Gram + Rods Anthrax, Flashcards
What are the general characteristics of B. spp.
Large Gram + Rods Endospore forming Thick Peptidoglygcan layer Teichoic and Lipo-teichoic acids NO OUTER MEMBRANE!
What type of pathogen is Bacillus anthracis?
Obligate mammalian pathogen
What type of pathogen is Bacillus cereus
RARE cause of OPPORTUNISTIC infections and food poisoning in animals
What is the insect pathogen in Bacillus spp?
B. thuringiensis
What are most species of Bacillus?
soil saprophytes
How fast do bacillus grow?
Rapid!! kim collins fast- google it!
What type of medium does bacillus grow on?
Gram + selective and non selective media
What type of growth can be expected on MacConkeys Plate?
NONE! MacConkeys is Gram - Selective
What are the hemolytic properties of Bacillus species?
varies
to what level are saprophytes identified?
Genus
What bacteria was used to test Kochs Postulates?
B. antracis
what are the oxygen requirements of B. anthracis?
Aerobic
B. anthracis motile or no?
non-motile
B. anthracis hemolytic or nah?
nah brah they aint
Most endospores protrude through the cell causing a club like appearance, is this characteristic true for B. anthracis?
No, Think of B. anthracis as a purple wedding band with a tiny diamond that barely touches (if even) the membrane. Squared ends
Microscopic evaluation of colonies will show what when looking at B. anthracis?
Medusa head colonies ( shes the one with all the snakes for hair that if you looked at her she turned to stone. The more you know!)
What virulence factors are associated with B. anthracis
Cell associated
Capsule ( NOT POLY SACCHARIDE!)- Polymers of D-glutamic acid
Extracellular
Anthrax Toxin
3 proteins- Edema factor, Lethal factor & protective Antigen
What source of genetics encodes the virulence factors of B. anthracis?
Plasmids
Which plasmids are required for virulence in B. anthracis?
Both Capsule and Toxin
Where is the capsule for B. antracis produced?
Only IN VIVO- IN THE ANIMAL
Capsule biosynthesis operon transcriptionally upregulated by CO_2_/ Bicarb signal
What molecules make up the B. anthracis capsule?
Polymers of D-glutamic acid
encoded by plasmid
Antiphagocytic
What stain associated with B. anthracis and what is the reaction called?
Polychromatic methylene blue
McFadyean rxn.
Capsules stain as pink shadow
What is the Edema factor?
Calmodulin-dependent adenlyate cyclase ( inhibits neutrophil function)
What is the lethal factor?
Zinc metalloprotease (cell death, hypoxia-induced tissue injury/shock)
What is the protective antigen?
Cell binding factor (translocation into cell)
Which factors are required for virulence of B. anthracis?
Edema, Lethal, Protective antigen
What do the three factors of the anthrax toxin cause?
increased vascular permeability and cell necrosis
pOX1 plasmid encodes?
Toxin
pOX2 plasmid encodes?
capsule
What determines the habitat of B. anthracis?
Dependent on susceptible animals for replication
( BacT kills host or vic a versa)
Dependent on Endospores for survival in soil
(exposure of carcass to O2 increases sporulation)
Ecological cycles of infection
(sporulation and germination have specific requirements)
What are predisposing factors that increase exposure of animals to anthrax spores in soil?
Hx: site of previous anthrax deaths
Flooding (endospores float to surface)
Soil conditions: Alkaline pH60-80degrees) During drought animals tend to forage closer to the ground thus increasing chances of coming in contact with spores
What is the most common transmission of B. anthracis?
exposure to endospores
When endospores germinate within phagolysosomes of a macrophage what happens?
septicemia and bacteremia
What mediates the escape of B. anthracis from phagocytic cell?
Phospholipase
what inhibits phagocytosis of vegetative cells (B. anthracis)
capsule and edema factor
How fast do Vegetative cells grow in the body? (B. anthracis)
Rapidly
Complete anthrax toxin causes what?
Cell death and affects vascular permeability
-per acute septicemia
Forms of Anthrax
Per acute septicemia happens in?
Ruminants (cattle and sheep)
Forms of Anthrax
Acute septicemia happens in?
