Evaluation of FTA® paper and phenol for storage, extraction and molecular characterization of infectious bursal disease virus

From cold chain to ambient temperature: transport of viral specimens- a review

The diagnosis of an aetiology is dependent on the collection, transport, and storage of the infectious sample. The transport of the sample plays a crucial role in the chain of diagnosis. It is important to maintain the biological integrity of the pathogen during the transport of the sample to achieve an accurate diagnosis. This is important, particularly for labile organisms like viruses that are inactivated easily compared to other microorganisms. Many transport media have been utilised to ensure the integrity of the virus during transport. While most of the transport media are focused on preserving the infectious properties of the virus, progress has been made to develop virus transport media to inactivate the virus and obtain the stability of the viral nucleic acid, enabling better molecular diagnosis of the virus aetiologies. This review summarises the various media used for the transport of virus samples and focuses on the need to develop virus transport media that inactivates the virus and preserves the viral nucleic acid.

Alternate Approach in Storing and Shipment of SARS-CoV-2 RNA Samples with the Use of FTA Cards

Shipment of COVID-19 specimens within the country or overseas at long distances requires cold chain facility using dry ice and triple packing to prevent the risk of COVID-19 infection to the personnel involved in sample transport. The present study aimed to utilize FTA card technology as an alternate means of sample transport and storage across the country. Twenty-one SARS-CoV-2 lab confirmed samples with different Ct value (High, medium & low) were used to detect viral load in samples loaded on FTA card and further compared with VTM samples. The SARS-CoV-2 RNA was detected by rRT-PCR after storing for 14 days at 4 °C and 37 °C. The present study evaluated the utility of FTA cards for preserving the SARS CoV-2 RNA for 14-day period. A significant difference (P < 0.05) was observed in the cycle threshold (ΔCt 4–5) values obtained from FTA and VTM viral samples but it did not affect the positivity. The SARS-CoV-2 RNA could be recovered efficiently from FTA sample stored at 4 °C and 37 °C for 14 days. Thus, FTA cards could be an alternate option for transporting the samples at ambient temperature for a long time.

Dried Blood Spots technology for veterinary applications and biological investigations: technical aspects, retrospective analysis, ongoing status and future perspectives

Dried Blood Spots (DBS) technology has become a valuable tool in medical studies, however, in veterinary and biological research DBS technology applications are still limited. Up-to-date no review has comprehensively integrated all the evidence existing across the fields, technologies and animal species. In this paper we summarize the current applications of DBS technology in the mentioned areas, and provide a scope of different types of dried sample carriers (cellulose and non-cellulose), sampling devices, applicable methods for analyte extraction and detection. Mammals, birds, insects and other species are represented as the study objects. Besides the blood, the review considers a variety of specimens, such as milk, saliva, tissue samples and others. The main applications of dried samples highlighted in the review include epidemiological surveys and monitoring for infections agents or specific antibodies for disease/vaccination control in households and wildlife. Besides the genetic investigations, the paper describes detection of environmental contaminants, pregnancy diagnosis and many other useful applications of animal dried samples. The paper also analyses dried sample stability and storage conditions for antibodies, viruses and other substances. Finally, recent developments and future research for DBS technology in veterinary medicine and biological sciences are discussed.

Comparison of three filter paperbased devices for safety and stability of viral sample collection in poultry

