U1.2

Question 1

The Infectious Process?

Answer 1

1. Contact
2. Infection
3. Disease

Question 2

Microbes are first acquired on the exposed areas of the body such as the…through contact with other living organisms or the environment?

Answer 2

skin, mucous membranes of the gastrointestinal tract(GIT), respiratory tract (RT), genitourinary tract (GUT), and conjunctiva

Question 3

__________ are microorganisms that stay on the body for only a short time after initial contact. They are
usually either destroyed by the host defenses or removed by the host behavior or activities such as cleaning (e.g., bathing, toothbrushing) or antisepsis

Answer 3

Transients

Question 4

• also referred to as the resident flora, indigenous flora, or microbiota
• is a relatively permanent population of organisms adapted to the body but do not produce disease under normal conditions.
• It consists of relatively fixed types of microorganisms regularly found in a given area at a given age.
• When disturbed, they promptly establish themselves in the same area.

Answer 4

Normal flora

Question 5

The resident microbiota vary in number and kind from one site to another. It has been calculated that
the normal human houses up to 10^14 in the __________, 10^12 on the ________, and up to 10^10 in the _______ and includes a variety of bacteria and fungi (only __________ __________); __________ are not considered members of the normal flora.

Answer 5

gastrointestinal tract; skin; mouth: Candida albicans; viruses

Question 6

The microbiota serve a number of functions such as?

Answer 6

a. Microbial antagonism
b. Nutritional function
c. Causative agents of disease

Question 7

Microbial antagonism:
The normal flora serves as their _______ protective mechanism by preventing _____________ of a given anatomic site by potential microbial pathogens.

Answer 7

host’s; colonization

Question 8

Microbial antagonism:

Their inhibitory capability is attributed to:

(1) competition for ________ and space for receptors or binding sites on host cells. For example, normal of the skin usually compete successfully with other microorganisms for available nutrients and may produce metabolic end-products that inhibit the growth of other microorganisms.

(2) maintaining conditions such as ______ so other microorganisms may not grow. Example, lactobacilli in the vagina degrade glycogen in the secretions to form _____ acid, and the acidic environment (pH 3 - 5) is unfavorable to most organisms.

(3) production of certain _______________ substances (e.g., proteins known as bacteriocins)

Answer 8

nutrients; pH; lactic; antimicrobial

Question 9

Nutritional function.

The normal microbiota of the intestines are sources of vitamin ____ and vitamin ____.

Answer 9

B; K

Question 10

Causative agents of disease.

Some members of the normal microbiota can be called as _________________ as they may produce disease when presented with an opportunity or under certain circumstances as:

(1) when in an unusual ________. Members of the normal flora are non-pathogenic in their usual habitat but can be pathogenic in other parts of the body.

(2) in _______________host. Opportunities brought by some compromise or weakness in the host’s resistance cause members of the normal microbiota to become opportunistic pathogens. There are some predisposing factors, or conditions that reduces a person’s resistance to infectious disease include hormonal imbalance, extreme youth or old age, pregnancy, and other underlying diseases such as diabetes mellitus.

Some microorganisms with greater infectious potential may evade the host defenses, infiltrate the body and cause infection.

Answer 10

opportunistic pathogens; habitat; immunocompromised