exam 2 Flashcards
1. There is a draining abscess of a cow, what are you differential diagnosis? A. mastitis due to stapylococcus aureus B. Mastitis due to Trueperella pyogenes C. mastitis due to corynebacterium pilosum D. A and B E. all of the above
answer : D
A. mastitis due to stapylococcus aureus (top dx for mastitis)
B. Mastitis due to Trueperella pyogenes (gave a picture given nasty lesions in udder and pyogenous means pus)
C. mastitis due to corynebacterium pilosum (causes UTI - not part of DDX)
- from the previous case, the cow mammary abscess picture.
you isolate 2 organisms, the first one is an obligate anaerobic gram negative bacteria consistent with Fusubacterium necrophorum. the second one is gram positive, faculative anaerobe, nonmotile, catalase negative diphteroids. (telling you its organism associated with lesions as before!) you immediately think of _______as the second agent.
a. staph aureus
b. corynebact. pseudo.
C. trueperella
D. streptococcus agalactiae
E. Listeria monocytogenes
Answer : E
a. staph aureus (is not a diphteroid, but it is catalyase positive. catalase is second test you do when there are gram positive cocci. catalayse positive are staph and negative are strep.)
b. corynebact. pseudo. (catalase positive. assocaited with mastitis? maybe. phagocytic intracellular orgainsims. most of these are catalase positive.)
C. trueperella (catalase negative)
D. streptococcus agalactiae ( not diphterpoid)
E. Listeria monocytogenes (is motile and is not dipteroid, is a rod)
key is the catalyase test because its distinguishes the two diphteroids. phagocytic intraceullular organism - most are catalayse positive bc it mandated destruction on hydrogen peroxide
Listeria is motile at what temperature?
25 celcius
T/F Listeria is a classic intracellular phagocytic organism
True
Which animal group are most frequently affected by Listeria?
a. avian
b. canines
c. ruminants
d. equine
c. ruminants
There are two important pathogens of Listeria.
L. monocytogens test postive in CAMP test with what bacteria?
L. invanovii test positive in CAMP test with what bacteria?
L. monocytogens : CAMP+ with S. aureus
L. invanovii : CAMP+ with R. equi
what type of cells does Listeria like to persist in?
hepatocytes
and epithelial cells/endotheial
but soto stressed hepatocytes
Which of the following is NOT a classical presentation of Listeria?
a. respiratory infection
b. septicemia
c. encephalitis
d. abortions
a. respiratory infection
these are classical signs of Listeria:
b. septicemia
c. encephalitis
d. abortions
T/F In studying Listeria, we have also discovered NK cells, cytotoxic T-cell activity, and activated macrophage response.
TRUE!
these are 3 of the MOST important cells in CMI.
Listeria has been a perfect model of the study of CMI
What is actA produced by Listeria?
protein that aids in intracellular movement by actin. Listeria hijacks actin inside the host cell.
remember motile at 25 celcius
T/F Listeria requires flagella once inside the cell
FALSE
because the actA protein allows Listeria to hijack actin from the host cell to use for intracellular movement
Listeria produces Internalins.
What are they?
surface proteins responsible for adhesion and entry to target cells. allows Listeria to penetrate cells.
T/F Listeria induce phagocytosis
True.
they want to be phagocytosed
What is the main virulence factor of Listeria bacteria?
LLO - Listeriolysin
it allows Listeria to break out of cells. releases the bact from phagosome into the cytosol.
activated at low pH
What is most likely the natural habitat of Listeria bacteria?
decomposing pant matter!
hence how ruminants are the most affects…from eating contaminated silage!
what is Silage disease?
ingestion of silage contaminated with Listeria, poor quality.
how ruminants get infected.
T/F up to 70% of humans are asymptomatic fecal carriers of Listeria.
True!
There are two routes of entry for Listeria.
what are they?
intestinal and CNS
What is the pathogenesis of the intestinal Listeria?
- cow eats infected silage. people drink infected milk
- attachment, entry, survival in cells
- dissemination
Which of the following is NOT route that Listeria can disseminate?
a. cell to cell
b. intestinal
c. bloodstream
d. phagocytes
b. intestinal
that is just a way it gets in!
Outline the pathogenesis of Listeria in the CNS.
- entry via a wound
- to trigeminal nerves
- CNS - meningitis
T/F Listeria is one of the top 5 causes of meningitis transferred from milk, in humans.
TRUE. ew.
T/F Listeria is not zoonotic.
