Microbiology Study Guide Questions/Answers Graded
A+ 2025/2026
Which organism causes most urinary tract infections? - E. coli
Voges-Proskauer = Pink; Phenylalanine = No color change
KIA = A/A; Citrate = Blue
Lysine = Purple (Control tube - yellow)
Indole = No color change; ONPG = Yellow
Urea = Pink; Motility = Positive
DNAse = No clearing
What is the identification? - Enterobacter species
Voges-Proskauer = No color change
Phenylalanine = No color change
Kligler iron agar = Yellow/yellow; Citrate = Green
Lysine = Purple (Control tube - yellow); Indole = Red
ONPG = Yellow; Urea = Yellow; Motility = Positive
What is the identification? - Escherichia coli
Which of the Haemphilus species are NOT normal flora? - H. ducreyi & H. aegyptius
Which two Haemophilus species require X and V factors for growth? - H. haemolyticus
(hemolytic) & H. influenzae (nonhemolytic)
Which two Haemophilus species require V factor for growth? - H. parahinfluenzae
(nonhemolytic) & H. parahaemolyticus (hemolytic)
Which two Haemophilus species are porphyrin test positive (fluorescence)? - H.
parainfluenzae (no hemolysis present) & H. parahaemolyticus (hemolysis)
Which organism causes pinkeye? - Haemophilus aegyptius
Which organism is transmitted sexually and causes a chancroid or soft chancre? -
Haemophilus ducreyi
Which gram negative bacilli satellite around staphylococci on sheep blood agar? What
nutrient is supplied by the staphylococci? - Haemophilus; V factor (NAD)
Which two enteric organisms are nonmotile? - Klebsiella & Shigella
Voges-Proskauer = Pink; Phenylalanine = No color change
TSI = A/A; Citrate = Blue
Lysine = Purple (Control tube - yellow)
Indole = No color change; ONPG = Yellow
Urea = Pink; Motility = Negative
