Lecture 17

Question 1

How do microbes enter the nose and throat in large numbers?

Answer 1

By attaching themselves to dust particles

Question 2

The normal upper respiratory flora includes 6 of these microbes. Name them

Answer 2

1: Staphylococcus species
2: Streptococcus species
3: Neisseria species
4: Branhamella catarrhales
5: Corynebacterium species
6: Haemophilus species

Question 3

True or false. The lower respiratory tract is usually sterile.

Answer 3

True

Question 4

True or false. A person with a tracheotomy is susceptible to infection in the lower respiratory tract.

Answer 4

True

Question 5

What enzyme restricts the size of microbial community in the eye?

Answer 5

Lysozyme. Remember that lysozyme is an enzyme that kills bacteria by destroying the cell wall and that Gram positive bacteria are more susceptible to lysozyme that Gram negative bacteria.

Question 6

The normal flora of the eye is the same as the upper respiratory tract. Name the 6.

Answer 6

1: Staphylococcus species
2: Corynebacterium species
3: Neisseria species
4: Branhamella catarrhales
5: Haemophilus species
6: Streptococcus species

Question 7

True or false. The urinary tract of the of the male urethra is normally sterile except the anterior portion.

Answer 7

True

Question 8

The three characteristics of the female urethra are:

Answer 8

1: It’s sterile
2: It contains low numbers of Gram-positive, non-pathogenic cocci
3: It has the same normal flora as the male urethra

Question 9

The normal flora of the male urethra include:

Answer 9

1: Staphylococcus epidermidis
2: Corynebacterium species
3: Mycoplasma species

Question 10

Which bacteria is present in both male and female’s external genitalia?

Answer 10

Mycobacterium smegmatis

Question 11

Which species are responsible for producing lactic acide from glycogen secured by the vagina wall?

Answer 11

Lactobacillus species

Question 12

What is the pH of the vagina?

Answer 12

4.4-4.6

Question 13

True or false. the pH of the vagina only allows basic-tolerant microbes.

Answer 13

False. They allow acid-tolerant microbes.

Question 14

Why does the vagina not produce glycogen pre-puberty and after menopause?

Answer 14

Lack of estrogen. The Lactobacillus species are absent.

Question 15

What four species does the normal flora of the vagina include?

Answer 15

1: Lactobacillus species
2: Corynebacterium species
3: Candida albicans
4: other yeast

Question 16

True or false. Germ-free animals lack a normal flora. They are considered sterile?

Answer 16

True

Question 17

What are Germ-free animal also called?

Answer 17

Gnotobiotic animals

Question 18

How are germ-free animals (mammals) obtained into life?

Answer 18

They are obtained by caesarian in sterile conditions.

Question 19

What can the study of germ-free animals and non germ-free animals help understand?

Answer 19

It helps determine if the normal flora is beneficial for harmful to animals.

Question 20

What is concluded from the study of germ-free and non germ-free animals concerning their floras

Answer 20

More benefits than harm is derived from having a normal flora.

Question 21

List 3 benefits of having a normal flora (for animals).

Answer 21

1: Some bacteria of the normal flora produce Vitamin K which is essential to mammals for blood coagulation (fat-soluble).
2: Aid in resistance to infectious disease by preventing pathogenic bacteria from getting established.
3: The immune of normal animals are better than those of germ-free.

Question 22

List 2 harms that normal animals have in comparaison to germ-free animals.

Answer 22

1: Tooth decay caused by Streptococcus mutans
2: Opportunistic pathogens.

Question 23

Explain the process in which a diet rich in beef, total fat, animal fat and animal protein lead to the formation of procaricinogens and how it involves our intestinal flora.

Answer 23

Animal fats and protein lead to the formation of pro carcinogens which are converted into carcinogens by our intestinal flora.