Australian Biosecurity Research Articles

Strategic approaches to identifying pathogens of imported ornamental fish and the risk posed to biosecurity in Australia

Strategic approaches to identifying pathogens of imported ornamental fish and the risk posed to biosecurity in Australia

Plant biosecurity policy-making modelled on the human immune system: What would it look like?

This paper takes inspiration from the field of bio-mimicry to suggest what a plant biosecurity system might look like if it was modelled on the human immune system. We suggest structural and institutional changes to current biosecurity systems that would facilitate adaptive preparation and response policies, focusing particularly on the Australian plant biosecurity system. By improving information exchanges, interpretation and managing overlapping complementary response capabilities of this system, novel policies emerge that increase resilience to harmful weeds, pests and diseases. This is achieved by adding an element of flexibility in invasion response to cope with different circumstances and contexts, rather than a 'one size fits all' approach. While we find bio-mimicry to be a potentially useful system design tool, there are key differences between the immune and biosecurity systems that the analogy makes clear. Perhaps the most important of these stems from the inability of immune systems to imagine future threats. (C) 2014 Elsevier Ltd. All rights reserved. (Less)

Feeding and Development of the Glassy-Winged Sharpshooter, Homalodisca vitripennis, on Australian Native Plant Species and Implications for Australian Biosecurity

In any insect invasion the presence or absence of suitable food and oviposition hosts in the invaded range is a key factor determining establishment success. The glassy-winged sharpshooter, Homalodisca vitripennis, is an important insect vector of the xylem-limited bacterial plant pathogen, Xylella fastidiosa, which causes disease in numerous host plants including food and feedstock crops, ornamentals and weeds. Both the pathogen and the vector are native to the Americas and are considered to be highly invasive. Neither has been detected in Australia. Twelve Australian native plant species present in the USA were observed over two years for suitability as H. vitripennis feeding, oviposition and nymph development hosts. Hosts providing evidence of adult or nymph presence were Leptospermum laevigatum, Acacia cowleana, Eremophila divaricata, Eucalyptus wandoo, Hakea laurina, Melaleuca laterita and Swainsona galegifolia. An oviposition-suitability field study was conducted with citrus, a favoured oviposition host, as a positive control. Citrus and L. laevigatum, A. cowleana, B. ericifolia×B. spinulosa, C. pulchella, E. divaricata, E. wandoo, H. laurina, and S. galegifolia were found to be oviposition hosts. Egg parasitism by the mymarid parasitoid Gonatocerus ashmeadi was observed on all Australian plants. A number of Australian plants that may facilitate H. vitripennis invasion have been identified and categorised as ‘high risk’ due to their ability to support all three life stages (egg, nymph and adult) of the insect in the field (L. laevigatum, A. cowleana, E. divaricata, H. laurina, and S. galegifolia). The implications of these host status and natural enemy research findings are discussed and placed in an Australian invasion context.

First Report of Pepper chat fruit viroid in Traded Tomato Seed, an Interception by Australian Biosecurity.

Pepper chat fruit viroid (PCFVd), a species of Pospiviroid, was first discovered in a capsicum crop in the Netherlands in 2006 (4) and was then reported only in Thailand (2) and Canada. The mechanism of international spread was not known, but movement with traded seed was suspected. PCFVd is transmissible through capsicum seed (4) and very probably through tomato seed, like other pospiviroids. The viroid causes disease in capsicum and tomato and experiments by others indicate a capacity to cause disease in potato. It poses a biosecurity threat to crops internationally. PCFVd was intercepted by the Australian Government Department of Agriculture, Fisheries, and Forestry (DAFF) in five shipments of tomato seed (Solanum lycopersicum) exported from Israel and Thailand in September and October 2012. Batches of up to 20,000 seeds were sampled from each seed lot in a shipment and total nucleic acids were extracted from sub-samples, each of about 400 seeds, following a method similar to Hoshino et al. (1). PCFVd was initially detected when reverse transcription PCR using the generic pospiviroid primers Pospi1-FW and Pospi1-RE (3) produced amplicons of 189 bp, which were then sequenced. The PCFVd specific primers AP FW1 and AP RE2 (4) were used to amplify the remainder of the viroid genome, which was directly sequenced. Overlapping sequences were aligned to produce complete sequences of 349 bases, one from seed from Thailand and two from seed from Israel (GenBank: KC762952, KC762953, KC762954). Searches of the GenBank nucleotide non-redundant database indicated close matches with sequences from PCFVd isolates from tomato in Thailand (2); alignments generated by BLAST showed the sequences differed from those from Thailand at only 2 to 18 nucleotide positions, equating to 95 to 99% identity. PCFVd sequences from seed from Thailand were almost identical (>99%) to the sequences from seed from Israel. Many sub-samples were negative, indicating that the number of contaminated seeds was very small in some shipments. The positive sub-samples as a proportion of the total number of sub-samples tested from the five shipments was 1/1, 1/5, 1/1, 12/50, and 7/50. Tomato and capsicum seed are produced in many countries and often traded through second countries. The infected tomato seed shipments intercepted by DAFF were destroyed or re-exported following Australian regulations. Other countries were informed through the International Plant Protection Convention. This pest viroid has not been intercepted by Australian authorities before and has not been detected in recent Australian survey work (data not shown).

