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At least 55 records · Page 3Linked to original sources

PubMed2000

Occupational asthma in a seafood restaurant worker: cross-reactivity of shrimp and scallops.

BACKGROUND: The case of a restaurant seafood handler with IgE-mediated occupational asthma and contact urticaria to both shrimp and scallops is presented. Independent hypersensitivity to both seafoods was demonstrated by skin testing, inhalation challenge, and immunoassays. Bronchial challenge with extracts of shrimp and scallops each produced an isolated early asthmatic response. OBJECTIVE: To investigate cross-reactivity of shrimp (phylum Arthropoda) and scallops (phylum Mollusca). METHODS: Shrimp and scallops extracts were prepared from raw seafood and seafood boiling water. Distillate was collected over boiling shrimp. Specific-IgE ELISA and immunoblot assays were accomplished for shrimp and scallops extracts inhibited by each other. RESULTS: SDS-PAGE of shrimp boiling water and distillate showed similar protein patterns. SDS-PAGE and immunoblot demonstrated prominent protein allergens for shrimp boiling water at 21, 26, and 35 to 38 kD; for raw shrimp at 26 and 38 kD; for scallops boiling water at 20, 35 to 39 and 42 kD; and for raw scallops at 36 to 38 and 41 kD. Significant inhibition of the 35 to 39-kD band of each shrimp and scallops extract was demonstrated on immunoblot inhibition by seafood of the opposite phylum. IgE ELISA inhibition demonstrated 17% to 28% inhibition of shrimp by scallops and scallops by shrimp. CONCLUSIONS: Seafood allergens aerosolized during food preparation are a source of potential respiratory and contact allergens. Shrimp and scallops demonstrate significant cross-reactivity. These findings confirm that the primary cross-reactive allergen of shrimp (phylum Arthropoda) and scallops (phylum Mollusca) is the 35 to 39 kD heat-stable allergen, previously demonstrated to be muscle topomyosin in both phyla.

Animals↗

PubMedDate not supplied

A precollaborative study of weight determination methods for quick frozen shrimp.

A precollaborative study compared the accuracy and precision of official AOAC methods with other selected methods for determining net weight of IQF-glazed shrimp and block-glazed shrimp, assessed the ruggedness of the methods with respect to changes in the levels of the factors under study, and selected candidate methods for use in a collaborative study. Methods tested for determining deglazed (frozen) net weight of IQF-glazed shrimp were (1) AOAC Method 963.18 and (2) the Water Bath Dip Method. Methods tested for determining thawed net weight of IQF-glazed shrimp were (1) AOAC Method 967.13, (2) Modified AOAC Method(mnb) 967.13, (3) Modified AOAC Method(pb) 967.13, (4) the Codex Method, (5) the Air Thaw Method, and (6) Modified AOAC Method 963.18. The same methods except Modified AOAC Method 963.18 were tested for determining thawed net weight of block-glazed shrimp. A total of 864 0.45 kg (1 lb), 0.90 kg (2 lb), and 1.35 kg (3 lb) IQF-glazed shrimp test samples and 234 2.25 kg (5 lb) block-glazed shrimp test samples were collected. During sample preparation, test samples were subjected to either water with or without sodium tripolyphosphate (STP). During deglazing (IQF-glazed shrimp only) and/or thawing, test samples were allocated in a factorial design to assess the effects of STP presence (no STP and STP), sieve mesh sizes (2.83 and 2.38 mm; 0.11 and 0.09 in.), and sieve diameters (20 and 30 cm; 8 and 12 in.). During weighing, test samples were further allocated to a sequence of weighing procedures designed to assess the effects of using sieve weights (dry and wet) in combination with paper towel use (no and yes) and tared pan weights when calculating determined net weights. On the basis of the results of this precollaborative study, Modified AOAC Method(pb) 967.13 and the Air Thaw Method seem to be the best methods to determine net weight of IQF-glazed and block-glazed shrimp. Therefore, to validate method choices in the collaborative study, the authors recommend analysis of IQF-glazed shrimp and block-glazed shrimp test samples, each prepared with or without STP, by Modified AOAC Method(pb) 967.13 and the Air Thaw Method. To fulfill AOAC requirements, IQF-glazed shrimp and block-glazed shrimp test samples, each prepared with or without STP, must be analyzed by official methods: AOAC Method 963.18 (IQF-glazed shrimp only) and AOAC Method 967.13. During testing, sieve mesh size will be either 2.83 or 2.38 mm (0.11 or 0.09 in.), sieve diameter will be limited to 30 cm (12 in.), and weighing procedure will be limited to tared pan.

