Microbiology Exam 1 Review

Koch’s 1st postulate

The microbe is found in all cases of the disease, absent in healthy individuals.

Koch’s 2nd postulate

The microbe is isolated from the diseased host and grown in pure culture.

Koch’s 3rd postulate

When the microbe is introduced into a healthy, susceptible host (or animal model), the same disease occurs.

Koch’s 4th postulate

The same strain of microbe is obtained from the newly diseased host. When cultured, the strain shows the same characteristics as before.

Important individuals for Virus discovery

Termin, Baltimore, Dubecco– discovered important class of virus(retrovirus), contains reverse transcriptase (from RNA back to DNA)

Twort and d’Herelle– Discovered bacteriophage, recognizing as viruses that infect bacteria

Contributors to discovery of DNA

Watson, Crick, Rosalind Franklin– discovered that DNA is double helix through x-ray crystallography

Frederick Sanger– Sanger sequencing, we are able to sequence genetic material of an organism

Played big part in disease warfare

Florence Nightingale– discovered there was disease spreading among soldiers, not due to nutrition, but an actual bacteria. 

What factors contribute to pathogenicity of disease?

Age (under 3 or 65+)

Genetics (O blood type = higher cholera risk)

Hygiene and behavior (sanitizing hands after contact w/ person)

Nutrition and exercise (elicit a better immune system response)

Occupation (nurse- exposure to pathogenic samples)

Immune status,(immunocompromised

What makes a disease virulent?

High mortality rate indicates virulence (ex: Marburg virus – 50% chance of death)

Rhinovirus (common cold)- low to no virulence

What makes an organism invasive?

Can spread through tissue readily+quickly. (Streptococcus pyogenes)

What is a zoonotic disease?

An infection that normally infects animals but is able to infect humans (Lyme disease, Plague - rats, fleas, chipmunks,