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Summary Background The WHO End TB Strategy requires drug susceptibility testing and treatment of all people with tuberculosis, but second-line diagnostic testing with line-probe assays needs to be done in experienced laboratories with advanced infrastructure. Fewer than half of people with drug-resistant tuberculosis receive appropriate treatment. We assessed the diagnostic accuracy of the rapid Xpert MTB/XDR automated molecular assay (Cepheid, Sunnyvale, CA, USA) to overcome these limitations. Methods We did a prospective study involving individuals presenting with pulmonary tuberculosis symptoms and at least one risk factor for drug resistance in four sites in India (New Delhi and Mumbai), Moldova, and South Africa between July 31, 2019, and March 21, 2020. The Xpert MTB/XDR assay was used as a reflex test to detect resistance to isoniazid, fluoroquinolones, ethionamide, amikacin, kanamycin, and capreomycin in adults with positive results for Mycobacterium tuberculosis complex on Xpert MTB/RIF or Ultra (Cepheid). Diagnostic performance was assessed against a composite reference standard of phenotypic drug-susceptibility testing and whole-genome sequencing. This study is registered with ClinicalTrials.gov , number NCT03728725 . Findings Of 710 participants, 611 (86%) had results from both Xpert MTB/XDR and the reference standard for any drug and were included in analysis. Sensitivity for Xpert MTB/XDR detection of resistance was 94% (460 of 488, 95% CI 92–96) for isoniazid, 94% (222 of 235, 90–96%) for fluoroquinolones, 54% (178 of 328, 50–61) for ethionamide, 73% (60 of 82, 62–81) for amikacin, 86% (181 of 210, 81–91) for kanamycin, and 61% (53 of 87, 49–70) for capreomycin. Specificity was 98–100% for all drugs. Performance was equivalent to that of line-probe assays. The non-determinate rate of Xpert MTB/XDR (ie, invalid M tuberculosis complex detection) was 2·96%. Interpretation The Xpert MTB/XDR assay showed high diagnostic accuracy and met WHO's minimum target product profile criteria for a next-generation drug susceptibility test. The assay has the potential to diagnose drug-resistant tuberculosis rapidly and accurately and enable optimum treatment. Funding German Federal Ministry of Education and Research through KfW, Dutch Ministry of Foreign Affairs, and Australian Department of Foreign Affairs and Trade.

In 2019, amongst half a million new rifampicin-resistant tuberculosis (TB) cases, 78% were multi drug-resistant TB (MDR-TB). Access to rapid and Universal-Drug susceptibility testing (DST) to patients in remote areas is a major challenge to combat drug-resistant TB. To overcome this challenge, we had recently reported the development of 'TB ConcentrationTransport kit' for bio-safe ambient temperature transport of dried sputum on filter-paper (Trans-Filter). The present study was conducted to evaluate the utility of DNA extracted from sputum on Trans-Filter in a Multiplex PCR-based sequencing assay (Mol-DSTseq) for diagnosing drug-resistant TB. The developed Mol-DSTseq assays were standardized on Mycobacterium tuberculosis clinical isolates (n = 98) and further validated on DNA extracted from sputum on Trans-Filter (n = 100). Using phenotypic DST as gold standard, the Mol-DSTseq assay showed 100% (95% Confidence Interval [CI] 79.4-100%) and 73.3% (95% CI 54.1-87.7%) sensitivity for detecting rifampicin and isoniazid resistance with a specificity of 85.1% (95% CI 66.2-95.8%) and 100% (95% CI:82.3-100%), respectively. For fluoroquinolones and aminoglycosides, the Mol-DSTseq assay showed a sensitivity of 78.5% (95% CI 49.2-95.3%) and 66.6% (95% CI 9.4-99.1%) with a specificity of 88.2% (95% CI 72.5-96.7%) and 100% (95% CI 93.1-100%), respectively. The Mol-DSTseq assays exhibited a high concordance of ~ 83-96% (κ value: 0.65-0.81) with phenotypic DST for all drugs. In conclusion, the 'TB Concentration and Transport kit' was compatible with Mol-DSTseq assays and has the potential to provide 'Universal-DST' to patients residing in distant areas in high burden countries, like India for early initiation of anti-tubercular treatment.

