Genotypic characterisation of Mycobacterium tuberculosis isolates from tuberculous meningitis patients at a tertiary neurocare centre in Southern India.

AIMS: Specific genotypes of Mycobacterium tuberculosis (MTB) have been reported to cause outbreaks of pulmonary tuberculosis (TB) in geographical areas that are endemic to TB. However, since there is little epidemiological evidence on the association of particular genotypes that cause tuberculous meningitis (TBM), we sought to investigate the association of specific MTB strains with infection of the central nervous system (CNS). MATERIALS AND METHODS: We carried out a genetic characterisation of 89 MTB isolates from TBM patients at a Southern Indian tertiary neurocare centre and compared the genotypes with strains of pulmonary TB isolated from Indian immigrants in New York City. We applied the standard methods of genotyping of MTB, namely, IS6110-based restriction fragment length polymorphism and spoligotyping for strain identification, along with principal genetic grouping and single-nucleotide polymorphism cluster analysis. RESULTS: The analysis revealed a high-level of diversity amongst the strain population. The genotypes of the isolates from TBM patients paralleled the pulmonary TB strain population recovered from the Indian immigrants in NYC. CONCLUSIONS: We conclude that there is no apparent association between genotypes of MTB and propensity to infect CNS tissue.

Incidence, characteristics and outcome of ICU-acquired candidemia in India.

PURPOSE: A systematic epidemiological study on intensive care unit (ICU)-acquired candidemia across India. METHOD: A prospective, nationwide, multicentric, observational study was conducted at 27 Indian ICUs. Consecutive patients who acquired candidemia after ICU admission were enrolled during April 2011 through September 2012. Clinical and laboratory variables of these patients were recorded. The present study is an analysis of data specific for adult patients. RESULTS: Among 1,400 ICU-acquired candidemia cases (overall incidence of 6.51 cases/1,000 ICU admission), 65.2 % were adult. Though the study confirmed the already known risk factors for candidemia, the acquisition occurred early after admission to ICU (median 8 days; interquartile range 4-15 days), even infecting patients with lower APACHE II score at admission (median 17.0; mean ± SD 17.2 ± 5.9; interquartile range 14-20). The important finding of the study was the vast spectrum of agents (31 Candida species) causing candidemia and a high rate of isolation of Candida tropicalis (41.6 %). Azole and multidrug resistance were seen in 11.8 and 1.9 % of isolates. Public sector hospitals reported a significantly higher presence of the relatively resistant C. auris (8.2 vs. 3.9 %; p = 0.008) and C. rugosa (5.6 vs. 1.5 %; p = 0.001). The 30-day crude and attributable mortality rates of candidemia patients were 44.7 and 19.6 %, respectively. Logistic regression analysis revealed significant independent predictors of mortality including admission to public sector hospital, APACHE II score at admission, underlying renal failure, central venous catheterization and steroid therapy. CONCLUSION: The study highlighted a high burden of candidemia in Indian ICUs, early onset after ICU admission, higher risk despite less severe physiology score at admission and a vast spectrum of agents causing the disease with predominance of C. tropicalis.

Detection of antibody to Mycobacterium tuberculosis protein antigens in the cerebrospinal fluid of patients with tuberculous meningitis.

Antibodies against Mycobacterium tuberculosis antigens were detected by enzyme-linked immunosorbent assay in cerebrospinal fluid (CSF) samples obtained from 442 patients with tuberculous meningitis (TBM) and 102 control patients. Antibodies were found in the CSF of 87% of patients with clinical (culture-negative) TBM, 72% of patients with culture-positive TBM, and 65% of patients with autopsy-proven TBM. That anti-M. tuberculosis antibodies were detected in the CSF of patients with clinically diagnosed cases more frequently than in patients with culture-positive cases suggests that the detection of antibodies in CSF tends to decrease as bacillary load increases. Of the patients with clinical TBM who were coinfected with human immunodeficiency virus (HIV), 70% exhibited anti-M. tuberculosis antibody in CSF, which suggests that antibody responses in this group were substantially weaker than those in HIV-negative patients with clinical TBM. Some groups showed a stronger response to certain antigens, which suggests that antigen recognition patterns may be specific for the stage of disease.