M3

Question 1

what is Koch’s postulate?

Answer 1

the microorganism is present in every case of the disease but absent from healthy organisms
suspected organism must be isolated and grown in a pure culture

Question 2

define mutalistic

Answer 2

relationship, where host and organism gain mutual value

Question 3

define parasitic

Answer 3

live on or in living creatures causing harm/damage to the host

Question 4

benefits of mutualism?

Answer 4

• organisms can produce nutrients or vitamins

- can exclude access/colonisation by pathogen (colonisation resistance)

Question 5

where is lactobacillus spp. present in oral cavity?

Answer 5

ONLY aproximal (majority is approximal and subgingival)

Question 6

where is fusobacterium spp.present in the oral cavity?

Answer 6

approximal and subgingival

Question 7

spirochaetes spp.?

Answer 7

subgingival

Question 8

define pathogen

Answer 8

A microbe capable of causing host damage.

Question 9

define virulence factor

Answer 9

a component of a pathogen that damages the host. this can include components essential for viability

Question 10

Virulence factor - Adhesin

Answer 10

enables binding of the organism to host tissue

Question 11

VF - invasin cell/ tissue

Answer 11

enables the organism to invade a host

Question 12

VF -impedin

Answer 12

enables organism to avoid host defense mechanisms

Question 13

VF - aggressin

Answer 13

causes damage to the host directly

Question 14

VF - modulin

Answer 14

induces damage to the host indirectly

Question 15

how can one be protected against Kochs postulates?

Answer 15

antibodies directed against the gene product protect the host

Question 16

what are the limitations for carrying out Kochs postulate?

Answer 16

• organisms cannot be cultured

- organism is a human pathogen

Question 17

what pathogens must cause disease for transmission?

Answer 17

obligate pathogens

Question 18

which pathogens do not have to cause disease for transmission?

Answer 18

opportunistic

Question 19

which pathogen hinders disease or prevents transmission?

Answer 19

accidental pathogens

Question 20

define epidemiology?

Answer 20

the study of the occurrence, spread and control of disease

consider for any organism

• infective dose
• virulence of the organism
• hosts status (resistance)

Question 21

define prevalence (epidemiology)

Answer 21

proportion of population affected

Question 22

define sporadic

Answer 22

occurs at irregular intervals or only in a few places

Question 23

define endemic

Answer 23

restricted to a certain place ie africa

Question 24

define epidemic

Answer 24

widespread ocurrence of infectious disease at a particular time

Question 25

define pandemic

Answer 25

outbreak of disease over the whole world