The efficacy of crab condos in capturing small crab species and their use in invasive marine species monitoring

Crab condos are designed to sample for invasive species, which are not specifically targeted using current Australian biosecurity methodologies. Smaller crab species are often excluded, overlooked and damaged to be collected via current trapping or collection methods. An artificial habitat collector such as the ‘crab condo’ (PVC tubes 25cm long and 50mm diameter arranged in a 3×3 square matrix) aims to provide shelter among an animal’s natural environment. Twenty condos were deployed on a weekly basis for 48 hours during the months of April and July 2012 within Hillarys Boat marina, Western Australia. Condos proved to be highly successful, capturing a total of 555 specimens from five different phyla, with over half (n=332) of specimens identified as crabs. The detection of 223 other smaller non-crab individuals, covering four different phyla highlighted the versatility of condos to sample a range of other small species, not only crabs. Given the recognized importance of early detection of marine pests at their early life stages and current lack of methods targeting small and cryptogenic species, the crab condo sampling method may fill an important gap in marine pest surveillance capacity.

Causes of Morbidity and Mortality of Wild Aquatic Birds at Billabong Sanctuary, Townsville, North Queensland, Australia

Infectious diseases are common causes of significant morbidity and mortality events of wild aquatic birds (WABs) worldwide. Reports of Australian events are infrequent. A 3-yr passive surveillance program investigating the common causes of morbidity and mortality of WABs was conducted at Billabong Sanctuary near Townsville, North Queensland, from April 2007 to March 2010. Forty-two carcasses were obtained and evaluated by clinico-pathologic, histologic, bacteriologic, and virologic (molecular) examinations. Morbidity and mortality were sporadic and more commonly observed in chicks and juvenile birds in April than other months of the year. Morbid birds were frequently unable to walk. Hemorrhagic lesions and infiltration of lymphocytes in various organs were the most common findings in dead birds. Identified bacterial diseases that could cause bird mortality were colibacillosis, pasteurellosis, and salmonellosis. Salmonella serotypes Virchow and Hvittingfoss were isolated from an Australian white ibis (Threskiornis molucca) chick and two juvenile plumed whistling ducks (Dendrocygna eytoni) in April 2007. These strains have been previously isolated from humans in North Queensland. A multiplex real time reverse transcriptase-PCR (rRT-PCR) detected Newcastle disease viral RNA (class 2 type) in one adult Australian pelican (Pelecanus conspicillatus) and a juvenile plumed whistling duck. No avian influenza viral RNA was detected from any sampled birds by the rRT-PCR for avian influenza. This study identified the public health importance of Salmonella in WABs but did not detect the introduction of the high pathogenicity avian influenza H5N1 virus in the population. A successful network was established between the property owner and the James Cook University research team through which dead birds, with accompanying information, were readily obtained for analysis. There is an opportunity for establishing a long-term passive disease surveillance program for WABs in North Queensland, an important region in Australian biosecurity, thus potentially significantly benefitting public health in the region and the country.

Managing the risk of exotic vertebrate incursions in Australia

Context Biological invasions are a profound contribution to human-induced environmental change. Although intentional introductions of vertebrate species have largely declined, global transport and communication networks continue to increase. As a consequence, more goods are being traded and the type of species being transported has changed, as well as the associated risks. Aims To analyse the frequency, and provide risk assessments, for exotic vertebrate species detected by border and post-border Australian biosecurity agencies in the past decade (1999–2010). Methods We collated detection records by emailing or telephoning representatives from agencies responsible for implementing Australian biosecurity. We calculated the risk of successful establishment (low, moderate, serious, extreme) for 137 identified vertebrate species not currently established in Australia. Generalised linear models were constructed to test whether the frequency of increasing risk of establishment was associated with either differences between vertebrate classes and/or different detection categories. Key results The majority of species detected were reported from illegal keeping. Individual species risk assessments revealed that reptiles were more likely to be of greater risk for future establishment than were birds, mammals or amphibians. Controlling for taxonomy, high-risk species were not involved in larger (i.e. number of individuals) incidents than were lower-risk species. Across years, the number of novel exotic vertebrate species detected ‘at large’ in Australia has significantly increased. Conclusions Several of the species detected by biosecurity agencies have attributes that give them the potential to become pests in Australia. Preventing incursions is by far the most cost-effective way to prevent future pest damage. Implications It is clear that a nationally coordinated framework for data collection and data sharing among agencies is urgently required. We present a minimum framework for the future collection of inter-agency data, necessary to assess and monitor the ongoing risk of vertebrate pest incursions in Australia.

