Article

Evaluation of FTA® cards as a laboratory and field sampling device for the detection of foot-and-mouth disease virus and serotyping by RT-PCR and real-time RT-PCR

FMDV Laboratory, Research and Development Center, Indian Immunologicals Limited, Rakshapuram, Gachibowli, Hyderabad 500032, India.
Journal of Virological Methods (Impact Factor: 1.78). 09/2008; 151(2):311-6. DOI: 10.1016/j.jviromet.2008.05.020
Source: PubMed

ABSTRACT

Foot-and-mouth disease virus (FMDV) samples transported to the laboratory from far and inaccessible areas for serodiagnosis pose a major problem in a tropical country like India, where there is maximum temperature fluctuation. 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. The present study evaluated the usefulness of FTA Classic Cards for the collection, shipment, storage and identification of the FMDV genome by RT-PCR and real-time RT-PCR. The stability of the viral RNA, the absence of infectivity and ease of processing the sample for molecular methods make the FTA cards a useful option for transport of FMDV genome for identification and serotyping. The method can be used routinely for FMDV research as it is economical and the cards can be transported easily in envelopes by regular document transport methods. Live virus cannot be isolated from samples collected in FTA cards, which is a limitation. This property can be viewed as an advantage as it limits the risk of transmission of live virus.

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Available from: Nagendrakumar Balasubramanian Singanalur, Apr 10, 2015
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    • "Flinders Technology Associates cards impregnated with clinical samples yielded no virus after two rounds of cell culture inoculation in BTY cells. The filter paper matrix of the FTA system is impregnated with chaotropic agent that inactivates the micro-organisms as confirmed by various earlier reports (Muthukrishnan et al., 2008; Linhares et al., 2012; Bankamp et al., 2013; Liang et al., 2014). Therefore, FMD virus spotted on the cards can be transported safely from the area of the outbreak to the laboratory. "
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    ABSTRACT: 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.
    Full-text · Article · Jan 2015 · Transboundary and Emerging Diseases
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    • "The utility of FTA ® cards (GE Healthcare, Buckinghamshire, UK) for collection, preservation and shipment of FMD infected samples to the laboratory was reported earlier (Muthukrishnan et al., 2008). Briefly, impression smears were made on the FTA ® cards directly from the tongue epithelial samples (O = 5, A = 5 and Asia 1 = 5) obtained from animals infected experimentally used for FMD vaccine potency studies and tongue epithelium of animals infected naturally in the field. "
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    ABSTRACT: A one-step, real-time reverse transcription-loop-mediated isothermal amplification assay (RT-LAMP) for rapid detection and serotyping of Indian foot-and-mouth disease virus (FMDV) is described. The RT-LAMP assay was found to be 10(3)-10(5) fold more sensitive in comparison with RT-PCR, with a detection limit ranging from 10(-3) to 10(-5) TCID(50) of virus samples of all three serotypes. The RT-LAMP assay and qRT-PCR could detect 100 percent of clinical samples of three serotypes, whereas the RT-PCR detected 69.7% of type O, 58.1% of type A and 60.0% of Asia 1 samples. The qRT-PCR has the same sensitivity as the RT-LAMP. The assay conditions with absence of cross reactivity within the three serotypes of FMDV and FMDV negative samples were established. The RT-LAMP assay could detect 100% of samples stored in FTA(®) cards. In comparison with the performance of the RT-PCR; the RT-LAMP appears to be more sensitive, rapid and specific, with the potential for use as a point-of-care (POC) test, especially in developing countries. The use of FTA(®) cards for the preservation of RNA samples coupled with the RT-LAMP assay for the identification of serotypes may help in achieving improved FMDV serotype identification both in the field and in the laboratory.
    Full-text · Article · Aug 2012 · Journal of virological methods
    • "FTA ® cards could be routinely used for transport of viral genetic material in envelopes by regular document transport facilities (Muthukrishnan et al., 2008). The user, however, needs to be aware that replication-competent virus cannot be recovered and further viral characterization with respect to biological properties is not possible (Muthukrishnan et al., 2008). Additional studies with different AIV subtypes should be considered to detect potential subtype-or strain-specific variations in resistance to inactivation of infectivity and/or RNA preservation on FTA ® cards. "
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    ABSTRACT: 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.
    No preview · Article · Mar 2011 · Journal of virological methods
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