Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
1.
Rev. biol. trop ; 61(3): 1175-1188, sep. 2013. ilus, graf, mapas
Article in English | LILACS | ID: lil-688468

ABSTRACT

The development of shrimp aquaculture in Mexican coasts of the Gulf of Mexico began to be explored using the Pacific white shrimp Litopenaeus vannamei in the mid 90´s. Many concerns over the risk of disease transmission to the economically important native penaeids, have been the main deterrent for the aquaculture of L. vannamei in the region. Concurrently, more than 10 years of research experience on the aquaculture suitability of the native Litopenaeus setiferus from the Terminos Lagoon, in the Yucatán Peninsula, have been accumulated. The aim of this study was then to determine the seasonal variations of the naturally acquired diseases and the possible detection of exotic pathogens. For this, random subsamples (n~60) of juveniles L. setiferus were collected from monthly captures. In order to detect the widest range of pathogens, including infectious hypodermal and hematopoietic necrosis (IHHNv) and white spot syndrome (WSSv) viruses, both histopathological and molecular methods were employed. Monthly prevalence (%) was calculated for every finding. We were able to detect a total of 16 distinct histological anomalies, most of which the presump- tive aetiological agent was readily identified. PCR results for viruses were negative. For some pathogens and symbionts, the prevalence was significantly different between the adult and juvenile populations. Prevalence of diseases tended to be higher in juvenile shrimp than in adults. The results of this study indicated that L. setiferus carry a wide variety of pathogens and symbionts that seem to be endemic to penaeids of the Gulf of Mexico, and those juveniles were more conspicuous to acquire pathogens and symbionts than adults.


Durante la década de los 90´s se introdujo el camarón blanco del Pacífico Litopenaeus vannamei a los Estados costeros mexicanos del Golfo de México con fines acuícolas, por lo que desde entonces existe preocupación por la posible introducción de enfermedades que puedan afectar a las poblaciones de camarones nativos. La investigación sobre la domesticación de especies nativas para una acuacultura sustentable se ha realizado por más de 10 años, sin embargo, aún existe escasa información sobre las enfermedades que se presentan de manera natural en estas poblaciones y posible trasfaunación. El presente estudio aborda el problema de las enfermedades encontradas en subpoblaciones de jóvenes y adultos de Litopenaeus setiferus del Área natural protegida Laguna de Términos, estado de Campeche, México. Técnicas de histología y biología molecular fueron utilizadas como herramientas de diagnóstico. Se encontró que L. setiferus es portador de patógenos y simbiontes endémicos del Golfo de México, y comparativamente, los jóvenes son más susceptibles en adquirir estas infecciones que los adultos, como probable respuesta al ambiente lacustre que ocupan. No se encontró evidencia de los virus IHHNv y WSSv, aunque en trabajos más recientes en algunos Estados del Norte ya se han detectado en poblaciones silvestres.


Subject(s)
Animals , Aquaculture , DNA Virus Infections/veterinary , Penaeidae/virology , DNA Virus Infections/epidemiology , Densovirinae/genetics , Gulf of Mexico/epidemiology , Polymerase Chain Reaction , Population Surveillance , Seasons , White spot syndrome virus 1/genetics
2.
J Environ Biol ; 2008 Jul; 29(4): 513-7
Article in English | IMSEAR | ID: sea-113817

ABSTRACT

This study was carried out to neutralize the WSSV one of the most virulent pathogen causing large economic damage in shrimp culture industry using the antiserum produced against recombinant WSSV envelope protein VP19 (rVP19) as a tool to evaluate WSSV infection mechanism. A fragment of VP19 was expressed in Sf21 insect cell using baculovirus expression system as fusion protein with 6 His-tag. Then, polyclonal antiserum against rVP19 was raised in white rabbit. A constant amount of WSSV (at 10(4) diluted stock) was incubated with various antiserum concentrations and injected into shrimp, Penaeus chinensis, for the neutralization challenge. At 9 days post injection, the shrimp in the positive control injected with WSSVshowed 100% mortality The shrimps injected with WSSV preincubated with preimmune serum showed 83.3% mortality at 15 days post injection. The shrimps injected with the WSSV preincubated with 1 microl, 5 microl or 10 microl r VP19 antiserum and shrimp mortalities showed 66.6%, 40.0% and 26.6% at 15 days post injection, respectively The high concentration of antiserum group showed lower mortality than those of the low concentration of antiserum group. This indicates that the WSSV can be neutralized by the rVP19 antiserum in a dose-dependent manner. The neutralization challenge result suggested that VP19 might play an important role in WSSV infection to shrimp.


Subject(s)
Animals , Antibodies, Monoclonal/administration & dosage , Aquaculture , Electrophoresis, Polyacrylamide Gel , Immune Sera/administration & dosage , Neutralization Tests , Penaeidae/immunology , Rabbits , Recombinant Proteins/genetics , Time Factors , Viral Envelope Proteins/genetics , White spot syndrome virus 1/genetics
4.
Indian J Exp Biol ; 2005 Jul; 43(7): 654-61
Article in English | IMSEAR | ID: sea-58678

ABSTRACT

Microbiological analysis of samples collected from cases of white spot disease outbreaks in cultured shrimp in different farms located in three regions along East Coast of India viz. Chidambram (Tamil Nadu), Nellore (Andhra Pradesh) and Balasore (Orissa), revealed presence of Vibrio alginolyticus, Vibrio parahaemolyticus, and Aeromonas spp. but experimental infection trials in Penaeus monodon with these isolates did not induce any acute mortality or formation of white spots on carapace. Infection trials using filtered tissue extracts by oral and injection method induced mortality in healthy P. monodon with all samples and 100% mortality was noted by the end of 7 day post-inoculation. Histopathological analysis demonstrated degenerated cells characterized by hypertrophied nuclei in gills, hepatopancreas and lymphoid organ with presence of intranuclear basophilic or eosino-basophilic bodies in tubular cells and intercellular spaces. Analysis of samples using 3 different primer sets as used by other for detection of white spot syndrome virus (WSSV) generated 643, 1447 and 520bp amplified DNA products in all samples except in one instance. Variable size virions with mean size in the range of 110 x 320 +/- 20 nm were observed under electron microscope. It could be concluded that the viral isolates in India involved with white spot syndrome in cultured shrimp are similar to RV-PJ and SEMBV in Japan, WSBV in Taiwan and WSSV in Malaysia, Indonesia, Thailand, China and Japan.


Subject(s)
Aeromonas/isolation & purification , Animals , Base Sequence , DNA, Viral/genetics , India , Microscopy, Electron , Penaeidae/microbiology , Polymerase Chain Reaction , Vibrio/isolation & purification , Virus Diseases/pathology , White spot syndrome virus 1/genetics
SELECTION OF CITATIONS
SEARCH DETAIL