Lecture 2 - Flora

Question 1

Most of the normal flora in the human body are ______. They exist mostly in the buccal pockets and in the GI.

Answer 1

Anaerobes

Question 2

Parts of the body that typically don’t house bacteria are the blood, _____, and deep tissues. This is because bacteria would have to cross epithelial barriers to reach these.

Answer 2

CSF

Question 3

There are a few important roles of the normal flora.

1. _____ stimulation
2. Elimination of invaders –> normal flora metabolism depletes resources for invaders
3. Nutrition and metabolism
4. Can be a common source of ______.

Answer 3

Immune

Infection

Question 4

Koch’s postulates are as follows:

1. _____ the microbe with the disease.
2. ______ the organism in pure culture.
3. Isolated organism causes disease in humans or animals –> keep in mind there may not be a good animal model for the particular disease being studied.
4. re-______ the organism from intentionally infected animal.

Answer 4

Associate

Isolate

re-isolate

Question 5

______ ______ (ID) is the number of organisms required to infect 50% of animals exposed.

______ _____ (LD) is the number of organisms required to kill 50% of exposed animals.

Answer 5

Infectious dose (ID)

Lethal Dose (LD)

Question 6

Typically, when an anaerobic infection is observed, it arises as a mixture of _____ anaerobes and strict anaerobes whereby the _____ anaerobes deplete residual O2 to allow the strict anaerobes to thrive.

Answer 6

FACULTATIVE (for both blanks.)

Question 7

Anaerobic metabolism produces foul smelling ______ as a byproduct.

Answer 7

Gas

Question 8

Clostridium are gram ____ rod, while bacteroides are gram ____ rods.

Answer 8

Positive

Negative

Question 9

Clostridium difficile is gram ___ and is an obligate _____. It is part of the normal flora of the large intestine, but can grow beyond its normal population size when competition is eliminated via _____ spectrum ______. This can cause pathology resulting in pseudomembranous _____.

Answer 9

Positive

Anaerobe

Broad spectrum

Antibiotics

Colitis

Question 10

Bacteroides Fragilis is gram ____ and is a strict _____. It has a _____ that inhibits phagocytosis. It is the most common cause of _____ abdominal infections and always occurs as a ____ infection.

Answer 10

Gram Negative

Anaerobe

Capsule

Anaerobic

Mixed

Question 11

Metronidazole is the drug of choice to combat all ______.

Answer 11

Anaerobes