Isolation and Identification of Pathogenic Enterococcus sp from Artemia Population from Puthalam Saltpan of Kanyakumari District, India

By : Michael Babu , T.Citarasu , T. Selvaraj , S. Maryjosephine Punitha , S.Albin Dhas

Page No: 97-116

Abstract
The present study reveals that Enterococcus sp. causes mortality in the natural habitat of Artemia. The aim of this work was to isolate, characterize the pathogen and also to experiment the pathogenic property of pathogen in the host and predator. The bacterial pathogen was isolated, characterized, and identified by 16S r DNA analysis. The external symptom of this infection was the appearance of black spot on body surface and followed by sluggish movement and death within 96 h post-infection. The optimum temperature, salinity and pH for the growth of pathogen were 35°C, 40 - 60 ppt and 8-10, respectively. The bacteria synthesized chitinase enzyme that helps to degrade the exoskeleton of Artemia and make black spots. This bacterium also reduced the hatching percentage of cyst and nauplii survival in Artemia. The study on prophenol oxidase activity conducted in the predator of Artemia, shrimp revealed an increase in prophenol activity after the injection of pathogen. The histopathological study of body tissue of Artemia showed the effect of internal tissue damage and necrosis by this bacterium. The identification by means of 16S rDNA and other biochemical test proved that the isolated pathogen was closely related to Enterococcus sp.

Authors :
Michael Babu, M., T. Citarasu, T. Selvaraj, S. Maryjosephine Punitha And S. Albindhas
Centre for Marine Science and Technology, Manonmaniam Sundaranar University, Rajakkamangalam-629 502, Tamil Nadu, India