Bacteriology Part 2

Question 1

Name some factors required for bacterial growth.

Answer 1

-metabolic energy ( fermentations, respiration, and photosynthesis)
-environmental factors
–nutrients
–ionic strength and osmotic pressure
–light
–temperature ( most are mesophilic with growth at 30-37 C)
–pH (grow best at 7.2-7.4)
–O2 and CO2

Question 2

Will having a fever inflammatory response help the bacteria thrive or slow it?

Answer 2

It will slow down the growth of pathogenic bacteria.

Question 3

True or false, facultative anaerobes can thrive in both areas with and without O2.

Answer 3

True.

Question 4

What is binary fission?

Answer 4

replication of bacteria

Question 5

what is generation time?

Answer 5

length of time required for a single bacterial cell to yield two daughter cells (30 mins - 20 hrs)

Question 6

What are the different phases of bacterial growth curve?

Answer 6

Lag phase - increase in cell size, active metabolism of cells but no division.
exponential/logarithmic phase - cells multiply at max rate.
maximal stationary phase - growth is ceased due to lack of nutrients and accumulation of toxin, death rate and multiplication is balanced.
decline/death phase - death of cells

Question 7

What are characteristics of fungi?

Answer 7

eukaryotic
non - photosynthetic heterotrophs
widely distributed in the environment.
grow aerobically and are strict aerobes
cell membrane contains sterols ( ergosterol) and plant like cell wall with chitin, gluten, and mannoproteins

Question 8

What are the two types of fungi?

Answer 8

branching hyphae multicellular mold
-contain spores
-mycelium
unicellular yeasts round single cells characterised budding
-reproduce both sexually (spores) and asexually (spores, budding, or fragmentation)
-resistant to classical antimicrobial drugs

Question 9

What are the three classes of exotoxins?

Answer 9

Type 1
-cell - surface
-disturbance of cell metabolism
-ex. clostridium prerfringens
Type 2
-membrane damaging
-ex. staph aureus
Type 3
-intracellular (ex. A-B toxins)
-ex. clostridium botulinum

Question 10

What is Lipo Teichoic acid?

Answer 10

An endotoxin found in gram positive cells
mediator of septic shock

Question 11

True or False, endotoxins are highly antigenic.

Answer 11

True, are good for making vaccines

Question 12

What is a biofilm?

Answer 12

Mass of bacteria that clings to surfaces. producing extracellular polymer matrix and exchange of nutrients
reduced susceptibility to abx.