Chapter 12: Aerobic Non–Spore-Forming Gram-Positive Bacilli: Corynebacterium, Listeria, Erysipelothrix, Nocardia, and Related Pathogens

Chapter 12. Aerobic Non–Spore-Forming Gram-Positive Bacilli: Corynebacterium, Listeria, Erysipelothrix, Nocardia, and Related Pathogens

Three months ago, a 53-year-old woman had surgery and chemotherapy for breast cancer. Four weeks ago, she developed a cough occasionally productive of purulent sputum. About 2 weeks ago, she noted a slight but progressive weakness of her left arm and leg. On chest examination, rales were heard over the left upper back when the patient breathed deeply. Neurologic examination confirmed weakness of the left arm and leg. Chest radiography showed a left upper lobe infiltrate. Contrast-enhanced computed tomography showed two lesions in the right hemisphere. Gram-stain of a purulent sputum specimen showed branching Gram-positive rods that were partially acid fast. Which of the following organisms is the cause of this patient’s current illness?

(A) Actinomyces israelii

(B) Corynebacterium ulcerans

(C) Aspergillus fumigatus

(D) Nocardia species

(E) Erysipelothrix rhusiopathiae

Three months ago, a 53-year-old woman had surgery and chemotherapy for breast cancer. Four weeks ago, she developed a cough occasionally productive of purulent sputum. About 2 weeks ago, she noted a slight but progressive weakness of her left arm and leg. On chest examination, rales were heard over the left upper back when the patient breathed deeply. Neurologic examination confirmed weakness of the left arm and leg. Chest radiography showed a left upper lobe infiltrate. Contrast-enhanced computed tomography showed two lesions in the right hemisphere. Gram-stain of a purulent sputum specimen showed branching Gram-positive rods that were partially acid fast.

The drug of choice to treat this patient’s infection is

(A) Penicillin G

(B) Trimethoprim–sulfamethoxazole

(C) Gentamicin

(D) Amphotericin B

(E) A third-generation cephalosporin

Movement of Listeria monocytogenes inside of host cells is caused by

(A) Inducing host cell actin polymerization

(B) The formation of pili (fimbriae) on the listeriae surface

(C) Pseudopod formation

(D) The motion of listeriae flagella

(E) Tumbling motility

An 8-year-old boy, who recently arrived in the United States, develops a severe sore throat. On examination, a grayish exudate (pseudomembrane) is seen over the tonsils and pharynx. The differential diagnosis of severe pharyngitis such as this includes group A streptococcal infection, Epstein-Barr virus (EBV) infection, Neisseria gonorrhoeae pharyngitis, ...