Sampling Small Quantities of Blood from Microbats

School of Veterinary Science, University of Queensland, St. Lucia, Queensland 4072, Australia Australian Biosecurity Cooperative Research Centre for Emerging Infectious Diseases, St. Lucia, Queensland 4072, Australia Biosecurity Queensland, Queensland Primary Industries and Fisheries, Department of Employment, Economic Development and Innovation, Yeerongpilly, Queensland 4105, Australia Corresponding author: E-mail: craig.smith@deedi.qld.gov.au

CLIMATE CHANGE: Challenges of Predicting Wildfire Activity

CLIMATE CHANGE: Challenges of Predicting Wildfire Activity

Vector Competence of Australian Mosquito Species for a North American Strain of West Nile Virus

Since the establishment of West Nile virus (WNV) into the United States, concern has arisen that this virus may also pose a serious threat to Australian biosecurity. The vector competence of 19 Australian mosquito species for a North American strain of WNV was evaluated. Mosquitoes collected from Cairns, Brisbane, and Sydney were exposed to blood containing 10(4.0+/-0.3) cell culture infectious dose(50)/mosquito WNV that was isolated from a crow during the 1999 New York outbreak. Mosquitoes were tested 12-15 days later to determine their infection, dissemination, and transmission rates. A number of Culex spp. demonstrated a high vector competence for this virus, with some populations of Culex annulirostris, the primary Australian Kunjin virus vector, displaying transmission rates up to 84%. Similarly, Cx. quinquefasciatus and Cx. gelidus were highly competent, with infection and transmission rates of >80% and >50%, respectively. Common Aedes spp., including Aedes notoscriptus, Ae. vigilax, and Ae. procax, were moderately susceptible, and some Verrallina spp. and Coquillettidia spp. were relatively refractory to infection. Thus, Australia possesses a number of competent mosquito species that could facilitate local transmission of WNV, should it be introduced.

Benefit cost analysis of an import access request

Invasive species outbreaks are often unintended side effects of trade. In this paper partial equilibrium trade models and stochastic bioeconomic impact simulation models are combined to present a benefit cost analysis template to assess market access requests. The template is used to assess the likely regional economic welfare implications of a decision by Australian biosecurity regulators to allow the Chilean table grape industry access to the national table grape market. We show that consumption benefits expected to accrue to Western Australia are exceeded by increases in likely invasive species damage resulting from grape imports, implying that insufficient consumer gains are grounds to deny market access.

Rooting Out Invasive Species: Lessons from Down Under

In a world where heightened airport security is the norm, Australia and New Zealand might seem like a parallel universe. Dogs patrol airport aisles, sniffing not for illegal drugs, but for wayward fruits and vegetables. While the luggage of outgoing passengers may be X-rayed for weapons, incoming visitors have their suitcases scanned for any kind of biological material. You can be required to surrender your shoes, not because they might contain explosives, but because you neglected to clean them off after hiking in some foreign rural area. The security in question is biosecurity—protection against incoming exotic species—and at these checkpoints, no packet of garden seed is too innocent to be seized. Both countries have powerful incentives for such stringent enforcement. Although Australia and New Zealand are highly urbanized societies, their economies feature a significant agricultural sector that is exceptionally vulnerable to the ravages of invasive species. More recently, though, many observers are adding the prospect of human health issues to the toll exacted by exotics. In fact, the gauntlet found at these countries’ international airports is just the most obvious aspect of how seriously local authorities and scientists regard the issue of biosecurity. Government policies and academic institutions regularly adopt a unique focus on the way in which plants and animals cross national boundaries, a perspective that may look downright xenophobic at first glance. Nevertheless, the experience of Australia and New Zealand can provide a valuable example to parts of the world that treat their boundaries in a more casual fashion, at least from a biological point of view. Accomplishments in these countries can offer important lessons to any country that must confront the combined impact of rising volumes of international trade and shifting climate patterns.

