MIDTERMS: L4 - GRAM-POSITIVE BACILLI Flashcards
Occurs in long chains, bamboo-rod appearance
Bacillus anthracis
MOTF
Capsule (poly-D-glutamic acid) - encoded in plasmid
pXO2
Anthrax toxin - Encoded on plasmid pXO1
BOTH TRUE
MOTF
1. Protective antigen - allows entry of lethal factor and edema factor
2. Lethal factor - Acts as adenylate
cyclase which increases the host cell’s CAMP
3. Lethal factor - major virulence factor, a zinc metalloprotease that inactivates protein kinase causing death
1,3 - true
2 - Edema factor
MOTF
- Most common anthrax - Cutaneous anthrax
- Most severe - pulmonary anthrax
1 true, 2 false
2 - GIT anthrax
Characterized by localized small erythematous papule which progresses to a ring of vesicles into ulceration called black eschar
Cutaneous anthrax
Malignant pustule (black eschar)
Woolsorter’s disease or ragpicker’s disease
Pulmonary anthrax
Removes contaminating organisms in solid media
heat or alcohol shock
62-65°C for 15-20 mins for B. anthracis
Rapid presumptive immunochromatographic test that identifies B. anthracis within 15 minutes
Red line alert test
B. anthracis appear as beaten egg whites in what plate:
A. BAP
B. PLET: polymyxin B lysozyme EDTA Thallous Acetate Agar
C. GELATIN
B. PLET: polymyxin B lysozyme EDTA Thallous Acetate Agar
irregular fringe-like margin with curled or
swirling projections MEDUSA HEAD/ LION
HEAD/ COMET TAIL
Bacillus anthracis
Ground glass colonies
B. anthracis appear as _____ in GELATIN
A. Medusa Heads
B. Inverted pine tree
C. Ground glass
B.
Anthrax drug of
choice
Intravenous (IV) Ciprofloxacin
ALL ARE CORRECT EXCEPT: Bacillus cereus 1. Gram positive 2. Spore forming 3. Non-motile 4. Encapsulated 5. Beta-hemolytic
3,4
BC are motile, non-encapsulated
- B. cereus cause short incubation type of food poisoning
- Emetic - fried rice
- Nausea and vomiting
Emetic
- Long incubation type food poisoning
- Meat
- Diarrhea
Diarrheal
Referred as hemolysin 4
Cytotoxin K
MOTF
- Enterotoxin - heat labile
- Emetic - heat stable
BOTH TRUE
B. cereus heat shock treatment
70°C for 30 mins 80°C for 10 mins
T OR F
B. cereus appear as feather colonies and ground glass appearance
False
Frosted glass appearance
- Used as insecticide or pesticide to control
insects such as moth, beetles, flies - Posses cellulite enterotoxin
B. thuringiensis
Clostridium botulinum
- Blocks release of acetylcholine from the
presynaptic nerve terminals in the autonomic nervous system and motor end plates resulting in flaccid paralysis
Botulism Toxin
Subterminal spores that resemble TENNIS
RACKET appearance
Clostridium botulinum
SELECT TRUE FOR Clostridium botulinum 1. Gram-negative 2. Tennis racket appearance 3. Aerobic 4. Beta hemolytic (except for type G) 5. Subterminal spores 6. Boxcar appearance
2,4,5
1 - gram positive
3 - strict anaerobic
ALL TRUE EXCEPT FOR: Clostridium tetani 1. Tack head bacillus 2. Terminal spore 3. Peritrichous flagella 4. Swarming colonies 5. Non-hemolytic 6. Ferment carbohydrates
5,6
5 - beta hemolytic
6 - Does not ferment any carbohydrates
Blocks inhibitory neurotransmitters (glycine,GABA)
Tetanospasmin
Gas Gangrene bacillus
Clostridium perfringens
ALL ARE TRUE FOR Clostridium perfringens except:
- Non-capsulated
- Non-motile
- No spores in ordinary media
- target/double zone of hemolysis
- Boxcar appearance
- Chopped-Meat glucose positive
1 - encapsulated
Most important toxin of C. perfringens - mediate destruction of cell membranes
Alpha toxin
MOTF
C. perfringens
1. CAMP test - Bowtie
2. Reverse CAMP - arrowhead
BOTH TRUE
MOTF
Clostridium difficile
1. Motile
2. Non-encapsulated
BOTH TRUE
MOTF
Clostridium difficile
Toxin A - potent cytotoxin
Toxin B - Potent enterotoxin; weakly cytotoxic
BOTH FALSE
Toxin B - potent cytotoxin
Toxin A - Potent enterotoxin; weakly cytotoxic
CAA (choose all apply) Clostridum difficile 1. Oval and subterminal spore 2. Non-hemolytic on BAP 3. Horse manure odor in CCFA 4. Exhibits chartreuse characteristics
1,2,3,4
CAA Corynebacterium diphtheriae 1. Acid fast 2. Motile 3. Spore-forming 4. Klebs-Loeffler bacillus 5. Gram positive 6. Club-shaped
4,5,6
- Non-af
- Non-motile
- Non-spore
Possess the metachromatic granules called
Babes-Ernst granules
Corynebacterium diphtheriae
Cervical and submandibular lymphadenopathy causing the “bull neck” appearance
Corynebacterium diphtheriae
Can also be performed for the better visualization of the organism’s typical Chinese letter appearance
Loeffler’s MB
Cornybacterium diptheriae in Modified Tinsdale Agar and Cystine Tellurite Blood Agar appear as:
Brown-black colonies with halo
CAA Corynebacterium diphtheriae 1. Catalase positive 2. Oxidase positive 3. Urease negative 4. Oxidase negative 5. Ferment glucose and maltose, not sucrose 6. Catalase negative
1,2,3,5
- Carry tox gene
- Bovine Mastitis
A. C. ulcerans
B. C. pseudotuberculosis
C. C. minutissimum
A. C. ulcerans
- Suppurative granulomatous lymphadenitis
A. C. ulcerans
B. C. pseudotuberculosis
C. C. minutissimum
B. C. pseudotuberculosis
CAA Listeria monocytogenes 1. Non - acid fast 2. Non spore forming 3. Facultative anaerobe 3.Tumbling motility - 22-28 degree celcius 4. Umbrella - semi-solid media 5. Catalase negative 6. Esculin hydrolysis positive
1,2,3,4,6
5 - catalase positive
Major virulence factor of L,monocytogenes
Listeriolysin
O:
CAA Erysipelothrix rhusiopathiae 1. Catalase positive 2. Non-motile 3. No capsule 4. Microaerophilic 5. Alpha hemolytic 6. Serovar 1 and 2 - human infection 7. H2s positive
2,3,4,5,6,7
1 - catalase negative
Chalky, dry, crumby colonies in SDA
Nocardia
Molar tooth colonies
Actinomyces
Implicated in acne vulgaris, endocarditis, shunt infections
Propionibacterium acnes
