LAB 9 - Non-Glucose Fermenting GNB

Question 1

non-fermenters

Answer 1

group of aerobic gnbs that are either incapable of using carbs as a source of E or degrade them via oxidative rather than fermentative metabolic pathways
(+/-) or O or NC in OF glucose media

Question 2

PARED APPLE SMELL

Answer 2

Alcaligenes faecalis

Question 3

Risk group III in this category

Answer 3

Burkholderia pseudomallei (melioidosis)
B. mallei (livestock -glanders)

Question 4

BCSA

Answer 4

Burkholderia cepacia Selective Agar

Question 5

NGFGNB ox -

Answer 5

Stenotrophomonas (gown)
Acinetobacter (lwoffi andbaumannii)

Question 6

TTR, pitter

Answer 6

M. lacunata

Question 7

sticky Acinetobacter

Answer 7

lwoffi

Question 8

gnb pairs

Answer 8

M. lacunata

Question 9

NC in OF test media

Answer 9

A. lwoffi
M. lacunata
Alcaligenes faecalis

Question 10

Wet motility neg

Answer 10

M. lacunata
Acinetobacter (lwoffi and baumannii)

Question 11

which GNNFB does not grow on mMAC

Answer 11

M. lacunata
P. fluorescens = scant growth
A. lwoffi grows at 48h

Question 12

NIT + (gas)

Answer 12

P. aeruginosa
others are ither V or -

Question 13

how to differentiate between P. fluorescens and P. putida

Answer 13

fluor = gelatin hydrolysis pos
putida = neg

Question 14

Brownian motility

Answer 14

passive
not true motility
jerky/oscillatory movement usually in one spot or lacking direction

Question 15

oxidation of glucose

Answer 15

• bacteria produce acids from carbs in aerobic conditions
• glucose oxidized to gluconic acid
• weak acid; only 1 molecule of acid produce from 1 molecule of glucose

Question 16

fermentation

Answer 16

• anaerobic process
• glucose first phosphorylated then split into two triose molecules
• further rxns = one or more acids = lactic, formic, succinic, or acetic acid
• more rapid than oxidation

Question 17

OF test

Answer 17

determines if a sugar is attacked by oxidation or fermentation
- one sealed wth mineral oil for anaerobic conditions while other tube is loosely capped for aerobic

Question 18

OF test ingredients

Answer 18

high carb content
low peptone concentration
phosphate
NaCl
Bromothymol blue indicator

Question 19

positive nitrate reduction

Answer 19

pos within 10 secs; red colour develops

Question 20

nitrate test

Answer 20

• test detects presence of nitrites (after reduction of nitrates)
• reagent A and B will react with nitrites = red colour
• if nitrate reduction did not occur, nitrates are still present so zinc will react with nitrates to make nitrites = red colour
• if no colour change after zinc, this means that no nitrates, and no nitrites which means, it’s gone further = denitrification

Question 21

fluorescein

Answer 21

• pyoverdin production by P. aeruginosa
• yellow-green diffusible, fluorescent pigment which is NOT soluble in chloroform,
• most strains of P. aeruginosa
• pigment production (+ fluorescence) noted by viewing BAP culture under short wave UV light

Question 22

pyocyanin

Answer 22

• P. aeruginosa only species that can produce this
• blue-green, diffusible, non-fluorescent pigment which is soluble in chloroform
• characteristic metallic sheen on BAP

Question 23

pyorubin production

Answer 23

brown to red in colour

Question 24

pyomelanin production

Answer 24

brown in colour

Question 25

most common cause of human diarrheal disease esp. in children

Answer 25

Campylobacter jejuni

Question 26

C. jejuni motility

Answer 26

darting motility pos