Rapid detection of drug-resistant Mycobacterium tuberculosis by Modified MODS assay suitable for resource-poor settings.

BACKGROUND: Cross contamination and biosafety are concerns with the microscopic observation drug susceptibility assay. To address these issues, we modified the MODS technique in the current study. METHODOLOGY/PRINCIPAL FINDINGS: Two hundred and seventy-five samples were processed on LJ media and drug susceptibility was performed by the Indirect agar proportion method. A modified MODS test was done in tissue culture bottles. GenoType MTBDRplus assay was performed to detect the resistance and mutational pattern associated with the resistances. Sensitivity, specificity, positive predictive value, and negative predictive value for the detection of tuberculosis by modified MODS were 97.44%, 80.00%, 97.44%, and 80.00% respectively. The perfect agreement was seen between modified MODS and the Indirect agar proportion method for drug susceptibility testing of isoniazid (kappa = 0.923) and rifampicin (kappa = 1). The contamination rate, cost and TAT for modified MODS were less as compared to the solid media. In the case of MDR-TB isolates S531L (66.66%) was the most prevalent mutation in the rpoB gene followed by S315T2 mutation (58.33%) and T8C (41.66%) in katG and inhA gene respectively. In hetero-resistant strains, C-15T mutation (37.50%) was the most common followed by A-16G (12.50%) in the inhA gene. In INH mono-resistant strains only two mutations were observed i.e., S-315T1(50%) and C-15T (50%) in the katG and inhA genes respectively. CONCLUSIONS/SIGNIFICANCE: Modified MODS proved to be cost-effective and user-friendly, with minimal risk to the handler and no cross-contamination between samples were observed. Hence, it can be used in low-income countries for early detection of tuberculosis and its resistance.

Seroprevalence of Rickettsial disease: A population-based survey from kashmir valley, North India.

Background: Limited studies have been done regarding the prevalence of Rickettsial diseases in India and as far as UT of Jammu and Kashmir is concerned, only a few hospital-based studies are available. Objectives: The present study was therefore planned to find the seroprevalence of Rickettsial diseases in Kashmir Valley. Materials and Methods: A multistage sampling procedure was used for the collection of samples from 10 districts of Kashmir Valley and a total of 1740 samples were collected. In addition, 802 healthy blood donors were included to establish baseline titers for Weil-Felix (WF) Test. Results: Of 1734 subjects, 73 were positive by the WF test. The overall seroprevalence of Rickettsial diseases was 4.1% with the highest prevalence of scrub typhus (2.30%) followed by the spotted fever group (1.5%) and typhus group (0.40%). Maximum seropositive subjects were from district Kulgam (6.97%) followed by Pulwama (5.92%), Shopian (5.79%), Anantnag (5.47%), Ganderbal (5.00%), Kupwara (4.72%), Baramulla (4.62%), Srinagar (2.63%), Bandipora (2.41%), and Budgam (0.54%), respectively. Seropositivity was higher in females and subjects who had contact with ticks and mites like those involved in the collection of firewood and grass or had contact with uncut grass or shrub. The seropositivity was also significantly higher in those working in paddy fields and those living near the forest (P < 0.05). Conclusion: The results of the present study confirm the existence of Rickettsial diseases in this region. This data would promote awareness of rickettsioses among local physicians and will also serve as a baseline to detect changing prevalence in the future.