Which organism is described as SHORT GNB with oxidase variable, X negative, V positive, XV positive, and porphyrins positive?

Prepare for the CAMLPR Microbiology Test. Utilize flashcards and engaging multiple-choice questions, each equipped with descriptions and explanations. Ready yourself for an excellent performance!

Multiple Choice

Which organism is described as SHORT GNB with oxidase variable, X negative, V positive, XV positive, and porphyrins positive?

This question tests how X and V factor requirements, along with porphyrin production, help distinguish small gram-negative coccobacilli in the lab. Pasteurella multocida is a short Gram-negative coccobacillus that often shows variable oxidase activity. It does not rely on X factor (X negative) and can utilize V factor when available (V positive, and growth can occur with both X and V present, i.e., XV positive). The porphyrin test being positive fits with Pasteurella, indicating it can synthesize heme precursors rather than needing exogenous heme. Taken together, these traits point to Pasteurella multocida rather than the other organisms listed.

This question tests how X and V factor requirements, along with porphyrin production, help distinguish small gram-negative coccobacilli in the lab. Pasteurella multocida is a short Gram-negative coccobacillus that often shows variable oxidase activity. It does not rely on X factor (X negative) and can utilize V factor when available (V positive, and growth can occur with both X and V present, i.e., XV positive). The porphyrin test being positive fits with Pasteurella, indicating it can synthesize heme precursors rather than needing exogenous heme. Taken together, these traits point to Pasteurella multocida rather than the other organisms listed.

More practice questions