Transmissible spongiform encephalopathies (TSEs), such as Creutzfeldt-Jakob disease (CJD) in humans and Bovine Spongiform Encephalopathy (BSE) in cattle, are caused by infectious agents composed primarily of:
A researcher is studying the genetic relatedness of different isolates of Mycobacterium tuberculosis. Which of the following molecular typing methods provides the highest discriminatory power for distinguishing between closely related strains?
A research laboratory is investigating the mechanism of action of a novel antiviral compound. In vitro studies demonstrate that the compound effectively inhibits the replication of a specific enveloped RNA virus. Further analysis reveals that the compound does not interfere with viral entry, genome replication, or protein synthesis. However, electron microscopy of infected cells treated with the compound shows an accumulation of viral glycoproteins within the endoplasmic reticulum and Golgi apparatus, with a significant reduction in the release of infectious virions. The MOST likely target of this antiviral compound is:
A 30-year-old female who recently returned from a hiking trip in the northeastern United States presents to her physician with a two-week history of a slowly expanding, erythematous rash with central clearing on her thigh. She also reports intermittent fatigue, arthralgias, and mild headache. Serological testing reveals a positive IgM and IgG response to Borrelia burgdorferi. Which of the following mechanisms is MOST significant in the pathogenesis of the clinical manifestations observed in this patient?
A research team is investigating the development of a novel vaccine against influenza virus. They are focusing on conserved epitopes within the hemagglutinin (HA) and neuraminidase (NA) proteins to elicit broadly neutralizing antibodies. Which of the following approaches is MOST likely to achieve this goal?
A clinical isolate of Klebsiella pneumoniae from a patient with a refractory urinary tract infection exhibits resistance to carbapenems (imipenem, meropenem, ertapenem). PCR analysis reveals the presence of the blaKPC gene. Which of the following enzymatic mechanisms is responsible for this resistance?
A patient with a history of travel to a rural area develops a febrile illness with jaundice and dark urine. Peripheral blood smear reveals intraerythrocytic parasites with a characteristic Maltese cross morphology. The MOST likely causative agent is:
Which of the following bacterial genera inherently possesses D-alanyl-D-lactate peptide subunits in its peptidoglycan precursors, conferring natural, high-level resistance to vancomycin?
Which of the following viruses is an enveloped, double-stranded DNA virus known to cause latent infections often reactivated during immunosuppression?
