Non Fermenting GNB Flashcards by Kyra Catedral

• Organisms that CANNOT UTILIZE CARBOHYDRATES WITHOUT_______
Therefore, they are also called______

OXYGEN

oxidative

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• Are able ferment carbohydrates but only…
• Does NOT form… in TSI

FORM SMALL AMOUNT AND VERY
WEAK ACIDS

Yellow colored media in TSI

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Do NOT UTILIZE CARBOHYDRATE (with or w/o O2)

Uses other compounds as source of energy Utilizes amino acids

Non-saccharolytic or non-oxidizers

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Oxidase negative

O+/ F+

Enterobacteriacea

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Oxidase positive

O+/ F-

Pseudomonadaceae

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Oxidase positive

O+/ F+

Vibrionaceae

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CHARACTERISTICS OF NON-FERMENTERS
→ Spore???
→ Aerobic condition???
→ TSI:???

Non-spore formers

Obligate aerobes → to utilize carbohydrates

K/K; H2S (-)

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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

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NF Grow better in____ than on ____

SBA than on MACCONKEY AGAR
(+/-)

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NF TEST RESULTS

OXIDASE TEST

GRAM STAIN

TSI

MOTILITY

POSITIVE

GRAM NEGATIVE BACILLI

K/K

MAJORITY ARE MOTILE

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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

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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

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• Commonly used test to differentiate Enterobacteriaceae from Non-lactose
fermenters

O-F CHO utilization patterns

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→ 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

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Commonly used test to differentiate Enterobacteria from Non-lactose fermenters

OXIDATION-FERMENTATION (O-F) TEST

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OF test uses…

HUGH AND LEIFSON culture media

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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

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RATIO???

peptone to CHO concentration for NF

For Enterobacteriaceae???

1:5

2:1

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HUGH and LEIFSON

→ O/F Basal media
→ CHO: (5)
→______ = indicator

Glucose, Maltose, Lactose, Mannitol, & Xylose (GMX ML)

Bromthymol blue

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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)

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OF TEST

→ POSITIVE FOR CLOSED TUBE:____
→______ COLOR → able to ferment carbohydrate
→ _____COLOR → No carbohydrate utilized

Enterobacteriaceae (Yellow color formation)

YELLOW

GREEN/BLUE GREEN

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Open: Green/Blue Green

Closed: Green/ Blue Green

Non-saccharolytic

Alcaligenes faecalis

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Open: Yellow
Closed: Green/ Blue Green

Oxidative

Pseudomonas

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Open: Yellow
Closed: Yellow

Fermentative

Enterobacteriaceae

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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

→ 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

Non Fermenting GNB Flashcards

(61 cards)