Special Examinations

Question 1

Special examination of Proteus

Answer 1

Dienes Phenomenon
* Positive Dienes reaction = Line of inhibition
* Negative Dienes reaction = No line of inhibition

Question 2

Explain Dienes Phenomenon
For which bacteria is it used?

Answer 2

Dienes Phenomenon is used for Proteus spp.

• Positive Dienes reaction = Line of inhibition
  -A visible line forms btw different strains of Proteus
• Negative Dienes reaction = No line of inhibition
  -There is no visible line, meaning that they are probably same strain of Proteus

Question 3

Special examination of Salmonella

Answer 3

• Phage-typing
• DNA Methods

Question 4

What is Phage-typing
Which bacteria is it used for?

Answer 4

Phage-typing is used for Salmonella spp.
* Use bacteriophage for detection of Phagotypes

Important Phage types:
1. S. Typhimurium - Multiresistent to antibiotics
2. S. Enteritidis - Common cause of food poisoning in humans

Question 5

What are the 4 DNA methods
Which bacteria is it used for?

Answer 5

DNA methods are used for Salmonella spp.

1. PCR analysis
2. RFLP = Restriction Fragment Length Polymorphism
3. DNA plasmid analysis
4. DNA probes

Question 6

Special Examination of Escherichia Coli (4)

Answer 6

• PCR reaction = Detection of E. Coli
• DNA probes = Detection of F antigens
• ELISA test = Detection of Enterotoxins
• DNA tests = Detection of Plasmid

Question 7

PCR reaction is used for detecting?

Answer 7

• Escherichia Coli

Question 8

DNA probe is used for detecting?

Answer 8

• F-antigen (Fimbrial)

Question 9

ELISA is used for detecting?

Answer 9

• Enterotoxins

Question 10

DNA test is used for detecting?

Answer 10

• Plasmid