Gwenn Merry

U.S. Food and Drug Administration | FDA · DSB BAMB

Background: The complexity of spermatogenesis makes development of appropriate in vitro testis models challenging. A novel in vitro mouse testis culture system has been reported but not yet evaluated as an alternative model for male reproductive toxicity testing. We assessed the effects of media composition on sperm differentiation and testis morp...

The mouse embryonic stem cell test (mEST) is a promising in vitro assay for predicting developmental toxicity. In the current study, early differentiation of D3 mouse embryonic stem cells (mESCs) under osteoblast culture conditions and embryotoxicity of cadmium sulfate were examined. D3 mESCs were exposed to cadmium sulfate for 24, 48 or 72hours, a...

Two real-time reverse transcription polymerase chain reaction (rRT-PCR) assays under consideration for deployment to multiple testing laboratories across the USA were evaluated for diagnostic sensitivity and specificity on tissue homogenates obtained from natural and experimental viral hemorrhagic septicemia (VHS)-infected fish. Estimates for diagn...

Eight laboratories worked collectively to evaluate 4 real-time RT-PCR (rRT-PCR) protocols targeting viral hemorrhagic septicemia virus (VHSV) being considered for deployment to a USA laboratory testing network. The protocols utilized previously published primers and probe sets developed for detection and surveillance of VHSV. All participating labo...

A new strain of Aeromonas hydrophila has been implicated in significant losses in farm-raised catfish. Outbreaks attributable to this new strain began in Alabama in the summer of 2009 and have spread to Arkansas and Mississippi in subsequent years. These outbreaks mostly afflicted market-sized fish and resulted in considerable losses in short perio...

Smallmouth bass, Micropterus dolomieu Lacepède, bluegill, Lepomis macrochirus Rafinesque (coppernose strain), koi carp, Cyprinus carpio L., and channel catfish Ictalurus punctatus (Rafinesque), were infected by intraperitoneal injection with viral haemorrhagic septicaemia virus genotype IVb (VHSV-IVb) at 15 °C. When clinical signs of disease develo...

The emergence of the viral hemorrhagic septicemia virus (VHSV) genotype IVb (VHSV‐IVb) in the Great Lakes of North America has led to concern that the virus might spread to natural fisheries and aquaculture in the southern USA. We exposed bluegills Lepomis macrochirus to VHSV‐IVb by intraperitoneal injection at six temperatures from 10°C to 30°C an...

With the emergence of viral hemorrhagic septicemia virus (VHSV) strain IVb in the Great Lakes of North America, hatchery managers have become concerned that this important pathogen could be transmitted by animals other than fish. Turtles are likely candidates because they are poikilotherms that feed on dead fish, but there are very few reports of r...

The American grass carp reovirus (AGCRV) Aquareovirus G is not strongly associated with disease in fish, but it is often detected by cell culture during routine inspections of healthy fish. The cytopathic effect of AGCRV does not involve the typical syncytia associated with most aquareoviruses. Instead, the AGCRV produces a pattern of cell rounding...

Infection by atypical Aeromonas salmonicida is regarded as the cause of ulcer disease (KUD) in koi carp Cyprinus carpio and goldfish Carassius auratus. However, other causes--including parasites, viral infection, and fungi--have been proposed. In our diagnostic work, we often fail to isolate A. salmonicida even when clear clinical signs of KUD are...

Herpesviral haematopoietic necrosis is a disease of goldfish, Carassius auratus, caused by Cyprinid herpesvirus-2 (CyHV-2) infection. Quantitative PCR was carried out on tissue homogenates from healthy goldfish fingerlings, broodfish, eggs and fry directly sampled from commercial farms, from moribund fish submitted to our laboratory for disease dia...

An aquareovirus was isolated from several fish species in the USA (including healthy golden shiners) that is not closely related to members of species Aquareovirus A, B and C. The virus, which is atypical (does not cause syncytia in cell cultures at neutral pH), was implicated in a winter die-off of grass carp fingerlings and has therefore been cal...

Six experimental ponds (1.8–2.2 ha each) were planted with rice Oryza sativa in August as forage for red swamp crawfish, Procambarus clarkii, and flooded in October. From late October through May, three ponds were aerated nightly for 10 hours (2200–0800 hours) with two 2.2-KW (3 hp) paddlewheel aerators per pond. The other three ponds were not mech...

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

GenBank Accession Numbers EF589098-EF589108 represent the complete genome of American grass carp reovirus strain AGCRV_PB01-155.

Cyprinid herpesvirus 2 (CyHV-2) is a pathogen of goldfish Carassius auratus auratus L. that causes herpesviral hematopoietic necrosis (HVHN) disease. The disease is associated with necrosis of hematopoietic tissues and anemia with high mortality. We have developed a real time 5'-nuclease PCR method (Taqman) that quantitatively detects CyHV-2 with a...

Observations of marks on channel catfish Ictalurus punctatus held for varying lengths of time in experimental ponds and on fish submitted for disease analysis suggested that aggressive biting among channel catfish may sometimes occur at relatively high rates in culture ponds. Studies in experimental pools indicated that larger fish sustained an ave...