Klebsiella species — MCQs

An 18-year-old male in his first year of college presents to the emergency room with a fever and a severe headache. He reports having unprotected sex with several partners over the past few weeks. Upon examination, the male demonstrates nuchal rigidity and photophobia. His past medical history is notable for a lack of vaccinations beginning from infancy due to his parents' belief that vaccinations may cause autism. The bacteria causing these symptoms would most likely demonstrate which of the following?

A previously healthy 17-year-old boy is brought to the emergency department because of fever, nausea, and myalgia for the past day. His temperature is 39.5°C (103.1°F), pulse is 112/min, and blood pressure is 77/55 mm Hg. Physical examination shows scattered petechiae over the anterior chest and abdomen. Blood culture grows an organism on Thayer-Martin agar. Which of the following virulence factors of the causal organism is most likely responsible for the high mortality rate associated with it?

A 25-day-old male infant presents to the emergency department because his mother states that he has been acting irritable for the past 2 days and has now developed a fever. On exam, the infant appears uncomfortable and has a temperature of 39.1 C. IV access is immediately obtained and a complete blood count and blood cultures are drawn. Lumbar puncture demonstrates an elevated opening pressure, elevated polymorphonuclear neutrophil, elevated protein, and decreased glucose. Ampicillin and cefotaxime are immediately initiated and CSF culture eventually demonstrates infection with a Gram-negative rod. Which of the following properties of this organism was necessary for the infection of this infant?

A 3-day-old boy is brought to the physician by his mother because of irritability and feeding intolerance for 1 day. His temperature is 39.2°C (102.6°F). Physical examination shows a bulging anterior fontanelle. A photomicrograph of a Gram stain of the cerebrospinal fluid is shown. Further evaluation shows that the organism expresses the K1 capsular polysaccharide. Which of the following is the most likely causal pathogen?

A previously healthy 46-year-old woman comes to the physician with a one-week history of productive cough and fatigue. Two weeks ago, she had fever, nasal congestion, rhinorrhea, and myalgias that resolved with supportive care. She has not traveled out of the United States. Pulmonary examination shows dullness to percussion and increased fremitus at the right middle lobe. An x-ray of the chest is shown. A sputum sample is most likely to show which of the following findings?

A 39-year-old man presents with a 4-week history of painless, non-discharging lesions on his penis and scrotum. He was diagnosed with chronic myeloid leukemia two years ago and treated with imatinib. He currently takes no medications. He has a 20-pack-year smoking history and drinks 1-2 beers on weekends. He reports unprotected intercourse with a woman while traveling abroad 4 months ago. His temperature is 37°C, pulse is 85/min, and blood pressure is 128/82 mm Hg. Examination reveals three non-tender lesions, each approximately 1 cm in size, on his genitalia. There is no inguinal lymphadenopathy. Which of the following is the most likely causative organism?

A 34-year-old woman presents with confusion, drowsiness, and headache. The patient’s husband says her symptoms began 2 days ago and have progressively worsened with an acute deterioration of her mental status 2 hours ago. The patient describes the headaches as severe, localized to the frontal and periorbital regions, and worse in the morning. Review of symptoms is significant for a mild, low-grade fever, fatigue, and nausea for the past week. Past medical history is significant for HIV infection for which she is not currently receiving therapy. Her CD4+ T cell count last month was 250/mm3. The blood pressure is 140/85 mm Hg, the pulse rate is 90/min, and the temperature is 37.7°C (100.0°F). On physical examination, the patient is conscious but drowsy. Papilledema is present. No pain is elicited with extension of the leg at the knee joint. The remainder of the physical examination is negative. Laboratory findings, including panculture, are ordered. A noncontrast CT scan of the head is negative and is followed by a lumbar puncture. CSF analysis is significant for: Opening pressure 250 mm H2O (70-180 mm H2O) Glucose 30 mg/dL (40-70 mg/dL) Protein 100 mg/dL (<40 mg/dL) Cell count 20/mm3 (0-5/mm3) Which of the following additional findings would most likely be found in this patient?

While testing various strains of Streptococcus pneumoniae, a researcher discovers that a certain strain of this bacteria is unable to cause disease in mice when deposited in their lungs. What physiological test would most likely deviate from normal in this strain of bacteria as opposed to a typical strain?

A 24-year-old man presents with a painless genital ulcer for the past 2 weeks. He reports that he recently has been having unprotected sex with multiple partners. Past medical history is unremarkable. On physical examination, a single ulcer is present on the dorsal shaft of the penis which is circumscribed, indurated, and partially healed. There is moderate inguinal lymphadenopathy but no buboes. Which of the following tests would confirm the most likely diagnosis in this patient?

A 32-year-old man comes to the physician because of low-grade fever and progressive painful lumps in his right groin for 6 days. The lumps have been discharging purulent fluid since the evening of the previous day. He had a shallow, painless lesion on his penis 3 weeks ago, but was too embarrassed to seek medical attention; it has resolved in the meantime. There is no personal or family history of serious illness. He has smoked one pack of cigarettes daily for 12 years. He is sexually active with multiple male partners and uses condoms inconsistently. His temperature is 38.0°C (100.4°F). Examination of his groin shows multiple masses discharging pus. The remainder of the examination shows no abnormalities. Which of the following is the most likely causal organism?