The Quizzes about Bacteriology – Part 4

A 70-year-old male is taken to the emergency room with a history of “cold-like” symptoms for at least 3 days. At the time of the visit, his temperature is 102°F and he experienced shaking, chills, chest pain, and a productive cough with bloody sputum. Blood agar culture reveals grampositive α-hemolytic colonies. If a quellung test was done on the colonies, which of the following bacteria would most likely be positive?

A 6-month-old infant is admitted to the hospital with acute meningitis. The Gram stain reveals gram-positive, short rods, and the mother indicates that the child has received “all” of the meningitis vaccinations. Which of the following is the most likely cause of the disease?

A 40-year-old man presents to the emergency medicine department 1 week following a foot injury. He is experiencing intense pain in the area of injury and the muscles of the jaw. Which of the following is the most common portal of entry for the etiologic organism?

A 22-year-old homeless person with a known drug abuse problem and multiple opportunistic infections has a positive PPD (purified protein) test. Which of the following is the most common way this infection is acquired?

A 31-year-old school teacher returns from foreign travel and experiences a sudden (1-2 days) onset of abdominal pain, fever, and watery diarrhea, caused by a heat-labile exotoxin that affects both the gut and the CNS. This infection is caused by an etiologic agent commonly acquired through which of the following routes?

A college student is surprised one morning by painful urination and a cream-colored exudate. Any person who acquires the gram-negative microbe that causes this infection is most likely to have acquired it via which of the following?

A 25-year-old college student with no history of allergic rhinitis has a 12-day history of facial pain, clear rhinorrhea, fever, headache, and back pain. Her symptoms do not respond to over-the-counter medication. Culture of the fluid from the sinus reveals Moraxella (Branhamella) catarrhalis.

Which of the following best characterizes M. catarrhalis?

A 16-year-old Hispanic female with poor oral hygiene and severe gingivitis presents with a temperature of 103.5°F and hypotension. Blood culture is positive for Capnocytophaga. Which of the following best characterizes Capnocytophaga?

Several employees in a veterinary facility experience a mild influenza-like infection after working on six sheep with an undiagnosed illness. The etiologic agent causing the human disease is most often transmitted to humans by which of the following methods?

An endocarditis patient under a physician’s care develops a urinary tract infection (UTI). A group D enterococcus (Enterococcus faecium) is isolated but the UTI does not respond to ampicillin and gentamicin treatments. Which of the following options would be considered the most clinically appropriate action?

A patient with symptoms of a UTI has a culture taken, which grows 5 × 103 E. coli. The laboratory reports it as “insignificant.” Which of the following is the most appropriate next step in management?

A patient appears in the emergency room with a submandibular mass. A smear is made of the drainage and a bewildering variety of bacteria are seen, including branched, gram-positive rods. Which of the following is the most clinically appropriate action?

A 55-year-old male develops malaise, fever up to 103.5°F, nonproductive cough, headache, and shortness of breath a few days after he repaired the cooling system of an old hotel. A chest x-ray reveals fluid in his lungs. From a sputum sample, a gram-negative rod grew slowly on a buffered cysteine containing charcoal-yeast agar. Which of the following antibiotic therapies is most appropriate for treating this patient?

A 60-year-old male resident from a nursing home presents to the emergency room with a fever of 105.8°F (41°C), shaking chills, severe pain to the right side of his chest that worsens with breathing, and a productive cough with blood-tinged sputum. During the previous 3 days, he noted cold-like symptoms. Gram stain evaluation of the sputum reveals gram-positive diplococci that grow into α-hemolytic colonies on blood agar. Which of the following antibiotic therapies is the most appropriate treatment for this patient?

A 12-year-old boy, after a camping trip near a wooded area in Northern California, is taken to the emergency room after complaining of a headache. He has an erythema migrans rash around what appears to be a tick bite. Which of the following is the antibiotic of choice for treating this patient?

A 6-year-old girl presents to her pediatrician with fever, headache, and a sore throat. She has swollen, tender cervical lymph nodes, and her oropharynx is red with a gray-white exudate covering both her tonsils. A rapid strep test of her throat swab is positive, and the culture subsequently grows β-hemolytic Streptococcus. Which of the following antibiotic therapies is most appropriate for treating this patient?

A young woman being treated with a broad-spectrum antimicrobial develops endoscopically observed microabscesses and diarrhea. Which of the following is the therapy of choice for this form of enterocolitis?

Although cholera, a Vibrio infection, has rarely been seen in the United States, there have been recent outbreaks of classic cholera associated with shellfish harvested from the Gulf of Mexico. Vibrios are shaped like curved rods, and infections more common than cholera may be caused by a variety of curved-rod bacteria. Which of the following best describes C. jejuni?

Vibrio cholerae is worldwide in distribution and continues to expand as water sources become polluted. Which of the following best describes this organism?

A 20-year-old female in post-Katrina New Orleans eats poorly cooked seafood (oysters, clams, and mollusks) for her birthday dinner. Twentyfour hours later, she develops explosive watery diarrhea and abdominal cramps. She is positive for V. parahaemolyticus. Which of the following best describes this organism?