FALSE
remember…in the milk…meningitis…
In a neurologic animal, where is the best place to sample to test for Listeria?
The spine!
It is in the CNS. will be cloudy fluid.
In a dead animal we would take sample of the brain, it is in the brain stem.
If you have a pt that is septic and suspect it may be infected with Listeria, where is the best place to get a sample for testing?
the Liver!
If you see a sheep circling in one direction and head pressing, you will be thinking?
um why is it doing that.
and maybe it is infected with Listeria and has encephalitis.
T/F in the encephalitis form of Listeria, on histology it will be common to see perivascular cuffing.
true!
T/F Histology will be an effective method to DX Listeria.
FALSE!
often hard to see a lot of Listeria bacteria.
should also do serology
T/F It is safe for a pregnant woman to be working around cattle that may be infected with Listeria.
Hell no.
False
What will commonly be seen in ruminants with septicemia due to Listeria infection?
Abortions
mainly in young.
bact can be in placentomes and cross to amniotic fluid
T/F Listeria can cause subclinical mastitis.
True
and then people drink their milk and get it!
so drink pasteurized milk….
T/F Purulent multifocal hepatitis is common with Listeria infections.
True!
and the liver is a good place to get tissue samples!
T/F chinchillas are quite susceptible to listerial septicemia
apparently so…TRUE
Please explain “cold enrichment”
listeria can do it!
so in general, you collect bact samples and place them in the fridge to slow replication.
but NOT with Listeria because remember it likes colder temps for replication.
What is the most common manifestation of Listeria in humans?
Meningitis!
from drinking that unpast. milk
What is a classic source of Listeria infection? (where does it like to be when outside host)
contaminated silages!
so if you suspect an outbreak, test the silage.
What type of immune response do we want the host to have against Listeria?
CMI
remember it is a facultative intraceullar organism
T/F Live attenuated vaccines show some potential in cattle
FALSE! in sheep
What technique can be used to help grow Listeria?
cold enrichment
Under what conditions does Listeria grow best?
a. increased O2, decreased CO2
b. decreased O2, increased CO2
b. decreased O2, increased CO2
it doesnt like oxygen all that much
T/F L. monocytoegenes tests CAMP negative when cross-streaked with S. aureus
FALSE, its CAMP POSITIVE
remember :
L. monocytogens : CAMP+ with S. aureus
L. invanovii : CAMP+ with R. equi
T/F Erysipelothrix rhusiopathiae is coagulase positive.
True
T/F Most gram+ bacteria can not persist in the environment for a long time.
FALSE
most gram+ can persist in environment because of their peptidoglycan layer!
What species is most common to be infected with Erysipelothrix rhusiopathiae?
swine! oink oink!
What age of swine is most commonly infected with Erysipelothrix rhusiopathiae?
3months - 3 years
this is a period where swine is pushed for production. change diet, crowded - stress!
pigs 3mo have developed immune system
In Turkeys and sheep, which gender is more frequently infected with Erysipelothrix rhusiopathiae?
Males! because they are stupid and fight
In Erysipelothrix rhusiopathiae, what benefit is the capsule?
protects them from being killed by phagocytic cells and allows for intracellular replication.
- anti-pahgoctyic
- allows intracell rep
In Erysipelothrix rhusiopathiae, what is the purpose of neuraminidase?
adherence!
It cleaves sialic acid resideson endothelial cells, so bact can bind and then bact can break off to cause thrombus, endocarditis, meningitis
T/F Erysipelothrix rhusiopathiae is resistance to drying
TRUE
and can survive in swine poop for 6 months
T/F Erysipelothrix rhusiopathiae is zoonotic caused by birds
FALSE - caused by fish.
people working with fish can get punctured by hooks and then wound gets contaminated….
What is one of the most common reservoirs for Erysipelothrix rhusiopathiae?
surface slime of fresh and salt water fish…..yummy!
What is the pathogenesis or Erysipelothrix rhusiopathiae?
- bact attachment and invade cells - neuroaminidase
- vascular damage and hyaline thrombus
- can survive inside phagocytes
What is the most common form of Erysipelothrix rhusiopathiae in swine?
a. septic form
b. Diamond skin disease
c. chronic form
b. Diamond skin disease
you know this!!! its been in just about every class!
T/F the acute form of Erysipelothrix rhusiopathiae causes low mortality in swine.
FALSE
causes high mortaility within a few days of infection if untreated.
Which form of Erysipelothrix rhusiopathiae in swine, has been known to have a “significant impact in industry”?
a. septic form
b. Diamond skin disease
c. chronic form
Chronic form!
mortality but mostly big decrease in production.
