Virulence

Question 1

what is mutualism?

Answer 1

both members benefit and may need each other to survive

Question 2

what is commensalism?

Answer 2

one benefits without affecting the other

Question 3

what is parasitism?

Answer 3

parasite benefits but harms the host

Question 4

what type of organism shows mutualistic and commensal relations?

Answer 4

normal flora which counts for 400-1000 different types

Question 5

what is resident microbiota?

Answer 5

most personal, specifically adapted to live in the body and main function is to out compete foreign bacteria

Question 6

what is transient microbiota?

Answer 6

only stay for hours to months due to competition and elimination via the immune system and chemical changes in the body

Question 7

what is an opportunistic pathogen?

Answer 7

cause disease under certain circumstances

Question 8

what things may cause opportunistic pathogens to cause disease?

Answer 8

immune suppression, changes to normal microbiota such as antibiotics or being in the wrong location

Question 9

where are resident microbiota present?

Answer 9

upper respiratory tract, upper and lower digestive tract, urinary and reproductive system and the skin and eyes

Question 10

why are resident microbiota present in the nose?

Answer 10

coolest part of the respiratory tract so has some unique bacteria

Question 11

what type of microbe are resident microbiota?

Answer 11

usually strict anaerobes but can be facultative anaerobes

Question 12

what prevents colonisation of the urethra?

Answer 12

urine flow

Question 13

what causes the foetus to be free if microbiota?

Answer 13

the amniotic fluid and mothers immunity

Question 14

how do the mouth and nose of a baby gain microbiota?

Answer 14

from the birth canal

Question 15

how does a baby gain microbiota in the intestine?

Answer 15

from their first meal

Question 16

how does a baby gain microbiota on their skin?

Answer 16

contact with nurses and doctors

Question 17

how long does it take to gain all resident microbiota?

Answer 17

the first few months of life

Question 18

what are virulence factors?

Answer 18

traits that interact with a host and enable the pathogen to adhere and gain access to nutrients and escape immune system

Question 19

what are the stages of infection?

Answer 19

exposure, adherence to skin or mucosa, invasion through epithelium, colonization and growth and tissue damage and disease

Question 20

how can a pathogen enter the body?

Answer 20

broken skin, ear, insect bite, nose, mouth, placenta, vagina, anus or urethra

Question 21

what is the main portal of entry?

Answer 21

mucous membrane

Question 22

how do microbes adhere to mucous membranes?

Answer 22

using ligands and adhesins

Question 23

what are ligands?

Answer 23

surface lipoprotein or glycoprotein that bonds to host cells receptors

Question 24

what are adhesins?

Answer 24

the bacterial equivalent to ligands

Question 25

where are adhesins found?

Answer 25

in fimbriae and flagella

Question 26

how is a biofilm formed?

Answer 26

microbe adheres and some bacteria colonise forming a biofilm

Question 27

what is invasion?

Answer 27

the use of extracellular enzymes to degrade the membrane

Question 28

what are the two types of toxins?

Answer 28

exotoxin and endotoxin

Question 29

what are the two types of extracellular enzymes?

Answer 29

hyaluronidase and coagulase and kinase

Question 30

what is the action of coagulase and kinase?

Answer 30

bacteria produce coagulase which causes the formation of a clot and then the bacteria later produce kinase which dissolves the clot and releases the bacteria

Question 31

how does hyaluronidase and collagenase work?

Answer 31

bacteria reaches epithelial surface and produce these enzymes to invade deeper inside tissues

Question 32

what is the difference between exotoxins and endotoxins?

Answer 32

exotoxin is secreted but endotoxin is part of the bacterial cell wall

Question 33

what are examples of some exotoxins?

Answer 33

cytotoxin

Question 34

how do exotoxins work?

Answer 34

bacteria secrete an exotoxin which then kills the host cells

Question 35

how do endotoxins work?

Answer 35

dead gram-negative bacteria release lipid A which induces the effects of disease and blood coagulation

Question 36

what are antiphagocytic capsules?

Answer 36

layer of polysaccharide around the bacterial cell

Question 37

what are the antiphagocytic factors?

Answer 37

capsules and antiphagocytic chemicals

Question 38

what virulence factor is associated with adherence?

Answer 38

adhesins and biofilms

Question 39

what virulence factor is associated with invasion?

Answer 39

extracellular enzymes ans toxins

Question 40

what virulence factor is associated with colonisation and growth?

Answer 40

capsules and anti-phagocytic chemicals

Question 41

what is a syndrome?

Answer 41

group of symptoms and signs

Question 42

what are the periods of infection?

Answer 42

incubation, prodromal, illness, decline and convalescence

Question 43

what is the incubation period?

Answer 43

no signs or symptoms shown

Question 44

what things effect the length of the incubation period?

Answer 44

virulence, dose, host immunity, site of infection

Question 45

what is the prodromal period?

Answer 45

short time that has generalised mild symptoms such as malaise and muscle aches

Question 46

do all cases have the prodromal period?

Answer 46

no

Question 47

what is the illness period?

Answer 47

most severe stage where symptoms are most evident and the immune system has not fully responded

Question 48

what is the decline stage?

Answer 48

the patients body returns to normal, the immune response vanquishes the pathogen, symptoms subside and immune response peaks

Question 49

what is convalescence?

Answer 49

patient recovers and tissue repairs

Question 50

what does the covalescence length depend on?

Answer 50

amount of damage, nature of pathogen, site of infection, overall wellbeing of patient