Brainscape's Knowledge GenomeTM

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


See full index

CELL MICRO S1 > Endospore > Flashcards

Endospore Flashcards

1
Q

which two are the main types of spore forming bacteria?

A

Clostridium and Bacillus

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

Bacillus oxygen requirements?

A

aerobic or facultative anaerobes

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

Clostridium oxygen requirements?

A

anaerobic

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

endspores are formed when?

what are the characteristics of endospores?

A
  • when NUTRIENT LIMITATION is reached
  • DORMANT
  • resistant to UV, HEAT, TOXIC CHEMICALS, IONISING RADIATION
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the heat resistance of endospores used for?

A

selection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how do endospores stain?

A

variably

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

where do endospore formers generally live/habitat?

A

soil

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

in a spore what is the exosporium like?

A

thin delicate layer, mostly protein

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

in a spore what is the spore coat like?

A

multiple layers of spore specific proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

in a spore what is the cortex like?

A

loosely packed peptidoglycan

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

in a spore what is the spore protoplast/ core composed of ?

A

normal cell wall
plasma membrane
cytoplasm and nucleoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the properties of the core?

A
  • dipicolinate
  • dehydrated (10-30% of total water content of a vegetative cell)—> heat and stress resistance
  • cont Small Acid-Soluble Spore Proteins (SASPs)—> dry heat, dessication, UV resistance. also C source during outgrowth
  • more ACIDIC pH than vegetative cell
  • low metabolic activity (low O2 uptake)
  • no macromolecular synthesis
  • low enzymatic activity
  • low/absent mRNA synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how are spores ACTIVATED (taken out of dormancy)?

A

1) heat shock-hours at 65°C

2) storage at low temp (4°C)

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

what happens when spores are activated and placed in favourable conditions?

A

GERMINATION

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

what are the 3 main stages of a spore?

A

1) ACTIVATION
2) GERMINATION
3) OUTGROWTH

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

Bacillus habitat?

A
  • mainly soil

- some parasites and pathogens

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

what disease does Bacillus anthracis cause?

A

agent of ANTHRAX

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

who does Bacillus anthracis cause disease of?

A

sheep, goats, cattle, transmissable to humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q 
describe cutaneous anthrax 
who does it affect
where do spores germinate 
appearance
treatment
A
  • most common form
  • animal workers
  • spores germinate in akin abrasions
  • skin ulcer- BLACK eschar (can become systemic)
  • AB treatment, if no treatment 20% mortality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

describe GI anthrax
cause
types

A
  • cause: undercooked contaminated meat

- types: abdominal (rare) & oral-pharyngeal (v rare)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

describe pathogenesis of abdominal anthrax

A
  • spored germinate in lower GI tract

- causes PRIMARY INTESTINAL LESION

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

what are the symptoms of abdominal anthrax?
how does it cause death?
high/low mortality?

A
  • nausea
  • severe abdominal pain
  • vomiting
  • bloody diarrhoea
    DEATH: caused by ANTHRAX TOXEMIA (HIGH mortality)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is the pathogenesis of pulmonary anthrax

A
  • spores inhaled
  • some spores mopped up by macrophages
  • others trafficked to the lymph nodes
  • GERMINATION in lymph (up to 60 days)
  • anthrax REPLICATE in lymph, causing disease (hemorrage, edema, necrosis caused by exotoxins released during replication)
  • CAPSULE inhibits phagocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are the symptoms of pulmonary anthrax?

A
  • flu like
  • fever
  • myalgia
  • cough
  • headache
  • vomiting
    -chills
  • abdominal pain
  • chest pain
    CYANOSIS and HYPOTENSION—> DEATH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

why is anthrax used in biological warfare?

A

80% MORTALITY (2-4 days) if ABs/no ABs

inhalational anthrax= 99% lethal in unvaccinated individuals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what virulence factors does Bacillus anthracis use?

A 
CAPSULE - made of poly-D-glutamate polypeptide
- smooth mucoid colonies 
- pX02 plasmid  
TOXIN- encoded on plasmid pX01 
- consists of 
1) PA (binding domain)
2) EF (Edema factor)
3) LF (Lethal factor)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how is Bacillus anthracis inf diagnosed?

