Bioactive Peptides from Loligo duvauceli (Indian Marine Squid) Orbigny against Multidrug Resistant Pyogenic Clinical Pathogens

The principal aim of the present investigation was the isolation, screening and testing of the antibacterial activity of the Loligo duvauceli extract derived from antimicrobial peptides (AMPs). A live marine animal specimen of L. duvaucelli (Indian squid) was collected from the trawling net of fishermen at Puthiyappa fishing harbor, Calicut, South West Coast of India. Ninty five percentages of methanol and ethanol were used to prepare the crude extract of marine invertebrate. Using the disc diffusion method, the antibacterial activity against the selected bacterial pathogens isolated from pus infection was studied. The antibacterial properties containing peptides were subjected to High Performance Thin Layer Chromatography (HPTLC) and partially purified. The HPTLC analysis of crude extracts ensured the presence of six different AMPs. Further, hemolytic assay, proteinase K treatment and heat treatment were undertaken to confirm the presence of proteins in the partially purified extracts (AMPs). The crude extract of L. duvaucelli showed antibacterial properties against all the tested clinical pathogens. The AMPs isolated from marine animals possessed antimicrobial properties. The HPTLC analysis of extracts revealed the presence of six different bioactive peptides and two AMPs among them exhibited effective antibacterial activities.