Isolation Purification and Characterization of Antimicrobial Peptides from Artificially Induced Mulberry Silkworm Bombyx Mori L

Abstract

Multidrug resistant (MDR) pathogens are imparting biggest threat to public health. As newlineper World Health Organization, MDR is one of the top 10 global health threats facing by newlinehumanity. Infection with MDR pathogens leads to the economic burden, prolonged newlinehospitalization, failure of the health care system and ultimately death. In the last decade it newlinewas evidenced that the rapid emergence of antimicrobial resistant pathogens endangering newlinethe efficacy of antibiotics. This raises the need to search for an alternative methods of newlinecombating antibiotic-resistant pathogens. The antimicrobial peptides (AMPs) are found newlineacross all organisms, inluding insects. Thanks to their biodiversity, insects symbolize the newlinelargest class of organisms in the animal kingdom and are enormously resistant to newlinemicrobial infections. In this present thesis the Bombyx mori L. was used as an newlineexperimental model to test the suitability of the hemolymph as a source of AMPs as it is newlinethe key effector molecules in the regulation of immune responses. Here, B. mori larvae newlinewere infected with different inoculum sizes of Pseudomonas aeruginosa ATCC 25668 newlinecells to examine the alteration in morpho-anatomical responses, physiological processes newlineand production of AMPs. The changes in the morpho-anatomical responses were newlinerecorded as changes in the integumet pigmentation from glossy white to black, loss of newlinelarval weight, gut weight and the weight of silkgland. Moreover, the melanization and newlinedehydration of the gut content and feces were also monitored. Ultraviolet-visible spectra newlineof the hemolymph collected from infected B. mori after 24 h of infection showed sharp newlinealteration in and#955;max from 278 to 285 nm suggesting bathochromic shift. Moreover, Fourier newlineTransform Infra Red (FTIR) analysis of the infected B. mori hemolymph showed a peak newlinePage | X newlineat 1550 cm-1, indicating the presence of and#945;-helical peptides. The peptide fraction was acquired from the hemolymph sample through methanol, glacial acetic acid and water mixture (90:1:9) extraction, followed by its further purification