Pathogenesis

Question 1

What are the ways humans interact with microbes

Answer 1

Colonization
Infection
Elimination

Question 2

What is Colonization?

Answer 2

This is a means of interaction whereby the host tolerates the microbe

Question 3

How about Elimination?

Answer 3

This involves the removal of the microbe from the body via the immune system

Question 4

Infection?

Answer 4

This is a situation where there is an injury at the cellular level as a result of the presence of microbes

Question 5

When does Colonization start?

Answer 5

at birth

Question 6

5 examples of body surfaces that are colonized

Answer 6

conjunctiva, skin, large intestine, vagina, external ear

Question 7

What about places that do not come in contact with the environment?

Answer 7

brain, muscle, blood and bone

Question 8

What is Normal Body Flora

Answer 8

These are a group of microorganism that exist naturally within cerain anatomical site in a healthy person.

Question 9

They can be classified based

Answer 9

Time at location

Relationship with host

Question 10

What are the ones based on time at location

Answer 10

Transient

Permanent

Question 11

What about relationship to host

Answer 11

Commensalism
Mutualism
Opportunistic

Question 12

human factors affecting microbes at any anatomic site

Answer 12

genetics
sex 
age
nutrition and diet 
pH
temperature

Question 13

Microbial factors affecting microbes at any sites

Answer 13

Biofilm
Specific Adherence
Tissue tropism

Question 14

Tissue tropism

Answer 14

this is the ability of an organism to infect a specific tissue, organ or set of organs.

Question 15

Specific Adherence

Answer 15

Specific adherence involvescomplementary chemical interactions between the host cell or tissue surface and the bacterial surface

Question 16

Biofilm

Answer 16

Biofilm formation is aprocess whereby microorganisms irreversibly attach to and grow on a surface and produce extracellular polymersthat facilitate attachment and matrix formation, resulting in an alteration in the phenotype of the organisms with respect to growth rate and gene transcription

Question 17

What microbes can be found on Skin

Answer 17

staphylococcus, cornyebacteria

Question 18

Microorganism on Conjunctiva

Answer 18

gram positive cocci

Question 19

Micro organism in Vagina

Answer 19

Lactobacillus

Question 20

Oral cavity microbes

Answer 20

Lactobacillus and streptococcus

Question 21

Microbes in GIT

Answer 21

H.pylori, bifidobacteria enterococci

Question 22

benefits of normal flora

Answer 22

synthesis of vitamins
stimulation of certain tissues
stimulation of the production of antibodies
preventing attachment of other microbes

killing of other bacteria via bacteriocin

Question 23

Bacteriocin

Answer 23

Bacteriocins area kind of ribosomal synthesized antimicrobial peptides produced by bacteria, which can kill or inhibit bacterial strains closely-related or non-related to produced bacteria, but will not harm the bacteria themselves by specific immunity proteins.

Question 24

Harmful effects of Normal flora

Answer 24

Low grade toxemia
Bacterial Synergism
Opportunistic Infections
Transfer to Susceptible host
Competition for nutrients

Question 25

clinical significance of normal flora

Answer 25

difficulty in interpretation of culture results applicable specimens knowledge of patients clinical condition

Question 26

pathogenesis

Answer 26

changes that occur in the body from the point an infective agent interacts with the body to the manifestation of the disease

Question 27

pathogenicity

Answer 27

the ability of a microbe to cause diseases

Question 28

pathogen

Answer 28

these are the agent that cause disease

Question 29

virulence

Answer 29

degree of pathogenicity

Question 30

invasiveness

Answer 30

the ability of a microbe to penetrate deep into tissues

Question 31

toxigenesis

Answer 31

ability of a microbe to produce toxins

Question 32

attributes of a pathogenic microbe

Answer 32

``` transmitability invasiveness toxigenesis adhesiveness host immune system evasion production tissue degrading enzymes ```

Question 33

transmitablity

Answer 33

ability to move from the infected host to a new susceptible host or reservoir

Question 34

mode of transmission

Answer 34

``` airborne contact vector droplets common vehicle transmission ```

Question 35

difference between airborne and droplets

Answer 35

droplets have particles above 5 microns and airborne particles are below 5 microns

Question 36

maintainace of transmitabilty

Answer 36

``` animal reservoirs transmission vehicles asymptomatic carriers clinical symptoms portal way of entry ```

Question 37

adherence

Answer 37

ability of a microbe to attach to cell surface

Question 38

types of adherence

Answer 38

Specific Adherence | NonSpecific Adherence

Question 39

NonSpecific Adherence

Answer 39

reversible attachment to a eukaryotic cell surface (docking)

Question 40

Specific Adherence

Answer 40

irreversible attachment to a eukaryotic surface. (anchoring)

Question 41

streptococcus pyogenes attach where

Answer 41

pharnyngeal epithelium causes sore throat | adhesin is protein F receptor amino terminus of fibronectin

Question 42

streptococcus mutans

Answer 42

adhesin glycosyl transferase receptor salivary glycoproteins attachment site pellicle of tooth disease dental cavities

Question 43

invasiveness types

Answer 43

active: induced by pathogen passive: induced by host cell e.g Listeria monocytogenes.

Question 44

types of bacterial toxins

Answer 44

``` exotoxins: are released from bacterial cells and may act at tissue sites or remote from bacterial cells Endotoxins aka(LPS) are cell associated and are released from growing bacterial cells ```

Question 45

Host Immune Evasion mechannism

Answer 45

antigen heterogeneity antigenic variation capsule formation IgA proteases formation