A
  • blood, skin lesions, respiratory secretions or by measuring specific antibodies in blood
  • G+ve rod, sometimes in chains
  • central (non- staining) spore occurs in soil and culture but not clinical samples
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how is Bacillus anthracis inf treated?

A

penicillin, doxycycline, fluoroquinolones started early

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

how is Bacillus anthracis inf prevented?
what are side effect rates like?
who uses prevetative measures?

A

VACCINE- 3 types: Russian, UK, US. (Russian= inoculation with live spores= high side effects, UK/US=dead cell free prep of bacterial filtrates)

  • used for those at occupational exposure
  • from strain that lacks plasmid pX02 (capsule)
  • wool sterilisation from areas where anthrax is endemic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

how predominant is Bacillus cereus?

A

one of the most abundant aerobic sporeformers in soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is the shape of Bacillus cereus colonies?

A

loosely spreading, may resemble fungi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what can Bacillus cereus cause? what is the short type type? symptoms? cause?

A

food poisoning

1) short incubation/emetic
- 1-6 hrs after eating
- nausea, vomiting, abdomina, pain
- caused by heat stable enterotoxin (cannot be destroyed by cooking—>rice kept warm)

33
Q

what can Bacillus cereus cause (long-type)?
symptoms? cause?
who does it affect?

A

2) long incubation/diarrheal
- 6-18 hours after eating
- diarrhoea
- caused by enterotoxin that CAN be destroyed by cooking
- toxin activates INTESTINAL ADENYLATE CYCLASE that causes intestinal fluid secretion
- Bacilli found in stools
- immunocompetent and compromised

34
Q

oxygen requirements of Clostridia?

A

mostly onligate anaerobes, some aerotolerant

35
Q

how do Clostridia metabolise?

A

fermentation

36
Q

where are Clostridia found?

A

ub in nature, soil, water, intestinal tract of animals

37
Q

how does Clostridia obtain nutrition?

A

they are SAPROPHYTES, involved in protein decomposition

38
Q

how pathogenic are Clostridia? what is disease caused by in Clostridia?

A
  • some pathogenic species

- disease caused by: production of highly toxic proteins

39
Q

what is the shape of Clostridium barkeri spore? postioning?

A

oval, terminal

40
Q

what is the shape of Clostridium botulinum spore? postioning?

A

oval, between centre and end

41
Q

what is the shape of Clostridium tetani spore? postioning?

A

spherical, terminal

42
Q

how does Clostridia obtain ENERGY (ATP)?

A

sub level phosporylation (no cytochrome system)

  • use wide variety of fermentable substrates
  • some ferment sugar producing end products (butyric acid, butanol, acetone)
43
Q

describe the range of pathogenic Clostridia?

A

can REMAIN at site of inoculation: Tetanus
not enter tissue at all: Botulism
some use destructive enzymes to invade necrotic tissue

HIGHLY powerful poisons

44
Q

what does C.Botulinum cause?

A

Botulism

45
Q

where is C.Botulinum found?

A

soil, water, decaying vegetation

46
Q

how can C.Botulinum cause fatalities?

A
  • ingest preformed toxin from food

- fatal food poisoning

47
Q

who is commonly affected by C.Botulinum?

A

animals- from their feeds

48
Q

which conditions cause toxin production in C.Botulinum ?

A

ANAEROBIC conditions may germinate spores—> vegetative cells—> prod toxin

49
Q

where does C.Botulinum infect?

A

sometimes wounds

  • INFANT botulism from ingestion of spores in soil/dust (& germination in anaerobic intestine)
  • HONEY added to formula feed may contain spores
50
Q

how is C.Botulinum diagnosed?

A

ELISA for toxin in suspected food injected into mice, culture attempted

51
Q

how is C.Botulinum infection prevented?

A

as C.Botulinum produces a toxin and not a spore, toxin is HEAT LABILE O cooking inactivates
is suspected case: ANTITOXIN
es

52
Q

which type of botox is used? what is botox used for?

A

Botulinum toxin type A

- treat patients with overactive muscles

53
Q

C.tetani causes which disease?

A

tetanus

54
Q

where is C.tetani found?

A

soil and intestines of animals

transiently in humans

55
Q

what is the shape of the terminal spore of C.tetani?