Animals↗

PubMed2006

Effect of high intensity ultrasound on the allergenicity of shrimp.

The tropomyosin fraction of shrimp proteins is potentially responsible for allergic reaction in individuals with genetic predisposition to allergy. However, there are no efficient and safe methods to reduce its allergenicity. High intensity ultrasound is known to change the structure of proteins. This study is aimed at assessing high intensity ultrasound's effect on the allergenicity of shrimp allergen. Shrimp and purified shrimp allergen were treated with high intensity ultrasound for 30-180 min. Extracts of treated samples were analyzed by enzyme-linked immunosorbent assay (ELISA) with pool serum of shrimp allergy patients and polyclonal anti-allergen antibodies and by immunoblotting after polyacrylamide gel electrophoresis. Shrimp treated with high intensity ultrasound showed a decrease in allergenicity measured with ELISA. A linear relationship between the immune response induced by treated shrimp allergen and the applied treatment time was observed. The decrease in allergenicity was confirmed by immunoblot assays with shrimp allergic patients serum. Allergenicity of shrimp allergen extracted from treated shrimp was higher than that of purified shrimp allergen with the same treatment time. Gel-filtration HPLC was applied for analysis of shrimp allergen after treatment with high intensity ultrasound. Some fractions were appeared with increasing treatment time. The results suggested that high intensity ultrasound could be used to reduce the allergenicity of shrimp.

Adolescent↗

PubMed2001

Effects of shrimp density on transmission of penaeid acute viremia in Penaeus japonicus by cannibalism and the waterborne route.

To investigate the effects of shrimp density on mortalities of Penaeus japonicus in experimental penaeid acute viremia (= white spot syndrome), shrimp injected intramuscularly with penaeid rod-shaped DNA virus (PRDV) were reared at different densities. In Expt 1, challenged (10(-6) dilution of a PRDV preparation) shrimp were reared collectively in a tank or individually in separate chamber units. A significant difference in cumulative mortalities was found between collectively (75.6%) and individually (1.2%) reared groups after 30 d. In Expt 2, effects of density on mortality were clearly shown when challenged (10(-5) dilution) shrimp were reared collectively in tanks at high (260 shrimp m(-2)), middle (135 shrimp m(-2)) and low densities (73 shrimp m(-2)). The cumulative mortalities for 14 d in the high, middle and low density groups were 72, 46 and 18%, respectively. In Expt 3, challenged (10(-5) dilution) shrimp were reared collectively in 3 tanks (Groups A, B and C) at the same high density (260 shrimp m(-2)): Group A, dead shrimp were immediately removed to avoid transmission of the pathogen through cannibalism and the waterborne route; Group B, dead shrimp were removed at scheduled times but were separated from living shrimp by a net partition to avoid cannibalism; and Group C, dead shrimp were removed twice a day at scheduled times. Resulting cumulative mortalities for 20 d in Groups A, B and C were 4, 24 and 64 %, respectively. These results show that the higher mortalities occur in P. japonicus reared at the higher densities in experimental PRDV infection, and this phenomenon is caused mainly by a higher opportunity of horizontal transmission of the virus through cannibalism and the waterborne route.

Acute Disease↗

PubMed2005

Effects of dopamine on the immunity of white shrimp Litopenaeus vannamei.

