2,4,6-trinitrotoluene (TNT) degradation by Indiicoccus explosivorum (S5-TSA-19).

2,4,6-trinitrotoluene (TNT), a nitro-aromatic explosive commonly used for defense and several non-violent applications is contributing to serious environmental pollution problems including human health. The current study investigated the remediation potential of a native soil isolate, i.e., Indiicoccus explosivorum (strain S5-TSA-19) isolated from collected samples of an explosive manufacturing site, against TNT. The survivability of I. explosivorum against explosives is indirectly justified through its isolation; thus, it is being chosen for further study. At a TNT concentration of 120 mg/L within an optimized environment (i.e., at 30 °C and 120 rpm), the isolate was continually incubated for 30 days in a minimal salt medium (MSM). The proliferation of the isolate and the concentration of TNT, nitrate, nitrite, and ammonium ion were evaluated at a particular time during the experiment. Within 168 h (i.e., 7 days) of incubation, I. explosivorum co-metabolically degraded 100% TNT. The biodegradation procedure succeeded the first-order kinetics mechanism. Formations of additional metabolites like 2,4-dinitrotoluene (DNT), 2,4-diamino-6-nitrotoluene (2-DANT), and 2-amino-4,6-dinitrotoluene (2-ADNT), were also witnessed. TNT seems to be non-toxic for the isolate, as it reproduced admirably in TNT presence. To date, it is the first report of Indiicoccus explosivorum, efficiently bio-remediating TNT, i.e., a nitro-aromatic compound via different degradation pathways, leading to the production of simpler as well as less harmful end products. Further, at the field-scale application, Indiicoccus explosivorum may be explored for the bioremediation of TNT (i.e., a nitro-aromatic compound)-contaminated effluents.

Study on aerobic degradation of 2,4,6-trinitrotoluene (TNT) using Pseudarthrobacter chlorophenolicus collected from the contaminated site.

2,4,6-trinitrotoluene or TNT, a commonly used explosive, can pollute soil and groundwater. Conventional remediation practices for the TNT-contaminated sites are neither eco-friendly nor cost-effective. However, exploring bacteria to biodegrade TNT into environment-friendly compound(s) is an interesting area to explore. In this study, an indigenous bacterium, Pseudarthrobacter chlorophenolicus, strain S5-TSA-26, isolated from explosive contaminated soil, was investigated for potential aerobic degradation of TNT for the first time. The isolated strain of P. chlorophenolicus was incubated in a minimal salt medium (MSM) containing 120 mg/L TNT for 25 days at specified conditions. TNT degradation pattern by the bacterium was monitored at regular interval using UV-Vis spectrophotometry, high-performance liquid chromatography, and liquid chromatography mass spectrophotometric, by estimating nitrate, nitrite, and ammonium ion concentration and other metabolites such as 2,4-dinitrotoluene (DNT), 2-amino-4,6-dinitrotoluene (2-ADNT), and 2,4-diamino-6-nitrotoluene (2-DANT). It was observed that, in the presence of TNT, there was no reduction in growth of the bacterium although it multiplied well in the presence of TNT along with no considerable morphological changes. Furthermore, it was found that TNT degraded completely within 15 days of incubation. Thus, from this study, it may be concluded that the bacterium has the potential for degrading TNT completely with the production of non-toxic by-products and might be an important bacterium for treating TNT (i.e., a nitro-aromatic compound)-contaminated sites.

BCG vaccination: Effects on the patterns of pediatric leprosy.

INTRODUCTION: Leprosy in pediatric population continues to remain as one of the major public health problems in India. BCG vaccination has been implicated in producing some protection against leprosy. OBJECTIVES: The present study intended to find out the patterns of leprosy in the pediatric age group (<12 years) and to determine the proportion of paucibacillary (PB) and multibacillary (MB) leprosy cases among the BCG-vaccinated and nonvaccinated groups. METHODOLOGY: It is a cross-sectional study among patients with leprosy up to the age of 12 years attending a tertiary care hospital in Eastern India by comprehensive history taking and through clinical examination. The history of BCG vaccination was enquired and the BCG scar was looked for to determine the BCG-vaccinated and nonvaccinated group. After collecting the data in a predesigned case sheet, the data were analyzed. RESULT: Of the 137 patients included in this study, 71.53% belonged to the 11-12 years age, 27.74% the 5-10 years age, and 1 patient the <5 year age group. The sex ratio was 1:1.63. PB leprosy was more common than MB leprosy. Smear positivity, deformity, and reaction were not very frequent. Among the vaccinated patients, the ratio of PB and MB leprosy was 5.3:1, while in the nonvaccinated group the ratio was 1.2:1. Data analysis showed that the proportion of MB leprosy was statistically significant in the nonvaccinated group than in the vaccinated group (p = 0.0352). CONCLUSION: Our study pointed that BCG vaccination might have a role in enhancing the cell-mediated immunity (CMI).