Question

A 10 year old child presents to his primary care physician with a complaint of severe ear pain.

The child had been swimming in the lake several days earlier. The culture from the ear grew
a gram negative rod with a grapelike odor. The colonies were flat and spreading with rough
edge and a metallic sheen. It was indole negative and oxidase positive. What is the likely
organism?
Select one:
a. Haemophilus influenzae
b. Pseudomonas aeruginosa
c. Escherichia coli
d. Moraxella catarrhalis

Answer 1

The likely organism is Pseudomonas aeruginosa, which is consistent with the given scenario of a child with severe ear pain after swimming in a lake.

Step-by-step explanation:

The likely organism in this case is Pseudomonas aeruginosa.

In the given scenario, the 10-year-old child presents with severe ear pain after swimming in a lake. The culture from the ear grew a gram-negative rod with a grapelike odor. The characteristics of the colonies, such as being flat and spreading with rough edges and a metallic sheen, along with being indole negative and oxidase positive, are consistent with Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a bacterium that thrives in wet and warm environments, making it a common cause of otitis externa (swimmer's ear). This infection can cause itching, redness, discomfort, and can progress to fever, pain, and swelling.