The total haemocyte count (THC), phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, phagocytic activity and clearance efficiency in response to pathogen Vibrio alginolyticus were measured when the white shrimp Litopenaeus vannamei (20.0+/-1.5 g) were injected individually with dopamine at 10(-8), 10(-7) and 10(-6)mol shrimp(-1), respectively. For the shrimp that received dopamine at 10(-7) and 10(-6)mol shrimp(-1), the THC decreased by 25% and 39%, phenoloxidase activity decreased by 15% and 32%, respiratory burst decreased by 21% and 36%, and SOD activity decreased by 50% and 63%, respectively, after 4 h. The phagocytic activity and clearance efficiency of shrimp that received dopamine at either dose decreased significantly after 2 h. The THC, phenoloxidase activity, respiratory burst, SOD activity, phagocytic activity and clearance efficiency returned to normal values after 16, 8, 8, 24, 16 and 4 h, respectively, for the shrimp that received dopamine at either dose. In another experiment, L. vannamei which had received dopamine at 10(-8), 10(-7) and 10(-6)mol shrimp(-1) were challenged after 1 h by injection with V. alginolyticus at 1.0x10(5) colony-forming units (cfu) shrimp-1 and then placed in seawater of 20 per thousand. The cumulative mortality of shrimp that received dopamine at either dose was significantly higher than that of shrimp that received saline after 8 h, and of shrimp that received saline at the termination of the experiment (48 h after the challenge). It is therefore concluded that dopamine administration at 10(-6)mol shrimp-1 or less causes immune modulation of L. vannamei.

Animals↗

PubMed2005

The effect of Sargassum fusiforme polysaccharide extracts on vibriosis resistance and immune activity of the shrimp, Fenneropenaeus chinensis.

Immunostimulants are valuable for control of shrimp diseases and the immunostimulatory effects of some polysaccharide additives for shrimp have been reported. In this study, the Sargassum fusiforme polysaccharide extract (SFPSE) was assessed as a feed additive when supplemented in the diet (0%, 0.5%, 1.0%, and 2.0%) for juvenile shrimp, Fenneropenaeus chinensis, in order to study the effects of SFPSE on vibriosis resistance and immune activity. Shrimp were cultured in the same pond with cages. The body weight, survival, the cumulative mortality after injection with Vibrio harveyi (30 microl V. harveyi suspension at 9.3 x 10(7) CFU ml(-1) per shrimp), the total haemocyte counts (THCs), the protein concentration and the phenoloxidase (PO) activity in supernatant of haemolymph, the lysozyme (LSZ) and superoxide dismutase (SOD) activity in muscle of the shrimp were assayed after 14 days feeding period. The results indicated that shrimp survival under the stress of V. harveyi was affected by the dietary SFPSE. The shrimp treated with 1.0% and 0.5% SFPSE displayed significantly lower cumulative mortalities after being injected with V. harveyi suspension 24 and 30 h later, respectively, compared with that of the control. However, cumulative mortality of 2.0% SFPSE treatment was not significantly different from that of the control. There was no significant difference of cumulative mortality between 0.5% and 1.0% SFPSE treatment groups. The immune activities of the shrimp also were affected by dosage of dietary SFPSE. The THCs of the shrimp rose with increasing SFPSE dosage. The protein concentration and PO activity in supernatant of haemolymph as well as muscular LSZ activity first rose then dropped with increasing SFPSE dosage. The protein concentration in supernatant of haemolymph appeared a maximum of 167.46 mg ml(-1) in 1.0% SFPSE treatment. The PO activity and LSZ activity reached the peaks as 13.20 U and 3.21 U mgprot(-1) in 0.5% SFPSE treatment, respectively. SOD activity of the shrimp was not significantly affected by dietary SFPSE. It is therefore suggested that oral administration of SFPSE at an optimal level of 0.5% and 1.0% for 14 days effectively improved vibriosis resistance and enhanced immune activity of the shrimp in general.

Animal Feed↗

PubMed1998

Cloning of a shrimp (Metapanaeus ensis) cDNA encoding a nuclear receptor superfamily member: an insect homologue of E75 gene.