Vale DRS Banks and Copeman

The two papers on echinococcosis in this issue describe part of the work of Dr David Banks during his PhD at James Cook University from 1981 to 1984, under the supervision of Associate Professor Bruce Copeman. Both men died recently, David in a plane crash at Lockhart River in 2005 and Bruce from multiple myeloma in 2006. David's early death led Bruce to finalise and submit their draft manuscripts for publication. Their work together during David's PhD along with the work of Dr Chris Baldock was instrumental in determining the epidemiology of echinococcosis in cattle in Australia. Researchers in this field have known of their work and have referred to it in their publications (see Jenkins et al. 2005, International Journal of Parasitology, volume 35, pages 1205–1219). David and Bruce were prevented from publishing these papers earlier due to the enormous workloads in their careers, which they appeared to accept with good humour. They were talented individuals whose skills and expertise were always in demand. David became the principal scientist of Biosecurity Australia and devoted much of his life to eradicating and preventing the spread of important animal diseases. Bruce was one of the key teaching and research parasitologists in the tropics for over 30 years. He supervised 52 postgraduate students including David, many of whom became senior scientists within their respective countries. Both David and Bruce were blessed with immense enthusiasm for their work, a quality they imparted to others. They were kind, considerate and thoughtful, the very best sort of people to be around. Between them they achieved a great deal and have been honoured with a number of awards such as the Kesteven Medal and the Order of Australia. Both men are already commemorated by their peers in two public lectures; the David Banks Memorial Lecture sponsored by the Australian Biosecurity Cooperative Research Centre, which is given each year in memory of David's contribution to the control of emerging infectious diseases, and the annual Bruce Copeman Oration sponsored by the Australasian College of Tropical Medicine (ACTM). The latter helps illustrate the breadth of Bruce's interests and enthusiasm. Bruce was one of a small group of 10 that founded the ACTM in Townsville in 1991. The fact that these two papers are now published also illustrates Bruce's amazing approach to life and death. When he realised that the myeloma would win in the end, Bruce retired from the School of Veterinary and Biomedical Science, but used the ‘free’ time to come in to work almost on a daily basis to finalise a lifetime of doctoral student publications. Bruce's last years have been some of his most productive, submitting 21 manuscripts for publication. Both scientists will be sadly missed.

Australian Biosecurity System for primary production and the environment

Australian Biosecurity System for primary production and the environment

Australian Biosecurity CRC for Emerging Infectious Diseases (AB-CRC)

The Australian Biosecurity Cooperative Research Centre for Emerging Infectious Disease (AB-CRC) was a successful applicant under the Federal Government?s 2002 CRC programme, and will be formally established from July 2003. The aim of the AB-CRC is to protect Australia?s health, livestock, wildlife and economic resources by developing new capabilities to monitor, assess, predict and respond to emerging and exotic disease threats which impact on national and regional biosecurity. Emerging diseases are defined as those which are novel, previously unrecognised diseases, or those which are increasing in incidence or geographic range. The threats may be natural, accidental (such as an infected traveller) or deliberate (as in bioterrorism).

Host-specificity of Candidate Agents for the Biological Control of Onopordum spp. Thistles in Australia: An Assessment of Testing Procedures

This paper describes a series of host-specificity tests carried out to evaluate the safety of eight insects for release in Australia as biological control agents of Onopordum spp. thistles; Larinus latus L., Lixus cardui Ol. and Trichosirocalus briesei Alonso-Zarazaga & Sanchez-Ruiz (Coleoptera: Curculionidae), Tephritis postica Loew and Urophora terebrans Loew (Diptera: Tephritidae), Botanophila spinosa Rondani (Diptera: Anthomyiidae), Tettigometra sulphurea Mulsant & Rey. (Hemiptera: Fulgoroidae) and Eublemma amoena (Hbn.) (Lepidoptera: Noctuidae). Preliminary tests were first carried out against key test plants in the country of origin to determine whether it was worth proceeding with formal testing under quarantine conditions in Australia. In the formal testing procedure, the test plant list was based solely on phylogenetic relationships. The life-stage of each insect tested was selected with respect to its biology and behaviour, e.g. only oviposition was tested for insect species with immobile endophagous larvae, while larval host utilization was tested for those with mobile larval stages. The initial laboratory experiments for each species used were caged no-choice tests, as confinement without choice can elicit extreme behavioural responses, making negative results extremely robust. Where positive results occurred, insects where re-exposed to the plant, but this time given a choice between the target and non-target plants. The results of these tests, plus data from open-field preliminary tests in the country of origin, helped interpret results and determine the risk posed by each candidate biological control agent to non-target plant species. Following submission, all eight candidates were approved for release by the Australian plant biosecurity and conservation authorities. Based on a comparison of the eight species tested, it is recommended that host-specificity testing be kept flexible and pragmatic, rather than moving towards a formulaic risk assessment procedure. Moreover, given the improved state of knowledge of plant phylogenies and the evolution of host utilization, it is time to base testing procedures purely on phylogenetic grounds, without the need to include less related test species solely because of economic or conservation reasons.