Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SHRIMP”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 775 records · Page 43Linked to original sources
PubMed2006

Isolation and characterization of two pigment-dispersing hormones from the whiteleg shrimp, Litopenaeus vannamei.

In crustaceans, the pigment-dispersing hormone (PDH) is released from the X-organ/sinus gland complex located in the eyestalks, and controls pigment dispersion in the chromatophores. Knowledge concerning the structure and activity of PDH in penaeid shrimps is remains limited, since natural PDH has been purified from only the Kuruma prawn, Marsupenaeus japonicus. In this study, two PDHs (Liv-PDH-A and -B) were purified from the sinus gland extracts of another penaeid species, the whiteleg shrimp, Litopenaeus vannamei, by two steps of reversed-phase HPLC, and their amino acid sequences were determined. They both consist of 18 amino acid residues, with a free N-terminus and an amidated C-terminus, the sequences of Liv-PDH-A and -B being NSELINSLLGIPKVMNDAamide and NSELINSLLGLPKVMNDAamide, respectively. These sequences are identical to those of mature PDHs deduced from cDNAs encoding L. vannamei PDH precursors cloned previously by other workers. Liv-PDH-A and -B showed significant pigment-dispersing activity in melanophores by in vivo bioassay.

Amino Acid Sequence↗
PubMed2006

Biophysical characterization of the non-fusogenic interaction between liposomes and the shrimp bifunctional lipoprotein-beta-glucan binding protein HDL/BGBP.

Shrimp High Density Lipoprotein-beta-Glucan Binding Protein (HDL/BGBP) has been studied by its role in nutrition and innate defense. Although the mechanisms of lipid loading are still unknown, HDL-BGBP binds and aggregates phospholipids vesicles in vitro. To gain insights into the HDL-BGBP mechanism of interaction with membranes, we have used fluorescence spectroscopy and electron microscopy. Data show that HDL-BGBP does not induce membrane fusion, leakage nor lipid exchange, although microstructural changes are clearly observed. This work supports a model where protein aggregation leads to liposome clustering. Such interaction may be a critical factor for the activation of the shrimp blood cell in vivo.

Animals↗
PubMed1979

Antennular sensilla of the brine shrimp, Artemia salina.

1. Scanning electron microscopy was used to characterize the external morphology of setae found on the antennules of adults and nauplii of the brine shrimp, Artemia salina (L.). The permeability of the antennular setae was studied by means of Slifer's crystal violet method. 2. Each antennule of an adult brine shrimp possessed a terminal cluster of sensory setae. Within a cluster there were two morphologically distinct kinds of sensilla, here designated type 1 and type 2. Three type 1 sensilla were observed on every antennule examined. The number of type 2 sensilla per antennule was usually four or five. 3. Type 1 sensilla of adults were 43 to 80 micrometer long and simple in external morphology. They were widest at the base, decreased in diameter gradually, and terminated as a finely tapered tip. No pores were resolved by scanning electron microscopy. 4. Type 2 sensilla of adults were shorter (shaft length, 12 to 23 micrometer) and displayed a single pore at the tip (average pore diameter, 0.4 micrometer). In thin section they were seen to possess a distinctive articular specialization of the cuticle at the base of the seta. 5. Dye penetration experiments indicated that type 2 sensilla were permeable to aqueous crystal violet, whereas type 1 sensilla were not. 6. The antennular setae of nauplii resembled type 1 sensilla in general shape, in being impermeable to crystal violet, and in lacking a terminal pore and basal articular specialization. Moreover, a total of three setae was normally present on each naupliar antennule, and the same number of type 1 sensilla was found on each adult antennule examined. If the three naupliar setae represent a developmental stage in the formation of three adult sensilla, available observations suggest that the larval setae are developmentally related to type 1, rather than to type 2 adult sensilla.

Animals↗
PubMed1999

Spectral sensitivity of vision and bioluminescence in the midwater shrimp Sergestes similis

In the oceanic midwater environment, many fish, squid, and shrimp use luminescent countershading to remain cryptic to silhouette-scanning predators. The mid-water penaeid shrimp, Sergestes similis Hansen, responds to downward-directed light with a dim bioluminescence that dynamically matches the spectral radiance of oceanic down-welling light at depth. Although the sensory basis of luminescent countershading behavior is visual, the relationship between visual and behavioral sensitivity is poorly understood. In this study, visual spectral sensitivity, based on microspectrophotometry and electrophysiological measurements of photoreceptor response, is directly compared to the behavioral spectral efficiency of luminescent countershading. Microspectrophotometric measurements on single photoreceptors revealed only a single visual pigment with peak absorbance at 495 nm in the blue-green region of the spectrum. The peak electrophysiological spectral sensitivity of dark-adapted eyes was centered at about 500 nm. The spectral efficiency of luminescent countershading showed a broad peak from 480 to 520 nm. Both electrophysiological and behavioral data closely matched the normalized spectral absorptance curve of a rhodopsin with lambda(max) = 495 nm, when rhabdom length and photopigment specific absorbance were considered. The close coupling between visual spectral sensitivity and the spectral efficiency of luminescent countershading attests to the importance of bioluminescence as a camouflage strategy in this species.

