A tracheal aspirate, obtained from a comatose patient on a ventilator, grew an oxidase-positive non-lactose fermenter that produced a distinctive odor of sliced apples. It proved to be:
Motile: positive
Nitrate: red after addition of reagents A, B, and zinc
OF medium:
Open tubes: glucose: blue, maltose: blue, lactose: blue, sucrose: blue
Closed tubes: glucose: green, maltose: green, lactose: green, sucrose: green
This organism is

Question

Quizplus · Accepted Answer

The organism is Alcaligenes faecalis, which is oxidase-positive, non-lactose fermenting, and produces a distinctive apple-like odor. It is motile and does not utilize carbohydrates in OF medium, consistent with the test results.

A Tracheal Aspirate, Obtained from a Comatose Patient on a Ventilator