yellow = it acidifies the tube = the organism is a fermenter
Hugh and Leifson Medium
T(2)
w/o mineral oil
remained open when acidifying the tube
organism is oxidizer
non-oxidizer
asaccharolytic
All species except B. mallei are motile, having one or several polar flagella
Optimum temperature of Non-fermenters range at 30 to 37 degrees (mesophilic)
Non-Fermenters
MAC (-) : Acidovorax facilis
Catalase (+) : Pseudomonas spp.
Biochemical Characteristics and Identification
Oxidase (+) reaction although the reaction can be weak and variable.
Non reactivity in 24 hours in commercial multitest kit system used for identification of enteribacteriaceae
No acid production in slant, butt of TSI or KIA
Biochemical Characteristics and Identification
Resistance to a variety of classes of antimicrobial agents such as
Aminoglycerides
Third generation cephalosporins
Penicillin
Fluoroquinolones
Different classification system
growth on MAC agar
Base reaction with oxidase test
Result of glucose oxidation fermentation test
Pigmentation: YELLOW
Chryseobacterium and Elizabethkingia spp.
Sphingomonas paucimobilis
Pseudomonas luteola
Pseudomonas oryzihabitans
Sphingobacterium spp.
Pseudomonas stutzeri
Pigmentation: PINK
Methylobacterium spp.
Roseomonas spp.
Pigmentation: PURPLE (MAC)
Acinetobacter sp.
Pigmentation: BLUE - GREEN
Pseudomonas aeruginosa
Pigmentation : VIOLET
Chromobacterium violaceum (fermenter)
Pigmentation : Lavender - Lavender - green (Blood AgarAgar)
Sternotrophomonas maltophilia
Pigmentation : TAN (occasionally)
P. stutzeri
Shewanella putrefaciens
Wrinkled Colonies
P. stutzeri
P. oryzihabitans
Burkholderia pseudomallei
Odor : SWEET
Alcaligenes faecalis
Mvroides odoratus
P. aeruginosa (fruity: grapes)
Odor: POPCORN
EO-4
Neisseria zoodegmatis
Non-Motile
Acinetobacter spp.
Moraxella spp.
Chryseobacterium and Elizabethkingia spp. (weak fermenters)
Sphingibacterium spp.
Oligella spp.
Oxidase Negative
Acinetobacter spp.
S. maltophilia
Pseudomonas luteola and P. oryzihabitans
Pseudomonas cepacia
H2S Positive
Shewanella putrefaciens
Pseudomonas
Gram negative bacillus / coccobacillus
strictly aerobic metabolism
motile with polar flagellum or polar tuft
Oxidase (+) except: P. luteolus and P. oryzihabitans
Catalase (+)
Usually grows in MAC agar
Usually an oxidized of carbohydrates but some species are asaccharolytic
Produce water soluble pigment
Pigment
Yellow-Green = Pyoverdin
Blue = Pyocyanin
Bright green = Pryoverdin + Pyocyanine
Pseudomonas Fluorescent Group
able to produce a yellow - green pigment (Pyoverdin)
P. aeruginosa
P. fluorescens
P. putida
P. monteilii
P. veronii
P. mosselii
Pseudomonas Non-Fluorescent Group
P. stutzeri
P. alcaligenes
P. mendocina
P. pseudoalcaligenes
P. oryzihabitans
P. luteola
Pseudomonas aeruginosa
pyoverdine & pyocyanin
motile & rod shape
sweetsweet, grapelike, taco like odor
Pyocyanin - non fluorescent pigment (bluish)
Pyoverdine - fluorescent pigment
Pyorubin - dark red
Pyomelanin - brown black
P. aeruginosa growth characteristics
37 to 42 C - can help to differentiate it from other P. spp.
doesn't ferment carbohydrates
many strains oxidize glucose
denitrification of nitrates and nitrites
(+): Oxidase and ADH
Citrate positivity
Acetamide utilizationutilization
Culture : Cetrimide Agar (Selective and Diff)
Cetrimide - Act as detergent and enhances the production of the two pigments
Lipopolysaccharide is reposible for many endotoxin properties of microorganism
Exotoxin
Most important
blocks protein synthesis
P. aeruginosa : Clinical Findings
wounds and burns - blue - green pus
necrotizing pneumonia
cystic fibrosis - chronic pneumonia
mild otitis externa in swimmers
invasive (malignant) otitis externa in patients with diabetes
Fatal sepsis - infants
ecythema gangrenosum - presence of erythema
folliculitis - poorly chlorinated tub
P. aeruginosa : TREATMENT
piperacillin and ticarcillin
third and fourth generation cephalosporins
carbapenems
fluoroquinolones
P. fluorescens & P. putida
can be isolated from respiratory specimens
can grow at 4 C
produces pigment: pyoverdin or fluorescein
produces acid from xylose
can't produce nitrate to nitrogen gas
Gelatin hydrolysis:
P. putida - negative
P. fluorescens - positive
P. mosellii
non pigmented
non hemolytic
(+): oxidase , catalase, ADH
optimal growth occurs at 30 C
True or False: NF may fail to grow or show poor growth on McConkey Agar
True
Pseudomonas Aeruginosa will not be able to ferment
the sugars that is contained in TSI (lactose, sucrose, glucose) so there will be no change in the rxn in the slant or butt meaning they are not able to degrade the sugars contained in the medium
Pyoverdin is the most frequently isolated pigment produce by pseudomonas followed by pyoverdine combine with flourescin
Hugh-Leifson OF Medium is a very important test for distinguishing oxidizers and fermenters belonging to the group non-fermenting, Gram-negative bacilli.