Historical and Morphology Flashcards
What is Yersinia pestis and what colour does it stain
The cause of the plague, stains pink
Gram-positive stain stains _______ in colour, these organisms have a _____ peptidoglycan layer ________ of the cell membrane and _________
dark purple
Thick
Outside
No other layer beyond this
Gram-negative stain stains _______ in colour, these organisms have a _____ peptidoglycan layer in the ________ and _________
light pink
Thinner
Cell Wall
Have an additional outer layer containing lipopolysaccharides
What was the milestone that happened in 1674
Anton van Leeuwenhoek, observed microorganisms “animalcules”
What is milestone that happened in 1798
Jenner used the first vaccine and begins a process that will lead to the eradication of smallpox in the 1970s
What is Spontaneous Generation
That organisms were generated from rotting organic material
What happened in 1850s
Semmelweis shows the value of hygiene
How did Semmelweis show the value of hygiene
He observed that women who delivered babies have a high chance of dying of child-bed fever.
Women who deliver at a different parts of the hospital or at a different time have different death rates, because of either getting an physician or midwife.
- In one group it was physicians coming from doing autopsies on cancer patients in the morning, they would not wash their hands and then would deliver babies in the afternoon, more wives were getting infected from the physicians
- The other group was midwives who did not do autopsies
He thought there were particles on the cadavers that were infecting the women giving birth
The death rates dropped significantly after he implemented hand washing for the physicians
What was Louis Pasteurs Experiement?
He boiled infusions long enough to kill everything but instead of sealing the flasks he bent their necks into an S-shape, which prevented air to enter while preventing the introduction of dust and microbes into the broth, his swan necks reminded microbe free because the dust was stuck in the neck, while the other flask exposed to the air became full of dust
What is pasteurization
The heating of milk to destroy all microbes
What did Louis Pasteur concluded from his experiment
That the microbes growing in the infusion arrived on the dust particles, not through spontaneous generation
What did Lister Nightingale do?
Lister uses antisepsis to control surgical infections (1870)
- Chemicals to wash skin and for instruments during surgery
What did Koch do?
In 1976, he demonstrated that anthrax is caused by Bacilllus anthracis
What happened in 1881
Lina Hesse suggests agar to solidify growth media for bacteria
When was the Golden Age of Microbiology and why
1880-1900
Many pathogens first identified
What happened in the 1940s
The development of antibiotics begins
What happened in the 1980s
The development of molecular techniques for diagnosis and engineering begins
Who discovered penicillin and how
Alexander Fleming
He discovered that mole was producing some kind of substance that is inhibiting the growth of these organisms, as you get closer to the mood the organisms are even smaller preventing bacterial growth
The mold is making some substance that is leaking through the agar plate, this is penicillin from the bacteria penicillium
What is Koch’s postulates
It is used to establish an organism as the cause of a disease. It was developed in the 1800s when he developed the cause of tuberculosis.
STEP 1) The same organism must be found in all cases of the disease
STEP 2) The organism must be isolated and grown in pure culture
STEP 3) Organisms from the pure culture must reproduce the disease when inoculated into a healthy susceptible animal
STEP 4) The organism must then again be isolated from the experimentally infected animal
How did Koch discover his Postulates
After he discovered the cause of anthrax, he was puzzled on how he could distinguish among bacteria
He solved this problem by taking specimens (e.g., blood, pus, and sputum) from disease victims and then smearing the specimen onto a solid surface such as a slice of potato or a gelatinous medium (now agar) and waited for bacteria and fungi print to in the specimen to multiply and form distinct colonies
He put samples of each colony into lab animals to see which caused the disease
What do Cocci organisms look like
Circular
What do Rod (bacilli) look like
Rod shaped
What does Steptococci look like
Circular chains, gram-positive
What do Staphylococci look like
Like grapes, gram positive