Degenerate primers were derived from the amino acid sequence in the DNA binding domain of the Drosophila ecdysone receptor (DmEcR). Several partial cDNAs were amplified from the shrimp epidermis by reverse transcription polymerase chain reaction (RT-PCR). One of these fragments shows the highest amino acid sequence homology to the insect ecdysone inducible gene E75. This partial cDNA was used as a probe to screen the swimming leg cDNA library of the shrimp, Metapenaeus ensis. A 3.6 kb cDNA clone was obtained. The longest open reading frame of this cDNA consists of 606 amino acids and its deduced amino acid sequence has all five domains typical of a nuclear receptor. The putative polyadenylation signal is located at about 400 bp 3' to the stop signal. The deduced amino acid sequence of this cDNA shows the highest identity to that of the E75A reported in Manduca sexta, Galleria melonella, Drosophila melanogaster, and Choristoneura fumiferana. Based on the amino acid sequence comparison, the shrimp nuclear receptor is considered the insect homologue of E75A. Northern blot analysis shows that the shrimp E75 is expressed in the epidermis, eyestalk and the nerve cord of the pre-molt shrimp. Moreover, E75 transcripts can be detected in the epidermal tissues of early pre-molt shrimp by in situ hybridization. To determine whether the shrimp could also express other E75s like the insects, 5' end RACE and RT-PCR were performed on epidermal cDNA of a single shrimp. Subcloning and DNA sequence determination of the PCR products confirmed the presence of two other forms of E75 (tentatively called E75C and E75D) in shrimp. By RT-PCR, different levels of E75 expression can be detected in the epidermis, nerve cord and the eyestalk of early pre-molt shrimp. In addition to the different levels of expression of the shrimp E75s in the epidermis, the pattern of their expression is also different during the molting cycle. This is the first report on the cloning of a shrimp nuclear receptor superfamily member.

Amino Acid Sequence↗

PubMed2000

Estimation of the dietary vitamin A requirement of juvenile grass shrimp, Penaeus monodon.

Two growth experiments were conducted to estimate the minimal dietary vitamin A requirement for juvenile grass shrimp, Penaeus monodon. In expt. 1, purified diets containing 0, 1,500, 3,000, 15, 000, 30,000, 45,000 and 60,000 retinol equivalent (RE)/kg (i.e., 0, 5,000, 10,000, 50,000, 100,000, 150,000, 200,000 IU/kg) of supplemental vitamin A (retinyl acetate) were fed to P. monodon (mean initial weight 0.97 +/- 0.01 g) for 8 wk. In expt. 2, diets with 0, 600, 1,200, 1,800, 2,400, 3,000, 3,600, and 4,500 RE/kg (i.e. , 0, 2,000, 4,000, 6,000, 8,000, 10,000, 12,000, 15,000 IU/kg) of supplemental vitamin A were fed to the shrimp (mean weight 0.68 +/- 0.01 g) for 6 wk. The basal unsupplemented diet contained 54 RE vitamin A/kg, and supplemental levels were confirmed by analysis. Each diet was fed to three replicate groups of shrimp. In expt. 1, shrimp fed diets supplemented with 300 RE vitamin A/kg had significantly greater weight gain (P < 0.05) than those fed the unsupplemented control diet and diets supplemented with >===" BORDER="0">30,000 RE vitamin A/kg. Survival rate was higher in shrimp fed diets supplemented with 1,500-30,000 RE vitamin A/kg than shrimp fed the control diet. Highest blood triglyceride concentration and body lipid concentration were in shrimp fed diets supplemented with 45,000 and 60,000 RE vitamin A/kg, respectively. Eye vitamin A concentration and hepatopancreatic total lipid concentration in shrimp generally increased as dietary vitamin A supplementation increased. In expt. 2, feed efficiency was highest in shrimp fed diets supplemented with 2,400, 3,000, 3,600 and 4,500 RE vitamin A/kg, followed by shrimp fed diets with 600 and 1,200 RE vitamin A/kg and finally the unsupplemented control group. Shrimp fed diets supplemented with vitamin A had significantly higher survival percentages than those fed the unsupplemented control diet. Weight gain percentage of the shrimp analyzed by broken-line regression indicated that the minimal dietary vitamin A concentration in growing P. monodon is 2,511 RE/kg ( approximately 8, 400 IU/kg).

Analysis of Variance↗

PubMed2003

Haemolymph parameters of Pacific white shrimp (Litopenaeus vannamei) infected with Taura syndrome virus.

