Intro to Microbiology

What is Koch’s Postulates?

the relationship between organism and disease

Define microbiology.

The study of microorganisms, including bacteria, fungi, viruses, and pathogenic protozoa, and the diseases they cause

What are the factors of infection?

• Infective dose

• Tissue affinity

• . Portal of entry

• Toxins (Exo and Endo)

• Enzymes

What are some enzymes that are factors of infection?

• Coagulase

• Collagenase

• hyaluronidase

What biological factors play a role in successful “infection”?

normal flora, phagocytosis, inflammatory response, and immunity

What is the goal of microbiology?

to obtain a specimen that is representative of the disease process; getting a sample from the actual infection site

What requirements do prokaryotics have?

temp, pH, oxygen tension, and nutrition

What pH range do bacteria live in?

6.5 to 7.5

How is bacteria classified?

by arrangement and characteristics

What is included in characteristics of bacteria?

size, color, density, elevation, form, consistency, odor, and hemolysis

What are endospores?

bacteria with a protective core and nuclear material

What are endospores resistant to?

heat, desiccation, chemicals, and radiation

What are the 4 phases of “life” in bacterial growth?

• Initial (lag phase)

• Exponential

• Stationary – no net increase or decrease

• Final (Logarithmic decline) – death phase

Spore formation occurs during what phase?

final phase of life (logarithmic decline)

What is the most critical element of bacterial growth?

temperature

T/F Yeast can be aerobic or anaerobic

true

What is the pH of yeast?

between 3 - 9.5; optimum is 4.5 - 5

What is the most common method of reproducing yeast?

budding

What is virology?

the scientific study of viruses and viral diseases

T/F Bacteria increases in size and divide, not viruses.

true

T/F Bacteria have both RNA/DNA, viruses only have one or the other.

true

What protein made by virus-infected host cells that stop viral replication are viruses sensitive to?

interferon

What are the types of viral replication?

attachment, penetration, un-coating, latent period, virus assembly, and viral release

T/F Viruses need living cells to grow and replicate

true

T/F viral culture is performed in specialized laboratories.

true

What is the oxygen requirements for obligate aerobes?

require O2 to survive

What is the oxygen requirements for obligate anaerobes?

growth inhibited or killed in the presence of O2

What is the oxygen requirements for facultatitve anaerobes?

can survive in absence of O2 but growth is limited

What organelle is a prokaryote most likely to have?

ribosome

What organism has a strict nutritional requirement?

fastidious organism

Spirochetes have what shape?

spiral shaped

At the end of which growth phase are all nutirents used up?

exponential

T/F Organisms that are saprophytic decompose things

true

Isolation of viruses are/is:

expensive and time consuming

What is the type of hemolysis that results in blood agar becoming clear?

beta hemolysis