Viruses of Fish: An Overview of Significant Pathogens

The growing global demand for seafood together with the limited capacity of the wild-capture sector to meet this demand has seen the aquaculture industry continue to grow around the world. A vast array of aquatic animal species is farmed in high density in freshwater, brackish and marine systems where they are exposed to new environments and potentially new diseases. On-farm stresses may compromise their ability to combat infection, and farming practices facilitate rapid transmission of disease. Viral pathogens, whether they have been established for decades or whether they are newly emerging as disease threats, are particularly challenging since there are few, if any, efficacious treatments, and the development of effective viral vaccines for delivery in aquatic systems remains elusive. Here, we review a few of the more significant viral pathogens of finfish, including aquabirnaviruses and infectious hematopoietic necrosis virus which have been known since the first half of the 20th century, and more recent viral pathogens, for example betanodaviruses, that have emerged as aquaculture has undergone a dramatic expansion in the past few decades

Visualising single molecules of HIV-1 and miRNA nucleic acids

BackgroundThe scarcity of certain nucleic acid species and the small size of target sequences such as miRNA, impose a significant barrier to subcellular visualization and present a major challenge to cell biologists. Here, we offer a generic and highly sensitive visualization approach (oligo fluorescent in situ hybridization, O-FISH) that can be used to detect such nucleic acids using a single-oligonucleotide probe of 19–26 nucleotides in length.ResultsWe used O-FISH to visualize miR146a in human and avian cells. Furthermore, we reveal the sensitivity of O-FISH detection by using a HIV-1 model system to show that as little as 1–2 copies of nucleic acids can be detected in a single cell. We were able to discern newly synthesized viral cDNA and, moreover, observed that certain HIV RNA sequences are only transiently available for O-FISH detection.ConclusionsTaken together, these results suggest that the O-FISH method can potentially be used for in situ probing of, as few as, 1–2 copies of nucleic acid and, additionally, to visualize small RNA such as miRNA. We further propose that the O-FISH method could be extended to understand viral function by probing newly transcribed viral intermediates; and discern the localisation of nucleic acids of interest. Additionally, interrogating the conformation and structure of a particular nucleic acid in situ might also be possible, based on the accessibility of a target sequence

Chytridiomycosis and Amphibian Population Declines Continue to Spread Eastward in Panama

Chytridiomycosis is a globally emerging disease of amphibians and the leading cause of population declines and extirpations at species-diverse montane sites in Central America. We continued long-term monitoring efforts for the presence of the fungal pathogen Batrachochytrium dendrobatidis (Bd) and for amphibian populations at two sites in western Panama, and we began monitoring at three new sites to the east. Population declines associated with chytridiomycosis emergence were detected at Altos de Campana National Park. We also detected Bd in three species east of the Panama Canal at Soberanía National Park, and prevalence data suggests that Bd may be enzootic in the lowlands of the park. However, no infected frogs were found further east at Tortí (prevalence <7.5% with 95% confidence). Our results suggest that Panama's diverse and not fully described amphibian communities east of the canal are at risk. Precise predictions of future disease emergence events are not possible until factors underlying disease emergence, such as dispersal, are understood. However, if the fungal pathogen spreads in a pattern consistent with previous disease events in Panama, then detection of Bd at Tortí and other areas east of the Panama Canal is imminent. Therefore, development of new management strategies and increased precautions for tourism, recreation, and biology are urgently neede

A project that designs and trials a pilot survey to map the distribution of chyridomycosis (caused by the amphibian chytrid fungus) in Australian frogs

[Extract] The aim of this tender was to design and trial a pilot survey to map the distribution of chytridiomycosis in Australian frogs. The project has 5 components: Scope Items 1 and 3 being desk top synthesis and evaluation activities, Scope Item 2 being a data gathering and proof of concept activity, Scope Item 4 being a field and laboratory based project testing the protocol developed in Scope Item 3, and Scope Item 5 assessing and evaluating the previous outputs and providing recommendations that need to be addressed to allow a national survey for chytridiomycosis to proceed in an effective manner. Diagnostic Tests: An analysis of published and unpublished literature identified that chytridiomycosis could be diagnosed by at least 11 tests, that can be collapsed into 5 categories; culture, microscopical examination of unstained epidermis, histology, capture ELISA and PCR. Although each diagnostic test has detection of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), as its final outcome and could on superficial assessment appear to be competing with each other, we discovered that this was true only in part. The tests have different functions and complement, rather than exclude, one another. For example, examination of fresh tissue is an essential test when culture of B.dendrobatidis from infected skin is being attempted in the laboratory. Histology is the diagnostic test of choice for retrospective surveys of archived specimens, and the sensitivity of diagnosis is increased by immunohistochemistry using polyclonal antibodies. For the proposed mapping survey, real-time PCR is the recommended diagnostic technique owing to its increased sensitivity and non-invasiveness

Feeding styles and child weight status among recent immigrant mother-child dyads

Background: Research has shown that parental feeding styles may influence children’s food consumption, energy intake, and ultimately, weight status. We examine this relationship, among recent immigrants to the US. Given that immigrant parents and children are at greater risk for becoming overweight/obese with increased time in the US, identification of risk factors for weight gain is critical. Methods: Baseline data was collected on 383 mother-child dyads enrolled in Live Well, a community-based, participatory, randomized controlled lifestyle intervention to prevent weight gain in recent immigrant mothers. Socio-demographic information together with heights and weights were collected for both mother and child. Acculturation, behavioral data, and responses to the Caregiver’s Feeding Styles Questionnaire (CFSQ) were also obtained from the mother. Results: The children’s average age was 6.2 ± 2.7 years, 58% male. Mothers had been in the country for an average of 6.0 ± 3.3 years, and are Brazilian (36%), Haitian (34%) and Latino (30%). Seventy-two percent of the mothers were overweight/obese, while 43% of the children were overweight/obese. Fifteen percent of mothers reported their feeding style as being high demanding/high responsive; 32% as being high demanding/low responsive; 34% as being low demanding/high responsive and 18% as being low demanding/low responsive. In bivariate analyses, feeding styles significantly differed by child BMIz-score, ethnic group, and mother’s perceived stress. In multiple linear regression, a low demanding/high responsive feeding style was found to be positively associated (ß = 0.56) with a higher child weight as compared to high demanding/high responsive, controlling for known covariates (p = 0.01). Conclusions: Most mothers report having a low demanding/high responsive feeding style, which is associated with higher child weight status in this diverse immigrant population. This finding adds to the growing literature that suggests this type of feeding style may be a risk factor for childhood obesity. Further research is needed to help understand the larger socio-cultural context and its influence on feeding dynamics among immigrant families and families of lower incomes. How parents establish a certain feeding style in their home country compared to when they move to the US “obesogenic” environment, should also be explored

Un nuevo morbillivirus de la neumonía equina y su transmisión a humanos

En Septiembre 22 y 23 de 1994, las autoridades veterinarias en Queensland y en el CSIRO Laboratorio Australiano de Salud Animal («Australian Animal Health Laboratory») fueron avisados de un brote de enfermedad respiratoria aguda en caballos en un establo en Brisbane, suburbio de Hendra. El entrenador de los caballos había sido hospitalizado por una enfermedad respiratoria y estuvo en condición crítica. En ese momento, la causa de enfermedad de los caballos era incierta y cualquier nexo entre la enfermedad humana y equina era un pensamiento improbable. Se investigaron causas de envenenamiento, enfermedad exótica, virósica, y bacteriana. EL historial de los caballos en este aspecto fue considerada importante; (Figura 1) dos semanas antes de la enfermedad del entrenador, el 7 de Septiembre, dos caballos habían sido llevados al Hendra desde un establo de pre-carrera en Cannon Hill (6 km). Uno de éstos, una yegua preñada, enfermó y murió en 2 días. El otro caballo fue trasladado luego y nunca llegó a enfermarse. Por el 26 de Septiembre, 13 caballos habían muerto: la yegua; otros 10 caballos en el establo de Hendra; un caballo, que tuvo contacto muy cercano con caballos en el establo de Hendra, en una propiedad vecina; y uno que había sido transportado desde el establo a otro sitio (150 km). Cuatro caballos de Hendra y otros tres (uno en un establo adyacente, uno llevado a Kenilworth, y uno a Samford) se consideraron que habían estado expuestos y se habían recuperado de la enfermedad. Algunos de estos caballos fueron asintomáticos. Nueve caballos de Hendra habían permanecido inafectados. Los caballos enfermos estaban anoréxicos, deprimidos, comúnmente febriles (temperatura hasta 41ºC), mostraron tasa respiratoria elevada, y llegaron a estar atáxicos. Una descarga nasal espumosa ocurrió antes de la muerte.Facultad de Ciencias Veterinaria

Un nuevo morbillivirus de la neumonía equina y su transmisión a humanos

En Septiembre 22 y 23 de 1994, las autoridades veterinarias en Queensland y en el CSIRO Laboratorio Australiano de Salud Animal («Australian Animal Health Laboratory») fueron avisados de un brote de enfermedad respiratoria aguda en caballos en un establo en Brisbane, suburbio de Hendra. El entrenador de los caballos había sido hospitalizado por una enfermedad respiratoria y estuvo en condición crítica. En ese momento, la causa de enfermedad de los caballos era incierta y cualquier nexo entre la enfermedad humana y equina era un pensamiento improbable. Se investigaron causas de envenenamiento, enfermedad exótica, virósica, y bacteriana. EL historial de los caballos en este aspecto fue considerada importante; (Figura 1) dos semanas antes de la enfermedad del entrenador, el 7 de Septiembre, dos caballos habían sido llevados al Hendra desde un establo de pre-carrera en Cannon Hill (6 km). Uno de éstos, una yegua preñada, enfermó y murió en 2 días. El otro caballo fue trasladado luego y nunca llegó a enfermarse. Por el 26 de Septiembre, 13 caballos habían muerto: la yegua; otros 10 caballos en el establo de Hendra; un caballo, que tuvo contacto muy cercano con caballos en el establo de Hendra, en una propiedad vecina; y uno que había sido transportado desde el establo a otro sitio (150 km). Cuatro caballos de Hendra y otros tres (uno en un establo adyacente, uno llevado a Kenilworth, y uno a Samford) se consideraron que habían estado expuestos y se habían recuperado de la enfermedad. Algunos de estos caballos fueron asintomáticos. Nueve caballos de Hendra habían permanecido inafectados. Los caballos enfermos estaban anoréxicos, deprimidos, comúnmente febriles (temperatura hasta 41ºC), mostraron tasa respiratoria elevada, y llegaron a estar atáxicos. Una descarga nasal espumosa ocurrió antes de la muerte.Facultad de Ciencias Veterinaria