The recent trend in mycobacterial strain diversity among extra pulmonary lymph node tuberculosis and their association with drug resistance and the host immunological response in South India.

Background: Tuberculosis (TB) though primarily affects the lungs it may also affect the other parts of the body and referred as extra pulmonary (EPTB). This study is focused on understanding the genetic diversity and molecular epidemiology of Mycobacterium tuberculosis (M.tb) among tuberculous lymphadenitis (TBL), a form of EPTB patients identified in Chennai, Tamil Nadu.

Spoligotype Diversity of over Two Decades from Tiruvallur, South India.

Geographically, most tuberculosis (TB) cases in 2018 were reported from India. This TB burden is compounded by MDR-TB and XDR-TB. The strategies for the management and control of TB in the community depend on an understanding of the mode of spread of the different strains of TB isolates in the community.

4-month moxifloxacin containing regimens in the treatment of patients with sputum-positive pulmonary tuberculosis in South India - a randomised clinical trial.

Background: Shortening tuberculosis (TB) treatment duration is a research priority. We tested the efficacy and safety of 3- and 4-month regimens containing moxifloxacin in a randomised clinical trial in pulmonary TB (PTB) patients in South India.

Methods: New, sputum-positive, adult, HIV-negative, non-diabetic PTB patients were randomised to 3- or 4-month moxifloxacin regimens [moxifloxacin (M), isoniazid (H), rifampicin (R), pyrazinamide (Z) and ethambutol (E)] or to a control regimen (2H R Z E /4R H ) [C].

Tuberculosis among the homeless in Chennai city, South India.

Background: In India from a national perspective, the incidence/prevalence of active tuberculosis (TB) among the homeless are unknown.

Methods: Homeless individuals, aged 15 years and above, were screened for TB by radiography and smear examination in Chennai city.

Results: 301 individuals were enrolled and screened for TB; 8% (24/301) had chest symptoms; 5.

PknB remains an essential and a conserved target for drug development in susceptible and MDR strains of M. Tuberculosis.

Background: The Mycobacterium tuberculosis (M.tb) protein kinase B (PknB) which is now proved to be essential for the growth and survival of M.tb, is a transmembrane protein with a potential to be a good drug target.

Tuberculous Lymphadenitis Is Associated with Enhanced Baseline and Antigen-Specific Induction of Type 1 and Type 17 Cytokines and Reduced Interleukin-1β (IL-1β) and IL-18 at the Site of Infection.

Tuberculous lymphadenitis (TBL) is characterized by an expansion of Th1 and Th17 cells with altered serum levels of proinflammatory cytokines. However, the cytokine profile at the site of infection, i.e.

Adequacy of examining one sputum specimen in tuberculosis drug resistance surveys.

Objective/background: Collection of one spot and one morning sputum specimen is recommended for tuberculosis (TB) drug resistance surveys. This was a retrospective analysis of Mycobacterium tuberculosis cultures isolated from two spot sputum specimens collected from smear positive TB patients in a TB drug resistance survey. It was conducted to understand the value of a second specimen.

Reduced systemic and mycobacterial antigen-stimulated concentrations of IL-1β and IL-18 in tuberculous lymphadenitis.

Background: Type 1, Type 17 and other pro-inflammatory cytokines are known to play an important role in resistance to pulmonary tuberculosis. The role of these cytokines in tuberculous lymphadenitis (TBL) is not well characterized.

Methods: To estimate the systemic and mycobacterial antigen - stimulated cytokine concentrations of Type 1, Type 17, other pro-inflammatory and regulatory cytokines in TBL, we examined both the systemic and the antigen-specific concentrations of these cytokines in TBL (n=31) before and after chemotherapy, and compared them with those with latent tuberculosis infection (LTB, n=31).

Drug resistance among extrapulmonary TB patients: Six years experience from a supranational reference laboratory.

Background & Objectives: There is limited information available about the drug resistance patterns in extrapulmonary tuberculosis (EPTB), especially from high burden countries. This may be due to difficulty in obtaining extrapulmonary specimens and limited facilities for drug susceptibility testing. This study was undertaken to review and report the first and second-line anti-TB drug susceptibility patterns in extrapulmonary specimens received at the National Institute for Research in Tuberculosis (NIRT), Chennai, India, between 2005 and 2012.

Prevalence and risk factors for adult pulmonary tuberculosis in a metropolitan city of South India.

Background: The present study measured the community prevalence and risk factors of adult pulmonary tuberculosis (PTB) in Chennai city, and also studied geographical distribution and the presence of different M. tuberculosis strains in the survey area.

Methods: A community-based cross sectional survey was carried out from July 2010 to October 2012 in Chennai city.

High rates of ofloxacin resistance in Mycobacterium tuberculosis among both new and previously treated patients in Tamil Nadu, South India.

