Association ofAeromonas hydrophilaandVibrio alginolyticuswith Larval Mortalities of Scallop (Argopecten purpuratus)

Riquelme, Carlos; Toranzo, Alicia E.; Barja, Juan L.; Vergara, Nelson; Araya, Rubén

doi:10.1006/jipa.1996.0035

Cited by 66 publications

(47 citation statements)

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“…The assays described in this study were first performed at 20°C, the temperature previously used for pathogenicity testing of larval scallops (Riquelme et al 1996) and larval Pacific oysters (Nottage & Birbeck 1986, Riquelme et al 1996, Gibson et al 1998). Other pathogenicity experiments were performed on larval Pacific oysters (Jeffries 1982) and larval hard clams and eastern oysters (Tubiash et al 1965) at temperatures as high as 27 to 28°C.…”

Section: Discussionmentioning

confidence: 99%

“…Mortality often results from infection with pathogenic bacteria (Brown 1981, Elston et al 1981, Elston 1984, 1999, Lodeiros et al 1987, Riquelme et al 1996. Outbreaks can result in major losses and great expense for shellfish growers.…”

Section: Introductionmentioning

confidence: 99%

“…However, the tube assay was less reliable when mildly pathogenic strains were examined because larvae in these tubes dispersed throughout the tube within 48 h. Therefore, it was important not to consider strains as pathogenic until the larvae were no longer swimming. The conical tube assay may be most useful for screening highly pathogenic strains.The assays described in this study were first performed at 20°C, the temperature previously used for pathogenicity testing of larval scallops (Riquelme et al 1996) and larval Pacific oysters (Nottage & Birbeck 1986, Riquelme et al 1996, Gibson et al 1998). Other pathogenicity experiments were performed on larval Pacific oysters (Jeffries 1982) and larval hard clams and eastern oysters (Tubiash et al 1965) at temperatures as high as 27 to 28°C.…”

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confidence: 99%

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Pathogenicity testing of shellfish hatchery bacterial isolates on Pacific oyster Crassostrea gigas larvae

Estes¹,

Friedman²,

Elston³

et al. 2004

Dis. Aquat. Org.

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Bacterial diseases are a major cause of larval mortality in shellfish hatcheries. Even with proper sanitation measures, bacterial pathogens cannot be eliminated in all cases. The pathogenicity of bacteria isolated from Pacific Northwest shellfish hatcheries to Pacific oyster Crassostrea gigas larvae was investigated. We found 3 highly pathogenic strains and 1 mildly pathogenic strain among 33 isolates tested. These strains appear to be members of the genus Vibrio. Although there have been many studies of bivalve bacterial pathogens, a standard method to assess bacterial pathogenicity in bivalve larvae is needed. Thus, we developed 2 methods using either 15 ml conical tubes or tissue culture plates that were employed for rapidly screening bacterial strains for pathogenicity to Pacific oyster larvae. The tissue culture plates worked well for screening both mildly pathogenic strains and LD 50 (lethal dose) assays. This method allowed for non-intrusive and non-destructive observation of the oyster larvae with a dissecting microscope. The LD 50 for the 3 highly pathogenic strains ranged between 1.6 and 3.6 × 10 4 colony forming units (CFU) ml -1 after 24 h and between 3.2 × 10 2 and 1.9 × 10 3 CFU ml -1 after 48 h.KEY WORDS: Pacific oyster larvae · Vibrio · Bacteria · Pathogenicity testing · Shellfish hatchery Resale or republication not permitted without written consent of the publisherDis Aquat Org 58: [223][224][225][226][227][228][229][230] 2004 genicity of bacteria isolated from bivalve hatcheries during routine monitoring and disease outbreaks. MATERIALS AND METHODSIsolates and reference strains. Bacterial isolates collected from Pacific oyster Crassostrea gigas larvae (n = 16) and juveniles (n = 12), European flat oyster Ostrea edulis juveniles (n = 1), and hatchery environments (n = 4) from the Pacific Northwest of the United States (Table 1) were stored at -80°C in Marine 2216 broth (Difco Laboratories) with 10% (v/v) glycerol. Subsequently, they were shipped on dry ice from AquaTechnics (Sequim) to the University of Washington (Seattle, Washington). The following control strains were included in the pathogenicity assays: RE 14 (nonpathogenic or negative control), RE 82 (pathogenic or positive control), and previously described larval bivalve pathogens Vibrio alginolyticus American Type Culture Collection (ATCC) 19108 and V. tubiashii ATCC 19106 (Tubiash et al. 1965, 1970). All cultures were maintained at -80°C for long-term storage.Isolates were grown for 24 h on Marine 2216 agar and incubated at 20 and 26°C in the first and second set of experiments, respectively. Experiments were conducted using sand-filtered Puget Sound seawater collected at the Seattle Aquarium (Seattle, Washington). Suspensions of the bacterial strains in filter-sterilized (0.22 µm) seawater were adjusted to an optical density (600 nm) of 0.2 to attain a uniform concentration of bacteria for the experiments. Bacterial density was confirmed by standard plate-count assays using Marine 2216 agar.Pathogenicity testing. Experi...

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

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Pathogenicity testing of shellfish hatchery bacterial isolates on Pacific oyster Crassostrea gigas larvae

Estes¹,

Friedman²,

Elston³

et al. 2004

Dis. Aquat. Org.

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“…Susceptibility of other cultured bivalve species to infections caused by bacteria belonging to the genus Vibrio has been found in several scallop species, including Aequipecten irradians (52), Euvola ziczac (22), Argopecten purpuratus (43,44), Pecten maximus (36), and Argopecten ventricosus (45), in oyster species, including Crassostrea virginica (11) and Crassostrea gigas (53), and also in abalone (Haliotis diversicolor supertexta) (30).…”

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confidence: 99%

Isolation of Vibrio alginolyticus and Vibrio splendidus from Aquacultured Carpet Shell Clam ( Ruditapes decussatus ) Larvae Associated with Mass Mortalities

Gomez‐León

Villamil

Lemos

et al. 2005

Appl Environ Microbiol

247

118

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Two episodes of mortality of cultured carpet shell clams (Ruditapes decussatus) associated with bacterial infections were recorded during 2001 and 2002 in a commercial hatchery located in Spain. Vibrio alginolyticus was isolated as the primary organism from moribund clam larvae that were obtained during the two separate events. Vibrio splendidus biovar II, in addition to V. alginolyticus, was isolated as a result of a mixed Vibrio infection from moribund clam larvae obtained from the second mortality event. The larval mortality rates for these events were 62 and 73%, respectively. Mortality was also detected in spat. To our knowledge, this is the fist time that these bacterial species have been associated with larval and juvenile carpet shell clam mortality. The bacterial strains were identified by morphological and biochemical techniques and also by PCR and sequencing of a conserved region of the 16S rRNA gene. In both cases bacteria isolated in pure culture were inoculated into spat of carpet shell clams by intravalvar injection and by immersion. The mortality was attributed to the inoculated strains, since the bacteria were obtained in pure culture from the soft tissues of experimentally infected clams. V. alginolyticus TA15 and V. splendidus biovar II strain TA2 caused similar histological lesions that affected mainly the mantle, the velum, and the connective tissue of infected organisms. The general enzymatic activity of both live cells and extracellular products (ECPs), as evaluated by the API ZYM system, revealed that whole bacterial cells showed greater enzymatic activity than ECPs and that the activity of most enzymes ceased after heat treatment (100°C for 10 min). Both strain TA15 and strain TA2 produced hydroxamate siderophores, although the activity was greater in strain TA15. ECPs from both bacterial species at high concentrations, as well as viable bacteria, caused significant reductions in hemocyte survival after 4 h of incubation, whereas no significant differences in viability were observed during incubation with heat-killed bacteria.Culture of carpet shell clams (Ruditapes decussatus) is a traditional activity that has great economical importance in Spain, particularly in Galicia (northwest region of Spain). Therefore, losses in production of this clam species would seriously affect the economy of this region.Globally, clam production is often affected by vibriosis, which leads to high mortality rates mainly in nursery cultures of juvenile bivalves (20,35). In Spain serious mass mortalities associated with Vibrio tapetis infections have been reported previously (15, 21). V. tapetis causes brown ring disease in Ruditapes species, which is characterized by the appearance of brown conchioline deposits that have variable distributions and variable thicknesses on the inner shell of diseased clams (41, 42).Susceptibility of other cultured bivalve species to infections caused by bacteria belonging to the genus Vibrio has been found in several scallop species, including Aequipecten irradians (52), Euvo...

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“…Mortalities up to 100% caused by V. tapetis occurred in a challenge study of Manila clams (Allam et al 2002). Other bacterial species causing disease in bivalves are Aeromonas hydrophila (Riquelme et al 1996a), Chlamydia (Leibovitz 1989), Chlamydia-like organisms (Morrison & Shum 1982, Renault & Cochennec 1995, Hine & Diggles 2002 and Rickettsia-like organisms (Elston 1986, Le Gall et al 1988, Wu & Pan 1999.…”

Section: Introductionmentioning

confidence: 99%

Immunohistochemistry of great scallop Pecten maximus larvae experimentally challenged with pathogenic bacteria

Sandlund¹,

Torkildsen²,

Magnesen³

et al. 2006

Dis. Aquat. Org.

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Three challenge experiments were carried out on larvae of the great scallop Pecten maximus. Larvae were bath-challenged with Vibrio pectenicida and 5 strains resembling Vibrio splendidus and one Pseudoalteromonas sp. Unchallenged larvae were used as negative controls. The challenge protocol was based on the use of a multidish system, where the scallop larvae (10, 13 and 15 d post-hatching in the 3 experiments, respectively) were distributed to 2 ml wells with stagnant seawater and exposed to the bacterial cultures by bath challenge. Presence of the challenge bacteria in the wells was verified by polymerase chain reaction (PCR). A significantly increased mortality was found between 24 and 48 h in most groups challenged with V. pectenicida or V. splendiduslike strains. The exception was found in larval groups challenged with a Pseudoalteromonas sp. LT 13, in which the mortality rate fell in 2 of the 3 challenge experiments. Larvae from the challenge experiments were studied by immunohistochemistry protocol. Examinations of larval groups challenged with V. pectenicida revealed no bacterial cells, despite a high degree of positive immunostaining. In contrast, intact bacterial cells were found in larvae challenged with V. splendidus. In the case of larvae challenged with the Pseudoalteromonas sp., positive immuno-staining was limited to visible bacteria inside the digestive area and cells of the mucosa. The experiments confirm that V. splendidus and V. pectenicida are pathogenic to scallop larvae, and that the Pseudoalteromonas strain is probably not a primary pathogen, although it cannot be ruled out as a secondary pathogen. KEY WORDS: Pecten maximus · Vibrio splendidus · Immunohistochemistry · Challenge experiments · LarvaeResale or republication not permitted without written consent of the publisher OPEN PEN

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Association ofAeromonas hydrophilaandVibrio alginolyticuswith Larval Mortalities of Scallop (Argopecten purpuratus)

Cited by 66 publications

References 0 publications

Pathogenicity testing of shellfish hatchery bacterial isolates on Pacific oyster Crassostrea gigas larvae

Pathogenicity testing of shellfish hatchery bacterial isolates on Pacific oyster Crassostrea gigas larvae

Isolation of Vibrio alginolyticus and Vibrio splendidus from Aquacultured Carpet Shell Clam ( Ruditapes decussatus ) Larvae Associated with Mass Mortalities

Immunohistochemistry of great scallop Pecten maximus larvae experimentally challenged with pathogenic bacteria

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