Question

: Enterobacteriaceae Biochemical Review: Several key reactions can serve as the first step in identifying members of the Enterobacteriaceae. These tests can be especially helpful when identifying organisms that are morphologically similar. (Section Total: 29 points)

2. Indicate the genera that match the colonial or other description provided (1 point per genus):

Lactose fermenter with pink precipitation: (2 points)

Mucoid, lactose fermenting colonies: (3 points)

Non-lactose fermenting stool pathogens: (4 points)

H₂S Producing as a key identification characteristic: (2 points)

These two genera, Klebsiella and Shigella share a unique characteristic in this family: (1 point)

Two primary stool pathogens that appear as non-lactose fermenters following 24 hours of incubation on MacConkey agar, but are ONPG positive: (2 points)

Vogues-proskauer positive genus: (4 points)

Citrate positive, lactose fermenting genera: (4 points)

Phenylalanine Deaminase positive: (3 points)

Answer 1

# the lactose fermenter - opportunistic pathogens

# mucoid lactose fermenting colonies-- klebsiella

# Non lactose fermenting stool pathogens - gastroenteritis pathogens.

# H2S producing as a key identification characteristic - E coli identification and media may contain the sodium thiosulfate and ferric ammonium citrate.

# The unique characteristic that klebsiella and shigella has - these are organisms which are the exception to the motility among the enterobacteriaceae.

# two primary stool pathogens are - vibrio and yersinia

# vogues - proskauer positive genus : cherry red color indicates the positive result. It depends on the digestion of glucose to acetylmethylcarbinol