Chitosan Extraction from F.solani sps, Study of its Antibacterial and Dye Degradation Ability.

Recent advances in fermentation technology have led to new innovative techniques to obtain useful by-products from various soil microbes. F.solani CBNR KRRR, isolated from the marine soils of Pichavaram, Tamil Nadu was used for the economic production of Chitosan using Hesseltine and Anderson medium. The polysaccharides were extracted by alkali-acid treatment, and characterized by infrared spectroscopy. The highest growth rate was with Henderson and Anderson medium with a mycelial dry weight of 14 g/L. The best yield of the chitosan so obtained is (33.57 mg/g or 3.3%). The antimicrobial activity of Chitosan was tested against E.coli and S.aureus using Growth kinetics. It was found that the Extracted Chitosan have antimicrobial activity comparable to the Commercial Chitosan as well as the standard antibiotic used. Subsequently the extracted Chitosan was also tested for its photocatalytic ability to degrade dye-methylene blue and was found to exhibit 94.5% inhibition in 72 hours.

Dengue disease status in Chennai (2006-2008): A retrospective analysis.

Background & objectives: Dengue is one of the most important Arboviral diseases in man with outbreaks in Southeast Asia and India. We report a retrospective analysis of the dengue positivity in the referred samples for three years period (2006 to 2008) at the Department of Virology, King Institute of Preventive Medicine, Chennai, Tamil Nadu, India. Methods: Serum samples from 1593 suspected cases (968 male and 625 female) were obtained. Of the 1593 cases screened, 1204 (75.5%) were paediatric cases and 389 (24.4%) adults. The samples were subjected to MAC ELISA and IgG ELISA. Results: Of the 968 patients, 686 (43.0%) were positive, of which 579 (84.0%) were in the paediatric age group (<14 yr) and 107 (15.5%) were adults. The IgM positivity being 356 (36.7%) in males and 330 (52.8%) in females. Of the 686 positives, 113 (16.47%) were positive for both IgM and IgG denoting secondary infection. There was a noticeable increased occurrence during the cooler months and during the monsoon and post-monsoon months. Interpretation & conclusions: The dengue IgM seropositivity among the suspected cases indicates active dengue virus activity. Increase in the probable secondary infections especially in a country like ours where multiple serotypes are prevalent raises concern over probable increase in the incidence of the more serious DHF/DSS. Studies need to be done to identify circulating serotypes of dengue virus to design preventive strategies.