Bright Singh, I S; Kulkarni, A; Rombout, J H W M; Sudheer, N S; Vlak, J M; Caipang, C M A; Kiron, V; Brinchmann, M F(Elsevier, October 26, 2012)
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Abstract:
Several oral vaccination studies have been undertaken to evoke a better protection against white spot
syndrome virus (WSSV), amajor shrimp pathogen. Formalin-inactivated virus andWSSV envelope protein
VP28 were suggested as candidate vaccine components, but their uptake mechanism upon oral delivery
was not elucidated. In this study the fate of these components and of live WSSV, orally intubated to black
tiger shrimp (Penaeus monodon) was investigated by immunohistochemistry, employing antibodies
specific for VP28 and haemocytes. The midgut has been identified as the most prominent site of WSSV
uptake and processing. The truncated recombinant VP28 (rec-VP28), formalin-inactivated virus (IVP) and
live WSSV follow an identical uptake route suggested as receptor-mediated endocytosis that starts with
adherence of luminal antigens at the apical layers of gut epithelium. Processing of internalized antigens is
performed in endo-lysosomal compartments leading to formation of supra-nuclear vacuoles. However, the
majority of WSSV-antigens escape these compartments and are transported to the inter-cellular space via
transcytosis. Accumulation of the transcytosed antigens in the connective tissue initiates aggregation and
degranulation of haemocytes. Finally the antigens exiting the midgut seem to reach the haemolymph. The
nearly identical uptake pattern of the different WSSV-antigens suggests that receptors on the apical
membrane of shrimp enterocytes recognize rec-VP28 efficiently. Hence the truncated VP28 can be
considered suitable for oral vaccination, when the digestion in the foregut can be bypassed
Bright Singh, I S; Rosamma, Philip; Chaithanya, E R; Swapna, Antony P; Afsal, V V(Elsevier, June 27, 2012)
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Abstract:
Anti-lipopolysaccharide factors (ALFs), a type of cationic antimicrobial peptides (AMPs), and their derivatives
are becoming predominant candidates for potential drugs in viral and bacterial diseases. This study
reports the first ALF from the mud crab Scylla tranquebarica (StALF, JQ899453) and the second ALF isoform
from the blue swimmer crab Portunus pelagicus (PpALF2, JQ899452). Both sequences encoded for precursor
molecules, starting with a signal peptide containing 26 amino acid residues, followed by a highly
cationic mature peptide, containing two conserved cysteine residues flanking a putative lipopolysaccharide
(LPS)-binding domain. BLAST analysis revealed that both PpALF2 and StALF exhibited significant
similarity with crustacean ALF sequences. The predicted molecular mass of the mature ALFs was 11.2 kDa
with an estimated pI of 10.0. PpALF2 and StALF also showed the typical pattern of alternating hydrophobic
and hydrophilic residues in their putative disulphide loop, suggesting that they comprise the same
functional domain. Phylogenetic analysis showed that PpALF2 and StALF have similar evolutionary status
and they were phylogenetically ancient immune effector molecules which may play an essential role in
the host defense mechanism. The spatial structures of PpALF2 and StALF possessed four beta-strands and
two alpha-helices. The results indicated that there were more than one ALF involved in crab immunity
against various pathogens. ALFs would provide candidate promising therapeutic or prophylactic agents
in health management and diseases control in crustacean aquaculture
Bright Singh, I S; Rosamma, Philip(Central ^Aarine Fisheries Research Institute, November , 2002)
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Description:
Winter School on
'RECENT ADVANCES IN
DIAGNOSIS AND
MANAGEMENT OF DISEASES
IN MARICULTURE'
7-27 November, 2002
Course Manual Indian Council of Agricultural Research
Central ^Aarine Fisheries Research Institute
Bright Singh, I S; Rosamma, Philip; Rejish Kumar, V J; Jayaprakash, N S(Blackwell Publishing Ltd, March 1, 2006)
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Abstract:
Surveys for bacteriological analysis of larval samples
to isolate the associated vibrios were carried out during
1985^1992, 2001 and 2002 in three di¡erent
hatcheries located on the southwest coast of India.
Vibrio isolates were examined for their species diversity,
virulence based on haemolysis in prawn blood
agar, lipolysis, proteolysis and chitinolysis and antibiotic
sensitivity.Vibrio cholerae was the predominant
species in the apparently healthy larval samples,
whereas V. alginolyticus and V. vulni¢cus dominated
during disease and morbidity. No correlation was
found between the hydrolytic properties and haemolytic
activity of the vibrios associated with the larvae.
All isolates were resistant to erythromycin and resistance
to oxytetracycline, ampicillin and streptomycin
sulphate was prevalent among the larger section of
the Vibrio population. This suggested that antibiotic
application may not be of much use to protect the larvae
fromvibriosis. This is the ¢rst report on the diversity
of Vibrio species associated with Macrobrachium
rosenbergii larvae and their virulence characteristics
based on haemolysis in prawn blood agar
Bright Singh, I S; Rosamma, Philip; Sreedharan, K(SBM, January 16, 2012)
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Abstract:
Aeromonas spp. are ubiquitous aquatic organisms, associated with multitude of diseases in several species of
animals, including fishes and humans. In the present study, water samples from two ornamental fish culture
systems were analyzed for the presence of Aeromonas. Nutrient agar was used for Aeromonas isolation, and
colonies (60 No) were identified through biochemical characterization. Seven clusters could be generated
based on phenotypic characters, analyzed by the programme NTSYSpc, Version 2.02i, and identified as:
Aeromonas caviae (33.3%), A. jandaei (38.3%) and A. veronii biovar sobria (28.3%). The strains isolated
produced highly active hydrolytic enzymes, haemolytic activity and slime formation in varying proportions.
The isolates were also tested for the enterotoxin genes (act, alt and ast), haemolytic toxins (hlyA and aerA),
involved in type 3 secretion system (TTSS: ascV, aexT, aopP, aopO, ascF–ascG, and aopH), and
glycerophospholipid-cholesterol acyltransferase (gcat). All isolates were found to be associated with at least
one virulent gene. Moreover, they were resistant to frequently used antibiotics for human infections. The
study demonstrates the pathogenic potential of Aeromonas, associated with ornamental fish culture systems
suggesting the emerging threat to public health