The 2017-19 activity at Mount Agung in Bali (Indonesia): Intense unrest, monitoring, crisis response, evacuation, and eruption.

After 53 years of quiescence, Mount Agung awoke in August 2017, with intense seismicity, measurable ground deformation, and thermal anomalies in the summit crater. Although the seismic unrest peaked in late September and early October, the volcano did not start erupting until 21 November. The most intense explosive eruptions with accompanying rapid lava effusion occurred between 25 and 29 November.

Experimental Hendra virus infection of dogs: virus replication, shedding and potential for transmission.

Objective: Characterisation of experimental Hendra virus (HeV) infection in dogs and assessment of associated transmission risk.

Methods: Beagle dogs were exposed oronasally to Hendra virus/Australia/Horse/2008/Redlands or to blood collected from HeV-infected ferrets. Ferrets were exposed to oral fluids collected from dogs after canine exposure to HeV.

A rapid assay for Hendra virus IgG antibody detection and its titre estimation using magnetic nanoparticles and phycoerythrin.

Detection of Hendra viral IgG antibody in animal sera is useful for surveillance following a virus outbreak. The commonly used enzyme-linked immunosorbent assay and fluorescence-based Luminex assay typically consist of three steps and take at least several hours to complete. We have simplified the procedure to two steps in an effort to develop a rapid procedure for IgG antibody, but not IgM antibody, detection.

Mouse fibroblast L929 cells are less permissive to infection by Nelson Bay orthoreovirus compared to other mammalian cell lines.

In recent years, bats have been identified as a natural reservoir for a diverse range of viruses. Nelson Bay orthoreovirus (NBV) was first isolated from the heart blood of a fruit bat (Pteropus poliocephalus) in 1968. While the pathogenesis of NBV remains unknown, other related members of this group have caused acute respiratory disease in humans.

Detailed morphological characterisation of Hendra virus infection of different cell types using super-resolution and conventional imaging.

Background: Hendra virus (HeV) is a pleomorphic virus belonging to the Paramyxovirus family. Our long-term aim is to understand the process of assembly of HeV virions. As a first step, we sought to determine the most appropriate cell culture system with which to study this process, and then to use this model to define the morphology of the virus and identify the site of assembly by imaging key virus encoded proteins in infected cells.

Hendra virus vaccine, a one health approach to protecting horse, human, and environmental health.

In recent years, the emergence of several highly pathogenic zoonotic diseases in humans has led to a renewed emphasis on the interconnectedness of human, animal, and environmental health, otherwise known as One Health. For example, Hendra virus (HeV), a zoonotic paramyxovirus, was discovered in 1994, and since then, infections have occurred in 7 humans, each of whom had a strong epidemiologic link to similarly affected horses. As a consequence of these outbreaks, eradication of bat populations was discussed, despite their crucial environmental roles in pollination and reduction of the insect population.

Vaccination of ferrets with a recombinant G glycoprotein subunit vaccine provides protection against Nipah virus disease for over 12 months.

Background: Nipah virus (NiV) is a zoonotic virus belonging to the henipavirus genus in the family Paramyxoviridae. Since NiV was first identified in 1999, outbreaks have continued to occur in humans in Bangladesh and India on an almost annual basis with case fatality rates reported between 40% and 100%.

Methods: Ferrets were vaccinated with 4, 20 or 100 μg HeVsG formulated with the human use approved adjuvant, CpG, in a prime-boost regime.

A treatment for and vaccine against the deadly Hendra and Nipah viruses.

Hendra virus and Nipah virus are bat-borne paramyxoviruses that are the prototypic members of the genus Henipavirus. The henipaviruses emerged in the 1990s, spilling over from their natural bat hosts and causing serious disease outbreaks in humans and livestock. Hendra virus emerged in Australia and since 1994 there have been 7 human infections with 4 case fatalities.

Promotion of Hendra virus replication by microRNA 146a.

Hendra virus is a highly pathogenic zoonotic paramyxovirus in the genus Henipavirus. Thirty-nine outbreaks of Hendra virus have been reported since its initial identification in Queensland, Australia, resulting in seven human infections and four fatalities. Little is known about cellular host factors impacting Hendra virus replication.

Isolation and characterisation of a novel Bohle-like virus from two frog species in the Darwin rural area, Australia.

Twelve captive magnificent tree frogs Litoria splendida and 2 green tree frogs L. caerulea on a property in the Darwin rural area (Northern Territory, Australia) either died or were euthanased after becoming lethargic or developing skin lesions. Samples from both species of frog were submitted for histopathology and virus isolation.

Immunization strategies against henipaviruses.

Hendra virus and Nipah virus are recently discovered and closely related emerging viruses that now comprise the genus henipavirus within the sub-family Paramyxoviridae and are distinguished by their broad species tropism and in addition to bats can infect and cause fatal disease in a wide variety of mammalian hosts including humans. The high mortality associated with human and animal henipavirus infections has highlighted the importance and necessity of developing effective immunization strategies. The development of suitable animal models of henipavirus infection and pathogenesis has been critical for testing the efficacy of potential therapeutic approaches.

A recombinant Hendra virus G glycoprotein-based subunit vaccine protects ferrets from lethal Hendra virus challenge.

The henipaviruses, Hendra virus (HeV) and Nipah virus (NiV), are two deadly zoonotic viruses for which no vaccines or therapeutics have yet been approved for human or livestock use. In 14 outbreaks since 1994 HeV has been responsible for multiple fatalities in horses and humans, with all known human infections resulting from close contact with infected horses. A vaccine that prevents virus shedding in infected horses could interrupt the chain of transmission to humans and therefore prevent HeV disease in both.

Assessment of virally vectored autoimmunity as a biocontrol strategy for cane toads.

Background: The cane toad, Bufo (Chaunus) marinus, is one of the most notorious vertebrate pests introduced into Australia over the last 200 years and, so far, efforts to identify a naturally occurring B. marinus-specific pathogen for use as a biological control agent have been unsuccessful. We explored an alternative approach that entailed genetically modifying a pathogen with broad host specificity so that it no longer caused disease, but carried a gene to disrupt the cane toad life cycle in a species specific manner.

Chloroquine administration does not prevent Nipah virus infection and disease in ferrets.

Hendra virus and Nipah virus, two zoonotic paramyxoviruses in the genus Henipavirus, have recently emerged and continue to cause sporadic disease outbreaks in humans and animals. Mortality rates of up to 75% have been reported in humans, but there are presently no clinically licensed therapeutics for treating henipavirus-induced disease. A recent report indicated that chloroquine, used in malaria therapy for over 70 years, prevented infection with Nipah virus in vitro.

Cane toad toxicity: an assessment of extracts from early developmental stages and adult tissues using MDCK cell culture.

Extracts of the cane toad (Bufo [Chaunus] marinus) adversely affected the growth of Mardin-Darby canine kidney (MDCK) cells during culture. In a similar manner to ouabain treatment, application of toad extracts over a 24 h period resulted in high levels of cytotoxicity, as indicated by cell detachment, increased membrane permeability and loss of mitochondrial function. Cell viability and growth were unchanged for controls (PBS) and increased with the application of Limnodynastes peronii tadpole and adult frog extracts.

Bohle iridovirus as a vector for heterologous gene expression.

The large double-stranded DNA (ds DNA) viruses were among the first to be used to construct recombinant viruses, but to date this has not been achieved with any members of the ds DNA virus family, Iridoviridae. We identified a non-essential gene, the viral homologue of eukaryotic initiation factor 2alpha (eIF-2alpha), in Bohle iridovirus (BIV, genus Ranavirus). A recombinant BIV was constructed with the neomycin resistance gene and the Bufo marinus (cane toad) adult globin gene inserted into the BIV eIF-2alpha region.

Development of real-time PCR assays for the detection and differentiation of Australian and European ranaviruses.

Serious systemic disease in fish and amphibians is associated with the ranaviruses, epizootic haematopoietic necrosis virus (EHNV) and Bohle iridovirus (BIV) in Australia, and European sheatfish virus (ESV) and European catfish virus (ECV) in Europe. EHNV, ESV and ECV are recognized causative agents of the OIE (Office International des Epizooties) notifiable systemic necrotizing iridovirus syndrome and are currently identified by protein-based assays, none of which are able to rapidly identify the specific agents. The aim of this study was to develop TaqMan real-time PCR assays that differentiated these viruses using nucleotide sequence variation in two ranavirus genes.

