Gram negative Rods

Question 1

G (-) , Growth on MacConkey agar, fast Lactose fermenter (pink colonies)

Answer 1

Klebsiella, E. Coli, Enterobacter

Question 2

G (-) , Growth on MacConkey agar, slow Lactose fermenter (pink colonies)

Answer 2

Citrobacter, Serratia

Question 3

G (-) , Growth on MacConkey agar, non-Lactose fermenter (white colonies), oxidase test (+)

Answer 3

Pseudomonas aeruginosa

Question 4

G (-) , Growth on MacConkey agar, non-Lactose fermenter (white colonies), oxidase test (-), TSI agar –> no H2S production

Answer 4

Shigella

Question 5

G (-) , Growth on MacConkey agar, non-Lactose fermenter (white colonies), oxidase test (-), TSI agar –> H2S production

Answer 5

Salmonella, proteus