A 72-year-old man on chemotherapy presents with fever (39.2°C), confusion, and neck stiffness two weeks after consuming unpasteurized cheese. Vital signs show HR 108, BP 136/82, RR 20, SpO2 98% on room air. Blood culture grows small gram-positive rods with characteristic tumbling motility. CSF analysis reveals elevated protein (180 mg/dL) and lymphocytic pleocytosis. No rash is noted. Which virulence mechanism enables this organism's direct cell-to-cell movement without extracellular phase?
- A)Formation of an antiphagocytic capsule made of hyaluronic acid
- B)Production of urease to increase local pH
- C)Polymerization of host actinGABARITO
- D)Release of a toxin that cleaves SNARE proteins
- E)Blockade of phagolysosome fusion by sulfatides
Explicação
Listeria monocytogenes uses actin polymerization to generate intracellular motility and spread directly from cell to cell. This strategy helps it evade humoral immune defenses and is one reason it is an important pathogen in neonates, pregnant patients, and im... Ver explicação completa e trilha adaptativa →