Date

12-2015 12:00 AM

Major

Animal Science

Department

Animal Science

College

College of Agriculture and Life Sciences

Project Advisor

Phil Gauger; Karen Harmon

Project Advisor's Department

Veterinary Diagnostic and Production Animal Medicine

Description

Streptococcus suis is an important pathogenic bacteria known to cause meningitis and fibrinous polyserositis in swine. Several bacterial real-time polymerase chain reaction assays (qPCRs) have been developed for use at the Iowa State University Veterinary Diagnostic Laboratory (ISU VDL); however, qPCR protocols for the detection of S. suis were lacking. qPCR is often considered an appealing alternative to culture-based or immunoassay-based diagnostic methods because of its ability to rapidly test a large volume of samples with a high degree of target specificity. One hundred seventy-four clinical samples were obtained from the ISU VDL and were tested by qPCR targeting the recombination/repair protein (recN) gene. Samples were collected both prospectively and retrospectively. Ninety-three BacT positive samples were analyzed across sample type (brain, lung, heart, joint fluid). A Pearson χ2 value of 4.024 and a P-value of 0.1337 suggests anatomical location does not affect testing outcome when α=0.05. The data were then aggregated based on case level and compared to the case diagnosis. Using this method, a qPCR positive result agreed with a diagnosis of S. suis 59.7±10.3% of the time, while the isolation of S. suis agreed with a diagnosis of infection in 75±8.2% of diagnostic cases.

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Dec 1st, 12:00 AM

Development of a Real-Time PCR Assay for the Detection and Diagnosis of Streptococcus suis in Clinical Samples

Streptococcus suis is an important pathogenic bacteria known to cause meningitis and fibrinous polyserositis in swine. Several bacterial real-time polymerase chain reaction assays (qPCRs) have been developed for use at the Iowa State University Veterinary Diagnostic Laboratory (ISU VDL); however, qPCR protocols for the detection of S. suis were lacking. qPCR is often considered an appealing alternative to culture-based or immunoassay-based diagnostic methods because of its ability to rapidly test a large volume of samples with a high degree of target specificity. One hundred seventy-four clinical samples were obtained from the ISU VDL and were tested by qPCR targeting the recombination/repair protein (recN) gene. Samples were collected both prospectively and retrospectively. Ninety-three BacT positive samples were analyzed across sample type (brain, lung, heart, joint fluid). A Pearson χ2 value of 4.024 and a P-value of 0.1337 suggests anatomical location does not affect testing outcome when α=0.05. The data were then aggregated based on case level and compared to the case diagnosis. Using this method, a qPCR positive result agreed with a diagnosis of S. suis 59.7±10.3% of the time, while the isolation of S. suis agreed with a diagnosis of infection in 75±8.2% of diagnostic cases.