Ch 29 molecular diagnostics Flashcards
What is targeted for Equine influenza virus isolation by PCR?
hemagglutinin
nucleoprotein
matrix gene
**are commonly targeted genes
What is the sample of choice for testing for EHV-1 and EHV-4?
nasal or nasopharyngeal swab virus isolation/PCR
Streptococcus equi subsp equi culture may be unsuccessful for what reasons?
–during incubation & early clinical phases of infection
-presence of other Beta-hemolytic streptococci especially S. equi subsp zooepidemicus
What is one of the pitfalls in using PCR as a diagnosis?
inability to distinguish between live and nonviable organisms
PCR for Strep equi subsp equi should be considered in what scenerios?
-detect asymptomatic carriers
-establish the S. equi infection status of asymptomatic horses
-determine the success of elimination of S. equi from the guttural pouch
What is considered the gold standard diagnosis of Rhodococcus equi?
culture of the organism from TTW fluid
PCR for what gene of R equi in a TW fluid sample from a foal with pneumonia can be considered diagnostic?
Vap A gene
PCR for testing of neural tissue is useful when?
for post mortem testing
WNV encephalitis diagnostics
-one or more of the following– isolation of WNV from blood, CSF or tissue
-four fold increase in plaque reduction neutralization antibody titers on paired serum samples taken two weeks apart
-detection of IgM antibody to WNV by IgM capture ELISA
Which serotype of EHV-1 is associated with neurologic outbreaks?
D752 genotype