A 48-year-old HIV-positive man with a CD4 count of 40 complains of progressive memory loss. Five months later, he became paralyzed and died. Autopsy revealed demyelination of many neurons, and electron microscopy shows clusters of naked viral particles. What is the most likely cause of the disease?
A truck driver was involved in a serious accident and received second and third degree burns over his body. He was placed in the burn unit, and on his twelfth hospital day, he suddenly developed a wound infection with a bluish green exudate. Treatment with chloramphenicol and tetracycline was unsuccessful. A gram-negative, motile organism was isolated that was oxidase positive. It did not ferment lactose, sucrose, or glucose but grew on MacConkey’s agar and produced a fruity aroma on that medium. Which of the following organisms was most likely isolated?
A 4-year-old boy presents to the pediatric emergency department with the classic meningitis triad of fever, headache, and nuchal rigidity. A lumbar puncture is performed, and analysis of fluid shows an increase in polymorphonuclear cells, an increased protein level, and a decreased glucose level. What is the most common cause of meningitis in a child of this age with this clinical picture?
A 50-year-old man develops non-bloody, watery diarrhea while working as an aid worker in a refugee camp in Cambodia. He arrived in the area 3 days ago. A stool smear shows no WBCs but revealed a gram-negative, curved bacilli, which is oxidase positive. He subsequently develops dehydration and electrolyte abnormalities, leading to cardiac and renal failure. Which of the following organisms is the most likely cause of this man’s enterocolitis?
A 56-year-old man, who is an alcoholic, was brought to your clinic due to expectoration of blood-tinged sputum. Microscopic study of the sputum revealed lancet-shaped, gram-positive organisms. Which of the following is the most likely causative agent?
A patient on chronic total parenteral nutrition (TPN) developed white patches around his chin, trunk, and diffusely around his extremities. Which of the following is/are incorrect regarding this organism?
A 63-year-old man had visited his favorite oyster restaurant near a shore. He ate two dozens of oysters. Two days later, he was admitted because of the abrupt onset of chills, fever, and lightheadedness. While in the ER, he developed erythematous skin lesions, which rapidly evolved into hemorrhagic bullae and eventually ulcers. The microorganism of major concern for this patient is:
An 8-year-old boy develops a severe sore throat. On examination, a grayish exudate (pseudomembrane) was seen over the tonsils and pharynx. What is the most likely cause of this boy’s pharyngitis?
Which parasites can be treated with mebendazole?
A 25-year-old male, who is fond of eating undercooked crabs and has poor hygiene, has a 3-week history of chronic cough with bloody sputum. What is the most likely diagnosis?