SM Virology & Molecular Diagnostics Flashcards

Which molecular method is used to detect and quantify HIV viral load in clinical practice?

Answer: Real-time quantitative RT-PCR (qRT-PCR)

Real-time qRT-PCR quantifies HIV RNA copies/mL in plasma, guiding treatment decisions and monitoring antiretroviral therapy effectiveness.

Herpes simplex virus (HSV) DNA PCR of cerebrospinal fluid is considered the gold standard for diagnosing:

Answer: HSV encephalitis

CSF HSV PCR has >95% sensitivity and specificity for HSV encephalitis, replacing brain biopsy as the standard diagnostic approach.

Which enzyme is the target of nucleoside reverse transcriptase inhibitors (NRTIs) used in HIV therapy?

Answer: Reverse transcriptase

NRTIs are nucleoside analogs that competitively inhibit HIV reverse transcriptase, terminating DNA chain elongation during reverse transcription of viral RNA.

Cytomegalovirus (CMV) disease in immunocompromised transplant patients is monitored using which laboratory approach?

Answer: CMV pp65 antigenemia or quantitative PCR from blood

CMV pp65 antigenemia assay and quantitative PCR are the standard methods for monitoring CMV viremia in transplant patients to guide preemptive antiviral therapy.

Which feature distinguishes a virus's tropism for specific cell types?

Answer: Interaction between viral surface proteins and specific host cell receptors

Viral tropism is determined by the compatibility between viral attachment proteins (e.g., glycoproteins, spikes) and specific host cell surface receptors required for entry.

In next-generation sequencing (NGS) for clinical microbiology, which application is most established for direct patient care?

Answer: Whole-genome sequencing for outbreak investigation and AMR gene detection

Whole-genome sequencing (WGS) is most established clinically for outbreak epidemiology and comprehensive identification of antimicrobial resistance genes in bacterial isolates.