Antibiotics — MCQs

A 37-year-old man previously treated with monotherapy for latent tuberculosis develops new-onset cough, night sweats and fever. He produces a sputum sample that is positive for acid-fast bacilli. Resistance testing of his isolated bacteria finds a mutation in the DNA-dependent RNA polymerase. To which of the following antibiotics might this patient's infection be resistant?

A 42-year-old homeless man presents to the emergency department complaining of pain in his right knee and fever. The patient is having difficulty walking and looks visibly uncomfortable. On examination, he is disheveled but his behavior is not erratic. The patient’s right knee is erythematous, edematous, and warm, with evidence of a 3 cm wound that is weeping purulent fluid. The patient has a decreased range of motion secondary to pain and swelling. The wound is cultured and empiric antibiotic therapy is initiated. Four minutes into the patient’s antibiotic therapy, he develops a red, pruritic rash on his face and neck. What is the most likely antibiotic this patient is being treated with?

A 26-year-old African American woman presents to the clinic with burning upon urination. The patient describes increased frequency, urgency, and a painful sensation at the urethra when urinating for the past 3 days. She also reports increased vaginal discharge and abnormal odor during the same time. The patient denies fever, flank pain, or hematuria (though the patient does report a dark brown color of the urine). Her past medical history is significant for Crohn disease that is controlled with sulfasalazine. Vital signs are within normal limits. What is the definitive treatment of the described condition?

A 46-year-old man presents to his primary care provider for an ulcerating skin lesion on his leg for the past week. He says that the week prior he slipped while hiking and scraped his left leg. Over the course of the next week, he noticed redness and swelling of the scraped area and the development of a nodule that eventually ulcerated. On exam, his temperature is 99.5°F (37.5°C), blood pressure is 136/92 mmHg, pulse is 88/min, and respirations are 12/min. Over his left lateral leg is an erythematous patch with a 2-cm nodule with central ulceration. Staining of a sample from the nodule demonstrates gram-positive organisms that are also weakly acid-fast. Morphologically, the organism appears as branching filaments. Which of the following should be used to treat this infection?

A 67-year-old man presents to the emergency department for altered mental status. The patient is a member of a retirement community and was found to have a depressed mental status when compared to his baseline. The patient has a past medical history of Alzheimer dementia and diabetes mellitus that is currently well-controlled. His temperature is 103°F (39.4°C), blood pressure is 157/108 mmHg, pulse is 110/min, respirations are 17/min, and oxygen saturation is 98% on room air. Physical exam is notable for a somnolent elderly man who is non-verbal; however, his baseline status is unknown. Musculoskeletal exam of the patient’s lower extremities causes him to recoil in pain. Head and neck exam reveals a decreased range of motion of the patient's neck. Flexion of the neck causes discomfort in the patient. No lymphadenopathy is detected. Basic labs are ordered and a urine sample is collected. Which of the following is the best next step in management?

A 31-year-old female with a bacterial infection is prescribed a drug that binds the dipeptide D-Ala-D-Ala. Which of the following drugs was this patient prescribed?

A 42-year-old man with hypertension and type 2 diabetes mellitus is admitted to the hospital because of swelling and redness of the left leg for 3 days. He has chills and malaise. He is treated with intravenous clindamycin for 7 days. On the 8th day at the hospital, he has profuse, foul-smelling, and watery diarrhea. He has nausea and intermittent abdominal cramping. His temperature is 38°C (100.4°F), pulse is 97/min, and blood pressure is 110/78 mm Hg. Bowel sounds are hyperactive. Abdominal examination shows mild tenderness in the left lower quadrant. Rectal examination shows no abnormalities. His hemoglobin concentration is 14.3 g/dL, leukocyte count is 12,300/mm3, and C-reactive protein concentration is 62 mg/L (N=0.08–3.1). After discontinuing clindamycin, which of the following is the most appropriate pharmacotherapy for this patient's condition?

An 89-year-old woman presents to clinic complaining of a cough. She reports that she has never had a cough like this before. She takes a deep breath and then coughs multiple times, sometimes so much that she vomits. When she tries to catch her breath after a coughing spell, she has difficulty. She reports the cough has persisted for 3 weeks and usually comes in fits. Vital signs are stable. Physical examination is benign. You send cultures and a PCR of her secretions, both of which come back positive for the organism you had suspected. You tell her to stay away from her grandchildren because her illness may be fatal in infants. You also start her on medication. The illness affecting this patient would be best treated by a class of antibiotics...

A 29-year-old woman comes to the physician because of a 4-day history of fever with chills, nausea, myalgias, and malaise. One week ago, she returned from a trip to Rhode Island, where she participated in a month-long program to become an assistant park ranger. Laboratory studies show a leukocyte count of 1,400/mm3. A peripheral blood smear shows dark purple, mulberry-like inclusions inside the granulocytes. A presumptive diagnosis is made and pharmacotherapy is initiated with the drug of choice for this condition. The bacteriostatic effect of this drug is most likely due to inhibition of which of the following processes?

A 13-year-old boy is brought to the emergency department because of a 2-day history of fever, headache, and irritability. He shares a room with his 7-year-old brother, who does not have any symptoms. The patient appears weak and lethargic. His temperature is 39.1°C (102.4°F) and blood pressure is 99/60 mm Hg. Physical examination shows several purple spots over the trunk and extremities. A lumbar puncture is performed. Gram stain of the cerebrospinal fluid shows numerous gram-negative diplococci. Administration of which of the following is most likely to prevent infection of the patient's brother at this time?