13.4 years with peak age at 35-44. Out of these 103 samples processed with LPA, 101(98%) were rifampicin resistant and 2 were rifampicin sensitive, 99(96%) were INH resistant and 4 (4%) were INH sensitive, 5(5%) were fluoroquinolone resistant, 98(95%) were fluoroquinolone sensitive, 12 (12%) were Aminoglycoside + Capreomycin resistant, 91(83%) were Aminoglycoside + Capreomycin sensitive. Conclusion: Multidrug resistant TB and its severe forms (Pre-extensive & extensively drug resistant TB) can be detected early with rapid tool- Line Probe Assay rapid and prevented timely by early initiation on treatment. Keywords: Pre-XDR TB; line probe assay in a high TB burden country.

Comparison of Line Probe Assay (LPA) and Mycobacterium Growth Indicator Tubes (MGIT) Assay for Second-line TB Drug Susceptibility Testing

BACKGROUND: Tuberculosis (TB) infection is one of the most prominent health issues in the world, including in Indonesia. TB is evolving into multidrug-resistant tuberculosis (MDR-TB) and requiring second-line TB drugs. Mycobacterium growth indicator tube (MGIT) is the gold standard for susceptibility testing of second-line TB drugs. Alternatively, line probe assay (LPA), which detects genes resistant to second-line TB drugs, takes a shorter time to run. This study aims to compare MGIT and LPA's ability to detect TB resistance to second-line TB drugs and observe mutation patterns of genes encoding second-line TB drugs.METHODS: This was an observational analytic study, using cross-sectional method. The data were acquired from the MDR-TB clinic’s medical records at the Dr. Hasan Sadikin Hospital from September to December 2019. LPA and MGIT test were conducted at the Health Laboratory Hall of West Java Province, then tested using Kolmogorov-Smirnov and chi-square statistic.RESULTS: From 121 subjects, 113 people were not resistant to the second-line TB drugs, which was examined using both LPA and MGIT (93.4%), p=0.991. Mutations were found in gyrA and rrs gene. There was no significant difference between the proportion of subjects resistant to the second-line of TB drugs tested using LPA and MGIT.CONCLUSION: LPA is an alternative method to MGIT because it requires a shorter time and reduces the risk of exposure that will improve MDR-TB patients management.KEYWORDS: line probe assay (LPA), multidrug-resistant TB, mycobacterium growth indicator tube (MGIT), second-line TB drugs

Estimation of genotype MTBDRPLUS line probe assay in detection of rifampicin and isoniazid resistance in comparison to liquid culture (BACTEC-960) drug susceptibility testing in a tertiary care hospital from Eastern India

Introduction and Aim: India has the uppermost trouble of Multidrug resistant tuberculosis (MDR-TB) is a major challenge controlling resistance, reducing transmission and improving handling outcomes in MDR-TB patients is dependent on susceptibility testing. Isoniazid (INH) and rifampicin (Rif) are the key first-line antituberculosis drugs, and resistance to these drugs i.e., MDR-TB, is likely to result in treatment failure and poor clinical outcomes. The present study was done to compare the performance of line probe assay test (GenoType® MTBDRplus) with liquid culture (MGIT 960) system for the detection of resistance to first-line drugs. Materials and Methods: We estimate the performance of LPAs to BACTEC MGIT 960 system for susceptibility testing of bacterial resistance to first-line drugs: rifampicin (RIF), isoniazid (INH). Results: We performing Drug susceptibility testing (DST), 219/258 MTB cultures were viable after subculture the results of DST using the MGIT 960 system were compared to those obtained by line probe assay. LPA detected a total 46/258 (17.81%) samples as drug resistant, of which 35/258 (13.70%) were resistant to both rifampicin and isoniazid (MDR), 6/258 (2.28%) were rifampicin mono?resistant samples and 11/258 (4.11%) were isoniazid mono?resistant. Out of the culture?positive samples (219), LPA detected 39/219 (17.83%) as drug?resistant, of which 31/219 (14.2%) were resistant to both rifampicin and isoniazid, 5/193 (2.08%) were rifampicin mono?resistant and 8/219 (3.7%) were isoniazid mono?resistant. Conclusion: Drug resistant TB poses an enormous threat to TB control programs worldwide. Effective treatment of MDR-TB is very expensive, particularly in middle income countries such as India.

Import and transmission of Mycobacterium orygis and Mycobacterium africanum, Norway

Background The aim of the current study was to improve our understanding of the origins and transmission of Mycobacterium africanum (MAF) in Norway. Methods Whole-genome sequences (WGS) were generated for all (n = 29) available clinical isolates received at the Norwegian National Reference Laboratory for Mycobacteria (NRL) and identified as MAF in Norway, in the period 2010–2020. Phylogenetic analyses were performed. Results The analyses indicated several imports of MAF lineage 6 from both East and West African countries, whereas MAF lineage 5 was restricted to patients with West African connections. We also find evidence for transmission of MAF in Norway. Finally, our analyses revealed that a group of isolates from patients originating in South Asia, identified as MAF by means of a commercial line-probe assay, in fact belonged to Mycobacterium orygis. Conclusions Most MAF cases in Norway are the result of import, but transmission is occurring within Norway.