Intro to Microbiology

The study of bacteria

Bacteriology

The study of fungi

Mycology

The study of viruses

Virology

Why use microbiology in veterinary medicine?

Culture for identification

To choose appropriate antibiotics/antifungals

to provide tailored dosages

How are bacteria identified?

By size, shape, arrangement, chemical reactivity

What are the three bacterial shapes?

Coccus, Bacillus, spirochetes

What are the 5 bacterial arrangements?

Single, Pairs “diplo”, Clusters “Staphylo”, Chains “strepto”, palisades - pleomorphic

Four ways bacteria move around

Gliding motion

Spirochete - rotary movement

Flagella - fine, hair like appendages

Pili or Fimbriae - like flagella

What are four specific requirements of bacteria

Temperature, pH, Oxygen, nutrition

What are the 4 distinct phases of bacterial growth

1. Lag phase - bacteria adapts to new media

2. Exponential growth phase - continues until nutrients are depleted, toxic waste builds up or space limits growth

3. Stationary phase - no increase or decrease

4. Logarithmic decline phase - Where death and sporulation usually occur

Four oxygen needs of bacteria

Strict (obligate aerobes) - only grow in the presence of air

Facultative anaerobes - Grow better in presence of air but can grow without

Microaerophiles - need oxygen but only small amounts

Strict anaerobes - lack the ability to grow in the presence of air

Optimum temperature for bacteria

35-37 degrees Celsius

What is the goal of sample collection?

To collect a sample that is representative of the disease process

A negative gram stain is what color? positive?

Pink = negative

Purple = positive