Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Infectious Agents > Bacillus > Flashcards

Bacillus Flashcards

1
Q

Most bacilli are _____

A

Ubiquitous soil, dust, air, and water saprophytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Bacillus spp.

A

Large, gram-pos, aerobic or facultative anaerobic rods

- produce endospores only under aerobic conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Clostridium spp.

A

Obligate anaerobic, large gram-pos rods that form endospores

- only the spores of clostridium can survive oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

B. cereus

A
  • food poisoning (enterotoxin) –> hemolytic exotoxin
  • gangrenous bovine mastitis (occurs with spore or vegetative form)
  • supperative wound infections
  • common soil saphrophyte and lab contaminant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

B. larvae

A
  • apiculture
  • bee foul brood
  • use oxytetracycline to treat hives*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

B. thruingiensis

A

Biologic insecticide

  • produces insecticidal crystal protein
  • exotoxin used in transgenic plants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

B. polymyxa

A

Produces protein ionophore antibiotic

- polymyxin B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

B. colistinus

A

Produces protein ionophore antibiotic

- colistin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Other names for B. anthracis

A
  • milzbrand
  • charbon
  • malignant carbuncle
  • woolsorter’s disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What animals are resistant to Anthrax?

A

Birds and poikilotherms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What animals are most susceptible to anthrax, in order from greatest to least?

A
  • cattle
  • deer
  • sheep
  • people
  • goats
  • horses
  • swine
  • dogs
  • also buffalo
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the infectious particle of anthrax?

A

The endospore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What form of anthrax do swine and carnivores get?

A

Are usually resistant, but can get the oral or pharyngeal form from ingestion
- GI infection accompanied by hematemesis and bloody diarrhea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Anthrax is not seen in ________ animals

A

Cold blooded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the major characteristic of anthrax?

A

Blood does not clot, will see frank blood coming from all body openings (even after death)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Endospores will survive ______ in the soil

A

“Forever” until the conditions are right for germination

- most resistant form of life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Autoclave

A

Set up specifically to kill spores

- 121 C, 15 psi, 15 min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Are vegetative anthrax cells easy to kill?

A

Yes, are no more resistant than other bacteria

  • die rapidly (30-60 min) in unopened carcasses due to aerobic nature of the organism
  • will form spores at air interfaces with tissues and exuded hemorrhagic fluids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Endemic areas of anthrax

A
  • Mississippi river delta (#1)
  • Texas gulf coast
  • SE South Dakota
  • NE Nebraska
  • Sacramento/San Joaquin Valley
  • Northwest Territory Great Slave Lake area
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the environmental requirements for anthrax growth?

A
  • alkaline soil
  • high nitrogen content from decaying vegetation, alternating rainy and dry spells
  • temp over 60 F
  • soils rich in calcium and nitrogen, spread by periodic flooding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Rainy periods allow for ______ formation, while dry periods allow for ______ formation

A

Vegetative cell; spore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Soil flora must lack certain______

A

Streptomyctes spp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How do alternating wet and dry periods contribute to epidemics?

A

Formation of large numbers of spores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What animals are common to overgrazing and ingestion of spores?

A

Cattle and horses

25
Q

Other sources of anthrax

A
  • bone meal
  • animal by produces
  • wool
  • boar bristle
  • brushes
  • hides
  • bongo drums
  • voodoo dolls
26
Q

Spread of anthrax occurs by

A
  • animal amplification
  • flies
  • carrion eaters
  • vultures
27
Q

Septicemic form of anthrax

A

Primarily infects herbivores

  • incubation period: 3-7 days
  • fatal 1-2 hr after first signs or by 24 hrs
  • symptoms: high fever, bleeding (more prolonged in horse than in cow)
  • horses and swine are reported to have low number of organisms in circulation during septicemia
  • equivalent to respiratory form!*
28
Q

Cutaneous form of anthrax

A

Intensely dark, painless edematous eschar

  • ulcer with necroticcenter
  • many become septicemic
  • heals rapidly with antibiotic therapy
  • most common in people, reported in rabbits, swine, and horses
29
Q

Pharyngeal form of anthrax

A

Seen in swine, dog, cat

  • subacute to chronic carbuncular lesions of jowl and tongue
  • swelling of lips, head, and throat, severe gastroenteritis
  • common in carnivores and scavengers
30
Q

Intestinal form of anthrax

A

Seen in people, dog, cat

  • bloody diarrhea, hematemesis
  • A. bacillus grows rapidly on cut surface of boiled vegetables –> growth spreads dully, dry, mealy and grayish white color
  • sporulation occurs early and profusely on these substances
31
Q

Respiratory (pneumonic) form of anthrax

A

Seen in people, usually becomes septicemic and rapidly fatal

32
Q

Meningitis form of anthrax

A

CNS sighs, only recognized in people and is generally rare (only occurred once)
- animals will typically die before meningeal form occurs

33
Q

Pathogenesis of anthrax: step 1

A

Ingestion, inhalation, skin exposure by spore contact

  • spores germinate at site of entry
  • may localize in regional lymph nodes or spread via lymphatics and blood
34
Q

Poly-D-glutamate capsule

A

Antiphagocytic, antiopsonic, nonimmunogenic and nonantigenic

is the only protein based capsule!

