Agricultural biosecurity

The prevention and control of new pest and disease introductions is an agricultural challenge which is attracting growing public interest. This interest is in part driven by an impression that the threat is increasing, but there has been little analysis of the changing rates of biosecurity threat, and existing evidence is equivocal. Traditional biosecurity systems for animals and plants differ substantially but are beginning to converge. Bio-economic modelling of risk will be a valuable tool in guiding the allocation of limited resources for biosecurity. The future of prevention and management systems will be strongly influenced by new technology and the growing role of the private sector. Overall, today''s biosecurity systems are challenged by changing national priorities regarding trade, by new concerns about environmental effects of biological invasions and by the question ‘who pays?’. Tomorrow''s systems may need to be quite different to be effective. We suggest three changes: an integration of plant and animal biosecurity around a common, proactive, risk-based approach; a greater focus on international cooperation to deal with threats at source; and a commitment to refocus biosecurity on building resilience to invasion into agroecosystems rather than building walls around them.     

Aptasensors for biosecurity applications

Nucleic acid (aptasensors) have found steadily increased utility and application over the past decade. In particular, aptamers have been touted as a valuable complement to and, in some cases, replacement for antibodies owing to their structural and functional robustness as well as their ease in generation and synthesis. They are thus attractive for biosecurity applications (e.g. pathogen detection) and are especially well suited because their in vitro generation process does not require infection of any host systems. Herein we provide a brief overview of the aptamers generated against pathogens and toxins over the past few years. In addition, a few recently described detection platforms using aptamers and potentially suitable applications for biosecurity will be discussed.     

Managing biosecurity threats in China

Compared to the extensive literature on bioterrorism and biosecurity in the United States, less analysis has been conducted on similar challenges in China. This article seeks to fill this void by providing an integrated and updated assessment of 3 major biosecurity threats China faces: biowarfare, bioterrorism, and biocrimes. An analysis of China's biosecurity threats and biodefense building suggest varying levels of risk associated with each threat type. First, a direct bioweapons attack on China is highly unlikely, although the threat of biowarfare cannot be simply written off. Second, potential perpetrators of bioterrorism have capabilities at their disposal for carrying out such attacks. While terrorist organizations in China do not have a strong interest in bioterrorism, the limited state capability to counter such a threat may increase the risk in the future. Third, unlike the threats of biowarfare and bioterrorism, potential perpetrators of biocrimes have both incentives and capabilities, and biocrimes can produce reactions far out of proportion to the actual number of casualties. Despite the distinct biosecurity challenges it faces, China has yet to articulate a differentiated and coherent strategy to effectively tackle the challenges. Assessing different types of biosecurity threats in terms of degrees of risk not only provides greater analytical clarity but also has important implications for the strategies required to manage the risks.     

A conductometric biosensor for biosecurity

The paper describes the development of a conductometric biosensor for detecting foodborne pathogens. The biosensor consists of two components: an immunosensor that is based on electrochemical sandwich immunoassay, and a reader for signal measurement. The architecture of the immunosensor utilizes a lateral flow system that allows the liquid sample to move from one pad to another. The biosensor provides a specific, sensitive, low volume, and near real-time detection mechanism. Results are presented to highlight the performance of the biosensor for enterohemorrhagic Escherichia coli O157:H7 and Salmonella spp., which are of concern to biosecurity. The lower limit of detection is approximately 7.9 x 10(1) colony forming units per milliliter within a 10-min process. The ability to change the specificity of the antibodies will enable the biosensor to be used as a detection device for other types of foodborne pathogens.     

The biosecurity of on-farm mortality composting

Composting is a natural biological decomposition process that takes place under aerobic and thermophilic conditions. It can be used for the day-to-day management of mortalities on farms and for carcass disposal in emergency animal disease (EAD) outbreaks. In mortality composting, carcasses are placed in piles or bins together with supplemental carbon sources such as sawdust, litter, straw or wood shavings. Composting is particularly suitable for broiler-farm mortalities and litter. In the case of emergency disease outbreaks, composting can be conducted either inside or outside the poultry house following killing. Composting has been successfully employed for emergency disposal of carcasses in a few cases in North America, but research is lacking on the biosecurity of the process. Composting is a well-established pathogen reduction technology, but process management and heterogenous pile conditions pose particular challenges for validating the microbiological safety of mortality composting. This paper reviews the available information on the biosecurity of mortality composting, identifies potential sources of risk, and highlights emerging research needs. Reports to date of the use of composting in EAD outbreaks are also discussed.     

Economic aspects of agricultural and food biosecurity

Concerns about biosecurity in the food system raise a variety of issues about how the system is presently organized, why it might be vulnerable, what we could reasonably do to better secure it, and the costs of doing so. Emphasizing the role of incentives in efficient resource allocation, this article considers economic dimensions of three aspects of the general problem. One is the global problem, or the way biosecurity measures can affect how countries relate to each other and the global consequences that result. Another is how to best manage the immediate aftermath of a realized threat in order to minimize damage. The third is how to seek to prevent realization of the threat. Some policy alternatives are presented.     

Surveillance of emerging infectious diseases for biosecurity

Science China Life Sciences - Emerging infectious diseases, such as COVID-19, continue to pose significant threats to human beings and their surroundings. In addition, biological warfare,...     

Eight strategies to engage industry in biosecurity

A significant portion of the domestic bio-research base-and the one most likely to provide translational research-is not engaged in biodefense. Despite the fact that more than one-third of all life science researchers are employed in commercial bio-research, fewer than 3% of the 1,500 U.S. bio-technology companies are involved in biosecurity initiatives. The bio-tech industry has largely not aligned itself to play an integral role in biosecurity, but there are a few policy changes that could dramatically alter this balance. These include engaging and motivating the bio-technology middle class, seeding secondary markets, focusing on system solutions, providing reagents and standards, aligning communications, and prioritizing translational research. By reaching out, policymakers can span the current chasm between the bio-industry and government, build a stable biodefense industrial base, establish solid working relationships, and secure better services and products. The rewards would be significant for government and industry alike.     

DNA barcodes for biosecurity: invasive species identification

Biosecurity encompasses protecting against any risk through 'biological harm', not least being the economic impact from the spread of pest insects. Molecular diagnostic tools provide valuable support for the rapid and accurate identification of morphologically indistinct alien species. However, these tools currently lack standardization. They are not conducive to adaptation by multiple sectors or countries, or to coping with changing pest priorities. The data presented here identifies DNA barcodes as a very promising opportunity to address this. DNA of tussock moth and fruit fly specimens intercepted at the New Zealand border over the last decade were reanalysed using the cox1 sequence barcode approach. Species identifications were compared with the historical dataset obtained by PCR-RFLP of nuclear rDNA. There was 90 and 96% agreement between the methods for these species, respectively. Improvements included previous tussock moth 'unknowns' being placed to family, genera or species and further resolution within fruit fly species complexes. The analyses highlight several advantages of DNA barcodes, especially their adaptability and predictive value. This approach is a realistic platform on which to build a much more flexible system, with the potential to be adopted globally for the rapid and accurate identification of invasive alien species.     

Strategic dilemmas of biosecurity in the European Union

Systems for societal/homeland security in both Europe and the United States are in flux to adjust to 21st century threats, such as terrorism, the proliferation of weapons of mass destruction, regional conflicts, state failures, and organized crime. It is important that reforms take place on both sides of the Atlantic that recognize the interdependence of Europe and the United States. Security, including biosecurity, for Europe is strongly connected to security in the U.S. Diseases transcend borders, and their consequences can be the same, irrespective of where the outbreak occurs or whether it is a natural occurrence or an act of bioterrorism. This article examines the political and strategic dilemmas and complexities that would confront the European Union (EU) in the event of a bioterrorism attack or a naturally occurring outbreak. Although several initiatives have been taken by the 15 member states and within the EU Commission, the EU is not institutionally prepared for transnational, rapidly moving diseases that could cause grave consequences in Europe and other regions, including the U.S. The prime responsibility for protecting European citizens against outbreaks rests with each member state. However, with intertwined and open European societies, the consequences would likely spill across borders. The EU Commission would have to become involved because such aspects as the internal market and freedom of movement would be affected. Responsibility, but not authority, would be pushed to the top. A coordinated EU response to such crises depends on European political leadership.     

Approaches to biosecurity in bovine embryo transfer programs

Although transfer of bovine embryos is much less likely to result in transmission of pathogens than transport of postnatal cattle, the epidemiologic risk associated with bovine embryo transfer merits examination. Much research has validated the efficacy of internationally approved processing protocols to render bovine in vivo-derived embryos free of specified pathogens. The purpose of this review is to summarize current sanitary recommendations for bovine embryo transfer, while emphasizing recent research to develop and validate novel approaches to biosecurity. Continued research will enable the development and validation of novel embryo treatments and culture reagents to minimize requirements for testing of embryo or oocyte donors, and testing of embryo recipients.     

Viruses,biosecurity and specific pathogen-free stocks in shrimp aquaculture

The greatest threat to the future of world shrimp aquaculture is disease, in particular the virulent untreatable viruses, infectious hypodermal and haematopoietic necrosis virus (IHHNV), taura syndrome virus (TSV), yellow head virus (YHV), and white spot syndrome virus (WSSV). To overcome these hazards, the industry of the future must be based on: (i) specific pathogen-free and genetically improved shrimp stocks; (ii) biosecure systems including enclosed, reduced water-exchange/increased water-reuse culture systems; (iii) biosecure management practices; and (iv) co-operative industry-wide disease control strategies. Specific pathogen-free shrimp are those that are known to be free of specified pathogens and such stocks will ensure that seed shrimp are not the conduit for introduction of pathogens and that if pathogens are encountered the stocks will not be severely affected. Commercially acceptable biosecure culture systems that are under cover and use recirculated sea water will need to be developed for shrimp production. Adherence to operating protocols that incorporate strict biosecurity practices, including restricted access and disinfection strategies, will need to become standard. Co-operative efforts will include: early warning surveillance; co-ordination of harvest and water exchange schedules of contaminated ponds; processor co-operation to ensure that processing wastes are not threats; quick response to outbreaks.     

Effectiveness of biosecurity measures in preventing badger visits to farm buildings

Background

Bovine tuberculosis caused by Mycobacterium bovis is a serious and economically important disease of cattle. Badgers have been implicated in the transmission and maintenance of the disease in the UK since the 1970s. Recent studies have provided substantial evidence of widespread and frequent visits by badgers to farm buildings during which there is the potential for close direct contact with cattle and contamination of cattle feed.

Methodology

Here we evaluated the effectiveness of simple exclusion measures in improving farm biosecurity and preventing badger visits to farm buildings. In the first phase of the study, 32 farms were surveyed using motion-triggered infrared cameras on potential entrances to farm buildings to determine the background level of badger visits experienced by each farm. In the second phase, they were divided into four treatment groups; “Control”, “Feed Storage”, “Cattle Housing” and “Both”, whereby no exclusion measures were installed, exclusion measures were installed on feed storage areas only, cattle housing only or both feed storage and cattle housing, respectively. Badger exclusion measures included sheet metal gates, adjustable metal panels for gates, sheet metal fencing, feed bins and electric fencing. Cameras were deployed for at least 365 nights in each phase on each farm.

Results

Badger visits to farm buildings occurred on 19 of the 32 farms in phase one. In phase two, the simple exclusion measures were 100% effective in preventing badger entry into farm buildings, as long as they were appropriately deployed. Furthermore, the installation of exclusion measures also reduced the level of badger visits to the rest of the farmyard. The findings of the present study clearly demonstrate how relatively simple practical measures can substantially reduce the likelihood of badger visits to buildings and reduce some of the potential for contact and disease transmission between badgers and cattle.     

Prioritising plant-parasitic nematode species biosecurity risks using self organising maps

The biosecurity risks from many plant-parasitic nematode (PPN) species are poorly known and remain a major challenge for identifying potentially invasive species. A self organising map (SOM) was used to prioritise biosecurity risks from PPN to the whole of continental Australia as well as each of the states and the Northern Territory separately. The SOM used the recorded worldwide distributions of 250 systematically selected species from 43 genera, and identified 18 different countries spanning Asia, Africa, North and Central America, Europe and the Pacific with very similar PPN assemblages to Australia as a whole. Many of the species in these countries are not recorded in Australia, and therefore pose a biosecurity risk. Analysed separately, the states and territories were identified as forming five separate clusters, each with a different region of the world, and with different characteristic PPN. Many of the PPN found in the regions clustered with an Australian state have not been recorded from anywhere in Australia, and others have very restricted distributions within Australia, thus posing different biosecurity risks. The SOM analysis ranked the risks of the different PPN based on likelihoods of establishment. The rankings confirmed the risks from frequently quarantined PPN, but more importantly identified species, which upon further investigation could be new threats. This method can be used to identify previously overlooked species for more detailed risk assessments.