Molecular evidence of the protozoan parasite Marteilia refringens in Crassostrea gigas and Crassostrea corteziensis from the Gulf of California

The search for exotic pathogens related to the outbreaks and in surveillance samplings of the Mexican oyster farms, is a recent activity achieved by academic institutions and state committees for Aquatic Animal Health, with remarkable results. In samples of Crassostrea gigas collected through December 2009, January 2010 and November 2010, and of C. corteziensis in September 2011, the protozoan Marteilia refringens was detected for the first time in the Gulf of California. The carrier oysters were from cultures without abnormal mortality rates, whereby, the use of histology, in situ hybridization and transmission electron microscopy studies are necessary to determine if M. refringens has become established in the Gulf of California oyster cultures. Detection of M. refringens is of great concern to the global oyster farming industry.

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Bonamiosis in Australasian aquaculture and in the New Zealand wild capture fishery.

10.1079/ac.91589.20203483402 ◽

2020 ◽

Author(s):

J Jones

Keyword(s):

New Zealand ◽

Western Australia ◽

Animal Health ◽

Aquatic Animal ◽

Research Division ◽

South Wales ◽

Large Numbers ◽

Disease Agent ◽

Oyster Farms ◽

The Impact

Abstract In Australasia, bonamiosis (the disease caused by haplosporidian parasites of the genus Bonamia) was first reported from the New Zealand dredge fishery in the 1980s, and was subsequently reported from oyster farms in both Australia and New Zealand.In New Zealand, Foveaux Strait separates Stewart Island from the South Island. The strait was famous for the quality of the dredge oyster beds that had been fished continuously since the 1860s and were believed to have been carefully managed through a limited effort fishery and a quota.In 1985, fishers reported the occurrence of large numbers of freshly dead oysters on the western central beds. Subsequent examination by aquatic animal health specialists from the Research Division of the Ministry of Agriculture and Fisheries (now the National Institute of Water and Atmospheric Research, Ltd.) revealed that affected oysters were infected with a species of the haplosporidian parasite, Bonamia exitiosus. Monitoring of the beds in the strait over the next 8 years documented the decline in catch and eventually, in 1993, the fishery was closed. Because of the shortage of oysters and the high prices that were anticipated, a number of aquaculture ventures began in New Zealand during the 1990s, mostly using suspended tray culture. However, attempts failed due to the disease. Also in the 1990s there were attempts to farm Ostrea angasi in Australia. Outbreaks of bonamiosis occurred in oyster farms in Tasmania, Victoria and Western Australia. The ongoing mortalities have made farming this type of oyster uneconomic in Western Australia. However, some farming of O. angasi is undertaken in New South Wales where bonamiosis has not been reported. This is one of the few examples of a non-introduced disease agent destroying a wild fishery and aquaculture. Recent research has suggested that the impact of the fishery may have triggered the epizootic in Foveaux Strait as well as causing outbreaks in cultivated oysters. This has lessons for fisheries managers.

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Perkinsus marinus in the pleasure oyster Crassostrea corteziensis cultivated on the southeast coast of the Gulf of California, Mexico

Latin American Journal of Aquatic Research ◽

10.3856/vol48-issue4-fulltext-2463 ◽

2020 ◽

Vol 48 (4) ◽

pp. 529-537

Author(s):

Lizeth Carolina Villanueva-Fonseca ◽

Manuel García-Ulloa ◽

Melina López-Meyer ◽

Brenda Paulina Villanueva-Fonseca ◽

Juan Antonio Hernández-Sepúlveda ◽

...

Keyword(s):

Gulf Of California ◽

Infection Intensity ◽

Eastern Oyster ◽

Perkinsus Marinus ◽

Water Parameters ◽

Southeast Coast ◽

Pathogen Prevalence ◽

The Usa ◽

Oyster Farms ◽

Crassostrea Corteziensis

The protozoan Perkinsus marinus has been associated with high mortality episodes of the eastern oyster Crassostrea virginica in the USA. The presence of P. marinus on the pleasure oyster Crassostrea corteziensis cultivated in two estuaries on the southeast coast of the Gulf of California was evaluated. Oysters were collected monthly (September 2016 to September 2017) and analyzed using Ray's fluid thioglycollate medium (RFTM) and polymerase chain reaction (PCR). Water parameters and oyster biometrics were also recorded. Pathogen prevalence increased over time from 0 to 100% in oysters from La Pitahaya, and from 0 to 83.33% in those from Bacorehuis. At both oyster farms, infection intensity was light (<1×104 parasites g-1 wet tissue), pathogen prevalence and infection intensity were correlated with oyster size and weight, and there was a strong correlation between P. marinus prevalence and intensity (La Pitahaya r = 0.91; Bacorehuis r = 0.82). The oysters that resulted positive for P. marinus by RFTM also were assayed using PCR. P. marinus presence was confirmed in 98.27% (114/116) of the oysters from La Pitahaya, and 95.83% (46/48) of those from Bacorehuis. The detection of P. marinus confirms that this pathogen is well established in the area with high expression during the warmer season. Despite the light infection intensity of this parasite at both sites, health surveillance of this bivalve in the region is highly advisable.

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Trends in Fisheries and Aquatic Animal Health

10.2174/97816810858071170101 ◽

2017 ◽

Cited By ~ 1

Keyword(s):

Animal Health ◽

Aquatic Animal

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Molecular Evidence of Hemolivia mauritanica, Ehrlichia spp. and the Endosymbiont Candidatus Midichloria Mitochondrii in Hyalomma aegyptium Infesting Testudo graeca Tortoises from Doha, Qatar

Animals ◽

10.3390/ani11010030 ◽

2020 ◽

Vol 11 (1) ◽

pp. 30

Author(s):

Patrícia F. Barradas ◽

Clara Lima ◽

Luís Cardoso ◽

Irina Amorim ◽

Fátima Gärtner ◽

...

Keyword(s):

Animal Health ◽

Clinical Manifestations ◽

Febrile Illness ◽

Molecular Evidence ◽

Large Animal ◽

Hard Tick ◽

Testudo Graeca ◽

Worldwide Distribution ◽

Organ System Failure ◽

Midichloria Mitochondrii

Tick-borne agents constitute a growing concern for human and animal health worldwide. Hyalomma aegyptium is a hard tick with a three-host life cycle, whose main hosts for adults are Palearctic tortoises of genus Testudo. Nevertheless, immature ticks can feed on a variety of hosts, representing an important eco-epidemiological issue regarding H. aegyptium pathogens circulation. Hyalomma aegyptium ticks are vectors and/or reservoirs of various pathogenic agents, such as Ehrlichia, Anaplasma, Babesia and Hepatozoon/Hemolivia. Ehrlichia and Anaplasma are emergent tick-borne bacteria with a worldwide distribution and zoonotic potential, responsible for diseases that cause clinical manifestations that grade from acute febrile illness to a fulminant disease characterized by multi-organ system failure, depending on the species. Babesia and Hepatozoon/Hemolivia are tick-borne parasites with increasing importance in multiple species. Testudo graeca tortoises acquired in a large animal market in Doha, Qatar, were screened for a panel of tick-borne pathogens by conventional PCR followed by bidirectional sequencing. The most prevalent agent identified in ticks was Hemolivia mauritanica (28.6%), followed by Candidatus Midichloria mitochondrii (9.5%) and Ehrlichia spp. (4.7%). All samples were negative for Babesia spp. and Hepatozoon spp. Overall, 43% of the examined adult ticks were infected with at least one agent. Only 4.7% of the ticks appeared to be simultaneously infected with two agents, i.e., Ehrlichia spp. and H. mauritanica. This is the first detection of H. mauritanica, Ehrlichia spp. and Candidatus M. mitochondrii in H. aegyptium ticks collected from pet spur-thighed tortoises, in Qatar, a fact which adds to the geographical extension of these agents. The international trade of Testudo tortoises carrying ticks infected with pathogens of veterinary and medical importance deserves strict control, in order to reduce potential exotic diseases.

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