-endocarditis
-arthritis
What lesion can be seen on the skin of swine with Erysipelothrix rhusiopathiae?
diamond pattern!
You are called to a swine farm and there is one pig that has not been putting on weight, has a stiff gait and has diamond skin lesion. what the heck is going on?
this pig probably has Erysipelothrix rhusiopathiae!!
The Erysipelothrix diamond lesions are a result of what type of hypersensitivity?
type 3!
The Erysipelothrix diamond lesions are a result of ____ being deposited in the SQ vasculature with subsequent thrombus formation.
antigen-antibody complexes
T/F In Erysipelothrix rhusiopathiae, persistence of antigen in joint tissues act as a stimulus for immune reaction (arthritis).
True!
thats why those piggies are stiff!
The mortailty rate in birds infected with Erysipelothrix rhusiopathiae?
a. 1-15%
b. 2-25%
c. 3-35%
d. 4-45%
b. 2-25%
In turkeys, Erysipelothrix rhusiopathiae is usually seen as what pathoneumonic presentation?
septicemia!
cyanotic skin.
swollen cyanotic snood
What are two of the chronic manifestations of Erysipelothrix rhusiopathiae in Turkeys?
vegetative endocarditis
arthritis
T/F Turkeys infected with Erysipelothrix rhusiopathiae can have petichial hemorrage of the SQ.
TRUE
but more common in swine…shine bright like a diamond!
People infected with Erysipelothrix rhusiopathiae, probably work with what species of animals?
FISH!
How can the host antibodies protect against Neuroaminidase produced by Erysipelothrix bacteria?
Antibodies can bind directly to the neuroaminidase, thus stopping it from cleaving sialic acid. then the bacteria cannot bind and is just a useless bacteria that will get phagocytosed. K bye!
Live attenuated vaccines for Erysipelothrix rhusiopathiae are effective against which form?
a. actue
b. diamond
c. chronic
a. acute
not so protective against chronic
You are working up a case on some swine that have diamond skin lesions. You took a sample and find there are long gram positive rods. What could this be?
Erysipelothrix rhusiopathiae
which form of Erysipelothrix rhusiopathiae would be most difficult to DX?
a. acute
b. diamond
c. chronic
c. chronic
the bacteria could be long gone and there may be just depositions of antigen/antibodies left.
What antibiotic would be best to TX swine infected with acute form of Erysipelothrix rhusiopathiae?
a. clavamox
b. ampicillin
c. metronidazole
d. penicillin
d. penicillin
for at least 5 days
but not so good in chronic form
T/F Penecillin is useful in treating all forms of Erysipelothrix rhusiopathiae.
FALSE.
nope. just acute form
What should be used to TX turkeys with Erysipelothrix rhusiopathiae?
Penecillin also!
T/F Erysipelothrix rhusiopathiae can be prevented in turkeys by vaccinating with a bacterin
True
T/F Erysipelothrix rhusiopathiae is part of the normal flora of fish.
True.
What is considered to be one of the most important human pathogens in regards to humans?
a. Listeria
b. bacillus
c. Bordetella
d. Shigella
b. bacillus!!!
Which bacteria is known as Antrhax?
a. Bordetella
b. Invasive Clostridia
c. bacillus
d. Yerisinia
c. bacillus
Does Bacillus form spores?
Hell yes it does
T/F Bacillus is not able to persists in the environment
FALSE.
you bet yo ass it can.
It’s anthrax.
T/F Bacillus is an intracellular bacteria.
FALSE
its neutrophilic
What are the two plasmids of Bacillus that contain virulence genes?
a. pX01 and pX03
b. pX01 and pX02
c. pXo2 and pX03
b. X01 and X02
In bacillus, what does pXO2 code for?
pX02 contains gene encoding the capsule for protection!
In bacillus, what does X02 contain?
AtxA, AcpA and gene for edema and lethal toxin
T/F Bacillus bacteria produces a capsule in the spore form.
FALSE.
spores do NOT have capsule.
the vegetative state has capsule.
Name the two regulatory proteins of virulence factors or Bacillus?
AtxA - anthrax toxin activator
AcpA - anthrax capsule activator
Which of the following Bacillus virulence factor proteins respond to environmental cues?
a. AtxA
b. AcpA
c. both a and b
c. both a and b
T/F the vegetative form of Bacillus produces a capsule.
TRUE
T/F If bacillus does not produce a capsule, it is still virulent.
