Shaikh . Sabah

Biological synthesis of nanoparticles has received increased attention due to a growing need to develop environmentally benign technologies in material synthesis. In present work silver nanoparticles (AgNps) were synthesized intracellular by using Pseudomonas aeruginosa sp. The silver nanoparticles were characterized by Transmission Electron Microscopy (TEM), UV-Visible Spectroscopy (UV). Larvicidal activities of silver nanoparticles were analyzed as per the standard procedures. The Pseudomonas aeruginosa synthesized AgNPs were found effective against the larvae and pupae of Cx. quinquefasciatus. The larvaes of Cx. quinquefasciatus were found highly susceptible to the synthesized AgNPs at the same test concentrations. The mortality could be observed after different hours of exposure. The present suggested that the bacterial mediated AgNPs can be use to kill larva, pupa of filarial vector and could be significantly reduce parasite transmission and therefore lead to reduced filarial risk.

Drinking water is an important resource that needs to be protected from pollution and biological contamination. Water borne diseases continue to be a dominant cause of water borne morbidities and mortality all over the world and helps in the spread of enteric diseases. A total of 38 water samples were tested by the new H2S test methods. According to the H2S test, 24 (63.15%) of the 38 samples had fecal coliforms, while 14 (36.84%) had no faecal contamination. From the 24 positive samples 47 isolates were investigated for the identification of faecal contamination. Out of 47 isolates, 21 (44.70%) were Pseudomonas, 14 (29.78%) were E.coli, 6 (12.76%) were Salmonella, 4 (8.5%) were Klebsiella and 2 (4.25%) were Staphylococcus spp. It is evident from the data presented in this work that H2S producing organisms are consistently associated with the presence of coliforms in water. Enteric bacteria such as Salmonella, and certain species of Klebsiella also produce H2S. The predominant H2S producing bacteria found in polluted drinking water in the present study were Salmonella spp., Klebsiella, Staphylococcus, and H2S producing variants of E.coli. Thus study indicated that the H2S test is a reliable and alternative indicator of fecal contamination in drinking water quality surveillance and screening of large number of water samples in short duration in the field where laboratory facilities are limited.