Table 102
I $+$ $\quad$ 1 Acid from Glucose $\quad$ Staphylococcus $\quad$

Table 10.2
I. Gram-positive
A. Catalase $+$
$\quad$ 1. Acid from glucose. $\quad$ Staphylococcus
$\quad$ 2. Glucose $\quad$$\quad$$\quad$$\quad$$\quad$ Micrococcus
B. Catalase-
$\quad$ 1. Coccus. $\quad$$\quad$$\quad$$\quad$ Streptococcus
$\quad$ 2. Rod $\quad$$\quad$$\quad$$\quad$$\quad$ Lactobacillus
II. Gram-negative
A. Oxidase-
1. Acid from lactose
$\quad$ a. Uses citric acid. $\quad$$\quad$$\quad$$\quad$ Citrobacter
$\quad$ b. Citric acid $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$ Escherichia
2. Lactose-
a. $\mathrm { H } _ { 2 } \mathrm {~S}$ produced
$\quad$ (1) Urease positive. $\quad$$\quad$$\quad$$\quad$ Proteus
$\quad$ (2) Urease negative $\quad$$\quad$$\quad$$\quad$ Salmonella
B. Oxidase $+$
$\quad$ 1. Rod. $\quad$$\quad$$\quad$$\quad$$\quad$ Pseudomonas
$\quad$ 2. Coccus. $\quad$$\quad$$\quad$$\quad$ Neisseria
-Use the dichotomous key in Table 10.2 to identify a gram -negative cell that ferments lactose and uses citric acid as its sole carbon source.

A) Escherichia
B) Citrobacter
C) Lactobacillus
D) Staphylococcus
E) Pseudomonas