Antimicrobial Potential of Hemolymph Lectin and Solvent Extracts of Tissues of Marine Crab, Atergatis integerrimus against Fish and Clinical Pathogens

Abstract

Marine crabs are a rich source of bioactive compounds with pharmacological properties and antimicrobial activity has been documented against clinically significant pathogens. The present study investigates the antimicrobial potential of solvent extracts of different tissues and hemolymph lectin of marine crab, Atergatis integerrimus against four fish and human pathogenic bacteria and four fungal pathogens. Among the four human pathogenic bacteria tested E. coli was sensitive to most of the solvent extracts while Enterococcus faecalis, was highly sensitive to the chloroform extract of carapace and butanol extract of hemolymph.  Maximum zone of inhibition was recorded with butanol extract of whole body against Streptococcus mutans and Bacillus subtilis. Fish pathogenic bacteria tested against the different tissue extracts showed maximum zone of inhibition with the butanol extract of ovary, whole body and crude hemolymph against Vibrio harveyi. Aeromonas hydrophila was sensitive to the acetone and ethylacetate extract of hepatopancreas. Butanol extract of the different tissues inhibited the growth of Aspergillus flavus and Aspergillus niger. Chloroform, ethyl acetate and butanol extracts inhibited the growth of Candida albicans to some extent. Pencillium notatum was resistant to almost all the tissue extracts tested. Based on the preliminary studies, few pathogenic bacteria and fungi were chosen to study the effect of the purified lectin of Atergatis integerrimus and antimicrobial activity was observed in all the tested pathogens at 100 µg concentration. Thus our study indicates that the tissue extract possess bioactive compounds that specifically target pathogenic microbes and the purified lectin, a defense molecule of crab also posses antimicrobial potential.