Basics Review

Question 1

What type of moisture environment do bacteria like?

Answer 1

Isotonic environment (similar the salt content of blood).

Question 2

What temperature range do most bacteria like (and the name of that group) that infect humans?

Answer 2

Mesophiles –> 35-37C (range 20 to 40)

Question 3

What pH environment do most human pathogenic bacteria grow best in?

Answer 3

A relatively neutral pH between 7.0 to 7.5

Question 4

What are some organic growth factors?

Answer 4

Nitrogen, carbon, vitamins, etc.

Question 5

What are some inorganic growth factors?

Answer 5

Potassium, iron, sulphur, etc.

Question 6

Endotoxins come from what type of bacteria only?

Answer 6

Endotoxins come from gram negative bacteria only. Part of organism: lipopolysaccharide from cell wall and is heat stable, acts in a location in a matter of hours.

Question 7

What are the clinical used taxonomies?

Answer 7

Typically Family, Genus and Species are the most importantly used taxonomy.

It goes:
Domain
Kingdom
Class
Order
Family
Genus
Species

Question 8

What are strict aerobes?

Answer 8

Strict aerobes cannot grow in the absence of O2.

Question 9

What are facultative anaerobes?

Answer 9

Facultative anaerobes can grow aerobically or anaerobically (ANO2). These are most of our routine organism, although not all.

Question 10

What are capnophilic bacteria?

Answer 10

Capnophilic bacteria need increased CO2 at 5-10% to grow but the O2 can be a bit higher (15%) –> with a candle jar or incubator at 5-10% CO2.

These organisms show minimal growth aerobically or anaerobically.

Question 11

What are microaerophilic bacteria?

Answer 11

Microaerophilic bacteria need reduced levels of O2 (5-10%) and increased CO2 (8-10%)–> jar with pack.
These organisms will not grow aerobically or anaerobically.

Question 12

What are the types of descriptions used for colony growth on media examination?

Answer 12

Main colony media growth descriptions:

1. Relative size (large, medium, small, tiny, pinpoint)
2. Colour (grey, white, red)
3. Hemolytic Reaction (if applicable, especially important for Streptococcus spp.)

Optional descriptions:

4. Texture (dry, wet, or mucoid)
5. Opacity (opaque vs translucent).

Question 13

What does fastidious and non-fastidious mean in the microbiology lab?

Answer 13

Fastidious = An organism that requires a special nutritional or environmental condition for growth. (From textbook glossary p1114).

Non-Fastidious = not fussy; “easy” to grow in lab.