Journal Article↗
PubMed1998

Reverse transcription polymerase chain reaction (RT-PCR) used for the detection of Taura syndrome virus (TSV) in experimentally infected shrimp.

Taura Syndrome Virus (TSV) has adversely affected the shrimp culture industries of the Americas. First recognized in 1992, this viral agent has spread throughout the shrimp growing regions of South and Central America to become established in North America in the short span of 5 yr. Diagnostic methods for TSV include histopathology, bioassay using susceptible Penaeus vannamei as the indicator species and in situ hybridization with TSV specific complimentary DNA (cDNA) gene probes. An additional method for detecting TSV is through the use of reverse transcription polymerase chain reaction (RT-PCR). Two oligonucleotide primers were selected using the sequence information from a cloned cDNA segment of the TSV genome. The primers, designated 9195 and 9992, used in the RT-PCR procedure amplify a 231 base pair (bp) fragment of the cDNA. Using the RT-PCR technique, TSV has been detected in the hemolymph of P. stylirostris and P. vannamei with experimentally induced TSV infections.

Animals↗
PubMed2000

Diseases of the eye of farmed shrimp Penaeus monodon.

Lesions were found in the eyes of cultured shrimp Penaeus monodon that displayed non-specific signs of disease, including lethargy, dark pigmentation, brown gills, empty midgut, anorexia, white tail muscle, necrosis of uropods and fouled cuticle. Eye lesions were associated with sexual development in moribund shrimp in at least 1 disease event. Suppurative inflammation, granuloma and malacia were observed in histological examination of the eye and the causative agents of lesions appear to be Vibrio spp. and a rod-shaped virus (similar to Lymphoid Organ Virus, Gill-Associated Virus [GAV] and Yellow-Head Virus). Suppurative inflammation was characterised by edema, infiltration of haemocytes and local sites of abscesses. Eyes with granuloma usually appeared white in pond-side examinations, and histology showed that fibrous tissue replaced ommatidia, ganglia and internal structures of the eye. Malacia of the eye was characterised by necrosis of nervous tissue, vacuolation and vascular proliferation in the medulla ganglia. Levels of presumptive Vibrionaceace were high in moribund specimens and Gram-negative rods were observed in some specimens as free particles in the interstitial fluid and haemolymph in the eye. Transmission electron microscopy showed that nerve cells in the fasciculated zone (near the basement membrane) contained cytoplasmic vesicles (1 to 3 microm in diameter) with particles (15 to 26 nm in diameter) and rod-shaped nucleocapsids. The rods were similar to those of GAV and were 130 to 260 nm long, 10 to 16 nm in diameter and had helical symmetry with a screw-like thread (2.4 to 3.5 nm pitch). Also, unidentified enveloped virions, averaging 74 nm in diameter, were observed in cytoplasmic vesicles in the fasciculated zone. In conclusion, it is suggested that bacterial and viral infections of the eye could result in impaired neuroendocrine functions, which may cause a range of clinical signs of disease.

Animals↗
PubMed2002

Simultaneous detection of white spot syndrome virus (WSSV) and Taura syndrome virus (TSV) by multiplex reverse transcription-polymerase chain reaction (RT-PCR) in pacific white shrimp Penaeus vannamei.

An assay using a single-tube, 1-step multiplex reverse transcription-polymerase chain reaction (RT-PCR) was established for the simultaneous detection of white spot syndrome virus (WSSV) and Taura syndrome virus (TSV). Three primer sets, 9195 F/9992 R, 94 F2/R2, and ITS F/28S R, were mixed at a ratio of 3:1:1 to amplify specific fragments of the TSV, WSSV, and Penaeus vannamei genome, respectively, in the RT-PCR reaction. Shrimp samples were experimentally infected with WSSV and TSV. PCR-amplified products detected in the nucleic acid extraction of shrimp pleopods produced 4 kinds of results. With no virus infection, 1 fragment of 892 base pairs (bp) was amplified from a ribosomal RNA gene by primer set ITS F/28S R as an internal control. In samples only infected by WSSV or TSV, 2 fragments could be seen: either from WSSV (530 bp) plus the internal control or TSV (231 bp) plus the internal control, respectively. In cases of co-infection with both viruses, all 3 amplified products were detected simultaneously. This study is the first report of Penaeus vannamei specimens co-infected with WSSV and TSV being detected using a PCR method via experimental infection.

Animals↗
PubMed2003

Elimination of shrimp endogenous peroxidase background in immunodot blot assays to detect white spot syndrome virus (WSSV).

False positive results were obtained in immunodot blot assays to detect white spot syndrome virus when horseradish peroxidase-conjugated sheep anti-mouse immunoglobin (Ig) serum was used as a secondary antibody with 3-3'-diaminobenzine tetrahydrochloride dihydrate as the detection substrate. The cause was considered to be a reaction of shrimp endogenous peroxidase (POD) with the substrate. In experiments designed to inhibit POD activity, 9 different reagents were used at different concentrations and for different treatment times. EDTA, sodium azide, HEPES-Na, NaHSO3, H2O2 and phenylthiourea (PTU) were able to inhibit POD activity by 44, 60, 64, 67, 79, and 90%, respectively. Phenylmethylsulfonyl fluoride did not inhibit POD, and neither periodic acid nor H2O2 in methanol were appropriate due to the formation of flocculant precipitates when added to shrimp extracts. It was concluded that of the treatments tested, 10 mM PTU for 2 h yielded optimal inhibition and that such pretreatment of samples eliminates false positive results in immunodot blot assays.

Animals↗
PubMed2003

Effect of methyl parathion on the susceptibility of shrimp Litopenaeus vannamei to experimental vibriosis.

Following increasing calls for environmental safety over the past 2 decades, persistent pesticides are being replaced by more rapidly degradable products. However, even these pesticides can affect non-target species, and may be associated with slow growth and increased susceptibility to viral and bacterial infections. In this study, juvenile white shrimp Litopenaeus vannamei (also named Penaeus vannamei) were challenged by intramuscular injection with Vibrio parahaemolyticus after 4 d prior exposure to methyl parathion in feed pellets at 0.080 microg g(-1). The bacterial injection control group consisted of shrimp fed pellets containing the methyl parathion-carrier solvent acetonitrile. Three additional control groups comprised 2 sterile saline-injection groups fed pellets containing methyl parathion or acetonitrile prior to injection, and 1 uninjected group fed normal pellets. Cumulative mortalities were recorded on the 4th and 8th days, and the presence of histological lesions was recorded on the 8th day. Cumulative mortalities were significantly higher in the group exposed to methyl parathion and bacteria on Day 8. Histological lesions, typical of vibriosis, were significantly associated with the injection of V. parahaemolyticus. The study provides strong experimental evidence that prior exposure to methyl parathion can increase the severity of Vibrio infections.

Animal Feed↗
PubMed2004

White spot syndrome virus (WSSV) detected by PCR in rotifers and rotifer resting eggs from shrimp pond sediments.

White spot syndrome virus (WSSV) was detected by PCR-dot blot hybridization in rotifer resting eggs from shrimp Penaeus chinensis culture-pond sediments. It was also detected in rotifers hatched from those eggs. Surface disinfection before analysis indicated that WSSV was probably present within the resting eggs. Results suggested that rotifer resting eggs may be an overwintering reservoir for WSSV in shrimp ponds.

Animals↗
PubMed2004

Cloning and sequencing of envelope proteins (VP19, VP28) and nucleocapsid proteins (VP15, VP35) of a white spot syndrome virus isolate from Korean shrimp.

Since our first report in 1998, white spot syndrome virus (WSSV) has become wide-spread on the southern and western coasts of Korea. Almost all shrimp in ponds die within 3 to 4 d after the first dead shrimp are observed with gross lesions ranging from abnormal red body discoloration to white spots in the cuticle. From one isolate, we cloned and sequenced WSSV genomic DNA coding for VP19 and VP28 envelope proteins and VP15 and VP35 nucleocapsid proteins. Putative protein sequences were submitted to GenBank and assigned accession numbers AY316119 (VP19), AY324881 (VP28), AY374120 (VP15) and AY325896 (VP35). At the nucleotide level, VP19, VP28 and VP15 sequences were, respectively, 99, 100 and 100% identical to those of China, Indonesia, Japan and the United States and the VP35 sequence was 100% identical to that of a Taiwanese isolate. The deduced amino-acid sequences were 99 to 100% identical to those from other countries. In VP19, C and T in the foreign isolates were replaced by T and A in the Korean isolate at Positions 57 and 218 nt, respectively, downstream of A (+) of the VP19 start codon. The change at Position 218 nt resulted in valine in the foreign isolates being replaced by aspartate in the Korean isolate.

Amino Acid Sequence↗
PubMed2004

Experimental infection of Pacific white shrimp Litopenaeus vannamei with Necrotizing Heptopancreatitis (NHP) bacterium by per os exposure.

Necrotizing Hepatopancreatitis Bacterium (NHPB), which causes Necrotizing Hepatopancreatitis, was successfully transmitted in individually isolated Kona stock Litopenaeus vannamei through per os exposure. Animals (140) were individually exposed orally to a 0.05 g piece of an NHPB-infected hepatopancreas and 120 control animals were each exposed to a 0.05 g piece of NHPB-negative hepatopancreas. Shrimp were maintained in Sterilite containers with approximately 41 of artificial seawater at 30 per thousand salinity and 30 degrees C for 60 d. Mortality of infected shrimp was observed from Day 16 to Day 51 post-exposure. Infected animals sustained reduced feeding activity and displayed empty guts. Some infected animals developed a pale hepatopancreas noticeable through the carapace. Survival probabilities fit a Weibull distribution and parametric survival analysis revealed lowered survival due to NHPB infection. Median survival time of NHPB-infected animals was 34.5 d. After correcting for background daily mortality in the controls, mean acute daily mortality of NHPB was estimated at 0.09, a value much lower than that estimated for other diseases in Kona stock L. vannamei such as White Spot Syndrome Virus (0.40) and Taura Syndrome Virus (0.30). A chronic, or carrier, state was not demonstrated in NHPB epizootics because all NHPB-positive animals experienced mortality and no animals surviving to 60 d post-exposure were diagnosed NHPB-positive through PCR or histology.

Animals↗
PubMed2006

A simple and rapid immunochromatographic test strip for detection of white spot syndrome virus (WSSV) of shrimp.

A simple strip-test kit for white spot syndrome virus (WSSV) detection was developed using monoclonal antibody W29 (against the VP28 structural protein) conjugated with colloidal gold as the detector antibody. A rabbit anti-recombinant VP28F118 (rVP28) protein antibody in combination with a W28 monoclonal antibody was used as the capture complex at the test line (T), and goat anti-mouse IgG antibody (GAM) was used as the capture antibody at the control line (C). For evidence, the ready-to-use strip was kept in a plastic case and stored in a desiccated plastic bag. A sample volume of 100 microl gill homogenate in application buffer was applied to the sample chamber at one end of the strip and allowed to flow by chromatography through the nitrocellulose membrane to the other end. In test samples containing WSSV, the virus bound to the monoclonal antibody conjugated with colloidal gold and the resulting complex was captured by the antibodies at T to give a reddish-purple band. Any unbound monoclonal antibody conjugated with colloidal gold moved across T to be captured by the GAM and formed a band at C. In samples without WSSV or with WSSV below the limit of detection of the kit, only the band at C was seen. This method was 4 times less sensitive than dot blotting, and about 2 000 000 times less sensitive than 1-step PCR. Nonetheless, it could be used to screen individual shrimp or pooled shrimp samples to confirm high levels of WSSV infection or WSSV disease outbreaks. The beneficial features of this kit are that simple, convenient and quick results can be obtained without the requirement of sophisticated tools or special skills.

Animals↗
PubMed2005

Ready-to-eat shrimp as an international vehicle of antibiotic-resistant bacteria.

The occurrence of antibiotic-resistant bacteria in foods of animal origin is a potential health threat because resistance can be transferred among bacteria, and antibiotic-resistant pathogens may not respond to antibiotic treatments. Thirteen brands of ready-to-eat shrimp representing four countries of origin were obtained from local grocery stores. Total heterotrophic plate counts were determined, and antibiotic-resistant bacteria were isolated. Total heterotrophic colony counts ranged from 3.3 to 5.6 log CFU/g, which was within approved quality limits. A total of 1,564 isolates representing 162 bacterial species were recovered during screening of resistance to 10 antibiotics: ampicillin, ceftriaxone, chloramphenicol, clindamycin, erythromycin, nalidixic acid, streptomycin, tetracycline, trimethoprim, and vancomycin. Six hundred fifty-seven (42%) of the isolates and 131 (81%) of the species had acquired resistance to antibiotics. Numerous resistant human pathogens were isolated, including Escherichia coli, Enterococcus spp., Salmonella, Shigella flexneri, Staphylococcus spp., and Vibrio spp. Nonresistant Yersinia spp. also were isolated. Ready-to-eat shrimp is sold with instructions to thaw the product before serving, which may result in consumer exposure to antibiotic-resistant bacteria. Widespread trade of this product provides an avenue for international dissemination of antibiotic-resistant pathogens.

Animals↗
PubMed2006

Contamination of cooked peeled shrimp (Pandalus borealis) by Listeria monocytogenes during processing at two processing plants.

Listeria spp. and Listeria monocytogenes contamination was evaluated in cooked peeled shrimp (final or semifinal product, 82 samples) and the shrimp-processing environment (two plants, 613 samples) in eight surveys conducted from 1998 through 2001. Listeria was detected in 12.5% (78) of the 695 samples (11.2% of the samples were positive for L. monocytogenes), but none of the samples of final product contained Listeria. One hundred seventy-two L. monocytogenes isolates were characterized by pulsed-field gel electrophoresis. Cleavage with macrorestriction enzymes AscI and ApaI yielded 14 different pulsotypes in the plants; two types were dominant, one in each plant. Sixty-three of the 106 isolates in plant A and 43 of the 66 isolates in plant B were of the dominant types. Certain strains, mainly of serotypes 1/2c and 4b and pulsotypes 1A and 2H, were persistent for long periods in both plants. Adaptation of good hygienic practices in the processing plants, including strict rules concerning traffic of staff and equipment, and existing hygienic requirements appeared to be effective in preventing contamination between areas within plants and in the final product. The persistence of Listeria strains in these two processing plants indicates the importance of detecting the places in the processing environment (e.g., transporters, equipment, floors, and drains) where L. monocytogenes can survive so that cleaning and disinfection efforts can be directed to such niches.

Animals↗
PubMed2006

Differentially expressed genes in hemocytes of Vibrio harveyi-challenged shrimp Penaeus monodon.

Differential Display PCR technique (DD-PCR) was used for the analysis of altered gene expression in hemocytes of Vibrio harveyi-infected Penaeus monodon. Forty-four combinations of arbitrary and oligo(dT) primers were used to screen for differentially expressed genes. A total of 79 differentially expressed bands could be identified from 33 primer combinations. These included 48 bands (61%) whose expression level increased and 31 bands (39%) decreased after V. harveyi challenge. Subsequently, forty-eight differential display fragments were successfully reamplified and cloned. A total of 267 clones were randomly selected and sequenced. The sequence analysis showed that 85 (31%) out of 267 clones were matched with sequences in the GenBank database which represented 24 different genes with known functions. Among the known genes, glucose transporter 1, interferon-related developmental regulator 1, lysozyme, profilin, SERPINB3, were selected for further confirmation of their differentially expression patterns by real-time PCR. The results showed increasing in expression level of the selected genes in shrimp hemocytes after microbial challenge suggesting the involvement of such genes in bacterial response in shrimp. The anti-lipopolysaccharide factor type 3 (ALFPm3) gene, previously reported in P. monodon (Supungul et al., 2002) was found among the up-regulated genes but diversity due to amino acid changes was observed. Increase in ALFPm3 transcripts upon V. harveyi injection is in accordance with that found in the previous study.

Amino Acid Sequence↗
PubMedDate not supplied

Determination of 4-hexylresorcinol in shrimp by liquid chromatography with fluorescence detection.

A method was developed to determine 4-hexylresorcinol in shrimp meat. The procedure is based on extraction of test portions with methanol followed by liquid chromatographic analysis of the extracts, using a reversed-phase column and fluorimetric detection (excitation: 280 nm, and emission: 310 nm). The confidence interval of the recovery in working range of 1.5-2.5 mg/kg was 81.6 +/- 0.8%. The relative standard deviation in the working range was 2.1%. Limits of quantitation and detection were 6.59 and 1.98 ng/mL extract, respectively, corresponding to 0.26 and 0.08 mg/kg in shrimp.

Animals↗
PubMed1975

Retention of Salmonella typhimurium by certain species of fish and shrimp.

Marine fish (Mugil cephalus, Fundulus heteroclitus, Trachinotus carolinus), lake shrimp (Penaeus setiferus), and channel catfish (Ictalurus lacustris punctatus) were exposed to Salmonella typhimurium and cultured after 2 hours and at daily intervals for 30 days. Salmonella typhimurium was recovered from all exposed animals after 2 hours and for 30 days in all animals except P setifurus. The organisms could not be recovered from those shrimp after the initial sampling period. Apparent salmonellosis developed in certain specimens of M cephalus and T carolinus 10 to 14 days after exposure to S typhimurium.

Animals↗