FALSE.
no capsule = avirulent
cannot persist or release toxins
In Bacillus, what is Lethal toxin (Letx) composed of?
Protective antigen (PA) lethal factor (LF)
In Bacillus, what is the function of the protective antigen (PA)?
allows bact to attach to the macrophage
In Bacillus, what is the function of lethal factor (LF)?
Killing of the macrophage or inducing a cytokine storm
Bacillus.
what happens at high concentrations of Lethal toxin?
It just straight up kills macrophages. BOOM.
In bacillus, what controls the lethal toxin and Edema toxin?
AtxA
which responds to environmental cues
Name the two toxins produced by Bacillus.
Edema toxin (EdTx) Lethal Toxin (Letx)
What is Edema Toxin? (what is it composed of?)
protective anitgen (PA) - bind to target edema factor (EF) - electrolyte and fluid loss in affected cells
If you were to create a vaccine for Bacillus, what virulence factor would you target?
a. capsule
b. protective antigen
c. edema factor
d. lethal factor
b. protective antigen
Which type of Bacillus anthracis can persist in dry environment for decades?
a. spores
b. vegetative
a. spores
the lazy vegetative state only survives in environment about 2 weeks.
T/F Bacillus spores like Nitrogen-rich soils.
False
calcium rich!
Herbivores or carnivores are more susceptible to anthrax?
herbivores!
Why are most birds totally resistant to anthrax?
high body temp does not allow for bacillus bact growth
What mode of infection induces the most virulent form of Bacillus?
a. ingested
b. inhaled
c. cutanous
b. inhaled
What is the second most virulent form of Bacillus that can cause high mortality?
a. ingested
b. inhaled
c. cutaneous
a. ingested
What is the most common presentation of anthrax in humans?
in spores in the skin!
necrosis, scarring, black tissue
What does anthrax do when it is not happy?
sporulate! so it can persist
Once an animal has died, what state will bacillus be in?
a. vegetative
b. spores
a. vegetative
T/F If you suspect an animal has anthrax, proceed with your necropsy and be sure to take samples.
FALSE.
NO NO NO! dont do it.
You are called to a sheep farm to inspect one sheep that has not been doing well. Today it has started bleeding from all body orifices. What is your first Differential DX?
a. E. coli
b. Actinobacillus
c. Shigella
d. Bacillus
d. Bacillis!!!
baaaaaaaaad news.
get it? baaaa…like a sheep…
What is the classical postmortem finding in an animal infected with bacillus?
widespread hemorrage….and they were probably bleeding from everywhere before death.
What species are most susceptible to Bacillus?
a. equine
b. ruminants
c. fish
d. canine
b. ruminants
You are called to a dairy farm. A cow died last night, and you notice rigor mortis has not set in….what is your first thought for differentals DX?
shit. Anthrax!
What else could result in a similar presentation to anthrax, where the animal is bleeding from everywhere?!
rhodenticide poison!
snake bite
plant poison
what bacteria is black leg?
a. clostridium mastitis
b. clostridium botulinum
c. clostridium chavuei
clostridium chavuei
T/F Bacillus is just as common in swine, carnivores, and horses as it is in ruminants.
FALSE.
Most common in ruminants!!!
Which of the following are modes of infection for human anthrax?
a. cutaneous
b. ingestion
c. inhalation
d. all of the above
d. all of the above
What is the fatality rate of cutaneous anthrax in people?
10-20%
What is the fatality rate of metabolic anthrax in people?
25-60%
What is the fatality rate of inhalation anthrax in people?
100%
What type of immune response is MOST desired when fighting Bacillus anthrax?
a. CMI
b. humoral
b. humoral
In a human infected with anthrax, what is the best method of treatment?
antibiotics to kill off any bacteria and also get treatment with the hyper-immune sera to bind any toxins released
In anthrax, why do we want a humoral immune response? What will the antibodies do to the bacteria?
The host antibodies will allow for binding the virulence factors.
most importantly the Protective antigen because then you will also knock out edema factor and lethal factors
What structure of Anthrax does McFadyean’s Methylene blue stain?
the capsule stains pink!
good diagnostic tool
Bacillus licheniformis is most associated with?
a. cutaneous lesions
b. food spoilage (silage)
c. abortion and bovine mastitis
d. ruminant diarrhea
b. food spoilage (silage)
Bacillus cereus is most associated with?
a. cutaneous lesions
b. food spoilage (silage)
c. abortion and bovine mastitis
d. ruminant diarrhea
c. abortion and bovine mastitis
