Bacteriology — MCQs

Which type of E. coli is characterized by the presence of LT (heat-labile) and ST (heat-stable) proteins?

Which of the following is true about the cholera vibrio?

Which is the most common causative agent of gas gangrene?

All statements are true except,

Which statement is true about the El Tor biotype of Vibrio cholerae?

Which serotype of Streptococcus pneumoniae most often produces mucoid colonies?

A patient with second and third-degree burns developed a wound infection on the twelfth day of admission, characterized by a bluish-green exudate. Treatment with chloramphenicol and tetracycline was unsuccessful. A gram-negative, motile organism was isolated that was oxidase-positive, 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?

An outbreak of gastroenteritis occurred in a youth group camp. Water at the camp, which was not chlorinated or filtered, was obtained from a spring on the premises. The farmland near the camp was grazed by cattle and sheep, and run-off from the pasture entered the camp spring. The isolated microorganism required an atmosphere containing reduced oxygen and increased carbon dioxide for its growth. In most cases, the gastroenteritis was self-limiting, and those requiring antibiotic treatment responded to erythromycin. Which is the most likely causative agent?

Which of the following organisms is unlikely to be found in the sputum of a patient with cystic fibrosis?

Which of the following conditions is NOT commonly associated with group A beta-hemolytic streptococci infection?