Mircobes and mammalians

Question 1

What are normal microbiota?

Answer 1

Populations of microorganisms routinely found growing on the body of healthy individual.

Question 2

What’s the difference between resident flora and transient flora?

Answer 2

Resident flora typically inhabit body sites for extended periods. Transient flora are temporary: they form associations for a short time and are replaced.

Question 3

When’s someone’s normal flora established?

Answer 3

During the birthing process

Question 4

What does it mean that the composition of the microflora is dynamic?

Answer 4

The composition changes in response to physiological variation within the host. Each member of the flora ecosystem is influenced by presence and condition of other members

Question 5

What are the two main functions of the normal microflora?

Answer 5

Protection against potentially harmful organisms

Development of immune system tolerance

Question 6

How does the ‘good’ bacteria protect the body against harmful organisms?

Answer 6

Normal flora competitively exclude pathogens through:
•Covering binding sites used for pathogenic attachment
•Consuming available nutrients
•Producing toxic compounds such as antibiotics

Question 7

How does the body’s normal microflora help to develop an immune system tolerance?

Answer 7

It prevents overreaction to harmless microbes/substances

Question 8

Define the term ‘symbiotic relationships’

Answer 8

A close, prolonged association between two or more different organisms of different species that may, but does not necessarily, benefit each member.

Question 9

Name the three types of symbiotic relationships

Answer 9

Mutualism
Commensalism
Parasitism

Question 10

Mutualism

Answer 10

An association in which both partners benefit

Question 11

Commensalism

Answer 11

An association in which one partner benefits and other is unharmed, eg flora living on skin

Question 12

Parasitism

Answer 12

An association in which the microbe benefits at expense of host eg pathogenic infection

Question 13

What the six types of pathogens?

Answer 13

Parasites
Protozoa
Fungi
Prokaryotes
Viruses
Prions

Question 14

Define the term ‘pathogenicity’

Answer 14

Pathogenicity refers to the ability of species to produce disease.

Question 15

Define the term ‘virulence’

Answer 15

Virulence refers to the ability of strains to produce disease.

Question 16

What does the term ‘infection’ refer to?

Answer 16

The invasion and multiplication of microorganisms such as bacteria, viruses, and parasites that are not normally present within the body.

Question 17

What are the eight classifications of infections?

Answer 17

Primary infection
Reinfection
Superinfection
Secondary infection
Focal infection
Cross infection
Nosocomial infection
Subclinical infection

Question 18

Primary infection

Answer 18

Initial infection with organism in host.

Question 19

Reinfection

Answer 19

Subsequent infection by same organism in a host (after recovery).

Question 20

Superinfection

Answer 20

Infection by same organism in a host before recovery.

Question 21

Secondary infection

Answer 21

When a new organism may set up an infection in a host whose resistance is lowered by preexisting infectious disease.

Question 22

Focal infection

Answer 22

A localised infection which can spread to other organs or structures in the body.

Question 23

Cross infection

Answer 23

The transfer of infection, especially to a hospital patient with a different infection or between different species of animal.

Question 24

Nosocomial infection

Answer 24

Cross infection occurring specifically in hospital.

Question 25

Subclinical infection

Answer 25

Where clinical effects are not apparent.

Question 26

What are the reasons to conclude a particular organism causes a specific disease?

Answer 26

1. The microbe must be present in every case of disease
2. Must be pure culture from diseased host
3. Same disease must be produced in susceptible experimental host
4. Must be recovered from experimental host