35
Q

Virulence requirements for B. anthracis

A

Requires 2 different plasmids

- 1 coding for capsule (PAOX-1), 1 coding for toxins (PAOX-2)

36
Q

Toxin actions

A
  • damages and kills phagocytes
  • increase capillary cell permeability
  • prevents clotting
  • blocks opsonization (activity of C3)
  • capillary thrombosis occurs
  • blood pressure falls
  • shock and death
37
Q

Toxin is a product of a ______ plasmid

A

110 Mdal

38
Q

Toxin structure

A

Tripartite subunit toxin, where 1 unit binds and 2 units are toxic
- exotoxin has AB structure where B bind to host cell and A enters cytoplasm

39
Q

Edema factor

A

Adenylate cyclase

- Na: K pump affected

40
Q

Protective antigen

A

2, binds to cell receptors, translocates EF and LF

- 63kDa protein forming a transmembrane channel

41
Q

Lethal factor

A

3, Cleaves and inactivates nitrogen activated protein kinase kinases (MAPKK1, MAPKK2)

  • enzymes control cell growth, embryonic development, oocyte maturation
  • MAPK regulates activity via phosphorylation
  • LF cleaves off enzyme responsible for activating MAPK
42
Q

LF is a ______ that cleaves the amino terminus

A

Protease

43
Q

Of the 3 components of toxin, which is the dominant virulence factor?

A

Lethal factor

- A776 amino acid protein with a putative zinc binding site

44
Q

The toxin is originally produced as a ______

A

240 kDa protein

- is post-translationally cleaved to 3 active fragments (EF, PA, LF)

45
Q

What conditions are the toxins not produced under?

A

42 C (possibly creates resistance in birds)

46
Q

Method of anthrax interaction with target cells

A

PA binds to host cell surface receptor R –> host cell surface protease cleaves PA, activating it to bind EF and LF —> EF and LF now competitively bind to high affinity receptor –> EF or LF, PA and R are endocytosed as a ternary complex –> EF is adenylate cyclase, increasing cAMP inactivating Na/K pump causing edema and cell death

47
Q

Splenomegaly

A

Blackberry jam appearance of spleen

- also occurs with other pathogens, is not specific to anthrax

48
Q

What to do if anthrax is suspected?

A

Aspirate peripheral blood from jugular vein for stains and culture
- do not take samples from ear, spleen, or tissues!

49
Q

Ruminants

A

Use a vaccutainer and a red top tube

50
Q

Horses and swine

A

Aseptic collection of spleen or liver may be necessary due to low levels of organisms in blood during septicemia

51
Q

Do you open the carcass?

A

NO!!!

  • cremate or bury (6ft) in lime (calcium oxide)
  • clean tools with 1.0% bleach or strong disinfectants
  • carcass should not be moved to prevent contamination
52
Q

How to stain anthrax smears

A

Use Wright’s, Giemsa, or methelyene blue, or Gram’s stain

  • in vivo: large blue bacilli, single or short chains, squared off ends and pink capsules with polychromatic stains
  • no spores usually
53
Q

Ascoli test

A

Done on environmental materials to determine if anthrax is present
- use high titered antisera

54
Q

Treatment

A

Penicillin (cidal) or tetracycline (static)

- effective only before a lethal concentration of toxins accumulates

55
Q

During outbreaks you _____ the sick and ______ normal

A

Treat; vaccinate

- do not do both!

56
Q

Anthrax immunity

A

Mainly humoral, antitoxic

57
Q

Sterne strain

A

Has plasmid for toxins, but not for capsule

  • rough, avirulent, nonencapsulated, spore vaccine
  • 2 doses and annual booster in enzootic area –> immunity develops about 7 days after vaccination
  • 1 does in epizootic (no antibiotics), live vaccine produces septicemia for up to 60 days
  • used in all livestock
58
Q

Alum-precipitated supernatant toxoid vaccine

A

Available for people

  • plasmid has been isolated and segments cloned to produce a more efficacious toxoid
  • not commercially available

Infectious Agents (44 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions