Chapter 9: Biochemical identification of Gram-Negative Bacteria

Question 1

Biochemical testing is based on what?

Answer 1

Phenotypic characteristics

Question 2

Used of antibodies to detect specific antigens located on the bacterial surface

Answer 2

Serotyping (serogrouping)

Question 3

The most important carbohydrate determination

Answer 3

Lactose Utilization

Question 4

Can be used to differentiate lactose fermenting (LF) bacterial species from nonlactose fermenters (NLFs)

Answer 4

Lactose Utilization

Question 5

What two enzymes are required for lactose degradation

Answer 5

Beta-galactoside permease and Beta-galactosidase

Question 6

What enzymes can transport lactose through a cell wall?

Answer 6

Beta-galactoside permease

Question 7

What enzyme can break lactose to yield subunites?

Answer 7

Beta-galactosidase

Question 8

Known as late or delayed LFs(dLFs)

Answer 8

Bacterial species that lack permease but have beta-galactosidase

Question 9

Determine the ability of a bacteria to ferment a specific carbohydrate incorporated in the medium

Answer 9

Oxidation-fermentation (O/F) Tests

Question 10

Asaccharolytic

Answer 10

Do not utilize carbohydrates

Question 11

What pathway is fermentation?

Answer 11

glycolysis pathway

Question 12

What is the end product of glycolysis?

Answer 12

Acid or acid with gas

Question 13

What pathway is oxidation?

Answer 13

Glycolysis pathway

Question 14

Does oxidation produce weak or strong acid?

Answer 14

weak acid that is neutralized by alkaline reactions from peptones

Question 15

What is the description of O/F basal media?

Answer 15

Lower concentration of peptones

Question 16

What is the purpose of O/F basal media

Answer 16

Help classify as oxidizer or fermenter and detects small amounts of acids

Question 17

What does Kligler Iron Agar contain?

Answer 17

glucose and lactose and detects fermentation

Question 18

For KIA (kligler iron agar) what does yellow indicate?

Answer 18

Acidic (below 6.8)

Question 19

For KIA what does red indicate?

Answer 19

alkaline (above 6.8)

Question 20

If there is a black color to the kligler iron agar what does it detect?

Answer 20

Production of hydrogen sulfide (H2S)

Question 21

ALK/ALK or K/K means?

Answer 21

No fermentation

Question 21

What is the purpose of the Orthpo-Nitrophenyl-beta-D=Galactopuranoside test (ONPG)

Answer 21

To determine if an organism found to be a dLF but is a true NLF

Question 21

What occurs in the Embden-Meyerhof pathway?

Answer 21

Glucose Metabolism

Question 22

This test the presence of enzymes capable of removing carboxyl group from certain amino acids

Answer 22

Amino acid utilization decarboxylase and dihydrolase

Question 22

Deaminase test uses is useful in differentiation of

Answer 22

Proteus
Morganella
Providencia

Question 23

This test determines whether an organism can use sodium citrate as a sole carbon source

Answer 23

Citrate utilization

Question 24

What is the primary function of the LIA slant

Answer 24

deamination or decarboxylation of lysine.

Question 25

Can be used in screening for stool pathogens

Answer 25

LIA slant

Question 26

This test determines whether the organism is capable of using sodium malonate as its sole carbon source

Answer 26

Malonate test

Question 27

Determined by microscopic examination of bacteria or observing growth in a semi-solid medium

Answer 27

Motility

Question 28

Oxidase is helpful in differentiating between?

Answer 28

Enterobacteriaceae
Pseudomonads
Neisseria

Question 29

This test is used to determine whether a microorganism can hydrolyze urea

Answer 29

Urease test

Question 30

The resulting alkaline pH from the hydrolysis of urea is indicated by what?

Answer 30

Bright pink color

Question 31

pH-based reactions, enzyme-based reactions, utilization of carbon sources, visual detection of bacterial growth, and detection of volatile fatty acids are principle of what?

Answer 31

Principles of Identification