Question 56

Which of the following organisms is an obligate intracellular bacterium transmitted by arthropod vectors and is a common cause of Rocky Mountain Spotted Fever?
  • Question 57

    During a community outbreak of influenza, a public health laboratory performs rapid antigen testing on nasopharyngeal swabs. A test for influenza A is positive, but the influenza B test is negative. Subsequently, RT-PCR is performed on the same sample, and it is negative for both influenza A and B viral RNA. The MOST likely explanation for this discordant result is:
  • Question 58

    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:
  • Question 59

    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?
  • Question 60

    A research team is investigating the mechanisms of antifungal resistance in Candida albicans. They identify a strain that exhibits resistance to azole antifungal agents. Further analysis reveals overexpression of a specific ATP-binding cassette (ABC) transporter protein in the resistant strain. This mechanism of resistance involves: