5-Anaerobes (2)

Bacteria that do not require oxygen for growth & reproduction Oxygen is detrimental to them

strict) anaerobe = tolerates no more than 0.5% oxygen

(moderate) anaerobe = tolerates small amounts (2-5%) oxygen

Bacteria that can grow in the presence or absence of oxygen

• Foul-smelling

• Gas bubbles

• Black Blood

• human/animal bite or abdominal surgery

• Sulfur granules

• Sterile body sites

• blood, bone marrow, deep wounds, CSF, other body fluids/ deep tissue

• Aspirates specimens= Suprapubic (urine), Culdocentesis ( uterus), Transtracheal ( lung)

• Contaminated body sites

• Ex- Specimens for routine culture superficial wounds/sores/ulcers swabs mouth/throat/sputum specimens stool/rectal swab (unless for C. difficile) vaginal/cervical/urethral swabs clean catch/catheterized urine

needle aspirate

best; anaerobes never exposed to air; expensive

Gas pak or evacuation/gas replacement---less expensive; anaerobes exposed to air

least expensive; accommodates one or two plates, but anaerobes exposed to air

• Plastic jar, lid with rubber seal, gas generating envelope, palladium catalysts

• lid feel warm

• moisture on the side of the jar

• Methylene blue indicator loses its blue color and turns white

• ( Resazurin indicator may be used; it turns from white to pink in absence of oxygen

• Lid crack

• Rubber seal is broken

• Catalyst not working

• Gas generating envelop defective

• Components = SBA + hemin/ Vit. K

• Purpose = nonselective/ most anaerobes grow well on

• Draw back = Facultative anaerobes also grow well on it

• Components = 20% bile and Esculin

• Purpose = Select and differentiate the B. fragilis group

• Components = laked SBA and antibiotics

• Purpose = enhance pigment of Prevotella / Recovers B. frag group

• Components = SBA + PEA

• Purpose = Inhibit gram negative facultatives, select for gram positive anaerobes, inhibits swarming proteus

• Components = SBA + antibiotics

• Purpose = same as PEA

• Many labs use PEA for anaerobes and CNA for aerobic culture

• Components = broth / hemin and vitamin k

• Purpose = holding broth

• Look over slide 32

• Components = egg yolks, provide fatty acids

• Purpose = detect lipase/ lecithinase production

• Lipase positive =iridescent sheen 0r pearly layer

• Lecithinase positive opaque precipitate under the colony

• Used to ID Clostridium species

• Components= Antibiotics, furctose, indicator

• Purpose= select for Clostridiodes difficlile

• horse stable odor yellow colonies (fructose-positive

• 3% or 15% (best) H202

bubbles

no bubbles

• reagent: para-dimethyl cinnamaldehyde

blue-green color

pink color

• Used to determine if the anaerobe is

  sensitive or resistant to antibiotics, such as

  Kanamycin (k), Vancomycin (Va), Colistin

  (Cl)

• zone of inhibition ( no growth)

no zone of inhibition (growth)

small gram positive bacilli with round, terminal spores , resemble a tennis racket or drum stick

pleomorphic gram positive bacilli; beaded, clubbed, palisades, diphtheroidal

pale staining gnb with tapered ends

pale staining gram negative bacilli with rounded ends, may be pleomorphic with coccoid bodies and chains

gram positive cocci, single, pairs &chains

Tiny, gram negative cocci, pairs and packets

dental,thoracic or abdominal surgery, or in tissue abscesses

mouth ,GI tract ,genital ,skin

Human normal (indigenous) flora aka inside the body

Actinomyces israelii

Veillonella

Peptostreptococcus

Prevotella & Porphyromonas

Fusobacterium

Bacteroides species

live outside the body ( soil, animals, water and plants)

The clostridium species

Wound: trauma to skin

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Food: especially spores in home canned vegies

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Infant: especially spores in honey

Bacteria grow and produce the most potent neurotoxin known that inhibits the release of acetylcholins, causing a flaccid paralysis

causes lockjaw ( tetanus)

Bacteria in the wound produce a potent neurotoxin, tetanospasmin that causes continuous muscle spasms

Gram positive bacilli with round terminalspores (“tennis racket” appearance)

Clostridium perfringens, Clostridiodes difficille

Bacteroides fragilis group

Clostridium perfringens

Peptostreptococcus species

Clostridium

Propionibacterium

Peptostreptococcus

Fusobacterium

Veillonella

wound infections - most common cause of gas gangrene (myonecrosis) in the US

Pathology caused by

enterotoxins (food poisoning)

exotoxins & enzymes (gas gangrene)

Large, gram positive bacilli

Box cars”: rectangle with square ends

Infections caused by toxins A and/or B

(Colitis PMC) and (diarrhea AAD)

gram positive bacilli

subterminal spores

Kanamycin, Vancomycin, Colistin

small gram negative bacilli/coccobacilli; some pleomorphism