Microbiology Test 3

The Gram stain from a blood culture shows gram-positive cocci in chains. The subcultured plates from the blood culture bottle show no growth. Additional testing should be done to detect the presence of:

Gram stain examination from a blood culture bottle shows dark blue, spherical organisms in clusters. Growth on sheep blood agar shows small, round, pale yellow colonies. Further tests should include:

Gram-positive cocci in chains are seen on a Gram stain from a blood culture. The organism grows as a beta-hemolytic colony. Further tests that could be performed include:

“Nutritionally variant” streptococci are:

The most frequent cause of prosthetic heart valve infections occurring within 2-3 months after surgery is:

Gram-positive cocci isolated from a blood culture have the characteristics shown in this table:

This organism is most likely:

During the previous month, Staphylococcus epidermidis has been isolated from blood cultures at 2-3 times the rate from the previous year. The most logical explanation for the increase in these isolates is that:

A 55-year-old man presents to the emergency room with chest pain and is found to have suffered a heart attack. He has a past history of hypertension, and high cholesterol. The patient is admitted and scheduled for a triple bypass procedure. During recovery,he becomes septic, developing a high grade fever and pneumonia. Gram-positive cocci in clusters, isolated from both his lungs via an induced sputum specimen and the surgical incision, produce beta-hemolytic, catalase-positive colonies on sheep blood agar.

Identify the organism most likely isolated and the biochemical test performed to confirm the identification.

A patient with a prosthetic heart valve visits the dentist for her yearly checkup. She presents to her primary care physician 2 weeks later with a high fever, chills, and shortness of breath and receives a diagnosis of subacute endocarditis. Multiple blood culture sets are drawn on the patient and sent to the lab. The bottles are positive for bacterial growth 24 hours later. Which organism would be expected to grow?

A blood culture from a 64-year-old male with lymphoma is positive blood culture at 18 hours incubation. The organisms are nonlactose fermenting gram-negative bacilli on MacConkey agar. Further testing gives the reactions shown in this table:

The genus is:

A blood culture bottle with macroscopic signs of growth is Gram stained and the technician notes small, curved gram-negative bacilli resembling “gull wings.” It is subcultured to blood and chocolate agar, and incubated aerobically and anaerobically. After 24 hours, no growth is apparent. The next step should be to:

Which of these specimen types is considered to be the most sensitive for the recovery of  Brucella in cases of chronic infection?

A college student attends a beach party where raw oysters and other shellfish are consumed. The next day, he has symptoms of septicemia. The blood cultures grow gram-negative bacilli with the characteristics shown in the table:

The most likely organism is:

The laboratory receives a blood culture from a veterinarian who has been ill for many weeks with fevers in the afternoon and evenings, arthritis, and fatigue. The blood culture is positive after 5 days, and the organism has the characteristics shown in this table:

What should the microbiologist do next?

Cutibacterium (formerly Propionibacterium) acnes is most often associated with:

Which one of the following anaerobes is inhibited by sodium polyanethol sulfonate (SPS)?

A patient has a suspected diagnosis of subacute bacterial endocarditis. His blood cultures grow non-spore-forming pleomorphic gram-positive bacilli only in the anaerobic bottle. What test(s) will give a presumptive identification of this microorganism?

Microorganisms resembling Mycoplasma pneumoniae have been isolated from the blood of patients treated with antibiotics that:

Cerebrospinal fluid test results that are most consistent with viral meningitis include:

The organism most commonly associated with neonatal purulent meningitis is: