LAB 9 - Non-Glucose Fermenting GNB Flashcards
non-fermenters
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
PARED APPLE SMELL
Alcaligenes faecalis
Risk group III in this category
Burkholderia pseudomallei (melioidosis)
B. mallei (livestock -glanders)
BCSA
Burkholderia cepacia Selective Agar
NGFGNB ox -
Stenotrophomonas (gown)
Acinetobacter (lwoffi andbaumannii)
TTR, pitter
M. lacunata
sticky Acinetobacter
lwoffi
gnb pairs
M. lacunata
NC in OF test media
A. lwoffi
M. lacunata
Alcaligenes faecalis
Wet motility neg
M. lacunata
Acinetobacter (lwoffi and baumannii)
which GNNFB does not grow on mMAC
M. lacunata
P. fluorescens = scant growth
A. lwoffi grows at 48h
NIT + (gas)
P. aeruginosa
others are ither V or -
how to differentiate between P. fluorescens and P. putida
fluor = gelatin hydrolysis pos
putida = neg
Brownian motility
passive
not true motility
jerky/oscillatory movement usually in one spot or lacking direction
oxidation of glucose
- 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
fermentation
- 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
OF test
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
OF test ingredients
high carb content
low peptone concentration
phosphate
NaCl
Bromothymol blue indicator
positive nitrate reduction
pos within 10 secs; red colour develops
nitrate test
- 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
fluorescein
- 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
pyocyanin
- P. aeruginosa only species that can produce this
- blue-green, diffusible, non-fluorescent pigment which is soluble in chloroform
- characteristic metallic sheen on BAP
pyorubin production
brown to red in colour
pyomelanin production
brown in colour
most common cause of human diarrheal disease esp. in children
Campylobacter jejuni
C. jejuni motility
darting motility pos