Background Near-patient access to appropriate tests is a major obstacle for the efficient diagnosis of tuberculosis (TB) and associated drug resistance. Methods We recently developed the “TB Concentration & Transport” kit for bio-safe, ambient-temperature transportation of dried sputum on Trans-Filter, and the “TB DNA Extraction” kit for DNA extraction from Trans-Filter for determining drug resistance by DNA sequencing. In the present study, we evaluated the compatibility of Kit-extracted DNA with Hain's line probe assays (LPAs), which are endorsed by National TB programmes for the detection of drug resistance in sputum collected from presumptive multidrug-resistant TB patients (n=207). Results Trans-Filter-extracted DNA was seamlessly integrated with the LPA protocol (Kit-LPA). The sensitivity of Kit-LPA for determining drug resistance was 83.3% for rifampicin (95% CI 52–98%), 77.7% for isoniazid (95% CI 52–94%), 85.7% for fluoroquinolones (95% CI 42–100%) and 66.6% for aminoglycosides (95% CI 9–99%), with a specificity range of 93.7% (95% CI 87–97) to 99.1% (95% CI 95–100) using phenotypic drug susceptibility testing (DST) as a reference standard. A high degree of concordance was noted between results obtained from Kit-LPA and LPA (99% to 100% (κ value: 0.83–1.0)). Conclusions This study demonstrates successful integration of our developed kits with LPA. The adoption of these kits across Designated Microscopy Centres in India can potentially overcome the existing challenge of transporting infectious sputum at controlled temperature to centralised testing laboratories and can provide rapid near-patient cost-effective “Universal DST” services to TB subjects residing in remote areas., The adoption of bio-safe “TB Concentration & Transport” kit by Microscopy Centres can potentially overcome the challenge of transporting infectious sputum to central laboratories and provide universal DST services to TB subjects residing in remote areas. https://bit.ly/2QrQ5qL

Background. Organisms possessing the bla NDM-1 gene (responsible for carbapenem resistance) with a class-1 integron can acquire many other antibiotic resistance genes from the community sewage pool and become multidrug-resistant superbugs. In this regard, hospital sewage, which contains a large quantity of residual antibiotics, metals and disinfectants, is being recognized as a significant cause of antimicrobial resistance (AMR) origination and spread across the major centres of the world and is thus routinely investigated as a marker for tracing the origin of drug resistance. Therefore, in this study, an attempt has been made to identify and characterize the carbapenem-resistant microbes associated with integron genes amongst the organisms isolated from the effluent treatment plant (ETP) installed in a tertiary respiratory care hospital in Delhi, India. Methods. One hundred and thirty-eight organisms belonging to Escherichia , Klebsiella , Pseudomonas and Acinetobacter spp. were collected from the incoming and outgoing sewage lines of the ETP. Carbapenem sensitivity and characterization was performed by the imipenem and imipenem-EDTA disc diffusion method. Later DNA extraction and PCR steps were performed for the Int-1 and bla NDM-1 genes. Results. Of the 138 organisms, 86 (62.3 %) were imipenem-resistant (Pbla NDM-1 gene (genotypic resistance) was present in 71 % (98/138) of organisms. 53.6 % (74/138) organisms were double gene-positive (bla NDM-1 + Int-1), of which 40 were producing the metallo-beta-lactamase enzyme, making up almost 28.9 % (40/138) of the collected organisms. Conclusion. The current study strengthens the hypothesis that Carbapenem resistant organisms are in a high-circulation burden through the human gut and hospital ETPs are providing an environment for resistance origination and amplification.

The present study aimed to evaluate the performance of the 'TBDetect' kit-based bio-safe fluorescent microscopy filter (BioFM-Filter) microscopy in comparison with direct smear microscopy and culture for the detection of pulmonary tuberculosis (TB) in a multi-centric setting in India.The TBDetect kit enables sputum concentration through filtration using the BioFM-Filter for improved and bio-safe smear microscopy. We evaluated the performance of the TBDetect kit in a six-site multi-centric validation study on sputum collected from 2086 presumptive TB patients.The combined positivity of TBDetect microscopy performed on these sputum samples was 20% (n = 417/2086) vs 16.1% of light-emitting diode fluorescence microscopy (LED-FM, n = 337/2086) and 16% of Ziehl Neelsen (ZN) smear microscopy (n = 333/2086). The increment in positivity of TBDetect over both LED-FM and ZN smears was significant (p 0.001). The overall sensitivity of TBDetect for six sites was ~55% (202/367, 95% confidence interval (CI): 50, 60%) vs 52% (191/367, 95% CI: 47, 57%) for LED-FM (p 0.14) and 50.9% (187/367, 95% CI: 46, 56%) for ZN smear (p 0.05), using Mycobacterium Growth Indicator Tube culture (MGIT, n = 1949, culture positive, n = 367) as the reference standard. A bio-safety evaluation at six sites confirmed efficient sputum disinfection by TBDetect; 99.95% samples (1873/1874) were sterile after 42 days of incubation. Scientists and technicians at the study sites indicated the ease of use and convenience of TBDetect microscopy during feedback.TBDetect added value to the smear microscopy test due to its improved performance, convenience and user safety. These findings indicate that equipment-free TBDetect technology has the potential to improve TB diagnosis in basic laboratory settings by leveraging on the existing nationwide network of designated microscopy centres and primary healthcare centres.

Introduction: Lowenstein Jensen (LJ) culture contamination is one of the most frequent problems encountered during Mycobacterium tuberculosis (M. tuberculosis) culture. Contaminated cultures are repeated at an additional cost and thus hinder diagnosis. This problem is of more significant concern in Extrapulmonary (EP) samples which have very fewer bacilli loads. Unfortunately, our current contaminant knowledge from past studies is minimal, which is entirely based on pulmonary samples, and not on EP samples. Development of newer culture methods will remain incomplete unless we have a good knowledge about contaminant profiles from both types of samples. Aim: To isolate and identify bacterial and fungal contaminants growing on LJ media during M. tuberculosis complex culture in both pulmonary and EP samples. Materials and Methods: LJ media pairs (5074) were inoculated, of which 2030 were inoculated with pulmonary samples and 3044 with EP samples. Mycobacterial, non-Mycobacterial and fungal growth were differentiated based on characteristics like colony morphology (on Chocolate agar, blood agar, Mackonkey Agar and Sabouraud’s Dextrose Agar), staining (Gram stain and Ziehl Neelsen) and biochemical reactions (Indole, Urea, Citrate and Triple Sugar Iron). Statistical analysis was done using SPSS version 20 (IBM®, New York, NY, USA) and Chi-square test was performed. Results: Overall Contamination Rate (CR) was 2.2%. Individually, CR was 2.9% (60/2030) in pulmonary samples and 1.7% (52/3044) in EP samples (p

Summary Background Monitoring sensitivity profiles of circulating hospital strains is a key activity of a hospital infection control policy. The hospital environment and equipment may be reservoirs for carbapenem-resistant bacteria. Mobile phones have been shown to be a potential source for the transmission of bacteria in the healthcare environment. Methods Bacteria were cultured from seven common electronic devices. These included touchpads, chargers, hands-free headphones/microphones, laptops, digital wristwatches and computer mice which were used by healthcare workers and non-healthcare workers including family members and patient attendants. The Gram-negative bacteria were further analysed for phenotypic and genotypic (blaKPC, blaNDM-1 genes) carbapenem resistance. Results 110 Gram-negative bacteria were isolated Mobile phones were found to be the most heavily contaminated devices and hands-free devices the least. 53.6% (n=59/110) Gram-negative bacteria were phenotypically carbapenem-resistant of which 36.37% (n=40) were metallo-β-lactamase positive. 40% (n=44/110) were genotypically resistant and 30% (n=33) were blaNDM-1 gene positive. 9% (n=10) bacteria had both blaNDM–1and blaKPC genes. Conclusions Carbapenem-resistant bacteria are widespread in India's hospital environment and present a challenge in healthcare. Electronic devices are a potential vehicle for the transmission of carbapenem-resistant bacteria. The results of the study support that hands-free electronic devices are less likely to be contaminated with carbapenem-resistant bacteria and that promoting the use of hands-free devices may help to reduce the spread of multidrug resistant bacteria in healthcare.

Drug-resistant tuberculosis (TB) is a major threat to TB control worldwide. Globally, only 40% of the 340,000 notified TB patients estimated to have multidrug-resistant-TB (MDR-TB) were detected in 2015. This study was carried out to evaluate the utility of high-resolution melt curve analysis (HRM) for the rapid and direct detection of MDR-TB in Mycobacterium tuberculosis in sputum samples. A reference plasmid library was first generated of the most frequently observed mutations in the resistance-determining regions of rpoB , katG , and an inhA promoter and used as positive controls in HRM. The assay was first validated in 25 MDR M. tuberculosis clinical isolates. The assay was evaluated on DNA isolated from 99 M. tuberculosis culture-positive sputum samples that included 84 smear-negative sputum samples, using DNA sequencing as gold standard. Mutants were discriminated from the wild type by comparing melting-curve patterns with those of control plasmids using HRM software. Rifampin (RIF) and isoniazid (INH) monoresistance were detected in 11 and 21 specimens, respectively, by HRM. Six samples were classified as MDR-TB by sequencing, one of which was missed by HRM. The HRM-RIF, INH- katG , and INH- inhA assays had 89% (95% confidence interval [CI], 52, 100%), 85% (95% CI, 62, 97%), and 100% (95% CI, 74, 100%) sensitivity, respectively, in smear-negative samples, while all assays had 100% sensitivity in smear-positive samples. All assays had 100% specificity. Concordance of 97% to 100% (κ value, 0.9 to 1) was noted between sequencing and HRM. Heteroresistance was observed in 5 of 99 samples by sequencing. In conclusion, the HRM assay was a cost-effective (Indian rupee [INR]400/US$6), rapid, and closed-tube method for the direct detection of MDR-TB in sputum, especially for direct smear-negative cases.