Pacific white shrimp (Litopenaeus vannamei) were injected with Taura syndrome virus (TSV) to assess shrimp immune responses and survival. TSV-infected shrimp suffered high mortality, but mock-infected and untreated shrimp experienced no mortality. Moribund shrimp were a pale, reddish colour and were lethargic and soft-shelled. Their haemolymph was clear red and coagulated poorly. In TSV-infected shrimp, the total haemocyte count (THC), hyalinocyte and granulocyte counts, and total plasma protein decreased significantly to 21%, 24%, 17% and 56% of untreated control values, respectively. Haemocyanin decreased to 67%, and clottable proteins to 80% of control values (P< 0.01). Copper and calcium ions, haemocytic transglutaminase (TGase) activity and plasma growth inhibitory activity against Vibrio harveyi also decreased significantly. Generation of intrahaemocytic superoxide anion, O(-2), in TSV-infected shrimp was significantly greater (P< 0.05) than in both control groups, no matter whether glucan stimulated or unstimulated. But the relative increase of intrahaemocytic O(-2) generation in TSV-infected shrimp response to glucan stimulation was lower in both controls. Plasma phenoloxidase (PO) activity increased significantly in TSV-infected shrimp. The plasma bacterial agglutinin titre against E. coli and V. harveyi, growth inhibition of E. coli and the concentration of magnesium ions in TSV-infected shrimp did not change significantly. In conclusion, ten of thirteen haemolymph parameters changed significantly during the host-TSV interaction. These parameters might be valuable references of shrimp health status.

Agglutination Tests↗

PubMed2005

Noradrenaline modulates the immunity of white shrimp Litopenaeus vannamei.

The total haemocyte count (THC), phenoloxidase activity, respiratory burst, superoxide dismutase (SOD) activity, phagocytic activity and clearance efficiency in response to pathogen Vibrio alginolyticus were measured when the white shrimp Litopenaeus vannamei (18.4 +/- 1.2 g) were injected individually with noradrenaline at 10(-8), 10(-7) and 10(-6) mol shrimp(-1). For the shrimp that received noradrenaline at 10(-8), 10(-7) and 10(-6) mol shrimp(-1), the THC decreased by 15%, 21% and 32%, phenoloxidase activity decreased by 15%, 31% and 31%, respiratory burst decreased by 13%, 21% and 32%, and SOD activity decreased by 46%, 56% and 55%, respectively, after 2 h. The phagocytic activity and clearance efficiency of shrimp that received noradrenaline at either dose decreased significantly after 2 h. The THC, phenoloxidase activity, respiratory burst, SOD activity, phagocytic activity and clearance efficiency returned to normal values after 4, 4, 8, 24, 16 and 8 h, respectively, in the shrimp that received noradrenaline at either dose. In another experiment, L. vannamei which had received noradrenaline at 10(-8), 10(-7) and 10(-6) mol shrimp(-1) were challenged after 1h by injection with V. alginolyticus at 1.0 x 10(5) colony-forming units (cfu)shrimp(-1) and then placed in seawater of 20 per thousand. The cumulative mortality of shrimp that received noradrenaline at either dose was significantly higher than that of shrimp that received saline after 4 h, and at the termination of the experiment (48 h after the challenge). It is therefore concluded that noradrenaline administration at 10(-6) mol shrimp(-1) or less causes immune modulation of L. vannamei.

Animals↗

PubMed2003

Disparate patterns of population genetic structure and population history in two sympatric penaeid shrimp species (Farfantepenaeus aztecus and Litopenaeus setiferus) in the eastern United States.

Analysing the population genetic structures of sympatric species provides opportunities to compare patterns of population genetic structure and phylogeography in order to gain insight into the factors that influence the development of the observed patterns. In this study, we compared the population genetic structures and phylogeographies of brown shrimp (Farfantepenaeus aztecus) and white shrimp (Litopenaeus setiferus), two sympatric penaeid shrimp species that inhabit the waters of the eastern USA, using sequence analysis of the mitochondrial DNA control region. Brown shrimp showed no significant phylogenetic structure or population subdivision, and closely related haplotypes were geographically dispersed. Mismatch analysis indicated that brown shrimp experienced a late-Pleistocene era sudden population expansion. In contrast, white shrimp had a complex haplotype phylogeny consisting of two distinct lineages and two less well-defined sublineages, and the haplotypes and lineages were geographically structured. Mismatch analysis for white shrimp also showed evidence of sudden population expansion, albeit for each lineage separately and more recently than in the brown shrimp. These disparate patterns may have developed as a result of species-specific differences in physiological tolerances and habitat preferences that caused greater fluctuations in white shrimp population sizes and reductions in long-term effective population size relative to that of the brown shrimp, and thereby increased the susceptibility of the white shrimp populations to stochastic genetic change.

Animals↗

PubMed1998

Chitin but not chitosan supplementation enhances growth of grass shrimp, Penaeus monodon.

The effect of chitin, poly-beta-(1 --> 4)-N-acetyl-glucosamine, and chitosan, a polymer of glucosamine obtained by the deacetylation of chitin, on growth and nutrient digestibility was studied in grass shrimp, Penaeus monodon. Shrimp were fed for 8 wk diets containing no supplement (control) or 2, 5 or 10 g/100 g chitin or chitosan. Each diet was fed to triplicate groups of shrimp with a mean initial body weight of 0.45 +/- 0.05 g. Significantly higher body weight gains were observed in shrimp fed the 5% chitin diet than in those fed the 10% chitin or the control diet. The weight gain of shrimp decreased as dietary chitosan supplementation level increased (r = 0. 87, P < 0.05). Feed efficiencies (FE) and protein efficiency ratios (PER) followed the same pattern. Lower protein and lipid digestibilities and lower body protein and lipid contents were observed in shrimp fed all chitosan-containing diets than in controls (P < 0.05). Carbohydrate digestibility was lower in shrimp fed the 10% chitosan diet than in those fed the control diet. Lower protein and lipid digestibilities, body lipid content and blood cholesterol concentration were observed in shrimp fed the 10% chitin diet compared with controls (P < 0.05). Higher weight gains, body lipid contents and blood cholesterol concentrations were observed in shrimp fed the 2 and 5% chitin diets than in those fed the chitosan diets. Shrimp fed the 5% chitin diet had higher protein and lipid digestibilities and higher body protein content than those fed the 5% chitosan diet (P < 0.05). These data suggest that dietary chitin, supplemented at 5%, enhances P. monodon growth, whereas chitosan depresses shrimp growth, regardless of the supplementation level.

Analysis of Variance↗

PubMed2004

Multiple pathogens found in growth-retarded black tiger shrimp Penaeus monodon cultivated in Thailand.

In 2001-2002 throughout Thailand, black tiger shrimp Penaeus monodon farmers reported very unusual retarded growth. We have called this problem monodon slow growth syndrome (MSGS). Based on decreased national production, estimated losses due to this phenomenon were in the range of 13 000 million baht (approximately 300 million US dollars) in 2002. Since rearing practices had not changed, it was considered possible that the MSGS problem may have arisen from a new or existing pathogen. To examine this possibility, cultivated shrimp were sampled from 32 commercial rearing ponds that reported abnormally slow growth from eastern, central and southern regions of Thailand. Shrimp were randomly sampled from each pond and grouped into normal and small shrimp. Normal shrimp were defined as those with body weights (BW) of 24 g or more while small shrimp were defined as those that weighed 16.8 g or less. Pleopods were used for detection of monodon baculovirus (MBV), heptopancreatic parvovirus (HPV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV) using specific polymerase chain reaction (PCR) assays. In addition, some shrimp were processed for normal histopathology and transmission electron microscopy (TEM). Most of the shrimp specimens were infected by at least 1 of these viruses but many had dual or multiple infections. Prevalence of HPV and combined HPV/MBV infections in the small shrimp was significantly higher than in the normal shrimp. In addition to the viruses, a new microsporidian species, gregarines and bacteria were also observed but were not significantly associated with the MSGS problem. Some of the small shrimp gave negative results for all these pathogens by PCR and histology and no new and unique histopathology was recognized in any of the samples. The findings suggested that HPV infection was a contributing factor but not the overriding factor responsible for MSGS. It is possible that MSGS is caused by an unknown pathogen or by some other presently unknown, non-pathogenic factor.

Animals↗

PubMed2006

White-spot syndrome virus (WSSV) introduction into the Gulf of Mexico and Texas freshwater systems through imported, frozen bait-shrimp.

We analysed 20 boxes of, frozen imported bait-shrimp (China: Parapenaeopsis sp. and Metapenaeopsis sp.) and 8 boxes of native, frozen bait-shrimp (Gulf of Mexico: Litopenaeus setiferus and Farfantepenaeus duorarum) by RT-PCR or PCR for Taura syndrome virus (TSV), yellowhead virus/gill-associated virus (YHV/GAV), white-spot syndrome virus (WSSV) and infectious hypodermal and hematopoietic necrosis virus (IHHNV). All 28 boxes of shrimp were negative for TSV, YHV/GAV and IHHNV; 2 boxes of imported bait-shrimp were WSSV-positive by 3 different PCR assays. Intramuscular injection of replicate groups of SPF (specific pathogen-free) L. vannamei juveniles with 2 different tissue homogenates prepared from the 2 WSSV-positive bait boxes resulted in 100% mortality of the test shrimp within 48 to 72 h post-injection. No mortality occurred among injected negative control groups. Histological and in situ hybridization analyses of 20 moribund treatment-shrimp demonstrated severe WSSV infections in each sample. Oral exposure of SPF L. vannamei postlarvae, PL (PL 25 to 30 stage; approximately 0.02 g) to minced tissue prepared from the 2 WSSV-positive bait-lots did not induce infection, possibly because of an insufficient infectious dose and/or viral inactivation resulting from multiple freeze-thaw cycles of the bait-shrimp during PCR testing. Use of an electric drill and collection of drill-tailings (tissue from approximately 20 to 30 shrimp) from frozen blocks of shrimp was successfully employed as an alternate tissue-sampling method without thawing. Our findings indicate that imported WSSV-infected bait shrimp, originating from China, are being sold in Texas for the purpose of sport fishing and represent a potential threat to freshwater and marine crustacean fisheries, as well as to coastal US shrimp farms.

Animals↗

PubMed1987

Identification of a shrimp-derived allergen as tRNA.

During an attempt to isolate shrimp allergens, evidence was obtained that shrimp ribonucleic acid was capable of eliciting a specific IgE response in man and an experimental animal model system. The shrimp ribonucleic acid was extracted from boiled whole shrimp (Peneaus indicus), and was isolated by salt precipitation and sequential chromatography over DEAE-Sephacel and BioGel P-100. The allergenic material was identified as a ribonucleic acid based on the following criteria: a maximal absorption at 258 nm, failure to stain positively with Coomassie Brilliant Blue on slab gel electrophoresis, positive staining with ethidium bromide, co-migration with yeast tRNA on submerged gel electrophoresis in 1.5% Agarose M, and sensitivity to ribonuclease T2 and 0.3 M NaOH. Treatment with protease did not alter its allergenic activity. The RNA was capable of binding allergen-specific IgE in sera from two shrimp-sensitive patients, as demonstrated by microELISA and solid-phase radioimmunoassay (SPRIA) using antigen-coated nitrocellulose filter paper discs and purified 125I-labeled goat anti-human IgE. RNA isolated from shrimp by a conventional tRNA isolation procedure also had the ability to specifically bind IgE in the sera of shrimp-sensitive patients. IgE antibodies to shrimp RNA did not recognize yeast tRNA or salmon testes DNA, and were not detected in sera of other subjects. The shrimp-derived RNA was further able to induce a reaginic response in mice. A combination of in vitro aminoacylation of shrimp tRNA and SPRIA resulted in the identification of the allergenic tRNA as tRNA(Tyr) and tRNA(Arg). Thus, shrimp tRNA is capable of inducing a specific IgE response in man.

Adult↗

PubMedDate not supplied

[Quality changes in iced shrimps (Pandalus borealis). II Changes in the contents of trimethylamine oxide and volatile nitrogen bases during automatic boiling and peeling (author's transl)].

Post mortem trimethylamine oxide (TMAO) in marine animals is reduced to trimethylamine (TMA), and the degradation of proteins causes an increase in the ammonia (NH3) content. During ice-storage NH3 and TMA usually make up the major part of the total content of volatile nitrogen bases (TVN) which are formed during the degradation process. The formation of TMA and NH3 is probably caused mainly by bacterial enzymes. The contents of TMA and TVN in marine fish and shrimps are important objective criteria in supporting organoleptic examinations of such raw materials. During automatic boiling, peeling and rinsing processes in shrimp factories, some of these water-soluble and volatile compounds will be extracted by the boiling water and possibly evaporated. In this investigation we have attempted to estimate the loss of TMAO, TMA and TVN in shrimp muscle during this automatic processing. The investigation includes experiments in the laboratory (Table I, Figure 1) and in two factories (Table II-III, Figure 2-3). The results show that about 50% of the contents of TMAO-N, TMA-N and TVN probably will be lost from the shrimps during automatic processing. Adding approximately 100% TMA-N and TVN to the analysed contents in boiled, peeled and rinsed shrimps will therefore probably give the same level of these compounds as that found in the raw shrimps used. An accurate measurement of the TMA- and TVN-content in shrimp produced under known condition in North-Norwegian shrimps factories could give an objective indication of the quality of the raw shrimps used. In accordance with Norwegian shrimp regulations, only the fresh, healthy shrimps are allowed to be produced.

Food Handling↗

PubMed2002

Dietary vitamin C and its derivatives affect immune responses in grass shrimp, Penaeus monodon.

Effects of L-ascorbic acid (AA) and its four derivatives, namely L-ascorbyl-2-sulfate (C2S), L-ascorbyl-2-polyphosphate (C2PP), L-ascorbyl-2-monophosphate-Na (C2MP-Na) and L-ascorbyl-2-monophosphate-Mg (C2MP-Mg) on the immune responses of juvenile grass shrimp, Penaeus monodon, were studied. The vitamin C deprived diet together with diets supplemented with either adequate or high (five times adequate) levels of AA, C2S, C2PP, C2MP-Na and C2MP-Mg were each fed to triplicate groups of shrimp (mean initial weight: 0.37 +/- 0.01 g) for 8 weeks. Significantly (P<0.01) higher weight gain (WG), feed efficiency (FE), survival, total haemocyte count (THC), superoxide anion (O2) production ratio and phenoloxidase (PO) activity were observed in shrimp fed diets supplemented with adequate and high levels of ascorbate than shrimp fed the vitamin C deprived diet, regardless of the ascorbate source. Among the ascorbate sources, shrimp fed C2MP-Mg and C2PP containing diets had higher THC than shrimp fed AA, C2S and C2MP-Na containing diets, regardless of the supplementation level. Shrimp fed adequate levels of C2MP-Mg and C2PP and high levels of C2MP-Mg containing diets had higher O2 production ratios than shrimp fed AA and C2S containing diets. Shrimp fed adequate levels of C2MP-Mg and C2PP and high levels of C2PP containing diets had higher PO activity than shrimp fed AA, C2S and C2MP-Na containing diets. These data suggest that dietary ascorbate enhances immune responses in P. monodon and different ascorbate sources may affect the immune responses differently.

Animal Nutritional Physiological Phenomena↗

PubMed1995

Neuroendocrine control of osmotic regulation in the freshwater shrimp Macrobrachium olfersii (Wiegmann) (Crustacea, decapoda): free amino acid concentrations in the hemolymph.

The participation of neuroendocrine factors present within the central nervous system in the regulation of hemolymph free amino acid (FAA) concentrations was examined in the freshwater shrimp Macrobrachium olfersii. Test shrimps were injected intramuscularly with homogenates prepared from the eyestalks (ES), ventral nerve cord (VNC), supraesophageal (SEG), or thoracic ganglia (TG) of donor shrimps previously exposed for 6 hr to a high-salinity medium (HSM, 21% salinity). After injection of the homogenate, the shrimps were maintained for up to 6 hr in either freshwater (FW) or HSM. Hemolymph was sampled by cardiac puncture and prepared for reverse phase HPLC, derivatizing the FAA with phenylisothiocyanate. An FAA profile was determined and the [FAA]:[Cl-] ratios for the four FAA present in highest concentration (Gly, Arg, Ala, and Pro for ES and VNC experiments; Glu, Leu, Ala, and Val for SEG and TG experiments) were obtained. Nonparametric analyses revealed specific, notable effects resulting from homogenate injection, e.g., ES homogenate increased [Pro]/[Cl-] ratios in FW-exposed shrimps; SEG homogenate increased [Glu]/[Cl-] and [Val]/[Cl-] ratios in HSM-exposed shrimps; and TG homogenate increased [FAA]/[Cl-] ratios for Glu, Leu, Ala, and Val in HSM-exposed shrimps. Total FAA concentrations decreased after exposure of the shrimps to HSM but were increased by the injection of ES homogenate in FW-exposed shrimps and by TG homogenate in HSM-exposed shrimps. The total [FAA]/[Cl-] ratio was also increased by TG homogenate in HSM-exposed animals. There were no clear effects on [Cl-] alone.(ABSTRACT TRUNCATED AT 250 WORDS)

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