Dynamics of seismogenic volcanic extrusion at Mount St Helens in 2004-05.

The 2004-05 eruption of Mount St Helens exhibited sustained, near-equilibrium behaviour characterized by relatively steady extrusion of a solid dacite plug and nearly periodic shallow earthquakes. Here we present a diverse data set to support our hypothesis that these earthquakes resulted from stick-slip motion along the margins of the plug as it was forced incrementally upwards by ascending, solidifying, gas-poor magma. We formalize this hypothesis with a dynamical model that reveals a strong analogy between behaviour of the magma-plug system and that of a variably damped oscillator.

Identification of a Bohle iridovirus thymidine kinase gene and demonstration of activity using vaccinia virus.

In recent years interest in the family Iridoviridae has been renewed by the identification of a number of viruses, particularly from the genus Ranavirus, associated with disease in a range of poikilotherms. Ranaviruses have been isolated from amphibian, piscine and reptilian species. Here we describe an open reading frame (ORF) identified in the genome of Bohle iridovirus (BIV) which contains a nucleotide binding motif conserved within the thymidine kinase (TK) genes of iridoviruses from other genera (lymphocystis disease virus, LCDV, type species of the genus Lymphocystivirus; Chilo iridescent virus, CIV, type species of the genus Iridovirus).

Promoter activity in the 5' flanking regions of the Bohle iridovirus ICP 18, ICP 46 and major capsid protein genes.

Bohle iridovirus (BIV) belongs to the genus Ranavirus, of which Frog virus 3 (FV-3) is the type species. We are developing BIV as a recombinant viral delivery vector, and as a first step we located specific BIV promoter sequences to drive foreign gene expression in the recombinant virus. By comparison with FV-3 sequences, the genes encoding ICP 18 and ICP 46 in BIV were identified and sequenced.

A single gene encoding the fiber is responsible for variations in virulence in the fowl adenoviruses.

Intertypic recombinant fowl adenoviruses (FAVs) were generated to determine regions of the viral genome involved in virulence. Recombinants were produced with two serotype 8 FAVs, mildly virulent CFA 3 and hypervirulent CFA 40. Restriction endonuclease fragments from the genomes of the two FAVs were used to transfect primary chicken kidney cells.

Comparison by restriction enzyme analysis of three fowl adenoviruses of varying pathogenicity.

Restriction enzyme studies have been used to divide the fowl adenoviruses (FAV) into 5 groups - A, B,C,D and E. More detailed restriction enzyme studies of a series of group E FAV field isolates showed that these methods could differentiate between mildly and hypervirulent FAV belonging to this group. We have mapped the genomes of the hypervirulent (CFA 40) and two of the mildly virulent FAV (CFA 44 and CFA 3), using 11 different restriction enzymes: HindIII, BglII, XbaI, NdeI, SpeI, DraI, NotI, StuI, NheI, SfiI, and AvrII.

Fractional moving blood volume: estimation with power Doppler US.

Purpose: To estimate the fraction of moving blood in tissue with power Doppler ultrasound (US).

Materials And Methods: Power Doppler US measurements of moving scatterers in a flow tube were made as a function of successive dilutions of the perfusate. Measurements were normalized relative to the maximum Doppler power in the center of the flow tube at the highest concentration and were used to calculate the fractional dilution of the perfusate for each run with each dilution used to represent increasing amounts of non-moving soft tissue in the sample volume.

Immunological and molecular comparison of fowl adenovirus serotypes 4 and 10.

Some discussion has centered on whether fowl adenovirus (FAV) serotypes 4 and 10 are distinct serotypes or in fact should be reclassified as a single serotype. We have undertaken a detailed characterisation of representatives of both serotypes in order to determine if types 4 and 10 should be grouped together or retained as distinct serotypes. Examination at the genomic level has revealed considerable similarities and few differences between these 2 serotypes.

Ultrasonic estimation of tissue perfusion: a stochastic approach.

Imaging of blood flow perfusion is an area of significant medical interest. Recently, the advantages of using the total integrated Doppler power spectrum as the parameter that is encoded in color has been shown to result in an approximately threefold increase in flow sensitivity, a relative insensitivity to acquisition angle and lack of aliasing. We have taken this mode a step further and demonstrated the potential for quantifying blood flow using correlation-based algorithms applied to the power signal.