Publications by authors named "Johnny Callahan"

Foot-and-mouth disease virus (FMDV) is a highly contagious agent that impacts livestock industries worldwide, leading to significant financial loss. Its impact can be avoided or minimized if the virus is detected early. FMDV detection relies on vesicular fluid, epithelial tags, swabs, serum, and other sample types from live animals.

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Porcine reproductive and respiratory syndrome virus (PRRSV) is a highly contagious respiratory virus causing severe morbidity in pigs worldwide. Control strategies for PRRSV often rely on detecting PRRSV, culling or isolating sick pigs, disinfecting pig barns, vaccination, and monitoring for virus spread. Given the high economic impact of PRRSV on pig farms, there is a great need for rapid and reliable PRRSV detection assays.

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We have systematically evaluated a dry-format, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) assay developed by Tetracore Inc. for the Cepheid SmartCycler platform to facilitate rapid diagnosis of dengue virus infections. A panel of related flaviviruses was used to evaluate the clinical specificity of the assay, and it was found to be specific to dengue.

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Rapid and accurate diagnosis is central to the effective control of foot-and-mouth disease (FMD). It is now recognized that reverse-transcription polymerase chain reaction (RT-PCR) assays can play an important role in the routine detection of FMD virus (FMDV) in clinical samples. The aim of this study was to compare the ability of 2 independent real-time RT-PCR (rRT-PCR) assays targeting the 5' untranslated region (5'UTR) and RNA polymerase (3D) to detect FMDV in clinical samples.

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Objective: To evaluate a portable real-time reverse transcriptase-polymerase chain reaction (RT-PCR) assay designed to detect all 7 viral serotypes of foot-and-mouth disease virus (FMDV).

Design: Laboratory and animal studies.

Study Population: Viruses grown in tissue culture and animals experimentally infected with FMDV.

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