Hatha, A A M; Vivekanandhan, G; Savithamani, K; Lakshmanaperumalsamy, P(Elsevier, November 27, 2001)
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Abstract:
A total of 319 strains of Aeromonas hydrophila were isolated from 536 fish and 278 prawns for a 2-year period. All the
strains were tested for resistance to 15 antibiotics and 100% of the strains was resistant to methicillin and rifampicin followed by
bacitracin and novobiocin (99%). Only 3% of the strains exhibited resistance against chloramphenicol. The multiple antibiotic
resistance (MAR) indexing of A. hydrophila strains showed that all of them originated from high-risk sources
Description:
International Journal of Food Microbiology 76 (2002) 165– 168
Hatha, A A M; Divya, P Sukumaran; Srinivasan, Durairaj(Hindawi Publishing Corporation, July 31, 2012)
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Abstract:
This study aimed at detecting the prevalence of antibiotic-resistant serotypes of Escherichia coli in Cochin estuary, India. E. coli
strains were isolated during the period January 2010–December 2011 from five different stations set at Cochin estuary. Water
samples from five different stations in Cochin estuary were collected on a monthly basis for a period of two years. Isolates were
serotyped, antibiogram-phenotyped for twelve antimicrobial agents, and genotyped by polymerase chain reaction for uid gene
that codes for β-D-glucuronidase. These E. coli strains from Cochin estuary were tested against twelve antibiotics to determine
the prevalence of multiple antibiotic resistance among them. The results revealed that more than 53.33% of the isolates were
multiple antibiotic resistant. Thirteen isolates showed resistance to sulphonamides and two of them contained the sul 1 gene.
Class 1 integrons were detected in two E. coli strains which were resistant to more than seven antibiotics. In the present study,
O serotyping, antibiotic sensitivity, and polymerase chain reaction were employed with the purpose of establishing the present
distribution of multiple antibiotic-resistant serotypes, associated with E. coli isolated from different parts of Cochin estuary.
Description:
Interdisciplinary Perspectives on Infectious Diseases
Volume 2012, Article ID 124879, 7 pages
Hatha, A A M; Vivekanandhan, A A; Julie Joice, G; Christol(Elsevier, May 28, 2004)
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Abstract:
Motile aeromonads isolated from the intestines of farm-raised freshwater fish such as Catla catla, Labeo rohita and
Ctenopharyngodon idella have been characterized to species level. Morphological and physiological grouping revealed 61%
Aeromonas hydrophila, 30% Aeromonas caviae, 7% Aeromonas sobria and 2% which remained unidentified. Hemolytic
activity was detected mostly in A. hydrophila, while only half of the A. sobria and A. caviae showed this activity. Antibiotic
resistance patterns of the strains revealed that they had acquired a relatively higher resistance to oxytetracycline, amoxycillin,
ampicillin, novobiocin and polymixin-B, implicating possible use of these antibiotics in the aquaculture systems.
Description:
International Journal of Food Microbiology 98 (2005) 131– 134
Jayaprakash, N S; Bright Singh, I S(School of Environmental Studies, 2005)
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Abstract:
The main objective of the work undertaken here was to develop an appropriate microbial technology to protect the larvae of M.rosenbergii in hatchery from vibriosis. This technology precisely is consisted of a rapid detection system of vibrios and effective antagonistic probiotics for the management of vibrios. The present work was undertaken with the realizations that to stabilize the production process of commercial hatcheries an appropriate, comprehensive and fool proof technology is required primarily for the rapid detection of Vibrio and subsequently for its management. Nine species of Vibrio have been found to be associated with larvae of M. rosenbergii in hatchery. Haemolytic assay of the Vibrio and Aeromonas on prawn blood agar showed that all isolates of V. alginolyticus and Aeromonas sp., from moribund, necrotized larve were haemolytic and the isolates of V.cholerae, V.splendidus II, V.proteolyticus and V.fluvialis from the larvae obtained from apparently healthy larval rearing systems were non-haemolytic.
Hydrolytic enzymes such as lipase, chitinase and gelatinase were widespread amongst the Vibrio and Aeromonas isolates. Dominance of V.alginolyticus among the isolates from necrotic larvae and the failure in isolating them from rearing water strongly suggest that they infect larvae and multiply in the larval body and cause mortality in the hatchery. The observation suggested that the isolate V. alginolyticus was a pathogen to the larvae of M.rosenbergii. To sum up, through this work, nine species of Vibrio and genus Aeromonas associated with M.rosenbergii larval rearing systems could be isolated and segregated based on the haemolytic activity and the antibodies (PA bs) for use in diagnosis or epidemiological studies could be produced, based on a virulent culture of V.alginolyticus. This could possibly replace the conventional biochemical tests for identification. As prophylaxis to vibriosis, four isolates of Micrococcus spp. and an isolate of Pseudomonas sp. could be obtained which could possibly be used as antagonistic probiotics in the larval rearing system of M.rosenbergii.