Data regarding prevalence of multi-drug resistant tuberculosis (MDR-TB) and associated common mutations is scarce from Punjab region. The study was designed to determine rate of MDR-TB among presumptive MDR-TB from Punjab and mutation patterns using GenoType MTBDRplus assay. Total of 812 consecutive sputum samples were received from January 2012 to July 2013, from 14 districts of Punjab at the National Reference Laboratory at New Delhi for diagnosis of MDR-TB as hand holding activity. Presumptive MDR-TB patients were identified on basis of criterion B defined by the programme. Smear positive and negatives patients were found to be 636/798 (79.7%) and 162/ 798 (20.3%) respectively. Total of 606 GenoType MTBDRplus tests were conducted and mutations in rpoB, kat G and inhA genes analyzed. Total of 94/606 (15.5%), 43/606 (7.1%) and 40/606 (6.6%) were found to be RIF and INH resistant, mono-RIF resistant and 40/606 (6.6%) mono-INH resistant respectively. Commonest known mutation for RIF in rpoB gene and INH in kat G gene was S531L (80/ 137; 58.4%) and S315T1 (119/134; 88.8%) respectively. Mutations in inhA were found in 21/134 (15.7%) strains. Average turn-around time (TAT) for dispatch of result toPunjab was 4.6 days. Prevalence of RIF resistance in Punjab was found to be 22.6%. Common mutations for RIF and INH were similar to that in other regions of country. GenoType MTBDRplus was found to be useful assay for rapid detection of MDR-TB, responsible for determining better management of MDR-TB patients under the programme.

In GenoType MTBDRplus assay [line probe assay (LPA)], when Mycobacterium tuberculosis (M. tuberculosis) sample DNA fails to hybridize to at least 1 rpoB wild-type probe and any mutation probe, it is inferred as rifampin (RIF)-resistant. In this study, we sought to identify such ‘inferred’ mutations in M. tuberculosis isolates (n = 203) by rpoB gene sequencing and determined their association with phenotypic resistance. D516Y, H526N, L511P mutations were associated with both phenotypically sensitive (59%, n = 38/64) and resistant (23.7%, n = 33/139) antimicrobial susceptibility testing (AST) results, whereas S531W mutation was associated with only RIF-resistant isolates (33%, n = 46/139). These results demonstrated that, at standard drug concentrations, some ‘inferred’ mutations may be missed by RIF-AST (phenotypically sensitive). The use of LPA permits identification of these RIF-resistant isolates, and incorporation of additional mutation probes (e.g., S531W) could further increase LPA specificity. Further studies are needed to establish the significance of the type of ‘inferred’ mutation with clinical/treatment outcomes.

There is limited information of level of drug resistance to first-line and second line anti-tuberculosis agents in treatment naïve pulmonary tuberculosis (PTB) patients from the Indian region. Therefore, the present prospective study was conducted to determine the antimicrobial susceptibility to first-line and second line anti-TB drug resistance in such patients. Sputum samples from consecutive treatment naïve PTB cases registered in Lala Ram Sarup (LRS) district, under RNTCP containing 12 Directly Observed Treatment Centre’s (DOTS), were enrolled using cluster sampling technology. A total of 453 samples were received from July 2011 to June 2012. All samples were cultured on solid medium followed by drug susceptibility to first and second line anti-tubercular drugs as per RNTCP guidelines. Primary multi-drug resistance (MDR) was found to be 18/453; (4.0%). Extensively drug resistance (XDR) was found in one strain (0.2%), which was found to be resistant to other antibiotics. Data of drug resistant tuberculosis among treatment naïve TB patients are lacking in India. The presence of XDR-TB and high MDR-TB in small population studied, calls for conducting systematic multi-centric surveillance across the country.

Purpose: There is scarcity of prevalence data of multi-drug-resistant tuberculosis (MDR-TB) data and common mutations responsible in North India. This study aimed to detect MDR-TB among MDR-TB suspects from Delhi and mutation patterns using GenoType MTBDRplus assay. Materials and Methods: All MDR suspects in five districts of New Delhi were referred to the laboratory from 1 st October 2011 to 31 st December 2012 as per criterion defined by Programmatic Management of Drug Resistant Tuberculosis (PMDT). GenoType MTBDRplus assay was performed on 2182 samples or cultures and mutations in the rpoB gene for rifampicin (RIF) and katG and inhA genes for isoniazid (INH) were analyzed. Results: A total of 366 (16.8%) MDR-TB cases were diagnosed. MDR rate was found to be 32%, 16.6% and 10.2% during criterion A, B and C respectively. The most common mutation detected for RIF was S531L (59.0%) and for INH was S315T1 (88.3%). Mutations S531L and S315T1 occurred significantly higher in MDR strains as compared to RIF mono-resistant and INH mono-resistant strains, respectively. Average laboratory turn-around time (TAT) for dispatch of result to districts for test conducted on samples was 4.4 days. Conclusion: GenoType MTBDRplus is a useful assay for rapid detection of MDR-TB. The common mutations for RIF and INH were similar to those seen in other regions. However, mutations determining MDR strains and mono-resistant strains differed significantly for both RIF and INH.

Background: Toll-like receptor 4 (TLR4) is an essential component of the innate immune response to various microorganisms. Genetic polymorphisms in TLR4 are often associated with susceptibility to mycobacterial infection. Objective: The present study examines the influence of TLR4 896 A/G (Asp299Gly) and 1196 C/T (Thr399Ile) polymorphism in the susceptibility to develop pulmonary tuberculosis (PTB) in Indians. Materials & Methods: Single nucleotide polymorphisms (SNPs) of the TLR4 gene were genotyped using PCR-RFLP and sequenced in 198 patients with PTB and 60 healthy controls. Results: The frequency of mutant allele 299Gly and 399Ile of the TLR4 gene (14.4%; p < 0.048; RR=1.919; OR=2.074 & 14.6%; p < 0.020, RR=2.197; OR=2.402) was predominant in PTB patient as compared to healthy controls (7.5% & 6.7%), respectively. Data was further analysed under the dominant model (CT+TT (Thr/Ile + Ile/Ile)) at 399 position revealed preponderance of mutant allele in PTB patients (25.8%; p < 0.045; OR=2.555). On the other hand, combined evaluation of polymorphisms showed heterozygous/heterozygous (AG299+CT399) genotype was higher (16.2% vs 6.7%; p=0.063) in PTB patients than in control subjects. However homozygous/homozygous (GG299+TT399) genotype was observed only in PTB patients (3%).Conclusion: The current observation suggests the contribution of mutant allele 'Gly' & 'Ile' towards the increased risk of development of tuberculosis in North Indian population. As per our knowledge, this is first Indian study indicating the synergetic effect of two mutant (Asp299Gly and Thr399Ile) / alleles influencing the PTB infection. Further investigation on association of TLR-4 as an innate immunity biomarker with tuberculosis diseases need to be evaluated.

RESUMEN MARCO DE REFERENCIA: El estudio se llev´o a cabo enel Departamento de Microbiolog´ia del InstitutoNacional de Tuberculosis y EnfermedadesRespiratorias de Nueva Delhi, India. OBJETIVOS: Dado que la tuberculosis (TB) de los ninos˜representa un indicador indirecto de la transmisi´onactiva de la enfermedad en una comunidad, seinvestigaron los tipos de farmacorresistencia en 97cepas del complejo Mycobacterium tuberculosisaisladas de los pacientes pedia´tricos y se analizaron susasociaciones filog´enicas. ME´ TODO: Se incluyeron en el estudio 111 pacientespedia´tricos que acudieron a la consulta externa duranteel per´iodo del estudio del 2009 al 2011 y cuyas muestrasde esputo se enviaron al departamento de microbiolog´iapara cultivo en medio l´iquido y pruebas de sensibilidad alos medicamentos. Se practic´o el antibiograma y elespoligotipado en los cultivos positivos que conten´iancepas identificadas del complejo M. tuberculosis. RESULTADOS: Los resultados de las pruebas desensibilidad a los cuatro principales medicamentosantituberculosos de primera l´inea pusieron enevidencia la pansensibilidad de 31 de las 97 cepas(32%) y la resistencia de 66 de las 97 cepas a por lomenos un medicamento antituberculoso (68%); 55 delas 97 cepas fueron resistentes como m´inimo aisoniazida y rifampicina (56,7%; es decir, TBmultidrogorresistentes). La mayor´ia de los aislados (n¼ 81/90 cepas, 90%) pertenec´ia a cepas del principalgrupo g´enico 1; los conglomerados predominantes porespoligotipado fueron el SIT1/Beijing (n ¼ 28), elSIT26/CAS1-Delhi (n¼27) y el SIT53/T1 (n¼6).

Background and Objectives: In spite of higher incidence and prevalence of tuberculosis, the diagnosis of extra-pulmonary tuberculosis (EPTB) in various clinical specimens (such as pleural fluid, ascitic fluids, CSF, lymph node aspirate etc), remains true challenge. Current tools for the diagnosis of tuberculosis in various body fluids are suboptimal. Clinicians underestimate these diseases, and use of insensitive conventional analytical method has contributed to the difficulties in managing patient with extra pulmonary tuberculosis. It is important to develop rapid, sensitive and specific test for early diagnosis of extra pulmonary tuberculosis because of the lack of sensitivity & specificity of the conventional methods as AFB smear by ZN technique and culture on LJ media. Pleural tuberculosis (TB) diagnosis often requires invasive procedures such as pleural biopsy. The study was undertaken to evaluate the combined utility of polymerase chain reaction (PCR) for different gene targets (IS6110, MPB64 and protein antigen b; Pab ) especially in pleural fluid specimens with adenosine deaminase (ADA) levels in the diagnosis of pleurisy. Methods: Total 430 clinical specimens (412 extra-pulmonary and 18 pulmonary tuberculosis) were recruited from the outdoor and indoor Department of National Institute of Tuberculosis and Respiratory Diseases, New Delhi during the 2011-2013 periods. All specimens were further processed for AFB smear, culture on LJ media, ADA level and conventional PCR (IS6110 & MPB 64 and Pab gene targets). Results: The PCR positivity IS6110, MPB64 P 181/412) gene target was found to be significantly low as compared to the IS6110 (65.3%; 269/412; X2=37.058; pc=0.000; Odds ratio 2.401; 95% CI=1.795-3.213) & MPB 64 (63.6%; 262/412; X2=31.245; pc=0.000; Odds ratio 2.229; 95% CI=1.669-2.978) gene targets in extra pulmonary tuberculosis cases. Further we have analyzed the combined utility of PCR with ADA levels among the body fluids (165 pleural fluid, 15 ascitic fluid, 1 lymph node and 1 cerebrospinal fluid; CSF). Our results indicated that the PCR alone can detect total 72.5% (132/182) TB cases, whereas ADA alone can detect 61.5% (112/182; considering cutoff value >40IU/L or confirmed cases of TB on clinic-radiological findings), M.tuberculosis in body fluids. Further data was compared in between single, two and three gene targets considering cut off value ADA >40IU/L levels in body fluids. Our observation showed that the positivity of tuberculosis cases were significantly higher through three gene targets (N=48/83; 57.8%; Mean of ADA >40IU/L =127.3) as compared to single gene target (N=10/83; 12.1%; Mean of ADA >40IU/L =68.2; X2=36.27; pc=0.000; Odds ratio 10.011; 95% CI=4.272-24.008) utilizing conventional PCR technology. No significant difference has been observed in other body fluids. The combined evaluation of both techniques (PCR and ADA) raised 14-15 % additional diagnosis of tuberculosis in body fluids (158/ 182; 86.8%; in pleural fluid= 147/165; 89.1%).Interpretation and Conclusion: Our results suggested that Protein antigen b (Pab) gene target showed less sensitivity as compared to IS6110 & MPB64. This study demonstrated the combined utility of both techniques (multigene target PCR with ADA level), enhanced the sensitivity of diagnosis of tuberculosis in body fluids. The study also confirmed the high diagnostic utility of PCR and ADA methods in diagnosis of tuberculosis in various paucibacillary body fluids in Indian scenario.

A total of 312 sputum samples from pediatric patients presumptive of multidrug resistant tuberculosis were tested for the detection of drug resistance using the GenoTypeMTBDRplus assay. A total of 193 (61.8%) patients were smear positive and 119 (38.1%) were smear negative by Ziehl–Neelsen staining. Line probe assay (LPA) was performed for 208 samples/cultures (193 smear positive samples and 15 cultures from smear negative samples). Valid results were obtained from 198 tests. Of these, 125/198 (63.1%) were sensitive to both rifampicin (RIF) and isoniazid (INH). 73/198 (36.9%) were resistant to at least INH/RIF, out of which 49 (24.7%) were resistant to both INH and RIF (multidrug resistant). Children with tuberculosis are often infected by someone close to them, so strengthening of contact tracing in the program may help in early diagnosis to identify additional cases within the household. There is a need to evaluate newer diagnostic assays which have a high sensitivity in the case of smear negative samples, additional samples other than sputum among young children not able to expectorate, and also to fill the gap between estimated and reported cases under the program.

We considered samples received for culture of mycobacteria using BACTEC MGIT 960 system over a period of 1 year. Tubes flagged positive by MGIT were evaluated for presence of serpentine cording. The cord formation was compared with isolates identified as Mycobacterium tuberculosis complex (MTC) based on p-nitrobenzoic acid (PNB) test. Cords were found in 591 isolates of which 584 (98.8%) were confirmed as MTC. The sensitivity and specificity of cord formation were found to be 99.7% and 89.9%, respectively.

Objective/Background With the introduction of novel molecular techniques that rely on rifampicin (RIF) susceptibility, resistance to isoniazid (INH) or other first-line drugs remains undetected. Such patients are prescribed first-line antituberculosis therapy and are on RIF monodrug therapy during the continuation phase, which may lead to therapeutic failure and emergence of multidrug resistance. We aimed to study INH resistance among RIF-susceptible Mycobacterium tuberculosis (MTB) isolates from retreatment patients. Methods The Drug Susceptibility Testing data for four first-line drugs (streptomycin [SM], INH, RIF, and ethambutol [EMB]) using BACTEC MGIT 960 (Becton Dickinson, Franklin 124 Lakes, NJ ,USA) and for two drugs (INH and RIF) using line probe assay was analyzed retrospectively at the Department of Microbiology, National Institute of Tuberculosis and Respiratory Diseases (New Delhi, India). Results We analyzed 4910 drug susceptibility results performed using the BACTEC MGIT960 liquid culture system from 2009 to 2015. We found that 969 (19.7%) isolates were sensitive to all four first-line drugs, 3941 (80.3%) isolates were resistant to one or more drugs, and 3041 (61.9%) isolates were resistant to both RIF and INH with or without resistance to any other drug (multidrug resistant). Monodrug resistance to SM and EMB was observed in 94 (1.9%) and 8 (0.16%) isolates, respectively. RIF resistance without INH resistance was observed in 22 (0.44%) isolates. There were 776 isolates sensitive to RIF, but resistant to INH. Among these, INH resistance with EMB and/or SM was observed in 367 (7.47%) isolates, whereas 409 (8.3%) isolates were resistant to INH alone. The results of line probe assay from 2012 to 2015 were also analyzed, and the resistance to INH alone among all isolates with valid results was found to be 9.32% (1462/15,676). More than 75% of these isolates harbor mutations in the kat G gene associated with high-level resistance. Conclusion INH resistance among RIF-susceptible isolates was present in 10–15% of the total cases. Among these cases, the use of RIF susceptibility alone will fail to detect INH resistance. Since higher rates of failure, relapse, or acquired resistance are linked with INH resistance, rollout of techniques focusing on RIF resistance must, therefore, be accompanied by strict monitoring for better management of patients.

INTRODUCTION: There is lack of information on the proportion of new smear-positive pulmonary tuberculosis (PTB) patients treated with a 6-month thrice-weekly regimen under Revised National Tuberculosis Control Programme (RNTCP) who develop recurrent TB after successful treatment outcome. OBJECTIVE: To estimate TB recurrence among newly diagnosed PTB patients who have successfully completed treatment and to document endogenous reactivation or re-infection. Risk factors for unfavourable outcomes to treatment and TB recurrence were determined. METHODOLOGY: Adult (aged ≥ 18 yrs) new smear positive PTB patients initiated on treatment under RNTCP were enrolled from sites in Tamil Nadu, Karnataka, Delhi, Maharashtra, Madhya Pradesh and Kerala. Those declared "treatment success" at the end of treatment were followed up with 2 sputum examinations each at 3, 6 and 12 months after treatment completion. MIRU-VNTR genotyping was done to identify endogenous re-activation or exogenous re-infection at TB recurrence. TB recurrence was expressed as rate per 100 person-years (with 95% confidence interval [95%CI]). Regression models were used to identify the risk factors for unfavourable response to treatment and TB recurrence. RESULTS: Of the1577 new smear positive PTB patients enrolled, 1565 were analysed. The overall cure rate was 77% (1207/1565) and treatment success was 77% (1210 /1565). The cure rate varied from 65% to 86%. There were 158 of 1210 patients who had TB recurrence after treatment success. The pooled TB recurrence estimate was 10.9% [95%CI: 0.2-21.6] and TB recurrence rate per 100 person-years was 12.7 [95% CI: 0.4-25]. TB recurrence per 100 person-years varied from 5.4 to 30.5. Endogenous reactivation was observed in 56 (93%) of 60 patients for whom genotyping was done. Male gender was associated with TB recurrence. CONCLUSION: A substantial proportion of new smear positive PTB patients successfully treated with 6 -month thrice-weekly regimen have TB recurrence under program settings.

Tuberculosis (TB) is a major cause of morbidity and mortality, especially in developing countries. Despite significant limitations, microscopy remains the cornerstone of the global TB control strategy. As the TB epidemic escalates, new diagnostic methods that are accurate and also economical and simple to manufacture and deploy are urgently needed. Although several promising antigens have been identified and evaluated in recent years, the reproducible production of high-quality recombinant mycobacterial proteins with minimal batch-to-batch variation is difficult, laborious, and expensive. To determine the feasibility of devising a synthetic peptide-based diagnostic test for TB, we have delineated the immunodominant epitopes of three candidate antigens, Ag85B, BfrB, and TrxC, that were previously identified to be immunogenic in TB patients. The results demonstrate that combinations of carefully selected synthetic peptides derived from highly immunogenic proteins can be the basis for devising an immunodiagnostic test for TB.

Tuberculosis (TB) remains a major global health problem and ranks as the second leading cause of death worldwide. An important cause of TB epidemic is the emergence of multi drug resistant (MDR) strains of Mycobacterium tuberculosis. Despite the availability of treatment that is expected to cure most cases of TB, levels of MDR-TB remain worryingly high in India.This study was carried out to ascertain the prevalence of MDR-TB among category I pulmonary TB treatment failure patients.This was a retrospective study involving 750 pulmonary tuberculosis patients enrolled at six district centres of Delhi State under RNTCP who failed to respond to CAT I treatment and whose sputum samples were submitted for culture and drug sensitivity testing (DST) over a period of three years (2009-2012). MDR-TB was defined as TB caused by bacilli showing resistance to at least isoniazid and rifampicin.Out of the total 750 patients included in the study, 470 (62.6 %) were culture positive. Of these, 377 (80.2%) were subjected to DST and rest 93 (19.7%) were excluded. Ultimately, DST result was available for 353 (93.6 %) cases. 239 (68%) cases were detected as multi drug resistant TB.High proportion of MDR-TB (68%) among culture positive CAT I treatment failure cases highlights the need for rapid diagnostic tests which will enable the detection of MDR-TB at an early stage and will thus minimize the risk of transmission as well as the possible errors associated with the treatment.

The present study was conducted to evaluate the performance of the Xpert(®) MTB/RIF assay and compare Xpert results with solid and MGIT 960 liquid culture system. A total of 134 patients who had failed the Category I or II regimen were recruited for evaluation. Xpert correctly identified all Mycobacterium tuberculosis isolates. The sensitivity and specificity of the Xpert assay for the detection of rifampicin resistance was respectively 98.2% and 97.0% when compared with MGIT 960 results.

Introduction: Generalized cutaneous lesions caused by Mycobacterium abscessus have not been reported in immuno competent individuals. Case presentation: We describe here a case of 13-year old male child who developed a non-healing sternal wound after being operated upon for atrial septal defect surgery. Routine pyogenic and fungal cultures were negative. The wound did not clear with repeated courses of antibiotics. The continued serosanguinous discharge from the wound site ultimately progressed to generalized pustular non-healing lesions possibly through secondary bacteremia. Pustular pus showed acid-fast bacilli in Ziehl-Neelsen staining and grew Nontuberculous Mycobacteria on conventional LJ Medium and rapid MGIT medium. The NTM isolated was identified as M. abscessus through culture characters, biochemical testing, PCR and DNA fingerprinting technique. Treatment with multiple drugs helped in clearing of the skin pustular lesions. Conclusion: This case of generalized lesions by abscessus infection appears to be the first ever reported finding.

Background Collection and processing of sputum samples for the detection of acid fast bacilli (AFB) is hazardous for health-workers in developing countries with limited facilities. The phenol ammonium sulfate (PhAS) method involves smear microscopy and Ziehl-Neelson (ZN) staining of precipitates/ floccules formed in sputum samples when PhAS is added. The present study has been designed to assess the performance and safety of this method. Materials and methods The study was conducted from January 2011 to March 2011 at the Department of Microbiology, Lala Ram Sarup Institute of Tuberculosis and Respiratory Diseases, New Delhi. A total of 1038 sputum samples were subjected to ZN staining before and after treatment with PhAS. The smear microscopy results of the PhAS treated and untreated samples were compared. In addition, 200 representative samples were inoculated after processing by petroff’s method directly for culture and after treatment with PhAS. Result The sensitivity, specificity, positive predictive value and negative predictive value of the PhAS solution treated ZN smear microscopy method were found to be 98.8%, 88.5%, 98.0% and 92.7% respectively in comparison with direct smear microscopy. The overall correlation between the two methods was found to be 97.3%. None of the PhAS treated samples grew Mycobacterium tuberculosis on culture. Conclusion Sputum microscopy with PhAS solution is a safe, reliable and inexpensive alternative for direct microscopy. This method can be conveniently applied for usage in microscopy centers with limited bio-safety facilities.

The transportation of sputum samples may sometimes take more than one week which results in an increased contamination rate and loss of positive cultures. The current study was planned to analyze the recovery rate of mycobacteria from transported samples with and without Cetylpyridinium chloride (CPC). Addition of CPC is useful for isolation of M. tuberculosis from sputum subjected to long-term storage.