Evaluation of a Paratuberculosis Quantitative Polymerase Chain Reaction Assay with Microscopic Correlation

dc.contributor.authorTyler, Ronald Dale Jr.en
dc.contributor.committeechairSriranganathan, Nammalwaren
dc.contributor.committeecochairLeRoith, Tanyaen
dc.contributor.committeememberSponenberg, D. Phillipen
dc.contributor.committeememberPrater, Mary R.en
dc.contributor.committeememberPickrell, Gary R.en
dc.contributor.departmentVeterinary Medical Sciencesen
dc.date.accessioned2014-03-14T21:32:08Zen
dc.date.adate2012-05-29en
dc.date.available2014-03-14T21:32:08Zen
dc.date.issued2012-05-01en
dc.date.rdate2012-05-29en
dc.date.sdate2012-03-20en
dc.description.abstractParatuberculosis is an intestinal condition in ruminants infected with Mycobacterium avium subspecies paratuberculosis (MAP) and precedes Johne's disease, a chronic enteric disorder in ruminants caused by MAP infection. Necropsy with histopathology provides definitive diagnosis of Johne's disease and positive culture of MAP from tissues provides definitive diagnosis of paratuberculosis. To determine assay sensitivity, 85 formalin-fixed paraffin-embedded (FFPE) tissues from ruminants diagnosed with Johne's disease were tested with a commercial paratuberculosis quantitative polymerase chain reaction (qPCR) assay and had a sensitivity of 92%. To determine assay specificity, 21 FFPE tissues from animals without gastrointestinal disease combined with 13 FFPE tissues from non-ruminant animals (frog, dove, turtle, dog, and 2 cats) with non-paratuberculosis mycobacterial diseases were tested with the commercial qPCR assay and had a specificity of 100%. Slides prepared from the FFPE tissue blocks were stained with hematoxylin & eosin (H&E) and Ziehl-Neelsen's (acid fast stain), then examined for granulomatous inflammation and scored on a scale from 0-4 based on the quantity of acid fast bacteria (AFB). Digital microscopy and morphometric software were used to compute an acid fast bacteria area index (AFBAI) to evaluate a more precise correlation with the qPCR results. The quantity of AFB in tissue slides showed medium to strong correlation with the appropriate qPCR results. The results indicate that the commercial qPCR assay can be used on FFPE tissues with good results and the qPCR results have medium-strong correlation with quantitative acid fast histopathology.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-03202012-143927en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-03202012-143927/en
dc.identifier.urihttp://hdl.handle.net/10919/41736en
dc.publisherVirginia Techen
dc.relation.haspartTyler_RD_T_2012.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectJohne's diseaseen
dc.subjectparatuberculosisen
dc.subjecthistopathologyen
dc.subjectqPCRen
dc.titleEvaluation of a Paratuberculosis Quantitative Polymerase Chain Reaction Assay with Microscopic Correlationen
dc.typeThesisen
thesis.degree.disciplineVeterinary Medical Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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