Bright Singh, I S; Vijayan, K K; Jayaprakash, N S; Alavandi, S V; Somnath Pai, S; Preetha, R; Rajan, J J S; Santiago, T C(Elsevier, October 2, 2005)
[+]
[-]
Abstract:
A Pseudomonas sp PS-102 recovered from Muttukkadu brackish water lagoon, situated south of Chennai, showed significant
activity against a number of shrimp pathogenic vibrios. Out of the 112 isolates of bacterial pathogens comprising Vibrio harveyi, V.
vulnificus, V. parahaemolyticus, V. alginolyticus, V. fluvialis, and Aeromonas spp, 73% were inhibited in vitro by the cell-free culture
supernatant of Pseudomonas sp PS-102 isolate. The organism produced yellowish fluorescent pigment on King's B medium,
hydrolysed starch and protein, and produced 36.4% siderophore units by CAS assay and 32 μM of catechol siderophores as
estimated by Arnow's assay. The PS-102 isolate showed wide ranging environmental tolerance with, temperatures from 25 to 40 °C,
pH from 6 to 8, salinity from 0 to 36 ppt, while the antagonistic activity peaked in cultures grown at 30 °C, pH 8.0 and at 5 ppt saline
conditions. The antagonistic activity of the culture supernatant was evident even at 30% v / v dilution against V. harveyi. The
preliminary studies on the nature of the antibacterial action indicated that the antagonistic principle as heat stable and resistant to
proteolytic, lipolytic and amylolytic enzymes. Pseudomonas sp PS 102 was found to be safe to shrimp when PL-9 stage were
challenged at 107 CFU ml−1 and by intramuscular injection into of ∼5 g sub-adults shrimp at 105 to 108 CFU. Further, its safety in a
mammalian system, tested by its pathogenicity to mice, was also determined and its LD50 to BALB/c mice was found to be 109 CFU.
The results of this study indicated that the organism Pseudomonas sp PS 102 could be employed as a potential probiont in shrimp
and prawn aquaculture systems for management and control of bacterial infections
Manjusha, M; Dr.Bright Singh,I S(School of Environmental Studies,Faculty of Marine Sciences, 2003)
[+]
[-]
Abstract:
The present study is the first comprehensive approach towards histopathology of White Spot Syndrome Virus (WSSV) in Penaeus indicus. WSSV could be demonstrated in the nuclei of all tissues, except those of midgut, subjected of electron microscopic observation. They were the nuclei of gill, foregut, heart, hepatopancreatic connective tissue, hindgut, nerve and dorsal aorta. A comparison was made between the electron microscopic and histopathological observations and a greater degree of correlation between the two in depicting the severity of the infection of the infection was unraveled. The study also illustrated variations in response and susceptibility of various tissues to WSSV infection. Accordingly, out of the tissues investigated, gill, foregut, hindgut and dorsal aorta exhibited advanced viral multiplication than the other tissues such as heart, midgut, nerve and hepatopancreas. Even though hepatocytes were not infected the connective tissue nuclei were packed with virions.