Non Fermenting GNB Flashcards
• Organisms that CANNOT UTILIZE CARBOHYDRATES WITHOUT_______
Therefore, they are also called______
OXYGEN
oxidative
• Are able ferment carbohydrates but only…
• Does NOT form… in TSI
FORM SMALL AMOUNT AND VERY
WEAK ACIDS
Yellow colored media in TSI
Do NOT UTILIZE CARBOHYDRATE (with or w/o O2)
Uses other compounds as source of energy Utilizes amino acids
Non-saccharolytic or non-oxidizers
Oxidase negative
O+/ F+
Enterobacteriacea
Oxidase positive
O+/ F-
Pseudomonadaceae
Oxidase positive
O+/ F+
Vibrionaceae
CHARACTERISTICS OF NON-FERMENTERS
→ Spore???
→ Aerobic condition???
→ TSI:???
Non-spore formers
Obligate aerobes → to utilize carbohydrates
K/K; H2S (-)
CHARACTERISTICS OF NON-FERMENTERS
→ POINT OF COLONIZATION:???
→ ENTRY TO STERILE SITES OF THE BODY:???
→ What type of PATHOGENS???
mucus membrane & skin of humans
trauma, burns, or wounds
OPPORTUNISTIC
NF Grow better in____ than on ____
SBA than on MACCONKEY AGAR
(+/-)
NF TEST RESULTS
OXIDASE TEST
GRAM STAIN
TSI
MOTILITY
POSITIVE
GRAM NEGATIVE BACILLI
K/K
MAJORITY ARE MOTILE
NF
TESTS FOR IDENTIFICATION
→ Flagellar morphology
• Mostly they are_____ via______
• But some strains have peritrichous flagella so you need to check if it is peritrichous, etc
motile
SINGLE POLAR FLAGELLA
NF
Non-fermenters are poorly indole
producers → thus, a modified indole test is used, specifically_______
Contains “Extractors” → (2)
• Add it after____
ERLICH’S reagent
XYLENE and ETHER
Incubation
NF
• Commonly used test to differentiate Enterobacteriaceae from Non-lactose
fermenters
O-F CHO utilization patterns
NF
→ Acetamide
Similar to citrate test → able to use ____ as a sole source of Carbon
• In acetamide →_____ is used to determine whether the organisms would be able to use it as a sole source of carbon
citrate
acetamide
Commonly used test to differentiate Enterobacteria from Non-lactose fermenters
OXIDATION-FERMENTATION (O-F) TEST
OF test uses…
HUGH AND LEIFSON culture media
HIGH CONC’N OF CHO (___%) and a LOW CONC’N OF PEPTONE OR PROTEIN (___%).
• High concentrations of CHO: To ENHANCE carbohydrates (slow production of acids)
• Low concentrations of peptone DECREASE formation byproducts of neutralize the acids
1; 0.2
RATIO???
peptone to CHO concentration for NF
For Enterobacteriaceae???
1:5
2:1
HUGH and LEIFSON
→ O/F Basal media
→ CHO: (5)
→______ = indicator
Glucose, Maltose, Lactose, Mannitol, & Xylose (GMX ML)
Bromthymol blue
OF TEST
Tubes containing an overlay → CLOSED TUBE using_____
→ OPEN TUBES → Used to demonstrate their ABILITY TO_____
→ POSITIVE FOR OPEN TUBE: (2)
mineral oil
OXIDIZE CARBOHYDRATES
Pseudomonas and Enterobacteriaceae (Yellow color formation)
OF TEST
→ POSITIVE FOR CLOSED TUBE:____
→______ COLOR → able to ferment carbohydrate
→ _____COLOR → No carbohydrate utilized
Enterobacteriaceae (Yellow color formation)
YELLOW
GREEN/BLUE GREEN
Open: Green/Blue Green
Closed: Green/ Blue Green
Non-saccharolytic
Alcaligenes faecalis
Open: Yellow
Closed: Green/ Blue Green
Oxidative
Pseudomonas
Open: Yellow
Closed: Yellow
Fermentative
Enterobacteriaceae
NITRATE REDUCTION TEST
Non-fermentative organisms can produce the enzyme ______ → which reduce______
NITRATE REDUCTASE
NITRATE TO NITRITE
NITRATE REDUCTION TEST
To check if Nitrate is reduced into nitrite → add______ and _____ → IF nitrite is present → produce________ color
→ If no color is produced, it is due to:
• Nitrate is not reduced to nitrite
• Sulfanilic acid and a-naphthylamine cannot react with nitrite, since nitrite was further reduced to gas
a-NAPHTHYLAMINE and SULFANILIC ACID
RED DIAZONIUM SALT (RED COLOR)
NITRATE REDUCTION TEST
→ To check which reason is the cause of no red color in the test: ADD_______
→ Zinc is known to react with_____
• RED COLOR →________
• NO COLOR →________
ZINC POWDER/DUST
NITRATE
NITRATE WAS NOT REDUCED
Nitrte was further reduced (no presence of nitrate)
Family Pseudomonadaceae (NFGNB)
I. Fluorescent group
P. aeruginosa
P. fluorescens
P. putida
Family Pseudomonadaceae (NFGNB)
I. NON-Fluorescent group
Soil denitrifiers
P. stutzeri
P. mendocina
Pigments they produce
Pseudomonas aeruginosa
P. fluorescens
P. putida
(pyoverdin and PYOCYANIN)
(pyoverdin)
(pyoverdin)
II. Pseudomallei Group
Resistant to polymyxin B and colistin
Burkholderia pseudomallei
B. mallei
B. cepacia
Ralstonia picketti
III.
IV.
V.
• Comamonas species*
• Acidovorax species
• Brevundimonas species*
• Stenotrophomonas maltophilia*
→ NOT A MAJOR NORMAL FLORA but grabs the opportunity to cause human infections
Most frequently isolated N-F (Non-fermentative Organism)
Pseudomonas aeruginosa (PAE)
→ FOUND IN ENVIRONMENT
→ Can survive in harsh environment
→ Major human pathogen in the group
→ MOST IMPORTANT OPPORTUNISTIC PATHOGEN
• Because of their Invasive and toxigenic properties
PAE
P. aeruginosa characteristics
→ Aerobic conditions and motility???
Pigments: (5)
OBLIGATE AEROBE; MOTILE
PYOCYANIN
PYOVERDIN
FLUORESCEIN
PYORUBRIN
PYOMELANIN
PAE
→ Fruity odor or corn tortilla-like odor
Due to the ____________ release (chemical of byproduct of metabolism)
→ Grow at what temperatures?!!
2-AMINOACETOPHENONE
RT° (20-25 C), 35-37°C and at 42°C
P. aeruginosa Laboratory Tests
Samples:
Smears:
SKIN LESIONS, PUS, URINE, BLOOD, SPINAL FLUID, SPUTUM, ETC
GRAM (-) RODS
PAE
Culture:
BAP →
Mac & EMB →
large, rough, dull grayish, feathered edged/ serrated and spreading colonies & mostly are beta-hemolytic;
Mucoid (capsular alginate)
NLF
PAE
BIOCHEMICAL TESTS
TSI
OXIDASE TEST
OXIDASE FERMENTATION
NITRATE REDUCTION
K/K
POSITIVE
GLUCOSE, FRUCTOSE, XYLOSE but NOT maltose, sucrose and lactose
POSITIVE
INFECTIONS ASSOCIATED WITH PAE
→ Severe wound infections in burn patients
→ UTI
→ Pneumonia (ventilator-associated)
→ Septicemia
→ Chronic lung infections in Cystic Fibrosis patients (mucoid strain)
→ Meningitis
→ Ecthyma gangrenosum
NOSOCOMIAL OR HOSPITAL ACQUIRED INFECTIONS
INFECTIONS ASSOCIATED WITH PAE
keratitis
corneal ulcers in contact lens wearers
Swimmer’s ear
Folliculitis (“hot tub folliculitis”) (Jacuzzi syndrome)
COMMUNITY ACQUIRED
PAE
VIRULENCE FACTORS
ATTACHMENT
Fimbriae
Polar flagella
PAE
LIPOPOLYSACCHARIDE ENDOTOXIN EFFECT & EXOTOXIN
Alginate capsule
Exotoxin A
Type III Secretion system
Exotoxin S,T,U,Y
PAE VIRULENCE FACTORS
TISSUE INVASION
→ Elastase
→ Protease
→ Collagenase
→ Hemolysin
→ Leukocidin
→ Pyocyanin
→ Pyoverdin
P. aeruginosa Treatment
→______ IS NOT RECOMMENDED
• Combination: ______ and _____
Because they can resist anitmicrobial
agents
→ Beta lactam drugs
→ Carbapenems
→ Fluoroquinolones
→ To provide good treatment → Do AST
SINGLE DRUG THERAPY
PENICILLIN BASED DRUG + AMINOGLYCOSIDE
P. fluorescens & P. putida
→ Fluorescent pseudomonads
→ Can grow at____ but cannot grow@____
→ Produces what pigment?
→ Environmental organisms but can cause infections in immune compromised individuals associated w/ Nosocomial infections (transfusion associated sepsis)
→ rarely associated with opportunistic infxns.
4°C; 42°C
PYOVERDIN
→ Isolated cases of septicemia, UTI, & pneumonia
P. putida
→ Contaminant
→ Rare cause of UTI & wound infections in humans
P. fluorescens
P. fluorescens & P. putida Laboratory Characteristics
MOTILITY
TEMPERATURE
OXIDASE
OF MEDIUM
MOTILE
GROWTH AT 35°C BUT NOT AT
42°C
POSITIVE
OXIDIZE GLUCOSE
P. fluorescens & P. putida Laboratory Characteristics
PYOCYANIN
PYOVERDIN
CETRIMIDE & ACETAMIDE
ARGININE
NEGATIVE
POSITIVE
NEGATIVE
POSITIVE
P. fluorescens & P. putida Laboratory Characteristics
CARBENICILLIN
KANAMYCIN
RESISTANT
SUSCEPTIBLE
Differentiating P. fluorescens & P. putida
What to do??
Protein metabolism
Gelatin hydrolysis
P. fluorescens
Protein metabolism
Gelatin hydrolysis
Proteolytic
Positive
P. putida
Protein metabolism
Gelatin hydrolysis
Non-proteolytic
Negative
→ “SOIL DENITRIFIERS”
Non-Fluorescent Group: P. stutzeri & P. mendocina
→ uses NH4 (source of NITROGEN) and ACETATE (source of CARBON)
→ Rare cause of eye infections, endocarditis, septic arthritis, postsurgical wound infxn, UTI, septicemia, and pneumonia
→ Motile
→ Grows at 42°C
Non-Fluorescent Group: P. stutzeri & P. mendocina
→ uses NH4 (source of NITROGEN) and ACETATE (source of CARBON)
→ Rare cause of eye infections, endocarditis, septic arthritis, postsurgical wound infxn, UTI, septicemia, and pneumonia
→ Motile
→ Grows at 42°C
Non-Fluorescent Group: P. stutzeri & P. mendocina
→ Colonies:
SMOOTH, BUTTERY, FLAT,
UNWRINKLED ON BAP
P. medocina
→ Colonies: DRY AND WRINKLED W/ BUFF OR LIGHT BROWN COLOR
P. stutzeri
P. stutzeri
ADH (Arginine Dehydrolase)
Starch hydrolysis
Negative
Positive
P. medocina
ADH (Arginine Dehydrolase)
Starch hydrolysis
Positive
Negative
