1. Lab Exercise 17:
Biochemical Differentiation of some Medically Important Gram-negative Bacilli

2. MacConkey Agar
Left: Shigella
- result
Right: Escherichia
+ result

3. Carbohydrate Fermentation Tests
Glucose w/ Durham Fermentation Tube

4. Carbohydrate Fermentation Tests
Sucrose Fermentation

5. Triple Sugar Iron
-/+/+

6. IMViC Series
Indole Test
broth with tryptophan

7. IMViC Series
Methyl Red Test

8. IMViC Series Voges-Proskauer Test 
Leave uncapped for minutes……..
MRVP broth

9. Citrate Utilization Test
IMViC Series
Citrate Utilization Test - +

10. Urease Test Slow positive Negative result (acidic)
Uninoculated urea agar
Positive result (alkaline)

11. Motility Test

12. A B 2. A 4. B A 3. B Answers: MacConkey agar
1. Which plate could have E. coli on it?
2. Which plate shows the presence of a lactose-fermenter?
3. Which plate could have Salmonella on it?
4. Which plate shows the presence of a
lactose non-fermenter?
                                                                                            A B
2. A 4. B
A 3. B
Answers:

13. What is the name of the lab procedure demonstrated here?
Answer: Stabbing the butt!

14. C U I M V Answer: Shigella sonnei
Use the chart on p. 181 and or the flow chart on p. 182 of your lab manual to figure out who I am! I M V C U
Answer: Shigella sonnei

15. C I M V U Answer: Escherichia coli
Use the chart on p. 181 and/or the flow chart on p. 182 of your lab manual to figure out who I am!
Answer: Escherichia coli

16. Answer: Serratia marcesensV C U
Use the chart on p. 181 and/or the flow chart on p. 182 of your lab manual to figure out who I am!
Answer: Serratia marcesens

17. Answer: Klebsiella pneumoniae
Use the chart on p. 181 and/or the flow chart on p. 182 of your lab manual to figure out who I am! I M V C
Answer: Klebsiella pneumoniae

18. Answer: Salmonella typhimurium
Use the chart on p. 181 and/or the flow chart on p. 182 of your lab manual to figure out who I am! I M V C U
Answer: Salmonella typhimurium

19. Answer: Proteus vulgaris
Use the chart on p. 181 and/or the flow chart on p. 182 of your lab manual to figure out who I am! I M V C U
Answer: Proteus vulgaris

20. Answer: Enterobacter aerogenes U
Use the chart on p. 181 and/or the flow chart on p. 182 of your lab manual to figure out who I am! I M V C
Answer: Enterobacter aerogenes U