| modified procedure for the recovery of naturally accumulated poliovirus from oysters. | methods were compared for their ability to recover poliovirus from oysters (crassostrea gigas) which had been allowed to accumulate virus via normal filtration activities. clarification procedures included glycine-nacl and polyelectrolyte extraction methods followed by a variety of acid precipitation concentration methods. polyelectrolyte flocculation followed by a beef extract-supplemented acid precipitation carried out at ph 3.5 yielded the most efficient recoveries. direct assay of homogenate ... | 1979 | 231934 |
| incidence of vibrio parahaemolyticus bacteriophages and other vibrio bacteriophages in marine samples. | vibrio bacteriophages were isolated by enrichment from 177 of 643 samples of marine molluscan shellfish, crustaceans, seawater, and sediments. the predominant bacteriophage types isolated were specific for some strains of vibrio parahaemolyticus. a high frequency of phage isolations was also observed with strains of agar-digesting vibrios (21 of 56) and psychrophilic vibrios (14 of 72) that were originally isolated from non-shellfish growing areas. no bacteriophages were isolated against v. algi ... | 1978 | 727781 |
| ecological relationship between vibrio parahaemolyticus and agar-digesting vibrios as evidenced by bacteriophage susceptibility patterns. | twenty bacteriophages active against vibrio parahaemolyticus and agar-digesting vibrios, isolated from oysters (crassostrea gigas) and dungeness crab (cancer magister) and by induction of a lysogenic agar digester, were tested as to their host range. these phages were specific for v. parahaemolyticus and various agar-digesting vibrios, and interspecies lysis occurred only between these two groups. v. alginolyticus, v. anguillarum and related species, v. cholerae, and a group of marine psychrophi ... | 1978 | 727782 |
| toxicity and mutagenicity of 2,4,-6-trinitrotoluene and its microbial metabolites. | tnt (2,4,6-trinitrotoluene) of explosive grade is highly toxic to marine forms that included fresh water unicellular green algae (selenastrum capricornutum), tidepool copepods (tigriopus californicus), and oyster larvae (crassostrea gigas), and mutagenic to salmonella typhimurium. on the basis of mutagenic assays carried out with a set of histidine-requiring strains of the bacterium, tnt was detected as a frameshift mutagen that significantly accelerates the reversion rate of a frameshift tester ... | 1976 | 773306 |
| experimental infection of mammals with larval echinocephalus sinensis (nematoda: gnathostomatidae) from oysters (crassostrea gigas). | | 1976 | 816443 |
| a haemagglutinin in the tissue fluid of the pacific oyster, crassostrea gigas, with specificity for sialic acid residues in glycoproteins. | an agglutinin for human red cells has a specificity for sialic acid and a high affinity for bovine salivary glycoprotein. digestion of the glycoprotein with pronase or neuraminidas indicated that binding of sialic acid to receptors in the agglutinin is the first step in the mechanism of formation of a stable complex between ligand and receptor. | 1977 | 891745 |
| absence of detectable hepatitis b antigen (hbag) in the commercial oyster, crassostrea gigas thunberg, in hong kong. | the locally grown commercial oyster in hong kong, crassostrea gigas thunberg, is faecally polluted particularly in the summer months at a time when oyster consumption and the incidence of viral hepatitis similarly increase. whole oysters and isolates of tissues including the digestive diverticula and mantle fluids, in unconcentrated or concentrated forms were examined by counterimmunoelectrophoresis for the presence of the hepatitis-b antigen (hbag); no antigen was detected in samples examined o ... | 1975 | 1221500 |
| agglutinin activity in pacific oyster (crassostrea gigas) hemolymph following in vivo vibrio anguillarum challenge. | hemolymph from the pacific oyster (crassostrea gigas) contains lectins that agglutinate horse (gigalin e) and human (gigalin h) erythrocytes. the gigalins also agglutinate bacteria, including vibrio anguillarum, and were adsorbed from oyster hemolymph at different temperatures by living, heat-killed, and freeze-dried v. anguillarum cells. baseline activities of the two gigalins were established by measuring their activities in oyster hemolymph over a period of 4 years. a normal distribution of g ... | 1992 | 1499833 |
| metal, mutagenicity, and biochemical studies on bivalve molluscs from spanish coasts. | three species of marine bivalve molluscs (chamelea gallina, ruditapes decussatus, and crassostrea gigas) have been studied in order to evaluate the levels of pollution on the south atlantic spanish littoral. several transition metals (cu, as, cd, sn, hg, pb) were determined as a general index of total contamination. animals from putative contaminated areas exhibited higher metal contents than those from cleaner waters. c. gigas showed 5-20-fold higher total metal content than the other two speci ... | 1992 | 1541252 |
| occurrence of faecal bacteria, salmonella and antigens associated with hepatitis a virus in shellfish. | an investigation was carried out over a one year period to examine jointly the occurrence of faecal bacteria, salmonella and the presence of antigens associated with the hepatitis a virus (hav) in oysters (crassostrea gigas), mussels (mytilus edulis, mytilus galloprovincialis) and cockles (cerastoderma edule), taken from 8 shellfish farming areas or natural beds along the french coast. for the faecal coliforms (fc) and faecal streptococci (fs), statistical analysis of the 176 samples examined sh ... | 1991 | 1663750 |
| haplosporidiosis of the pacific oyster, crassostrea gigas. | haplosporidan parasites were observed in 10/100 spat and 1/171 adult pacific oysters, crassostrea gigas, reared in matsushima bay, japan. eight of the infected spat contained mild to severe plasmodial infections. the multinucleated plasmodia were 6-12 microm x 7-15 microm and were associated with an infiltration of hemocytes that occurred throughout the vesicular connective tissues of all infected oysters. two oysters, one adult and one spat, contained advanced sporogonic infections. these were ... | 1991 | 1787325 |
| evidence of neutralizing activity against t3 coliphage in oyster crassostrea gigas hemolymph. | to investigate defense reactions of bivalve molluscs against viruses, experimental in vitro assays have been developed using t3 coliphage as a test virus. a native neutralizing factor in oyster crassostrea gigas serum showed high individual variability and was enhanced significantly by repeated sampling of hemolymph from the same oysters. the responsible factor is apparently thermolabile and sensitive to edta treatment. because of an inhibitory effect by the enzymatic inhibitor, phenylmethylsulp ... | 1990 | 2210005 |
| a method for the enumeration of poliovirus in selected molluscan shellfish. | a virus extraction procedure was developed and evaluated on five commercially important molluscan shellfish species: crassostrea virginica (eastern oyster), mya arenaria (softshell clam), mytilus edulis (blue mussel), mercenaria mercenaria (hardshell clam), and crassostrea gigas, (pacific oyster). shellfish tissue homogenates were spiked with poliovirus, extracted, and plaque assayed. mean virus recoveries were: c. virginica, 63.8%; m. arenaria, 42.1%; m. edulis, 67.3%; m. mercenaria, 48.3%; and ... | 1989 | 2559103 |
| survival of vibrio vulnificus in shellstock and shucked oysters (crassostrea gigas and crassostrea virginica) and effects of isolation medium on recovery. | when two species of shellstock oysters were artificially contaminated with vibrio vulnificus, the bacterium survived when the oysters were stored at 10 degrees c and below. large numbers of endogenous v. vulnificus cells were found after 7 days at both 0.5 and 10 degrees c in uninoculated control oysters (crassostrea virginica). oysters allowed to take up v. vulnificus from seawater retained the bacterium for 14 days at 2 degrees c. the presence of v. vulnificus in the drip exuded from the shell ... | 1989 | 2619304 |
| patterns of experimental contamination by protogonyaulax tamarensis in some french commercial shellfish. | as a result of the proliferation of toxic marine dinoflagellates along european coasts and the recent discovery of paralytic poisons in french shellfish, experimental studies were conducted on four species of shellfish from the brittany coasts. contamination rates of a culture of toxic protogonyaulax tamarensis, were determined for mytilus edulis, crassostrea gigas, pecten maximus and ruditapes philippinarum. mussels and scallops were very rapidly contaminated showing high toxin accumulation rat ... | 1989 | 2629173 |
| evidence for colonization and destruction of hinge ligaments in cultured juvenile pacific oysters (crassostrea gigas) by cytophaga-like bacteria. | several strains of cytophaga-like gliding bacteria (clb) were isolated as numerically dominant or codominant components of bacterial populations associated with proteinaceous hinge ligaments of cultured juvenile pacific oysters, crassostrea gigas. these bacteria were morphologically similar to long, flexible bacilli occurring within degenerative lesions in oyster hinge ligaments. among bacteria isolated from hinge ligaments, only clb strains were capable of sustained growth with hinge ligament m ... | 1989 | 2757377 |
| limitations of the a-1m method for fecal coliform enumeration in the pacific oyster (crassostrea gigas). | use of the a-1m method, which was originally devised for testing water samples, has recently been extended for enumeration of fecal coliforms and escherichia coli in shellfish and other food products. results of our study indicate that while this method is reliable for analysis of growing waters, the use of the a-1m method for testing pacific oysters may be less reliable because bacteria not belonging to the coliform group but which are sometimes present in these animals also give a positive rea ... | 1987 | 3301793 |
| in vitro binding of parasites (bonamia ostreae) and latex particles by hemocytes of susceptible and insusceptible oysters. | bonamia ostreae is a protozoan parasite that has caused severe losses in the flat oyster (ostrea edulis) industry in europe. the cupped oyster (crassostrea gigas), recently introduced and cultured in europe, is not infected by the disease. in vitro tests were conducted to determine whether there was a difference in the ability of hemocytes from each species to recognize and bind inert foreign particles (fluorescent latex beads) and purified, infective b. ostreae. the results indicated no differe ... | 1988 | 3350192 |
| elevated temperature method for recovery of vibrio cholerae from oysters (crassostrea gigas). | of 222 vibrio cholerae isolates from diverse clinical and environmental sources, 219 produced visible growth in alkaline peptone broth when incubated overnight at 42 degrees c. in field trials conducted to compare enrichment at incubation temperatures of 42 and 35 degrees c, significantly higher rates of isolation (p less than 0.05) and recovery (p less than 0.01) of v. cholerae from oysters were observed at 42 degrees c. | 1987 | 3606095 |
| [demonstration of silver and lead contamination of oysters (crassostrea gigas) and mussels (mytilus edulis) in french coastal waters. microanalytical study by secondary ion emission]. | the oyster crassostrea gigas and the marine mussel mytilus edulis collected from french coastal waters of the channel, atlantic ocean and mediterranean sea were shown to contain silver and lead. for the oysters, the highest silver and lead levels were detected in the marennes oléron samples; for the mussels, the highest silver levels were detected in the seine bay samples and the lead ones in the boulogne samples. target organs for uptake, storage and excretion, including macrophage haemocytes, ... | 1985 | 3918774 |
| bacteria in bivalve shellfish with special reference to the oyster. | the bacterial flora of the pacific oyster crassostrea gigas, the sea mussel perna viridis and the arkshell clam scapharca cornea differed considerably from that of seawater in both numbers and generic composition. the numbers of heterotrophic bacteria in the bivalve shellfish, including the anaerobes and spore-forming bacteria, were greater than that in the surrounding water. pseudomonas spp. were the dominant organisms, comprising over one third of the 321 strains characterized after isolation ... | 1985 | 4030530 |
| microbial flora of pacific oysters (crassostrea gigas) subjected to ultraviolet-irradiated seawater. | the ability of oysters to purge themselves of microbial contaminants was investigated by identifying the microorganisms retained by oysters after they have been subjected to ultraviolet (uv) light-treated seawater. a uv intensity of 960 muw per min per cm(2) reduced the microbial count of seawater from 263 to 13 per ml. the coliform multitube test (mpn) was reduced from a high of 17 to <0.18 per 100 ml. over 75% of the microorganisms found in treated seawater were acinetobacter/moraxella, vibrio ... | 1972 | 4551037 |
| occurrence of vibrio parahaemolyticus and related hemolytic vibrios in marine environments of washington state. | samples of sediment, water, and fauna were tested for the presence of vibrio parahaemolyticus and the related biotype v. alginolyticus. altogether, 379 samples were analyzed quantitatively by using a starch-agar medium. invertebrate and sediment samples were invariably positive for v. parahaemolyticus, whereas water samples were quite variable. samples of the pacific oyster (crassostrea gigas), obtained on a regular basis for 26 months from a single environment, showed a close correlation betwee ... | 1970 | 4921057 |
| microbial flora of irradiated dungeness crabmeat and pacific oysters. | the microorganisms in dungeness crabmeat (cancer magister) and pacific oysters (crassostrea gigas) were identified by the replica-plating and computer analysis method. the initial flora of the shellfish and the flora change during storage at 7 c were determined. the microbial flora shifts in both shellfish were also determined after irradiation at 0.1 and 0.4 mrad and during subsequent storage at 7 c. the achromobacter species predominated in the initial flora of crabmeat (77.0%). the predominan ... | 1966 | 5970827 |
| properties of pseudomonas enalia, a marine bacterium pathogenic for the invertebrate crassostrea gigas (thunberg). | bacteriological investigations of dead and dying oysters in populations of crassostrea gigas grown in hood canal, oyster bay, and willapa bay, washington, were undertaken. living, and presumably normal, oysters within the same sample set were also examined. results indicated that the natural flora of crassostrea gigas (thunberg) is composed of organisms representing the genera pseudomonas, achromobacter, flavobacterium, and vibrio. pollution indicator organisms such as escherichia coli were not ... | 1967 | 6053175 |
