Gram positive bacilli
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- AEROBIC gram positive bacilli genera (5)
-
corynebacterium
lactobacillus
listeria monocytogenes
erysipelothrix rhusiopathiae
bacillus -
Name 3 general characteristics of all Corynebacterium species:
(shape, behavior, test) -
-Club-shaped GPB
-Capable of snapping/pallisading
-Catalase positive - What special staining morphology is unique to corynebacterium diptheriae?
- -When stained w/ methylene blue, shows metachromatic food granules that LOOK like spores
- What type of hemolysis does C. diptheriae exhibit?
- Beta; therefore it could be confused with beta streps.
- Name 2 types of growth media for culturing C. diptheriae:
-
-Loeffler serum agar
-Tellurite agar - Why is Loeffler serum agar used?
- It allows for a good staining reaction of C. diptheriae
- What is the purpose of tellurite agar?
-
Isolation & differentiation of C. diphtheriae.
Differentiation: C. dipht will turn black, other colonies will remain clear/white. - what causes diptheria?
-
exotoxin produced by the organism;
coded by lysogenic phage - List 3 symptoms of diptheria:
-
-pharyngeal membrane
-edema
-fever - how many types of corynebacterium, what are they:
-
4:
-corynebacterium diptheriae
-diptheroids (12)
-Corynebacterium jeikeium
-corynebacterium urealyticum - when does diptheria develop from a corynebacterium diptheroid strain?
- when a lysogenic phage (encoding the toxin that causes the disease) infects the bacterium.
- symptoms of diptheria
- swellign of neck, lymphadenopathy, Bull's Neck
- 3 strains of colonial morphology of corynebacterium on tellurite agar:
-
-gravis (very grave; severe)
-mitis (little mite; not severe)
-intermedius duh - what is the Elek test for?
- confirming the virulence of corynebacerium diptheriae (make sure it actually is producing the toxin)
- 3 steps in the diagnostic strategy for corynebacterium diptheriae
-
1. doctor clues us in
2. colonial morphology on tellurite tells how virulent the strain is.
3. virulence testing (elek) confirms the virulence -
What are the diptheroids?
Where are they normal flora? -
A general group of about 12 corynebacterium species;
-Normal flora on skin/mucous memb/vagina; -
What diphtheroid is most commonly an infection causer?
Where is it normal flora? -
-Corynebacterium jeikeium
-Human skin - What is the DPT vaccine for?
- Diphtheria and Pertussis - but should only be given to folks under 5 yrs old.
-
What bacteria causes encrusted cystitis?
Explain the infection. - C. urealyticum. It produces urease; surrounds itself w/ NH3 to combat antibiotic, results in a chronic UTI.
- what is commonly inserted into the vagina to maintain its physiology because it's such a wonderful part of the normal flora?
- lactobacillus. also common in mouth.
- lactobacillus morphology
- long, thin GPB
- lactobacillus is it a pathogen?
- rarely; in yogurt and probiotics. in the normal flora.
- two things that differentiate corynebacterium from lactobacillus:
-
Coryne Lacto
Catalase positive Catalase negative
snapping no snapping
club-shaped long and thin
small/dry/white tiny/clear/alpha
beta alpha - listeria monocytogenes gram stain
- gram positive COCCObacilli; very small so look for one
- 3 basic characterist of listeria:
-
1. gram stain = coccobacilli
2. weak positive catalase
3. weak B-hemolysis confuses w/ strep cuz its small/off-white/translucent too - pathogenicity of listeria; where, to whom, what diseases?
-
where; in dairy products, cold, processed meats like hot dogs.
whom: in neonates or immunocomp adults;
diseases: meningitis, septicemia - which organism is commonly confused with weakly B-hemolytic Streps?
- listeria monocytogenes
- what is commonly confused with listeria?
- weakly B-hemolytic streps
- How specifically is Listeria similar to Strep?
-
-Bile esculin positive makes you think it's enterococcus or strep D nonentero.
-Hippurate hydrolysis positive makes you think it's Strep group B - what are 2 ways to detect motility of listeria?
-
at room temp (cooler)
-hanging drop shows tumbling!!
-semi-solid stab shows umbrella!! - What weird combo is used to treat listeria?
- amoxacillin + aminoglycoside
- positive biochem tests of listeria;
-
bile esculin
catalase
hippurate hydrolysis
beta hemolysis
motility
all are positive! - Name two basic characteristics of erysipelothrix rhusiopathiae:
-
-Long, gram pos bacilli
-Catalase negative - What type of disease does e. rhusiopathiae cause:
- Erysipeloid - a zoonotic cellulitis in vets and butchers, that may turn to bacteremia.
- ERYSIPELOTHRIX RHUSIOPATHIAE IS THE ONLY GRAM POSITIVE BACILLUS TO PRODUCE:
- H2S - Hydrogen sulfide positive
- basic description of bacillus gram stain
- large gram positive bacilli with spores
- bacillus is catalase
- positive
- listeria is catalase
- weakly positive
- erysipelothrix rhusiopathiae is catalase
- negative!
- corynebacterium is catalase
- positive
- lactobacillus is catalase
- negative
- all bacillus are ___ and ___ except Anthracis:
-
beta hemolytic
motile - what is the pathogen of the bacilli?
- bacillus anthracis
- what bacteria makes chains of gpb with round to oval cntral spores? looks like bamboo?
- bacillus anthracis
- What does tenacious mean?
- Colonies like to stick togehter
- what chemically makes anthracis tenacious?
- it has a protein capsule instead of glycocalyx/sugar. Thus it sticks
- hemolysis of bacillus anthracis?
- not beta like its family; its gamma!
- which bacteria has a rhizoid margin
- bacillus anthracis
- what happens when you touch the top of an anthracis colony with a needle?
- sticks to the needle like an egg-white peak cuz of the protein capsule in place of sugar
- What are three pathogenic forms of anthracis?
-
-cutaneous
-pulmonary
-enteritis - What is the main cutaneous anthrax characteristic, and another name for this form?
- Black escher - spores under the skin cause pustules which turn black.
- How is cutaneous anthrax often transmitted?
- Through handling goat hides
-
How is pulmonary anthrax transmitted?
What is another name for it? -
Via inhalion of spores released during wool shearing.
Aka, Woolsorter's disease. - least common and most likely to be fatal anthrax form:
- enteritis. From infected meat.
- what is used to treat anthrax?
- penicillin/ ciprofloxacin
- 6 essentials for I.D. Anthrax:
-
1. Gamma colonies
2. Large tenacious GPB with spores
3. Catalase +
4. Non-motile
5. I.D. by public health labs
6. Level 3 safety safety cab necessary - where are saprophytic bacilli often found?
- as plate contaminants on cultures.
- type of hemolysis of Saprophytic bacillus
- Beta, like almost all other bacilli, except anthracis
- bacillus cereus causes 2 TWO! really gross things:
-
-emetic food poisoning
-diarrhetic food poisoning - What are the 2 main differences between emetic and diarrhetic food poisoning?
-
The incubation times and associated foods.
-Emetic: 1-6 hr incubation, assoc. w/ fried rice. -Diarrhetic: 6-24 hr incubation, assoc. w/ meats and sauces.