Horses
Forms of anthrax
Pulmonary infection in? what is the condition called?
humans (wool sorters disease)
Forms of anthrax
Pharyngeal infection in?
pigs, dogs
Forms of anthrax
intestinal infection in?
man, pigs, horse
Forms of anthrax
Cutaneous infection in? and whats the condition?
Humans ( malignant carbuncle)
what are the ante-mortem signs of per acute/ acute septicemia (cattle sheep deer) (B. anthracis)
rapidly fatal disease high fever bleeding from orifices shock respiratory distress
what are the post-mortem signs of per acute/ acute septicemia caused by B. anthracis? (cattle sheep deer)
dark, unclotted blood
incomplete rigor mortis
splenomegaly: Large “ current-jelly” spllen
widespread edema bacteremia (80% of bacteria in blood @ time of death)
What is the onset time of anthrax infection in horse?
~96 h
What are the clinical signs of anthrax infection in horses?
colic and diarrhea
edema mainly in point of infection ( intestine, throat (asphyxiation))
septicemic as in ruminant
What signs are associated with swine and anthrax infection?
Typically in pharyngeal tissue
Ulcerative lesion serves as portal of entry
followed by regional lymphadenitis
associated with consumption of contaminated meat and bone meal
Obstructive edema may cause death
Ulcerative hemorrhagic enteritis and mesenteric lymphadenitis
What is expected with Anthrax and carnivores
similar to swine patterns
exposure through tainted meat my trigger septicemia
What are the diagnostic techniques for anthrax?
Blood smear- presumptive Dx
Aerobic culture and PCR from blood
(flourescent antibody Staining)
Do you conduct a field necropsy if anthrax is on your DDx list?
NO Never Dont do it! AH AH AH stop it right now!
Call the state/ federal officials- let the tax payers pay for it you have better things to do
If you happen to open up the carcass what should you collect to confirm/rule out anthrax?
spleen
Tests from the past were susceptible to what and what was the appearance on the plates?
penicillin (string of pearls)
what type of agent is anthrax?
BSL-3
Select agent
REPORTABLE Dz
What can you treat in an anthrax infection?
vegetative cells only
When are antimicrobials effective in an anthrax infection?
if given early,
some localized forms may resolve without treatment
What antimicrobials are used for anthrax infection?
Penicillin
tetracycline
doxycycline
ciprofloxacin
How do you control anthrax infections prior to infection?
VACCINATE YO SELVES FOOL
endemic and high risk areas only
What is the response to anthrax in range/pastured cattle?
quarantine herd ( atleast 30d after last death)
Use PPE
Treat all animals in heard with long- acting ABX (OXYTET)
Move herd from field/pasture/range
Examine animals daily (treat feverish animals)
Vaccinate 8-12d after Tx
properly dispose of carcasses
disinfect
What should you do if you identify a case of anthrax?
notify the authorities- let someone else deal with it
if you have to deal with it dig a hole (>6.5ft) bury animal or human or whatever really under layer of quicklime (anhydrous calcium oxide)
What are the DDx for anthrax
Blackleg- Clostridium chavuoei Botulism- C. Botulinum Poisoning- plants, heavy metal, snake bite Lightning strike Peracute babesiosis
Cutaneous anthrax- humans; what is the prognosis and complications?
10-20% mortality
SQ edema and septicemia
Creepy neck picture looks like a leach but you know dead tissue
GI anthrax- humans; prognosis and complications?
25-60% mortalilty
CONSUMPTION OF CONTAMINATED MEAT
pharyngeal lesions, sore throat and dysphagia, regional lymphadopathy, inappetence, nausea, vomiting blood and bloody diarrhea ( CHA CHA CHA), massive septicemia and toxemia,
Pulmonary or inhalation of anthrax- humans; prognosis and complications
YOU GON DIE 100% experts say you die all of the time
pulmonary edema, hemorrhagic pneumonia, sometimes meningitis
ACUTE ONSET
Spores may remain dormant until engulfed by pulmonary alveolar macrophages.
The most common staphylococcus isolates from dogs?
S. psuedintemedius
Blackie, 5yr F Dog presented with unresolving skin lesions, purulent and blood secretion oozing from lesions, whats causing this?
S. psuedintermedius
chains of cocci on microscopic evaluation?
streptococcus
Staph enterotoxin exerts its pathogenic effect by?
Superantigen, binding indiscriminately to T cell receptor and MHC II receptor.