General diagnosis of poultry viruses primarily relies on detection of viruses in samples, but many farms are located in remote areas requiring logistic transportation. Filter paper cards are a useful technology that offer an alternative for collecting and preserving samples without hazardous exposure. The goal of this study was to compare three filter papers: the Flinders Technology Associates filter (FTA®) card, dried blood spot (DBS) card and qualitative filter paper (FP) grade 2 to collect poultry samples. In particular, we have used Newcastle disease virus (NDV) to evaluate safety and a Marek's disease virus (MDV) attenuated vaccine (CVI988) to evaluate stability of viral DNA. This experiment was divided into two parts. The first part was to determine the DNA stability and detection limit of CVI988 in samples collected in different paper supports after four storage times (3, 7, 14 and 30 days post spot). The second part was to determine the safety of papers by evaluating the viral inactivation efficacy using NDV as a representative virus. Results showed that all papers could preserve CVI988 DNA at all times, with a detection limit of 0.5 PFU/5 µl for FTA® and DBS cards, and 5 PFU/5 µl for FP. Our results showed that the NDV remained viable and infectious on the DBS card and FP, while no viable virus was detected on the FTA® card, suggesting that the FTA® card was safest to use. Therefore, the use of the DBS card and FP for infectious sample collection should be discouraged and reconsidered. RESEARCH HIGHLIGHTS The detection limits of the FTA® card, DBS card and FP for CVI988 detection were 0.5, 0.5 and 5 PFU/5 µl, respectively. All three filter papers could preserve viral DNA for at least 30 days of post spot. The DBS card and FP are not suitable for collecting NDV samples, which is one of the major economical threats for the poultry industry worldwide.

Comparative protective immunity provided by live vaccines of Newcastle disease virus or avian metapneumovirus when co-administered alongside classical and variant strains of infectious bronchitis virus in day-old broiler chicks

This study reports on the simultaneous administration of live NDV or aMPV subtype B vaccines alongside two live IBV (Massachusetts-H120 and 793B-CR88) vaccines in day-old maternal-antibody positive commercial broiler chicks. In the first experiment, chicks were divided into four groups; one unvaccinated and three groups vaccinated with live NDV VG/GA-Avinew, live H120 + CR88, or VG/GA-Avinew + H120 + CR88. In the second experiment, live aMPV subtype B vaccine was used in place of NDV. Clinical signs were monitored daily and oropharyngeal swabs were taken at regular intervals for vaccine virus detection. Blood was collected at 21 dpv for serology. 10 chicks from each group were challenged with virulent strains of M41 or QX or aMPV subtype B. For IBV, after 5 days post challenge (dpc), tracheal ciliary protection was assessed. For aMPV, clinical scores were recorded up to 10 dpc. For NDV, haemagglutination inhibition (HI) antibody titres were assayed as an indicator of protective immunity. In both experiments, ciliary protection for IBV vaccinated groups was maintained above 90%. The protection against virulent aMPV challenge was not compromised when aMPV, H120 and CR88 were co-administered. NDV HI mean titres in single and combined NDV-vaccinated groups remained above the protective titre (>3 log2). Both experiments demonstrated that simultaneous administration of live NDV VG/GA-Avinew or aMPV subtype B alongside H120 and CR88 vaccines does not interfere with protection conferred against NDV, IBV or aMPV.

A systematic review of FTA cards® as a tool for viral RNA preservation in fieldwork: Are they safe and effective?

BackgroundDetection and characterization of viral RNA pathogens from fieldwork are challenging due to the instability of the RNA molecule. FTA cards® have proved useful for sample storage and latter identification of pathogens with importance for agricultural, animal and human health: however, for optimal handling, processing, and biosafety measures are not well-established.

ObjectiveThis systematic review aims to summarize the reported effectiveness of FTA cards® for storage and transport of viral RNA, as well as the conditions for their handling and use in downstream processes. Finally, the biosafety measures required to protect researchers and clinical lab workers are considered.

MethodsWe performed a systematic review following the PRISMA statement. We searched MEDLINE (PubMed), Scopus and Web of Science using the keywords “FTA cards” AND “RNA”. Articles were screened by title and abstract, and after examination of inclusion and exclusion criteria, relevant information was extracted. The quality of the studies was assessed, and the evidence was qualitatively summarized.

ResultsA total of 175 records were retrieved, and 11 additional documents were found by checking references of the eligible articles. A total of 47 articles were included. Samples from animals accounted for 38.3% of the publications, which identified viruses that cause disease in poultry, wild birds, suids, or bovids. Three different methods for RNA extraction were reported. Other factors that vary across reports include the size of RNA amplicon, storage temperature, and duration of storage. Only fourteen articles tested the inactivation of the virus on the FTA card®, and in one case, the virus remained infective.

ConclusionFTA cards® could be a suitable option for RNA virus storage and transport for fieldwork in areas where proper conditions for RNA preservation are difficult to achieve. Three different protocols have been used for RNA detection from this matrix. Biospecimens in the form of dried blood spots should be considered potentially infectious unless specifically treated to inactivate viral pathogens.

Heterologous live infectious bronchitis virus vaccination in day-old commercial broiler chicks: clinical signs, ciliary health, immune responses and protection against variant infectious bronchitis viruses

Groups of one-day-old broiler chicks were vaccinated via the oculo-nasal route with different live infectious bronchitis virus (IBV) vaccines: Massachusetts (Mass), 793B, D274 or Arkansas (Ark). Clinical signs and gross lesions were evaluated. Five chicks from each group were humanely killed at intervals and their tracheas collected for ciliary activity assessment and for the detection of CD4+, CD8+ and IgA-bearing B cells by immunohistochemistry (IHC). Blood samples were collected at intervals for the detection of anti-IBV antibodies. At 21 days post-vaccination (dpv), protection conferred by different vaccination regimes against virulent M41, QX and 793B was assessed. All vaccination programmes were able to induce high levels of CD4+, CD8+ and IgA-bearing B cells in the trachea. Significantly higher levels of CD4+ and CD8+ expression were observed in the Mass2 + 793B2-vaccinated group compared to the other groups (subscripts indicate different manufacturers). Protection studies showed that the group of chicks vaccinated with Mass2 + 793B2 produced 92% ciliary protection against QX challenge; compared to 53%, 68% and 73% ciliary protection against the same challenge virus by Mass1 + D274, Mass1 + 793B1 and Mass3 + Ark, respectively. All vaccination programmes produced more than 85% ciliary protection against M41 and 793B challenges. It appears that the variable levels of protection provided by different heterologous live IBV vaccinations are dependent on the levels of local tracheal immunity induced by the respective vaccine combination. The Mass2 + 793B2 group showed the worst clinical signs, higher mortality and severe lesions following vaccination, but had the highest tracheal immune responses and demonstrated the best protection against all three challenge viruses.

Genotypes of infectious bronchitis viruses circulating in the Middle East between 2009 and 2014

We are reporting on the infectious bronchitis virus (IBV) genotypes circulating within seven Middle East countries and the alterations in genotype distributions between 2009 and 2014. Tissue samples on FTA cards were received over the six-year period. Viral RNA was extracted using phenol chloroform and subjected to nested RT-PCR targeting a 393 bp region of the S1 gene before being followed by sequencing. From the 461 submitted samples, 363 were IBV positive by RT-PCR (77.01%). Of these, 355 (97.80%) gave sequences that can be genotyped. They belonged to six genotypes; 793B (43.66%), IS/1494/06 (18.31%), Massachusetts (Mass) (12.96%), IS/885/00 (11.27%), Q1 (11.27%) and D274 (2.25%). The prominence of 793B is not surprising, given that 793B vaccine strains are widely used in the Middle East. Sequence analysis demonstrated that the majority of 793B (67.13%) and Mass (81.13%) strains were closely related to vaccine strains based on 99-100% homology with the partial-S1 gene. Vaccinal strains belonging to the D274 genotype were present but only at a low level. Variable proportions of 793B, Mass, D274, IS/1494/06, IS/885/00 and Q1 field strains were identified in different countries. After 2012, the 793B field strain showed distinct clustering compared to strains from earlier years. Translated amino acid alterations were minimal but still may have played an important role in the persistence of this virus despite the use of live 793B vaccines. Huge challenges for an efficient protection against virulent IBVs and chicken production are posed by co-circulating793B, Mass and D274 viruses with less than 99% homology to the respective vaccine strains, along with the recently emerged variant IBVs, despite active IBV vaccination strategies in the Middle East, continuous surveillance of IBV genotypes is essential in formulating optimal control strategies, including the choice and development of new vaccine strains and formulation of vaccination programmes.

Evaluation of the Flinders Technology Associates Cards for Storage and Temperature Challenges in Field Conditions for Foot-and-Mouth Disease Virus Surveillance

Foot-and-mouth disease virus (FMDV) samples transported to the laboratory from far and inaccessible areas for diagnosis and identification of FMDV pose a major problem in a tropical country like India, where wide fluctuation of temperature over a large geographical area is common. Inadequate storage methods lead to spoilage of FMDV samples collected from clinically positive animals in the field. Such samples are declared as non-typeable by the typing laboratories with the consequent loss of valuable epidemiological data. In this study, an attempt was made to evaluate the robustness of Flinders Technology Associates (FTA) cards for storage and transportation of FMDV samples in different climatic conditions which will be useful for FMDV surveillance. Simulation transport studies were conducted using FTA impregnated FMDV samples during post-monsoon (September-October 2010) and summer season (May-June 2012). FMDV genome or serotype could be identified from the FTA cards after the simulation transport studies with varying temperature (22-45°C) and relative humidity (20-100%). The stability of the viral RNA, the absence of infectivity and ease of processing the sample for molecular methods make the FTA cards an useful option for transport of FMDV genome for identification and type determination. The method can be used routinely for FMDV research as it is economical and the cards can be transported easily in envelopes by regular courier/postal systems. The absence of live virus in FTA card can be viewed as an advantage as it restricts the risk of transmission of live virus.

Evaluation of Fast Technology Analysis (FTA) Cards as an improved method for specimen collection and shipment targeting viruses associated with Bovine Respiratory Disease Complex

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Sample quality is a critical consideration in nucleic acid-based diagnostic assay performance.

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Educational efforts are important to ensure that specimen collection occurs in the correct disease timeframe.

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FTA paper stabilizes nucleic acids for veterinary diagnostic testing.

In order to improve the analytic quality of respiratory specimens collected from cattle for nucleic acid-based diagnosis, a study was undertaken to verify realtime PCR efficiency of specimens collected and stabilized on FTA Cards™, filter paper which is treated chemically. Nucleic acids collected using FTA Cards without the need for a cold-chain or special liquid media handling provided realtime PCR results consistent (96.8% agreement, kappa 0.923 [95% CI = 0.89–0.96]) with the same specimens collected using traditional viral transport media and shipped on ice using the U.S. Department of Transportation mandated liquid handling requirements. Nucleic acid stabilization on FTA Cards was evaluated over a temperature range (−27 °C to +46 °C) for up to 14 days to mimic environmental conditions for diagnostic sample handling between collection and processing in a routine veterinary laboratory. No significant difference (P ≥ 0.05) was observed in realtime PCR cycle threshold values over the temperature range and time storage conditions for Bovine Viral Diarrhea virus, Bovine Respiratory Syncytial virus, Bovine Coronavirus, and Bovine Herpesvirus I. The four viruses evaluated in the study are associated with Bovine Respiratory Disease Complex where improvements in ease and reliability of specimen collection and shipping would enhance the diagnostic quality of specimens collected in the field, and ultimately improve diagnostic efficiency.

Viral diagnostics: will new technology save the day?

Technology for infectious agent detection continues to evolve, particularly molecular methods that first emerged in the mid-1970s. The goals of new technology in diagnostics, whether in humans or in animals, including poultry, are to achieve the highest sensitivity and specificity possible to accurately identify the infection status of an individual or flock in the shortest time possible. Ease of use, low cost and increased information from a single test (e.g. multiplexing) are also critical areas frequently targeted for improvement. New tests and modifications of current tests are reported often, and diagnostic tests are now commonly developed by commercial companies. As one would expect, most advances in diagnostic technology are applied first to human health, and then may be adapted to animal health if practical. In the present review the trends and novel innovative technologies in primarily viral diagnostics are reviewed and the practicality of these methods and application for poultry health are discussed briefly. Also, influenza will seem to be over-represented in viral diagnostics since it is frequently used as a proof-of-concept target for novel technology due to its importance for animal and public health. Finally, the review is intended to be a brief survey of some of the innovative diagnostic technologies reported in recent years. It is not entirely comprehensive of all technology and the author makes no claims or endorsements of any of the technology or products mentioned.

The use of FTA® filter papers for diagnosis of avian influenza virus

Avian influenza viruses (AIVs) infect a wide range of host species including domestic poultry and wild birds; also, AIVs may infect humans in whom some highly pathogenic viruses (HPAIV) may cause acute fatal disease. Accurate laboratory diagnosis of AIV infections requires time-consuming and logistically complex precautionary measures for shipment of specimens or viruses to avoid biohazard exposure. The feasibility was investigated of the Flinders Technology Associates filter paper (FTA® card) for infectivity of AIVs and to preserve viral RNA for detection by RT-qPCR, sequencing and by DNA microarray assay. The infectivity of AIV subtype H6N2 and HPAIV subtype H5N1 was inactivated completely within one hour after adsorption to the FTA card at room temperature. FTA-adsorbed viral RNA remained stable for five months. Swab samples obtained from chickens infected experimentally with H5N1 virus and spotted directly onto the FTA® cards allowed a sensitive and straightforward diagnosis by RT-qPCR. FTA® cards were also suitable for examination of field samples, although AIV RNA was detected with reduced sensitivity in comparison to direct examination of swab fluids. The use of FTA® cards will facilitate safe transport of samples for molecular diagnosis of AIV avoiding the need for an uninterrupted cold storage.

Exploiting mosquito sugar feeding to detect mosquito-borne pathogens

Arthropod-borne viruses (arboviruses) represent a global public health problem, with dengue viruses causing millions of infections annually, while emerging arboviruses, such as West Nile, Japanese encephalitis, and chikungunya viruses have dramatically expanded their geographical ranges. Surveillance of arboviruses provides vital data regarding their prevalence and distribution that may be utilized for biosecurity measures and the implementation of disease control strategies. However, current surveillance methods that involve detection of virus in mosquito populations or sero-conversion in vertebrate hosts are laborious, expensive, and logistically problematic. We report a unique arbovirus surveillance system to detect arboviruses that exploits the process whereby mosquitoes expectorate virus in their saliva during sugar feeding. In this system, infected mosquitoes captured by CO(2)-baited updraft box traps are allowed to feed on honey-soaked nucleic acid preservation cards within the trap. The cards are then analyzed for expectorated virus using real-time reverse transcription-PCR. In field trials, this system detected the presence of Ross River and Barmah Forest viruses in multiple traps deployed at two locations in Australia. Viral RNA was preserved for at least seven days on the cards, allowing for long-term placement of traps and continuous collection of data documenting virus presence in mosquito populations. Furthermore no mosquito handling or processing was required and cards were conveniently shipped to the laboratory overnight. The simplicity and efficacy of this approach has the potential to transform current approaches to vector-borne disease surveillance by streamlining the monitoring of pathogens in vector populations.

Comparison of commercial viral genomic extraction kits for the molecular detection of foodborne viruses

When genetic material is extracted from viruses responsible for food illnesses, two broad types of possibilities are offered: conventional methods, which are well established but usually long and exacting to perform, or commercial kits, which are faster and easy to use but much more expensive. Thus, it is important to evaluate some performance parameters such as the analytical sensitivity to be able to select the optimal technique for each situation. The principal objective of this study was to establish and compare the analytical sensitivities of three commercial genetic material extraction methods (TRIzol reagent, FTA cards, and QIAGEN kits) along with three selected viruses, adenovirus, hepatitis A virus, and rotavirus. Viral detection was carried out using a standard PCR technique for adenovirus and reverse transcription PCR for rotavirus and hepatitis A virus. The results obtained showed that with the QIAGEN kit, the sensitivity was 2 logs lower than with the two other methods for all three viruses studied. Nevertheless, despite their lower analytical sensitivities, the other two extraction methods should not be overlooked and ought to be considered when evaluating the most efficient approach suitable for a specific commodity, since food-related outbreaks may be traced to a wide variety of food types.