Bright Singh, I S; Rosamma, Philip; Swapna, Antony P; Valsamma, Joseph(Elsevier, June 21, 2011)
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Abstract:
White Spot Syndrome Virus (WSSV) is the most devastating disease affecting shrimp culture around the
world. Though, considerable progress has been made in the detection and molecular characterization of WSSV
in recent years, information pertaining to immune gene expression in shrimps with respect to WSSV infection
remains limited. In this context, the present study was undertaken to understand the differential expression
of antimicrobial peptide (AMP) genes in the haemocytes of Penaeus monodon in response to WSSV infection
on a time-course basis employing semi-quantitative RT-PCR. The present work analyzes the expression profile
of six AMP genes (ALF, crustin-1, crustin-2, crustin-3, penaeidin-3 and penaeidin-5), eight WSSV genes (DNA
polymerase, endonuclease, immediate early gene, latency related gene, protein kinase, ribonucleotide
reductase, thymidine kinase and VP28) and three control genes (18S rRNA, β-actin and ELF) in P. monodon in
response to WSSV challenge. Penaeidins were found to be up-regulated during early hours of infection and
crustin-3 during late period of infection. However, ALF was found to be up-regulated early to late period of
WSSV infection. The present study suggests that AMPs viz. ALF and crustin-3 play an important role in
antiviral defense in shrimps. WSSV gene transcripts were detected post-challenge day 1 itself and increased
considerably day 5 onwards. Evaluation of the control genes confirmed ELF as the most reliable control gene
followed by 18S rRNA and β-actin for gene expression studies in shrimps. This study indicated the role of
AMPs in the protection of shrimps against viral infection and their possible control through the up-regulation
of AMPs
Antimedian graphs are introduced as the graphs in which for every triple
of vertices there exists a unique vertex x that maximizes the sum of the
distances from x to the vertices of the triple. The Cartesian product of
graphs is antimedian if and only if its factors are antimedian. It is proved
that multiplying a non-antimedian vertex in an antimedian graph yields
a larger antimedian graph. Thin even belts are introduced and proved to
be antimedian. A characterization of antimedian trees is given that leads
to a linear recognition algorithm.
Bright Singh, I S; Anas, A; Paul, S; Jayaprakash, N S; PhIlip, R(Inter-Research, November 9, 2005)
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Abstract:
Chitosan is a biocompatible and biodegradable natural polymer with established
antimicrobial properties against specific microorganisms. The present study demonstrates its
antibacterial activity against 48 isolates of Vibrio species from prawn larval rearing systems. The
antibacterial activity had a positive correlation with the concentration of chitosan. This work opens
up avenues for using chitosan as a prophylactic biopolymer for protecting prawn larvae from
vibriosis.
Rosamma, Philip; Kumar, S; Achuthankutty, C T(2006)
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Abstract:
Aquaculture farms, particularly in Southeast Asia are
facing severe crisis due to increasing incidences of
White Spot Syndrome Virus (WSSV). Actinomycetes
have provided many important bioactive compounds of high prophylactic and therapeutic value and are
continually being screened for new compounds. In this
communication, the results of a study made to determine
the effectiveness of marine actinomycetes against the white spot disease in penaeid shrimps are presented.
Twenty-five isolates of actinomycetes were tested for
their ability to reduce infection due to WSSV among
cultured shrimps. When these actinomycetes were
made available as feed additives to the post-larvae of
the black tiger shrimp Penaeus monodon for two weeks and challenged with WSSV, the post challenge survival
showed variations from 11 to 83%. However, six
isolates have shown to be the most potential candidates
for further study.
Bright Singh, I S; Rosamma, Philip; Sudheer, N S(Springer, May 29, 2012)
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Abstract:
White spot syndrome virus (WSSV), the most
contagious pathogen of cultured shrimp, causes mass
mortality, leading to huge economic loss to the shrimp
industry. The lack of effective therapeutic or prophylactic
measures has aggravated the situation, necessitating the
development of antiviral agents. With this objective, the
antiviral activity in the aqueous extract of a mangrove plant
Ceriops tagal in Penaeus monodon was evaluated. The
Ceriops tagal aqueous extract (CTAE) was non-toxic to
shrimps at 50 mg/ml when injected intramuscularly at a
dosage of 10 lL/animal (0.5 mg/animal) and showed a
protective effect against WSSV at 30 mg/ml when mixed
with WSSV suspension at a 1:1 ratio. When the extract was
administered along with the diet and the animals were
challenged orally, there was a dose-dependent increase in
survival, culminating in 100 % survival at a concentration
of 500 mg/kg body weight/day. Neither hypertrophied
nuclei nor the viral envelope protein VP28 could be demonstrated
in surviving shrimps using histology and indirect
immunofluorescence histochemistry (IIFH), respectively.
To elucidate the mode of action, the temporal expression of
WSSV genes and shrimp immune genes, including antimicrobial
peptides, was attempted. None of the viral genes
were found to be expressed in shrimps that were fed with
the extract and challenged or in those that were administered
CTAE-exposed WSSV. The overall results suggest
that the aqueous extract from C. tagal can protect
P. monodon from white spot syndrome virus infection.
Description:
Arch Virol (2012) 157:1665–1675
DOI 10.1007/s00705-012-1346-3
Bright Singh, I S; Vici, V; Sarita,G Bhat(Academic Press, March 10, 2000)
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Abstract:
The fresh water prawn, Macrobrachium rosenbergii, has proven potential for use as an
aquaculture species (Hanson & Goodwin, 1997; Kurup, 1984). In India alone, culture of
this species of prawn in low saline areas requires about 200 million seed per year
(Kurup, 1984). In hatcheries poor survival rate has been associated with vibriosis at
di#erent stages of the larval cycle. Members of the family Vibrionaceae associated with
the larvae of M. rosenbergii were shown to be pathogenic under laboratory conditions
(Bhat et al., 2000, in press). Vibrios have been associated with mortality of penaeid
prawns by several workers (Aquacop, 1977; Hameed, 1993; Karunasagar et al., 1994).
Two methods have been suggested to protect both the larvae and juveniles from
vibriosis; one is the administration of bacterins prepared from pathogenic strains
(Itami et al., 1989, 1991; Adams, 1991; Song & Sung, 1990; Sung et al., 1991) and the
other is the utilization of yeast 1-3 and 1-6 glucans as immunostimulants for
enhancing the non-specific defense system (Sung et al., 1994; Song et al., 1997). In the
light of these observations it was hypothesised that bacterins and yeast glucans may
also be e#ective in protecting the larvae of M. rosenbergii from vibriosis as has been
achieved in the case of penaeids. To examine this hypothesis, the ability of bacterins
and an extracellular glucan-producing yeast to increase the overall survival and
metamorphosis of larvae in a hatchery, as well as to protect against an experimental
challenge under laboratory conditions, was evaluated
Description:
Fish & Shellfish Immunology (2000) 10, 559–563
doi:10.1006/fsim.2000.0278
Prajith, K K; Dr.Madhusoodana,Kurup B(Cochin University of Science and Technology, December , 2011)
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Abstract:
In India a study conducted by CIFE and CIBA (1997), concluded that
shrimp farming does more good than harm and it is not eco-unfriendly
(Krishnan and Birthal, 2002). Upsurge in coastal aquaculture activity
induced by high profitability is reported to have caused adverse impacts on
coastal ecosystems and social environments (Parthasarathy and Nirmala,
2000). The crustacean farming sector has received criticism for excessive
use of formulated feed containing high protein, of which around 50% gets
accumulated at the pond bottom as unconsumed (Avnimelech, 1999; Hari
et al., 2004, 2006). The wasted feeds undergo the process of degradation
and results in the release of toxic metabolites to the culture system.
Reduction of protein in the feed, manipulation and utilisation of natural
food in the culture system are the remedy for the above problems. But
before reducing the feed protein, it should be confirmed that the feed with
reduced protein is not affecting the growth and health of the cultured
animal. In the present study, biofloc technology is identified as one of the
innovative technologies for ensuring the ecological and environmental
Sustainability and examines the compatibility of BFT for the sustainable
aquaculture of giant prawn, M. rosenbergii. This thesis starts with a general introduction (Chapter-1), a brief review of the most relevant literature (Chapter-2), results of various experiments (Chapter-3-6), summary (Chapter-7) and recommendations and future research perspectives in the field of biofloc based aquaculture (Chapter – 8). The major objectives of this thesis are, to improve the ecological and economical sustainability of prawn farming by the applicationof BFT and to improve the nutrient utilisation in aquaculture systems.
Description:
School of Industrial Fisheries, Cochin University of Science and Technology
Ravi, Divakaran; Dr.Sivasankara Pillai, V N(Cochin University of Science and Technology, January 15, 2002)
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Abstract:
The most common and conventional method for removing turbidity from
water is by coagulating with alum or iron salts, and settling the precipitate in
suitably designed clarifiers followed by filtration. But the sludge produced is
bulky, difficult to dewater and accumulates in the dumping grounds causing
environmental problems. Synthetic polymers such as polyacrylamide and
polyethyleneoxide have been investigated for their ability to remove turbidity.
They overcome many of the disadvantages of conventional methods, but are
cost—effective only when rapid flocculation and reduction in sludge volume are
demanded. Considering the aforementioned situation, it was felt that more easily
available and eco-friendly materials must be developed for removing turbidity
from water. The results of our studies in this direction are presented in this
thesis. The thesis comprises of nine chapters, with a common bibliography at
the end. Chapter 1 gives an introduction to the nature of turbidity and colour
usually present in water. Chapter 2 discusses the nature and availability of the
principal material used in these studies, namely chitosan. Chapters 3 to 8, which
deal with the actual experimental work, are further subdivided into (a)
introduction, (b) materials and methods, (c) results and discussion and (d)
conclusions. Chapter 9 summarises the entire work so as to put the results and
conclusions into proper perspective.
Description:
School
of Environmental Studies, Cochin University of Science and Technology,