A

drumstick shape (like the stick part of a lollipop?)

56
Q

how does C.tetani enter the body?

how does this cause disease?

A

via a wound

wound prod necrotic cells, allows anaerobic conditions to develop, spores germinate and toxin produced

57
Q 
what are the 2 types of tetanus? 
describe 
cause
source
fatality rate
A

1) generalised
2) neonatal
- if umbilical stump is infected (via soil or bindings containing spores)
- lack of passive immunity from mother
- high fatality (>200,000 deaths p/a)

58
Q

describe the pathogenesis of tetanus

A
  • toxin migrates via peripheral nerve axons to CNS (site of action)
  • symptoms take 3-21 days to develop, last 3-4 weeks
  • SPASTIC PARALYSIS- convulsive contractions of voluntary muscles (inc neck and jaw—>lockjaw)
  • DEATH: caused by respiratory muscle spasms
    50% mortality
59
Q

how does tetanus toxin cause uncontrolled muscle spasms?

A
  • tetanus toxin binds to inhibitory neurones
  • inhibitory neurones fire but DON’T RELEASE GLYCINE O excitatory neurones have no opposition
  • causes muscle spasms
60
Q

how is tetanus diagnosed?

A

usually by clinical picture
BUT organism can be isolated:
- look for G+ve, drumstick shape
OR half spread agar plate with ANTITOXIN, will show HAEMOLYTIC TOXIN PRODUCTION

61
Q

how is tetanus prevented?

what about following injury?

A

vaccination- DPT cont formalin-inactivated toxin
has 100% efficacy
following injury: given tetanus IMMUNOGLOBINS but mortality is 20-30%

62
Q

what disease does C.perfringens cause?

how?

A

gas gangrene

-caused by contamination of wounds w/ Clostridia spores

63
Q

where is C.perfringens found normally?

A

GI and vagina flora

64
Q

C.perfringens can grow in which conditions?

A

anaerobic (deep necrotic wounds w/ reduced blood supply)

65
Q

what happens to C.perfringens after germination?

A
  • secrete exotoxin (causes tissue damage & spread of organism)
  • carbohydrate may be fermented—> large quantities of gas(smell)—>constriction of blood vessels
66
Q

what kinds of things can cause gas gangrene?

A
  • surgery
  • battlefield casualties
  • motor vehicle crashes
  • farm injuries
  • post-abortal sepsis
67
Q

how is gas gangrene diagnosed?
on which media?
what do we look for?

A

1) clinical picture—> smell
2) X-ray—> gas
but to be DEFINITIVE: need
3) ISOLATION AND IDENTIFICATION
- Robertsons meat media
- blood agar (incubate anaerobically)
look for LARGE G+ve rods, RANCID smell on meat media

68
Q

how can egg yolk medium be used to test for C. Perfringens?

A

LECITHIN in egg yolk medium is HYDROLYSED if ALPHA TOXIN is produced —> opaque area around colony
- can be neutralised by ANTITOXIN ANTIBODY—> Nagler reaction

69
Q

how is gas gangrene prevented?

A

proper cleaning of wounds

70
Q

how is gas gangrene treated?

A

ABs have little effect on necrotic areas

SURGERY may be required to remove affected parts

71
Q

other than gas gangrene, what else can C.perfringens cause?

A

food poisoning

ENTEROTOXINS are produced

72
Q

which disease does C.difficile cause?

A

Pseudomembraneous colitis

73
Q

how is a C.difficile infection diagnosed?

A

ELISA test for toxins A and B in stools

74
Q

how is C.difficile infection treated?

A

stop the causative AB therapy

  • anti diarrhoea drugs
  • Metronidazole and Vancomycin
75
Q

what causes Pseudomembrane Colitis?

A

after AB therapy

76
Q

what does Psudeomembranous Colitis cause?

A

diarrhoea

77
Q

how common is C.difficile infection?

A

most common nosocomial GI infection

78
Q

what are the 2 major types of toxin in C.difficile?

A

toxin A- 308kD ENTEROtoxin
toxin B- 269kDa CYTOtoxin

both stimulate the production of PROINFLAMMATORY CYTOKINES—>imp in pathogenesis of pseudomembranous colitis

CELL MICRO S1 (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions