Microbiology

Question 1

True/false?

Usually a single disease is caused by a single microbe.

Answer 1

False.

Rarely…

Question 2

What diseases are the exception to the single disease, single microbe idea?

Answer 2

Rabies virus and syphillus

Question 3

What is presumptive ID?

Answer 3

Genus level

Question 4

What is definitive ID?

Answer 4

Species level

Question 5

What are the 4 major components for ID?

Answer 5

Selection of a battery of tests
Incubation for substrate utilization
Detection of metabolic activity
Analysis of metabolic profiles

Question 6

What is biosynthesis?

Answer 6

Metabolites from catabolic reactions in fueling stages are now used to produce amino acids, sugars etc in anabolic (building) reactions.

Question 7

Describe polymerization and assembly

Answer 7

Products of biosynthesis are assembled (polymerized) into larger macromolecules (proteins, lipopolysaccharides).

Question 8

What are the phases of bacterial growth?

Answer 8

Lag phase
Exponential (Log) phase
Stationary phase
Death phase

Question 9

What is considered lag phase?

Answer 9

Initially after cultivation (bacteria metabolically active, acclimating to new environment, not much growth).

Question 10

What is happening during the exponential phase?

Answer 10

Binary fission

Question 11

What is the difference between gram positive and gram negative organisms?

Answer 11

Gram pos organisms have a thicker peptidoglycan layer that contains teichoic acids which resists decolorization. They take up counterstain, but CV is not altered. Gram neg have periplasmic space that contains muerein layer and is gel like and an outer membrane.

Question 12

Describe cellular appendages

Answer 12

Capsule- outermost layer of gram pos and neg (helps bacteria evade human immune system and aids in formation of biofilms)
Fimbriae or pili- hairlike proteins that help aid in attachment.
Flagella- motility

Question 13

What is biofilm?

Answer 13

An accumulation of various microorganisms that are embedded in a polysaccharide matrix, allows adherence to prosthetics and implants.

Question 14

Why do some bacteria produce endospores?

Answer 14

Hardy state that allows them to survive harsh conditions and escape common antimicrobial treatments: disinfection, UV, heat etc.

Question 15

Iatrogenic?

Answer 15

Physician induced

Question 16

What holding media is used which maintain viability of organisms but don’t support growth?

Answer 16

Amie’s and Stuart’s

Question 17

Describe areobes

Answer 17

Can’t grow anaerobically (grow well in 21% O2, and 0.3% CO2, ambient air).

Question 18

Describe anaerobes

Answer 18

Grow only in or near 0% O2 levels (5-10% H and CO2 both, 80-90% N).

Question 19

Describe Microaerophiles

Answer 19

Only grow under reduced O2 levels (5-10% O2, 8-10% CO2).

Question 20

Describe facultative anaerobes.

Answer 20

Can grow under aerobic or anaerobic conditions.

Question 21

Describe obligate.

Answer 21

Can grow only aerobically or anaerobically, not both.

Question 22

Describe capnophiles

Answer 22

Likes increased CO2 (5-10%) and 15% O2