| capillary gc/ms determination of organic sulfur compounds detected in oyster and mussel caught in the sea as an oil pollution index. | the organic sulfur compounds usually contained in crude oil were used as a marker of oil pollution in shellfish. the oyster (crassostrea gigas) and mussel (mytilus edulis) were caught in the seto inland sea of japan. capillary-column gas chromatography/mass spectrometry (gc/ms) of extracts showed the presence of organic sulfur compounds of dibenzothiophene and alkyl dibenzothiophenes (c1-c3). the concentration factor of organic sulfur compounds in the oyster and mussel was determined by gas chro ... | 1983 | 6630402 |
| [ecological studies on the microbial flora of raw oysters (crassostrea gigas) harvested in hiroshima and the tohoku district]. | | 1983 | 6668346 |
| behavior of escherichia coli and male-specific bacteriophage in environmentally contaminated bivalve molluscs before and after depuration. | we monitored the differential reduction rates and elimination patterns of escherichia coli and male-specific (f+) bacteriophage during uv depuration for 48 h in oysters (crassostrea gigas) and mussels (mytilus edulis) contaminated by short-term (1 to 3 weeks) and long-term (more than 6 months) exposure to sewage in the marine environment. the time taken to reduce levels of e. coli by 90% was 6.5 h or less in all cases. in contrast, the amounts of time needed to reduce levels of f+ bacteriophage ... | 1995 | 7487015 |
| oysters, crasostrea gigas, as the second intermediate host of gymnophalloides seoi (gymnophallidae). | gymnophalloides seoi has drawn medical attentions since the discovery of the first human case and a highly endemic area on a southwestern coastal island of shinangun, korea. marine bivalves especially oysters were strongly suspected as the source of infection. in this study the oysters, crassostrea gigas, naturally produced from the endemic area were examined whether they contain gymnophallid metacercariae. all of 50 oysters examined were infected with the metacercariae of a gymnophallid, with t ... | 1995 | 7735781 |
| further evidence of regular sporulation by haplosporidium nelsoni in small oysters, crassostrea virginica. | during a field study to determine the susceptibility of the pacific oyster crassostrea gigas to chesapeake bay oyster pathogens, sporulation of haplosporidium nelsoni was observed in eastern oysters crassostrea virginica being used as controls. the c. virginica were obtained from 2 sources on 19 may 1993, a wild population in the upper rappahannock river, virginia (59.6 mm mean shell height) and a hatchery-reared population from chesapeake mari-culture that was held in the wye river, maryland (4 ... | 1994 | 7799147 |
| iron milk medium method for recovering clostridium perfringens from shellfish: collaborative study. | eleven laboratories participated in a collaborative study analyzing shellfish (oysters, crassostrea gigas) for the detection and enumeration of clostridium perfringens by the iron milk medium (imm) method. the imm method was compared to aoac official method 976.30. shellfish were artificially inoculated with c. perfringens cells (vegetative and spores) at low (1 x 10(3) colony forming units [cfu]/g), medium (1 x 10(4) cfu/g), and high (1 x 10(6) cfu/g) levels. negative controls (zero level) were ... | 1994 | 8199470 |
| bacteriophage as models for virus removal from pacific oysters (crassostrea gigas) during re-laying. | a study was undertaken to examine the feasibility of using naturally-occurring bacteriophages to assess the impact of re-laying on levels of viral contamination in crassostrea gigas, the pacific oyster. two phages were chosen. one, male-specific (f+), was enumerated using salmonella typhimurium. the other, a somatic phage, was detected using an, as yet, uncharacterized escherichia coli. investigations, using a variety of re-laying sites, demonstrated that numbers of f+ phage in oyster tissue dec ... | 1993 | 8405159 |
| tem ultrastructure of the tegumental layer of gymnophalloides seoi (digenea: gymnophallidae). | a transmission electron microscopic study was performed on the ultrastructure of the tegumental layer of gymnophalloides seoi (digenea: gymnophallidae) metacercariae and adults. the metacercariae were obtained from naturally infected oysters, crassostrea gigas, and the adults from experimentally infected c3h mice. the tegumental layer generally revealed a small number of foldings, numerous small vacuoles, sines, and muscle bundles. beneath the muscle layer, nuclei of the tegumental cells were lo ... | 1995 | 8528622 |
| antibodies specific for channel catfish virus cross-react with pacific oyster, crassostrea gigas, herpes-like virus. | | 1995 | 8581033 |
| in vitro interaction of perkinsus marinus merozoites with eastern and pacific oyster hemocytes. | this study compared hemocyte responses of eastern and pacific oysters to perkinsus marinus, in vitro. except for the percentage of hemocytes associated with p. marinus there was little or no significant difference between eastern and pacific oysters with regard to their hemocytic response to p. marinus. in phagocytosis assays, merozoites were bound to all hemocyte types but in unequal proportions, unlike zymosan which was found predominantly associated with granulocytes. the number of merozoites ... | 1995 | 8617400 |
| detection, isolation, and experimental transmission of mikrocytos mackini, a microcell parasite of pacific oysters crassostrea gigas (thunberg). | denman island disease, characterized by clinical signs of focal green lesions on the body surface or within the mantle, palps, and adductor muscle of pacific oysters (crassostrea gigas), is caused by a protozoan parasite of unknown taxonomic affiliations, mikrocytos mackini. detection of m. mackini was more sensitive and rapid by use of tissue imprints than histological sections. of several isolation procedures investigated, centrifugation of homogenized infected tissues through a 15% sucrose so ... | 1996 | 8812573 |
| transient expression of luciferase reporter gene after lipofection in oyster (crassostrea gigas) primary cell cultures. | transient expression of the luciferase gene, under transcriptional control of several heterologous promoters, was obtained in heart primary cell cultures of the pacific oyster, crassostrea gigas. drosophila heat shock protein 70 promoter (hsp70), cytomegalovirus, and simian virus early promoters, controlling the luciferase gene, were transfected into the cell cultures using liposomes. two culture media were used to establish primary cell cultures and tested as transfection media. parameters such ... | 1996 | 8817924 |
| study on neurotoxic shellfish poisoning involving the oyster, crassostrea gigas, in new zealand. | lipid-soluble polyether marine toxins were isolated from 80% methanol extract of oysters, crassostrea gigas, harvested in 1993 at tiki road, coromandel peninsula, new zealand, by chromatography on columns of lh-20 and ods (c18), followed by reversed-phase high-performance liquid chromatography. they were identified as known brevetoxins, pbtx-2 and 3. pbtx-3 was also isolated from oysters collected at rangaunu harbour in february 1994 and june 1995, followed by the above procedures. | 1996 | 8896197 |
| a nationwide survey of naturally produced oysters for infection with gymnophalloides seoi metacercariae. | a nationwide survey was performed to know the geographical distribution of gymnophalloides seoi (digenea: gymnophallidae) metacercariae in korea, by examining the infection status of locally produced oysters, crassostrea gigas. a total of 24 coastal areas (myons) of 14 guns ( = counties) in kyonggi-do, chollabuk-do, chollanam-do, kyongsangnam-do, kyongsangbuk-do, or kangwon-do, where natural oysters are produced but g. seoi has never been reported, and 13 areas (myons) of shinan-gun, chollanam-d ... | 1996 | 8925242 |
| distribution of trace metals in the pacific oyster, crassostrea gigas, and crabs from the east coast of kyushu island, japan. | | 1997 | 8952933 |
| [some examples of introductions and transfers of mollusks]. | human beings have always introduced non-indigenous species into new environments. such is the case with shellfish, which the romans, fine connoisseurs, transferred from france to italy to mature. the pacific oyster (crassostrea gigas) and the manila clam (ruditapes philippinarum) are among the most significant examples of these introductions. the author examines the causes, conditions, results, and economic and biological repercussions of these examples. the well known cases of the introduction ... | 1996 | 9019237 |
| [international trade in bivalve mollusks and the current situation in france and in europe]. | over the last century and a half, trade in shellfish has introduced into france four new species intended for aquaculture, as follows: -the portuguese oyster (crassostrea angulata) -the american clam (mercenaria mercenaria) -the pacific oyster (c. gigas) -the manila clam (ruditapes philippinarum). the development of hatcheries and air transport facilities has led to increased trade in these species among the countries of the european union (france, ireland, italy, the netherlands, portugal, spai ... | 1996 | 9019238 |
| microinjection of bivalve eggs: application in genetics. | new strategies for embryonic manipulation have been developed in recent years through plant and animal research. however, research on marine invertebrate embryos has suffered from a lack of basic tools, such as microinjection. here we present a technique developed for microinjecting eggs and embryos of the oyster crassostrea gigas and the mussel mytilus edulis. in experimental trials, approximately 40% of microinjected embryos survived. this technique was used to microinject beta-galactosidase, ... | 1997 | 9116873 |
| rock-shells (thais clavigera) as an indicator of as, cu, and zn contamination on the putai coast of the black-foot disease area in taiwan. | this study presents the distribution of arsenic (as), copper (cu), and zinc (zn) in various seafoods-oysters (crassostrea gigas), false fusus (hemifuscus tuba), venus clams (cyclina sineasis), green mussels (perna viridis), blood clams (arca granosa), flounders (psettodes erumei), and rock-shells (thais clavigera) collected from the putai coast of the black-foot disease (bfd) area in taiwan. special attention is paid to evaluate the relationships among as, cu, and zn and effect of body size on m ... | 1997 | 9175516 |
| sex and meiosis in autotetraploid pacific oyster, crassostrea gigas (thunberg). | sex and meiosis were studied in induced autotetraploids of the pacific oyster (crassostrea gigas thunberg) and were compared with sex and meiosis in autotriploids and normal diploids. tetraploid oysters reached sexual maturity at 1 year of age in an approximately 1:1 sex ration. in contrast with the abnormally high frequency of hermaphrodites among triploids, tetraploids had about the same level of hermaphrodites as normal diploids. fecundity of tetraploids was comparable to that of normal diplo ... | 1997 | 9202417 |
| [rearing crassostrea gigas (bivalvia:ostreidae) in a semi-rigid net]. | a culture system, consisting of a semi-rigid net, with an abs frame filled with styrofoam was used for the culture of the pacific oyster crassostrea gigas, from 3.0 mm length seed. the culture system was tested in three locations, two inside san quintín bay and one in san martín island. the mean monthly growth was 8.69 mm and 8.96 mm in the bay and 7.33 mm in san martín island. these growth rates show that this species can attain commercial sizes in 6 months, using the culture system tested. | 1996 | 9246371 |
| promoters from drosophila heat shock protein and cytomegalovirus drive transient expression of luciferase introduced by particle bombardment into embryos of the oyster crassostrea gigas. | using high velocity particle bombardment, we transferred a reporter gene into early stages of the oyster crassostrea gigas and showed the expression of the introduced genes in these embryos at later stages of development. we tested two promoters: (1) the heat shock protein 70 promoter of drosophila; (2) the cytomegalovirus early promoter, both linked to the luciferase reporter gene. the hsp 70-luc (pdrluc) construct allowed an expression level up to 55-fold higher than the control in a heat indu ... | 1997 | 9304877 |
| specific inhibition of chemiluminescent activity by pathogenic vibrios in hemocytes of two marine bivalves: pecten maximus and crassostrea gigas. | hemocytes from two adult bivalves, pecten maximus and crassostrea gigas, were exposed to 12 different bacterial strains including 2 alteromonas spp. (u1 and t413), 2 type strains of vibrios (v. anguillarum atcc 19264 and v. alginolyticus atcc 17749), 1 vibrio (s322) pathogenic to c. gigas larvae, 2 vibrios (v110 and v117) virulent to ostrea edulis larvae, and 5 different strains of a same vibrio sp. (group a496) isolated from moribund p. maximus larvae. after 1.5 h contact with bacteria, zymosan ... | 1998 | 9446738 |
| nocardia crassostreae sp. nov., the causal agent of nocardiosis in pacific oysters. | seven strains of bacteria were isolated from pacific oysters, crassostrea gigas, with a focal or systemic disease. the strains were aerobic, gram-positive, acid-fast, produced a mycelium which fragmented into irregular rod-like elements, had a peptidoglycan containing meso-diaminopimelic acid, arabinose and galactose as major sugars, mycolic acids with 46-58 carbon atoms and g + c-rich dna. all of these properties are consistent with the classification of the organisms in the genus nocardia. a p ... | 1998 | 9542093 |
| field studies on imposex and organotin accumulation in the rock shell, thais clavigera, from the seto inland sea and the sanriku region, japan. | field studies on imposex and organotin (butyltin and phenyltin) contamination in the japanese molluscs (the rock shell, thais clavigera, and the pacific oyster, crassostrea gigas) were conducted along the coast of both the seto inland sea and the sanriku region, japan, during february-march 1996. the percentage occurrence of imposex in the rock shell, thais clavigera, was still 100% at all sites surveyed (22 and seven sites in the seto inland sea and the sanriku regions, respectively). observed ... | 1998 | 9646517 |
| vibrio splendidus biovar ii as the causative agent of bacillary necrosis of japanese oyster crassostrea gigas larvae. | recurrent outbreaks of a disease leading to mass mortalities in an oyster (crassostrea gigas) hatchery located in western japan were investigated. the disease occurred regularly in 2- to 8-d-old larvae and has been experimentally controlled in the hatchery by treating the larval rearing water with streptomycin, without ascertaining the etiological agent. the signs of the disease and the course of infection resembled bacillary necrosis reported in oysters and other bivalve molluscs in the usa and ... | 1998 | 9684317 |
| impact of dietary supplement of crassostrea gigas extract (jcoe) on glutathione levels and glutathione s-transferase activity in rat tissues. | male sprague dawley rats received various amounts of extract of crassostrea gigas by gavage every day for 2 weeks or one month. at these times, groups of animals were sacrificed and samples of major organs analyzed for levels of glutathione (gsh) and glutathione s-transferase (gst) activities. following the two week protocol, gsh levels were significantly increased in the mucosa of the large intestine; at one month the small intestine and spleen were elevated. gst activity increased in liver und ... | 1998 | 9706474 |
| the antioxidant effects of crassostrea gigas extract (jcoe) in human volunteers. | since several in vitro and animal studies of an extract from crassostrea gigas (jcoe) have demonstrated its antioxidant properties and other interesting effects, a preliminary human trial was carried out. seven healthy male volunteers aged 23-37 received orally 3 x 2 capsules of jcoe per day for 8 days. on days 0, 1, 4, 8 and 15 (7 days after completion of the schedule) blood samples were drawn and the antioxidant potential of serum was tested. a statistically significant increase in the bufferi ... | 1998 | 9706475 |
| sialic acid in hemolymph and affinity purified lectins from two marine bivalves. | sialic acids have been implicated in a variety of complex biological regulatory and signalling events and their functional importance is reflected by their presence in a wide variety of phyla. potentially they may inhibit intermolecular and intercellular interactions. lectins that exhibit specificity for sialic acid or sialoglycoconjugates are ubiquitous in the body fluids of invertebrates and this has supported the assumption that these lectins are involved in defense against microbes that expr ... | 1998 | 9787762 |
| effects of five natural gonadotropin-releasing hormones on cell suspensions of marine bivalve gonad: stimulation of gonial dna synthesis. | gonadotropin-releasing hormones (gnrh) constitute a family of neuropeptides which are important regulators of reproduction in vertebrates. the effect of mammalian gnrh (mgnrh), salmon gnrh, chicken gnrh-i, chicken gnrh-ii, and lamprey gnrh-i on [3h]thymidine incorporation into dna of dissociated gonadal cells of marine bivalves has been studied. the incorporation of [3h]thymidine is linear between 1.5 and 8 h of incubation. all five gnrhs significantly increased dna synthesis in gonial cells of ... | 1999 | 9882550 |
| bonamia-like parasite found in the suminoe oyster crassostrea rivularis reared in france. | considering the economic importance of the pacific oyster crassostrea gigas to the french shellfish industry, the appearance of major diseases in this species could cause dramatic decreases in production. suminoe oysters, of the non-indigenous species crassostrea rivularis (gould), were introduced into france to test their ability to adapt to local conditions. these oysters were imported after careful examination, and were maintained in laboratory quarantine. some mortalities occurred 7 mo after ... | 1998 | 9891734 |
| isolation of hiv-1 protease-inhibiting peptides from thermolysin hydrolysate of oyster proteins. | the peptides inhibiting hiv-1 protease were isolated from the hydrolysate of oyster (crassostrea gigas) proteins prepared with thermolysin. the amino acid sequences of the peptides were determined as leu-leu-glu-tyr-ser-ile and leu-leu-glu-tyr-ser-leu. these sequences exist in some proteins of variola major virus or human cytomegalovirus. chemically synthesized leu-leu-glu-tyr-ser-ile and leu-leu-glu-tyr-ser-leu showed ic50 values of 20 and 15 nm, respectively, and behaved as competitive inhibit ... | 1998 | 9918775 |
| trichodina sp. infestation of crassostrea gigas oyster gills in brittany, france. | | 1999 | 10222190 |
| analysis of the effects of perkinsus marinus proteases on plasma proteins of the eastern oyster (crassostrea virginica) and the pacific oyster (crassostrea gigas). | we employed two in vitro buffer systems to determine the potential pathogenic effects of perkinsus marinus serine proteases on the plasma proteins of the eastern oyster (crassostrea virginica) and the pacific oyster (crassostrea gigas). specifically, this study characterized the oyster plasma protein targets of p. marinus proteases. additionally, protease-specific inhibitory activity was revealed upon comparison of artificial (pbs) and endogenous (plasma-based) diluents employed during protease ... | 1999 | 10486230 |
| patterns in metazoan parasite communities of some oyster species. | metazoan parasite communities of crassostrea gigas and ostrea edulis from great britain, crassostrea virginica from mexico, and saccostrea commercialis from australia are described and summarized in terms of species composition, species richness, total number of individuals and dominance. metazoan parasite communities in all host species were composed of turbellarians and the metacercarial stage of digeneans, with the exception of s. commercialis where only metacercariae were found. arthropods, ... | 1999 | 10654396 |
| comparative efficiencies of different non-toxic microalgal diets in detoxification of psp-contaminated oysters (crassostrea gigas thunberg). | experimental psp contamination of adult pacific oysters (crassostrea gigas) by the toxic dinoflagellate alexandrium minutum halim (120 cells.ml-1 continuously maintained in each flume) was carried out in a recirculated seawater system to obtain toxin levels above the safety threshold. in these conditions, 150 to 300 micrograms stx.eq.100 g-1 of shellfish tissues were produced at 16 degrees c within 8 to 15 days, corresponding to field values observed along french coasts. diets based on non-toxic ... | 2000 | 10701176 |
| amylase mrna expression in crassostrea gigas during feeding cycles. | a crassostrea gigas digestive gland copy dna (cdna) library constructed in the lambda phage zapii (stratagene, la jola, usa) was screened with an amylase heterologous proble. to get access to the complete cdna, a polymerase chain reaction extension was conducted using dna extracted from the phages. the complete cdna sequence is 1688 base pairs (embl = y08370). the deduced protein sequence is 519 aminoacids long with a 19 aminoacid signal peptide. similarity with pecten maximus amylase is 72%. a ... | 2000 | 10707321 |
| evaluation of f-specific rna bacteriophage as a candidate human enteric virus indicator for bivalve molluscan shellfish. | escherichia coli is a widely utilized indicator of the sanitary quality of bivalve molluscan shellfish sold for human consumption. however, it is now well documented that shellfish that meet the e. coli standards for human consumption may contain human enteric viruses that cause gastroenteritis and hepatitis. in this study we investigated using f-specific rna bacteriophage (frna bacteriophage) to indicate the likely presence of such viruses in shellfish sold for consumption. frna bacteriophage a ... | 2000 | 10742200 |
| inhibitory effects of ovoglobulins on bacillary necrosis in larvae of the pacific oyster, crassostrea gigas. | in order to develop an alternative method to antibiotics for preventing bacillary necrosis in bivalve mollusc larvae, we examined the effects of ovoglobulins (proteins derived from the whites of hens' eggs) on the survival of larvae of the pacific oyster crassostrea gigas. the pathogenic vibrio tubiashii (atcc 19106) was used to infect larvae of the pacific oyster. v. tubiashii showed strong pathogenicity to oyster larvae, causing 100% mortality after experimental exposure for 24 h at a concentr ... | 2000 | 10753597 |
| storage metabolism in the pacific oyster (crassostrea gigas) in relation to summer mortalities and reproductive cycle (west coast of france). | we describe seasonal changes in the biochemical composition of digestive gland, adductor muscle and gonad and surrounding mantle area in crassostrea gigas from the western atlantic coast of france. seasonality in histology of storage tissues and glycogen storage capacity in isolated vesicular cells were also studied. proteins, the main muscle components did not contribute to the gametogenetic effort. glycogen and lipids were stored in the digestive gland, gonad and surrounding mantle area during ... | 2000 | 10818269 |
| structure and expression of mgdf, a new member of the transforming growth factor-beta superfamily in the bivalve mollusc crassostrea gigas. | to gain insight into the evolution of the structure and functions of transforming growth factor (tgf)-beta superfamily members, a cdna encoding a new member from the bivalve mollusc crassostrea gigas named mgdf (molluscan growth and differentiation factor) was identified by pcr using degenerate primers. the mgdf precursor exhibits characteristic features of the tgf-beta superfamily and shows highest homology with human bmp2 and drosophila dpp. conversely, the mgdf gene displays a distinct patter ... | 2000 | 10866797 |
| development of a pcr procedure for the detection of a herpes-like virus infecting oysters in france. | a pcr-based procedure for detecting a herpes-like virus that infects the japanese oyster, crassostrea gigas, in france was developed. two primers were designed to provide specific amplification products ranging in size from 917 to 1001 bp when carried out on oyster herpes-like virus dna. no amplification was observed of oyster genomic dna nor of the dna from vertebrate herpesviruses. crude samples were prepared and submitted to nested pcr, allowing amplification of dna fragments of the expected ... | 2000 | 10921841 |
| infection of cultured embryo cells of the pacific oyster, crassostrea gigas, by pantropic retroviral vectors. | the inability to stably introduce and express foreign genes has hampered basic research in molluscan species. we cultured cells from dissociated embryos of the pacific oyster, crassostrea gigas, and infected these primary cultures with pantropic retroviral vectors containing the envelope glycoprotein of vesicular stomatitis virus. luciferase transgene expression mediated by different heterologous promoters was demonstrated for at least 9 d after infection of the cells. surprisingly, the promoter ... | 2000 | 10949999 |
| detection of bonamia ostreae based on small subunit ribosomal probe. | bonamia ostreae is a protozoan parasite of the flat oyster, ostrea edulis, which has caused significant loss of oysters in europe over the last decade. b. ostreae was purified from infected flat oysters and dna was extracted. the nearly complete small subunit rdna gene of b. ostreae was amplified using universal oligonucleotides and the pcr product was cloned and sequenced. blast research with this sequence revealed similarities to haplosporidium nelsoni, haplosporidium costale, and minchinia te ... | 2000 | 10963400 |
| enzymatic activities in european flat oyster, ostrea edulis, and pacific oyster, crassostrea gigas, hemolymph. | enzymatic activities in the hemolymph of healthy and bonamia-infected ostrea edulis and crassostrea gigas were studied with a commercial kit for the detection of 19 enzymes: 15 and 16 enzymes, respectively, were detected in the hemolymph of o. edulis and c. gigas and 10 of them showed relatively high activity levels. most of them existed in both the cell-free fraction of the hemolymph and in the hemocytes. the cell-free hemolymph fraction of bonamia ostreae-infected european flat oysters showed ... | 2000 | 11023742 |
| characterization of a cdna encoding a 72 kda heat shock cognate protein (hsc72) from the pacific oyster, crassostrea gigas. | a full-length cdna encoding a 72 kda heat shock cognate protein (hsc72) was isolated from a crassostrea gigas hemocyte library. this cdna is 75% identical to a human hsc70 cdna. c. gigas cdna contains a 659 amino acid open reading frame encoding a 72 kda protein which is 87% identical to a human hsc70 protein. northern blotting indicated that even if the hsc72 gene was constitutively expressed in oyster hemocytes, it could be stimulated by heat shock in vitro as well as in vivo. homologies obser ... | 2000 | 11092738 |
| concomitant herpes-like virus infections in hatchery-reared larvae and nursery-cultured spat crassostrea gigas and ostrea edulis. | concomitant sporadic high mortalities were reported in france in may 1994 among batches of hatchery-reared larval pacific oysters crassostrea gigas and european flat oysters ostrea edulis in 2 hatcheries, and in june and july 1994 among batches of cultured spat of both species in a shellfish nursery. histological observation showed the presence of cellular abnormalities in moribund animals. transmission electron microscopy revealed the presence of herpes-like virus particles in infected larvae a ... | 2000 | 11104068 |
| haplosporidiosis in the pacific oyster crassostrea gigas from the french atlantic coast. | two cases of haplosporidian infection occurred during 1993 in pacific oysters crassostrea gigas from the french atlantic coast. the localization and ultrastructure of the plasmodia are described. in situ hybridization of infected tissue sections was conducted with dna probes for oyster-infecting haplosporidians. the haplosporidium nelsoni-specific dna probe msx1347 hybridized with the c. gigas parasite, and the h. costale-specific probe sso1318 did not hybridize. total genomic dna was extracted ... | 2000 | 11104072 |
| in vitro production of peroxynitrite by haemocytes from marine bivalves: c-elisa determination of 3-nitrotyrosine level in plasma proteins from mytilus galloprovincialis and crassostrea gigas. | peroxynitrite is increasingly proposed as a contributor to defence system in marine bivalve. it can be formed by combination of superoxide and nitric oxide, and can react with tyrosine residues of proteins giving rise to 3-nitrotyrosine. | 2001 | 11231884 |
| determination of cadmium partitioning in microalgae and oysters: contribution to the assessment of trophic transfer. | alternative methodologies have been applied to the study of cadmium transfer in a food chain: water, microalgae (skeletonema costatum and tetraselmis suecica), oysters (crassostrea gigas). the potential bioavailability of cd in organisms was assessed through partitioning at the cell or tissue levels, and the predictive value of this method was evaluated by determining directly the metal transfer in an experimental food chain model. cd concentrations were lower in s. costatum than t. suecica, in ... | 2001 | 11243323 |
| transcript analysis of the genes encoding aminopeptidase n and alanine aminotransferase, two enzymes involved in protein turnover, in the pacific oyster, crassostrea gigas. | molecular probes have been developed to detect aminopeptidase n (apn) and alanine aminotransferase (alat) transcripts in the pacific oyster crassostrea gigas. degenerate primers were designed using apn and alat sequences stored in the embl database. amplification of c. gigas genomic dna using these primers resulted in amplification of a 344-bp apn fragment and a 530-bp alanine aminotransferase fragment. the deduced amino acid sequence of the apn fragment displayed 75 and 73% identities with sequ ... | 2001 | 11250541 |
| evidence for interspecies transmission of oyster herpesvirus in marine bivalves. | since 1991, numerous herpesvirus infections associated with high mortality have been reported around the world in various marine bivalve species. in order to determine whether these infections are due to ostreid herpesvirus-1 (oshv1), a previously characterized pathogen of the japanese oyster (crassostrea gigas), pcr analysis was carried out on 30 samples of larvae collected from four bivalve species (c. gigas, ostrea edulis, ruditapes decussatus and ruditapes philippinarum), most exhibiting mor ... | 2001 | 11257192 |
| response of haemocyte lysosomes to bacterial inoculation in the oysters ostrea edulis l. and crassostrea gigas (thunberg) and the scallop pecten maximus (l). | data are presented that demonstrate the application of the neutral red retention assay (nrr) to monitor the effects of a bacterial inoculation on the haemocyte lysosomes of the european flat oyster ostrea edulis, pacific oyster crassostrea gigas and scallop pecten maximus. bivalves were acclimated to three temperature regimes (5, 15 and 25 degrees c), at constant salinity for 7 days in the laboratory. once baseline responses to acclimation temperature had been established, the effects of an in v ... | 2001 | 11308076 |
| stress and stress-induced neuroendocrine changes increase the susceptibility of juvenile oysters (crassostrea gigas) to vibrio splendidus. | oysters are permanently exposed to various microbes, and their defense system is continuously solicited to prevent accumulation of invading and pathogenic organisms. therefore, impairment of the animal's defense system usually results in mass mortalities in cultured oyster stocks or increased bacterial loads in food products intended for human consumption. in the present study, experiments were conducted to examine the effects of stress on the juvenile oyster's resistance to the oyster pathogen ... | 2001 | 11319116 |
| toxicity to bivalve hemocytes of pathogenic vibrio cytoplasmic extract. | using a chemiluminescence (cl) test, it had been previously demonstrated that vibrio pectenicida, which is pathogenic to pecten maximus larvae, was able to inhibit completely the cl activity of p. maximus hemocytes and partially inhibit those of crassostrea gigas. conversely, a vibrio sp. strain, s322, pathogenic to c. gigas larvae was more active in reducing the cl activity of oyster hemocytes than of scallop hemocytes. using this same cl biotest, v. pectenicida and s322 cytoplasmic extracts we ... | 2001 | 11356051 |
| a review of gymnophalloides seoi (digenea: gymnophallidae) and human infections in the republic of korea. | studies on gymnophalloides seoi (digenea: gymnophallidae) and human infections are briefly reviewed. this minute intestinal fluke was first discovered from a korean woman suffering from acute pancreatitis and gastrointestinal troubles. it was described as a new species by lee, chai and hong in 1993. the southwestern coastal village where the patient resided was found to be a highly endemic area, and additional endemic areas have been identified. the parasite is very small, 0.33-0.50 mm long and ... | 2001 | 11441510 |
| ultrastructure of mikrocytos mackini, the cause of denman island disease in oysters crassostrea spp. and ostrea spp. in british columbia, canada. | an ultrastructural study was carried out on mikrocytos mackini, the cause of denman island disease in pacific oysters crassostrea gigas in western canada. three forms were identified, quiescent cells (qc), vesicular cells (vc) and endosomal cells (ec). qc occurred in the vesicular connective tissue (vct), haemocytes (hyalinocytes), adductor and heart myocytes, and extracellularly. they had a central round to ovoid nucleus, < 7 cisternae of inactive nuclear membrane-bound golgi, few vesicles and ... | 2001 | 11558731 |
| a vibrio splendidus strain is associated with summer mortality of juvenile oysters crassostrea gigas in the bay of morlaix (north brittany, france). | juvenile oysters crassostrea gigas cultured in the bay of morlaix (france) have suffered unexplained summer mortalities for over a decade. in the present study, we tested the hypothesis that a bacterial pathogen could be responsible for this phenomenon. a first attempt failed to isolate a bacterial pathogen from moribund or weak oysters. only non-pathogenic, probably opportunistic, bacteria were isolated. as an alternative approach, we focused on oysters presenting reduced stress-response capaci ... | 2001 | 11678229 |
| determination of total metals in cultivated oysters (crassostrea gigas) from the northwest coast of mexico by microwave digestion and atomic absorption spectrometry. | bivalves such as oysters often accumulate heavy metals, and therefore can be used to monitor changes of pollutant concentrations in the environment. cultivated oysters from the northwest coast of mexico are widely used for human consumption and thus have an important commercial value. information was gathered on the concentration of these elements in oysters (crassostrea gigas) cultivated on the coast of sonora. oysters were randomly collected from april to october 1997, from 6 different locatio ... | 2001 | 11767161 |
| impact of the copepod mytilicola orientalis on the pacific oyster crassostrea gigas in ireland. | infections of a population of crassostrea gigas by the copepod mytilicola orientalis were examined at an oyster growing site at dungarvan, county waterford, ireland. twenty-one samples, each consisting of 20 to 30 oysters have been examined over 2 yr. condition, sex, reproductive stage, length, weight, glycogen content and other parasite burdens of the oysters were examined in relation to the degree of infection of m. orientalis; 14.38% of oysters were infested. mean abundance was 0.6 oyster(-1) ... | 2001 | 11775796 |
| genetic manipulations in aquaculture: a review of stock improvement by classical and modern technologies. | the aim of this review was to highlight the extent to which the genetic technologies are implemented by the aquaculture industry. the review shows that some of the modern genetic technologies are already extensively applied by the diverse aquaculture industries, though not to the same extent for all important aquacultured species (according to fao 1998 figures). some species (common carp, atlantic salmon, rainbow trout, channel catfish, nile tilapia, and the pacific oyster) received concentrated ... | 2001 | 11841164 |
| herpes-like virus detection in infected crassostrea gigas spat using dig-labelled probes. | an in situ hybridization protocol for detecting the herpes-like virus which infects french pacific oysters, crassostrea gigas, was developed. two dna probes were synthesized by incorporation of digoxigenin 11-dutp during pcr. two oyster herpes-like virus specific primer pairs, a5/a6 and c1/c6, were used. both dig-labelled probes were able to detect 50 pg of herpes-like virus pcr amplified dna in southern blot hybridizations. the probes hybridized with viral dna in paraffin sections of infected c ... | 2002 | 11849678 |
| french scallops: a new host for ostreid herpesvirus-1. | sporadic high mortalities were reported among larval french scallops (pecten maximus). electron microscopy of moribund larvae revealed particles with the characteristics of a herpesvirus in association with cellular lesions. pcr and dna sequencing showed that the virus is a variant of ostreid herpesvirus-1 that has already been described in clams and oysters. this is the first description of a herpesvirus infection of a scallop species. the virus was transmitted successfully from an extract of i ... | 2001 | 11883198 |
| detection of oyster herpesvirus dna and proteins in asymptomatic crassostrea gigas adults. | since 1972, several herpes-like virus infections have been reported among different bivalve species around the world. most of these reports involved larvae or juveniles presenting high mortalities. two case reports of herpes-like viruses concerned adult oysters, crassostrea virginica in usa and ostrea angasi in australia. molecular techniques including pcr and in situ hybridization (ish) have been recently developed to detect the oyster herpesvirus genome. in the present study, 30 pacific oyster ... | 2002 | 11900847 |
| kinetics of metal elimination in oysters from a contaminated estuary. | in oysters crassostrea gigas translocated from a metal-enriched estuary (gironde, france) to a comparatively clean site, the bay of bourgneuf (france), cd, cu and zn concentrations were determined monthly in the whole soft tissues, or in different fractions (cytosolic or insoluble) of gills and digestive glands. in all cases, the concentrations of all of the three metals decreased logarithmically and half-lives were always shortest for cd (86-251 days). after 4 months, the cd concentration had b ... | 2002 | 11912053 |
| characteristics of trophic transfer of polychlorinated biphenyls in marine organisms in incheon north harbor, korea. | the trophic transfer of polychlorinated biphenyls (pcbs) was characterized for zooplankton (primarily paracalanus spp. and acartia spp.), pacific oyster (crassostrea gigas), shore crab (hemigrapsus penicillatus), and goby (acanthogobius hasta) in the aquatic system of incheon north harbor, korea. the congener pattern in the species was clearly divided by the main pcb uptake route. compared with zooplankton and oyster, the fraction of heavier homologues increased in crab and goby that take pcbs f ... | 2002 | 11951959 |
| immunochemical quantification of metallothioneins in marine mollusks: characterization of a metal exposure bioindicator. | a recombinant metallothionein cgmt1, from the pacific oyster crassostrea gigas, was synthesized and used as antigen in the development of antibodies and a specific enzyme-linked immunosorbent assay (elisa). the elisa showed that rabbit anti-cgmt1 igg reacted with purified cgmt1 and mts from other marine bivalves, indicating its suitability as a reagent to quantify mts and for monitoring of metal contamination in field animals. application of this assay to tissues excised from metal exposed c. gi ... | 2002 | 12013122 |
| [characterization of pathogenic bacteria of the cupped oyster crassostrea gigas]. | the french mollusc production is mainly based on the pacific cupped oyster, crassostrea gigas. since 1991, outbreaks of mass mortality of juveniles are reported during the summer period. these outbreaks are a major concern of oyster industry. several studies have established given bacterial strains to be pathogenic for bivalve species, including oysters. here we present a study of mortality outbreaks of c. gigas, as initiated in 1995. in a first step, bacterial strains were isolated during mass ... | 2002 | 12017771 |
| comparative susceptibility of veliger larvae of four bivalve mollusks to a vibrio alginolyticus strain. | the susceptibility of 7 d old veliger larvae of the scallops argopecten ventricosus and nodipecten subnodosus, the penshell atrina maura, and the pacific oyster crassostrea gigas to a pathogenic strain of vibrio alginolyticus was investigated by challenging the larvae with different bacterial concentrations in a semi-static assay. the results indicate that the larvae of the 2 scallop species are more susceptible to the v. alginolyticus strain than those of the oyster and the penshell. signs of t ... | 2002 | 12113308 |
| protease inhibitors and haemagglutinins associated with resistance to the protozoan parasite, perkinsus marinus, in the pacific oyster, crassostrea gigas. | perkinsus marinus is a protozoan responsible for dramatic mortality in the eastern oyster, crassostrea virginica, but not in the pacific oyster, c. gigas. to understand the host-parasite relationship, we inoculated p. marinus trophozoites into the shell cavity of c. gigas and measured, over 2 months, (i) intensity of infection, (ii) protease inhibitory activities against p. marinus proteases and against bovine z-chymotrypsin, (iii) plasma haemagglutinin titre, (iv) plasma protein concentration, ... | 2002 | 12403320 |
| effects of toxic dinoflagellates and toxin biotransformation in bivalves. | attempts were made to elucidate the different responses of shellfish to paralytic shellfish poison (psp) and the psp donor alexandrium minutum t1. five species of edible bivalves (crassostrea gigas, meretrix lusoria, mytilus edulis, ruditapes philippinarum, and soletellina diphos) were collected and examined for susceptibility to psp and psp donor. it was determined that all five bivalves had low susceptibility to psp following an intramuscular injection (> 300 mu/20 g). the abnormal effects on ... | 2002 | 12503874 |
| hepatitis a virus detection in oysters (crassostrea gigas) in santa catarina state, brazil, by reverse transcription-polymerase chain reaction. | shellfish are readily contaminated with viruses present in water containing sewage because of the concentration effect of filter feeding. hepatitis a virus (hav) is the main cause of acute hepatitis worldwide and may lead to severe illness or even death. it is transmitted through fecal and oral routes and causes widespread endemic and asymptomatic infections in young children. here we describe a method for the detection of hav rna in shellfish involving the extraction of total rna from oyster me ... | 2003 | 12636311 |
| comparison of two microalgal diets. 1. influence on the biochemical and fatty acid compositions of raw oysters (crassostrea gigas). | oyster farming in france is a traditional activity. each year, 149 000 tons of oysters are fattened before being sold. more and more oyster farmers supplement the diet of oysters by microalgae to optimize the fattening process and to improve both the growth and flesh quality of oysters. in the present study, oysters were supplemented by two microalgae: skeletonema costatum and tahitian isochrysis clone. the ash, protein, carbohydrate (including glycogen), and lipid contents were analyzed. the gr ... | 2003 | 12643666 |
| comparison of two microalgal diets. 2. influence on odorant composition and organoleptic qualities of raw oysters (crassostrea gigas). | oyster farming is of real economic interest in france. oyster farmers attach more and more importance to improving the growth and the quality of their oysters. some fatty acids known to be aroma precursors originate from microalgae such as skeletonema costatum and tahitian isochrysis clone. these microalgae were used to fatten oysters in order to observe their role in the development of oysters' aroma. this study shows that the profile of fatty acids of oysters is influenced by the contribution ... | 2003 | 12643667 |
| isolation and 18s ribosomal dna gene sequences of marteilioides chungmuensis (paramyxea), an ovarian parasite of the pacific oyster crassostrea gigas. | to develop sensitive detection techniques with the aim of elucidating the life cycle of marteilioides chungmuensis, an intracellular paramyxean infecting the ovary of the pacific oyster crassostrea gigas, we isolated the parasite at the sporont stage from infected oysters using a freeze-thaw procedure at -20 degrees c and differential centrifugations in discontinuous sucrose and percoll gradients. dna was extracted from the isolated sporonts, and a pcr amplicon of 18s small subunit ribosomal rna ... | 2003 | 12747642 |