Brainscape's Knowledge GenomeTM

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


See full index

INF > MECHANISMS OF BACTERIAL VIRULENCE > Flashcards

MECHANISMS OF BACTERIAL VIRULENCE Flashcards

1
Q

WHAT IS PATHOGENICITY?

A

THE ABILITY TO CAUSE DISEASE

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

WHAT IS VIRULENCE?

A

THE EXTENT OF PATHOGENICITY (THE EXTENT OF THE ABILITY TO CAUSE DISEASE)

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

WHAT ARE PATHOGENICITY AND VIRULENCE MEDIATED BY?

A

BY THE SO CALLED ‘VIRULENCE FACTOR’ GENES

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

WHAT DOES ID50 STAND FOR?

A

INFECTIOUS DOSE FOR 50% OF TEST POPULATION

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

WHAT DOES LD50 STAND FOR?

A

LETHAL DOSE (TYPICALLY OF A TOXIN) FOR 50% OF THE TEST POPULATION

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

HOW IS LD50 EXPRESSED?

A

the weight of chemical administered per kilogram body weight of the animal (e.g. 250ng/kg)

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

EXAMPLES OF VERTICAL TRANSMISSION?

A
  • PLACENTA/BIRTH TRANSMISSION

- THROUGH GAMETES

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

PORTALS OF ENTRY FOR A PATHOGEN?

A
  • MUCUS MEMBRANES (EPITHELIUM)
  • SKIN DAMAGE
  • VERTICAL TRANSMISSION
  • SPECIALISED ENTRY (VECTOR BORNE, DELIBERATE INTRODUCTION)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

DESCRIBE THE SPECIALISED PORTALS OF ENTRY FOR A PATHOGEN?

A
  • VECTOR BORNE (INFECTION SPREAD BY ORGANISMS LIKE MOSQUITOES)
  • DELIBERATE INTRODUCTION (BIOTERRORISM, NEEDLE SHARING)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

WHAT ARE FIMBRIAE/PILLUS?

A
  • PROTEIN APPENDAGES (POLYPEPTIDE CHAINS) THAT OFTEN MEDIATE INITIAL ATTACHMENT OF BACTERIA TO CERTAIN RECEPTOR STRUCTURES ALLOWING THEM TO COLONISE VARIOUS SURFACES
  • THEY ARE TIPPED WITH ADHESION PROTEINS THAT BIND LIGANDS ON THE HOST TISSUE
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

APART FROM FIMBRIAE AND PILUS, WHAT ELSE CAN MEDIATE BACTERIAL ADHESION AND ENTRY?

A

FLAGELLA (HAIRLIKE STRUCTURE THAT PRIMARILY HAS A ROLE IN MOTILITY)

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

WHAT IS BIOFILM?

A

a complex structure of microbiome having different bacterial colonies or single type of cells in a group; adhere to the surface

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

EXAMPLES OF MEDICAL CASES WHERE BIOFILMS CAUSE PROBLEMS?

A
  • DENTAL PLAQUES
  • CYSTIC FIBROSIS (BIOFILMS FORM IN THE LUNGS, DIFFICULT TO GET RID OF, CAN BE FATAL)
  • MEDICAL CATHETERS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ADVANTAGES OF A BIOFILMS FOR THE BACTERIA?

A
  • CAN PREVENT PHAGOCYTOSIS AS A PHYSICAL BARRIER
  • PREVENT ACCESS OF RECOGNITION PROTEINS
  • PREVENT ACCESS OF ANTIBIOTICS AS A DIFFUSION BARRIER
  • STOP CELLS BEING ‘WASHED AWAY’ AND ALLOWS DIVISION OF LABOUR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

WHAT IS THE ROLE OF CAPSULAR POLYSACCHARIDES (CPS) IN BACTERIA?

A
  • STRUCTURAL DEFENSE AGAINST IMMUNITY

- CAN PREVENT PHAGOCYTOSIS AND INACTIVATE ASPECTS OF HUMORAL IMMUNITY

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

WHAT ARE CAPSULAR POLYSACCHARIDES?

A

Polysaccharide capsules are structures found on the cell surface of a broad range of bacterial species. The polysaccharide capsule often constitutes the outermost layer of the cell, and therefore is often involved in mediating direct interactions between the bacteria and its environment. It is due to these interactions that polysaccharide capsules have been implicated as important virulence factors for many bacterial pathogens.

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

WHAT ARE SIDEROPHORES USED FOR BY PATHOGENS?

A

TO STRIP ESSENTIAL IRON FROM THE HOST CELL

18
Q

WHAT IS THE MOST IMPORTANT NUTRIENT PATHOGENS NEED TO ACQUIRE?

A

IRON

19
Q

WHAT IS NUTRITIONAL VIRULENCE?

A

PATHOGEN USING NUTRIENTS OTHERWISE ESSENTIAL FOR THE HOST IMMUNE RESPONSE

20
Q

WHAT IS A TOXIN?

A

A SUBSTANCE THAT CONTRIBUTES TO PATHOGENICITY

21
Q

WHAT IS TOXIGENICITY?

A

ABILITY TO PRODUCE A TOXIN

22
Q

WHAT IS TOXEMIA?

A

PRESENCE OF TOXIN IN HOST’S BLOOD

23
Q

WHAT IS TOXOID?

A

INACTIVATED TOXIN USED IN A VACCINE

24
Q

WHAT IS ANTITOXIN?

A

ANTIBODY AGAINST A SPECIFIC TOXIN

25
Q

WHAT IS BOTULINUM?

A
  • AN EXTREMELY STRONG TOXIN
  • USED IN BOTOX
  • LD50: 0.03 ng/kg
26
Q

LD50 FOR SHIGA TOXIN?

A

250 ng/kg

27
Q

WHAT ARE EXOTOXINS?

A

TOXINS BACTERIA PRODUCE ONLY AFTER THEY ENTER A HOST I.E. TOXINS PRODUCED AND RELEASED IN RESPONSE TO HOST ‘SIGNALS’

28
Q

HOW MANY GROUPS OF EXOTOXINS ARE THERE?

A

4

29
Q

THE GROUPS OF EXOTOXINS?

A
  • SIMPLE SINGLE POLYPEPTIDE TOXINS
  • MULTI POLYPEPTIDE TOXIN COMPLEXES
  • SMALL ‘DRUG-LIKE’ MOLECULES (NATURAL PRODUCTS)
  • TOXINS DIRECTLY ‘INJECTED’ BY SPECIALIST SECRETION SYSTEMS
30
Q

WHAT ARE SUPER-ANTIGENS?

A
  • A TYPE OF SIMPLE SINGLE POLYPEPTIDE TOXIN

- DIRECTLY SHORT-CIRCUIT IMMUNE SIGNAL PATHWAYS; CAUSE OVERACTIVATION OF THE IMMUNE SYSTEM LEADING TO A CYTOKINE STORM

31
Q

WHAT IS A CYTOKINE STORM AND WHAT ARE THE SYMPTOMS?

A

OVERACTIVATION OF THE IMMUNE SYSTEM (CAN BE CAUSED BY TOXINS CALLED SUPER-ANTIGENS) WHICH CAM BE FATAL
SYMPTOMS: FEVER, NAUSEA, VOMITING, DIARRHEA. SHOCK AND DEATH

32
Q

SOME PATHOGENS CAN USE HOST’S IMMUNE SIGNALS AS:

A

GROWTH FACTORS

33
Q

TOXIN GROUP ‘SMALL DRUG LIKE MOLECULES’ IS ALSO REFERRED TO AS?

A

NATURAL PRODUCTS

34
Q

WHAT IS THE ORIGIN OF MOST ANTIBIOTICS?

A

MOST OF THEM ARE NATURAL PRODUCTS (SMALL DRUG LIKE MOLECULES) ISOLATED FROM BACTERIAL PATHOGENS

35
Q

HOW DO BACTERIA USE ANTIBIOTICS THEY NATURALLY PRODUCE?

A

THEY USE THEM TO KILL OTHER BACTERIA/FUNGI

36
Q

TOXINS DIRECTLY INJECTED BY SPECIALIST SECRETION SYSTEMS ARE MORE COMMON IN GRAM NEGATIVE OR GRAM POSITIVE BACTERIA?

A

GRAM NEGATIVE

37
Q

WHAT IS A LIMITATION OF TOXINS DIRECTLY ‘INJECTED’ BY SPECIALIST SECRETION SYSTEMS?

A

CLOSE CONTACT WITH THE HOST CELL (E.G. MACROPHAGE) IS REQUIRED; RISK OF GETTING KILLED

38
Q

HOW CAN LONG RANGE NANOSYRINGE TOXIN DELIVERY SYSTEMS BE UTILISED BY HUMANS?

A

HUMANS CAN PUT USEFUL SUBSTANCES IN THEM TO DELIVER VIA THE SAME MECHANISM (INSTEAD OF TOXINS, E.G. ANTIBODIES CAN BE INSERTED OR APOPTOSIS SIGNALS TO TARGET CANCER CELLS ETC.)

39
Q

TOXINS DIRECTLY INJECTED BY SPECIALIST SECRETION SYSTEM RESEMBLE A:

A

SYRINGE

40
Q

WHAT ARE THE METHODS BACTERIA USE TO DEAL WITH PHAGOCYTOSIS?

A

INHIBITION:
- DIRECT
- INDIRECT
- DIRECT INHIBITION BY INDUCTION OF APOPTOSIS
SURVIVING PHAGOCYTOSIS:
- INHIBITION BY INTRACELLULAR SURVIVAL IN PHAGOCYTE (LETTING ITSELF GET TAKEN UP ONCE INSIDE THE CELL ‘HIDING’ FROM THE IMMUNE SYSTEM)

INF (40 decks)

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