Periodic drug resistance surveillance provides useful information on trends of drug resistance and effectiveness of tuberculosis (TB) control measures. The present study determines the prevalence of drug resistance among new sputum smear positive (NSP) and previously treated (PT) pulmonary TB patients, diagnosed at public sector designated microscopy centers (DMCs) in the state of Tamil Nadu, India. In this single-stage cluster-sampling prevalence survey, 70 of 700 DMCs were randomly selected using a probability-proportional to size method.

The Assessment of Viability of M. Tuberculosis after Exposure to CPC Using Different Methods.

Settings. National Institute for Research in Tuberculosis, Chennai. Objective.

Prevalence of tobacco use in urban, semi urban and rural areas in and around Chennai City, India.

Background: Tobacco use leads to many health complications and is a risk factor for the occurrence of cardio vascular diseases, lung and oral cancers, chronic bronchitis etc. Almost 6 million people die from tobacco-related causes every year. This study was conducted to measure the prevalence of tobacco use in three different areas around Chennai city, south India.

Equivalence of acid alone or acid-alcohol as decolourizing agent in Ziehl-Neelsen method.

Background: Microscopists opine that acid-alcohol decolourized slides may enhance acid-fast bacilli (AFB) smear positivity, and published documents on equivalence of acid and acid-alcohol in ZN staining method are not easily accessible.

Setting: National Institute for Research in Tuberculosis, Chennai, India.

Objective: To document the equivalence of 25% sulphuric acid (ZN-acid method) and 3% hydrochloric acid-alcohol (ZN-alcohol method) as decolourizing agents in ZN method for detection of acid-fast bacilli.

Quality indicators in a mycobacteriology laboratory supporting clinical trials for pulmonary tuberculosis.

Background: Documentation of structured quality indicators for mycobacteriology laboratories supporting exclusively controlled clinical trials in pulmonary tuberculosis (PTB) is lacking.

Objective: To document laboratory indicators for a solid (Lowenstein-Jensen medium) culture system in a mycobacteriology laboratory for a period of 4years (2007-2010).

Methods: The sputum samples, collected from PTB suspects/patients enrolled in clinical trials, were subjected to fluorescence microscopy, culture and drug sensitivity testing (DST).

Performance indicators of fluorescence microscopy for sputum samples in pulmonary tuberculosis.

To get insight into the sensitivity of fluorescence microscopy for diagnostic and follow-up sputum samples from pulmonary tuberculosis patients in clinical trials, the yield of smear positivity - among culture positive sputum samples - encountered in diagnostic and follow-up samples was retrospectively analyzed from the data available in a mycobacteriology laboratory in India. The sensitivity of fluorescence microscopy for diagnostic and follow-up samples respectively was found to be 94.3% and 60.

Phage cocktail to control the exponential growth of normal flora in processed sputum specimens grown overnight in liquid medium for rapid TB diagnosis.

The mechanical pressure exerted during centrifugation and the chemical pressure experienced when sputum specimens are processed, leave the tubercle bacilli in the sputum unsuitable for rapid detection especially in phage based assays. Thus, growing Mycobacterium tuberculosis in broth, at least overnight, is mandatory for allowing the tubercle bacilli to recoup. During this time the surviving colonizing flora grow faster and overgrow tubercle bacilli interfering with TB diagnosis.

Sensitivity of Ziehl-Neelsen method for centrifuged deposit smears of sputum samples transported in cetyl-pyridinium chloride.

Background & Objectives: Sensitivity of Ziehl-Neelsen (ZN) method is known to be low for liquefied sputum smears. Information on the ZN sensitivity for centrifuged deposit smears is not known. This study was carried out to determine the sensitivity of ZN method for acid fast bacilli (AFB) in centrifuged deposit smears and liquefied sputum smears made from sputum samples transported in cetyl-pyridinium chloride (CPC) solution.

Comparison of variants of carbol-fuchsin solution in Ziehl-Neelsen for detection of acid-fast bacilli.

To evaluate Ziehl-Neelsen (ZN) staining using variants of carbol-fuchsin solution, duplicate smears from 416 samples were stained with ZN, one set with 1% basic fuchsin and the other 0.3%. Another set of duplicate smears from 398 samples were stained with ZN, one with 1% basic fuchsin and the other 0.

Increased detection by restaining of acid-fast bacilli in sputum samples transported in cetylpyridinium chloride solution.

Setting: Seventeen health facilities in a Tuberculosis Unit, and the Tuberculosis Research Centre (TRC), Chennai, India.

Aim: Evaluation of restaining by the auramine-phenol method for detection of acid-fast bacilli (AFB) in direct smears of samples transported in cetylpyridinium chloride (CPC) solution.

Methods: Among patients attending the above health facilities, 730 samples were collected in CPC and transported to the TRC.