Enter your email to get your 85% OFF code and unlock the full USMLE question bank on the app.
Free notes, MCQs, tables & flowcharts for USMLE Step 3 Microbiology
A 51-year-old man comes to the physician because of a 4-day history of fever and cough productive of foul-smelling, dark red, gelatinous sputum. He has smoked 1 pack of cigarettes daily for 30 years and drinks two 12-oz bottles of beer daily. An x-ray of the chest shows a cavity with air-fluid levels in the right lower lobe. Sputum culture grows gram-negative rods. Which of the following virulence factors is most likely involved in the pathogenesis of this patient's condition?
AIgA protease
BExotoxin A
CCapsular polysaccharide
DP-fimbriae
EHeat-stable toxin
A 60-year-old man presents with fever and cough productive of rust-colored sputum and is diagnosed with community acquired pneumonia. The causative organism is isolated, and a Gram stain is shown in Figure 1. Which of the following most correctly describes additional features of the most likely causative organism?
ACatalase negative, alpha hemolytic, optochin sensitive
BCatalase positive, alpha hemolytic, optochin sensitive
CCatalase negative, alpha hemolytic, optochin resistant
DCatalase positive, beta hemolytic, optochin sensitive
ECatalase negative, beta hemolytic, optochin sensitive
A 2-year-old boy is brought in by his parents to his pediatrician. The boy was born by spontaneous vaginal delivery at 39 weeks and 5 days after a normal pregnancy. The boy has received all age-appropriate vaccinations as of his last visit at 18 months of age. Of note, the boy has confirmed sickle cell disease and the only medication he takes is penicillin prophylaxis. The parents state that they plan on enrolling their son in a daycare, which requires documentation of up-to-date vaccinations. The pediatrician states that their son needs an additional vaccination at this visit, which is a polysaccharide vaccine that is not conjugated to protein. Which of the following matches this description?
APneumovax
BMenactra
CPrevnar
DHib vaccine
ELive attenuated influenza vaccine
+ 7 more in the PDF
Browse all chapters