Dr. GRD College of Arts and Science

About: Dr. GRD College of Arts and Science is a based out in . It is known for research contribution in the topics: The Internet & Vehicular ad hoc network. The organization has 127 authors who have published 89 publications receiving 797 citations.

Optimization of Antimicrobial Production by a Marine Actinomycete Streptomyces afghaniensis VPTS3-1 Isolated from Palk Strait, East Coast of India

Abstract: Totally 25 marine soil samples were collected from the region of Palk Strait of Bay of Bengal, Tamil Nadu, and were subjected to the isolation of actinomycetes. Sixty-eight morphologically distinct isolates were obtained and 37% (25) of them had antimicrobial activity. The potential producer was named as Streptomyces sp. VPTS3-1 and the phylogenetic evaluation on the basis of 16S rDNA sequence further categorized the organism as Streptomyces afghaniensis VPTS3-1. Further, the antimicrobial compound was extracted from the isolate using various solvents and the antimicrobial efficacies were tested against bacterial and fungal pathogens. In addition, in vitro optimization of parameters for the antimicrobial compound production revealed that the suitable pH as 7–8, the period of incubation as 9 days, temperature (30°C), salinity (2%), and starch and KNO3 as the suitable carbon and nitrogen sources respectively in starch–casein medium.

Fusarium keratitis in South India: causative agents, their antifungal susceptibilities and a rapid identification method for the Fusarium solani species complex.

Abstract: Summary Seventy Fusarium isolates derived from human keratomycosis were identified based on partial sequences of the b-tubulin (b-TUB) and translation elongation factor 1a (EF-1a) genes. Most of the isolates were confirmed as members of the F. solani species complex (75.71%), followed by the F. dimerum species complex (8.57%), the F. fujikuroi species complex (8.57%), the F. oxysporum species complex (4.29%) and the F. incarnatum-equiseti species complex (2.86%). A combined phylogenetic tree was estimated including all the 70 isolates. Isolates belonging to different species complexes formed separate clades. In this study, we also report the first isolation of F. napiforme from human keratomycosis. A new method based on a specific EcoRI restriction site in the EF-1a gene was developed for the rapid identification of F. solani. In vitro antifungal susceptibilities of the isolates to seven antifungals were determined by broth microdilution method. Terbinafine, natamycin and amphotericin B proved to be the most effective drugs, followed by voriconazole. The minimal inhibitory concentrations of clotrimazole, econazole and itraconazole were generally high (64 l gm l 1 ). The interactions between the two most effective antifungals (natamycin and terbinafine) were determined by checkerboard microdilution method. Synergism (71.8%) or no interaction (28.2%) was revealed between the two compounds.