Question

Enterococcus hydrolyzes Esculin, shows growth in 6.5, and is positive for PYR. What is the classification of this organism?

1) Gram-negative
2) Gram-positive
3) Aerobic
4) Anaerobic

Answer 1

The organism that hydrolyzes esculin, shows growth in 6.5% NaCl, and is positive for PYR is a Gram-positive bacterium, typically belonging to Group D enterococci.

Step-by-step explanation:

Based on the properties described - the ability to hydrolyze esculin, growth in 6.5% NaCl, and a positive result for the PYR test - the organism in question can be classified as a Gram-positive bacterium. The properties described are characteristic of certain strains of enterococci, specifically the Group D enterococci. These bacteria are able to grow in bile salt environments like the bile esculin agar mentioned and are known to be PYR positive. The classification of an organism includes its cell wall structure (Gram-positive or Gram-negative), metabolism (aerobic or anaerobic), as well as other physiological characteristics. Gram-negative bacteria, on the other hand, do not possess these traits. Therefore, the correct classification of this organism is Gram-positive.