Intro Microbiology (Lab info included) Flashcards
Chemolithoautotrophic
Grows on inorganic compounds
Doesn’t need organic compounds to replicate
Name 3 scientists that tests on spontaneous generation
- John Needham
- Lazzaro Spallanzani
- Louis Pasteur
What did the swan-neck experiment do?
It was used to disprove the idea of spontaneous generation. The swan neck makes the air able to move in freely into the flask but traps the microbe in the depression
What experiment(s) supported spontaneous generation
Needham’s hay experiment where he boiled hay in a jar and left it to be exposed in the air and showed that there is microbial growth
Who was the scientists that made the first (debatable) microscope?
Robert Hooke
What was Koch’s contribution to the concept of ‘disease’?
He came up with the germ theory of disease that states that microbes are the causative agents for disease
What is the purpose of Koch’s postulates?
To prove whether the cause of the disease is a particular microorganism
What are Koch’s postulates?
- Be found in all cases of the disease
- Be isolated from the diseased host in pure culture
- Produce same disease in experimentally-infected host
- Be re-isolated from the experimentally-infected host
What else did Koch contributed in microbiology?
Invented agar plates to sustain microbes
Staining microbes with methylene blue
Who are the three scientists that contributed to penicillin?
- Fleming
- Florey
- Chain
Who discovered penicillin?
Fleming
How was penicillin discovered?
Fleming was studying about staphylococcus bacteria and accidentally left it out in the open as he left. A fungus grew on it and it was shown that the staphylococcus bacteria was avoiding the area where the fungus grew.
What did Florey and Chain contribute to the development of penicillin?
They further purified penicillin and developed it into mass production that helped win the war
Normal flora
Microorganisms lives in our body/gut that helps us function
What does normal flora do?
It helps build the immune system of individuals, synthesise vitamins, break down molecules that our gut could not normally break down, and help differentiate foreign organisms that enters the body
Where do we get normal flora from?
Can be from out mother during birth, can also be developed as we grow from the environments we interact in
Are normal floras dangerous to us?
They are usually not dangerous when they are located in their local environment. But they can be dangerous if they are placed in another part of our body as the environment would not be suited for their growth and instead would cause complications
Two types of pathogens
Opportunistic pathogens - Only causes disease in specific conditions e.g. immunosuppressants
Obligate pathogens - Viral infection that preys upon organisms e.g. T4 virus
Why is tuberculosis hard to diagnose?
Their symptoms contain common cold and coughing which can be easily mistaken as influenza. The disease is also latent, meaning you can carry the disease with no symptoms at all
Is TB difficult to treat?
Generally TB have readily available treatments in hospitals however there are antibiotic resistant TB variants that causes further complications and higher mortality rate as there is no cure for antibiotic resistant TB. Moreover, treatment is expensive
What are the traits of an opportunistic pathogen?
- Have abnormally high cell density
- Located in areas where they usually are not supposed to be at
- Immune system is comprimised
How does antibiotic consumption contribute to diseases?
Overconsumption of antibiotic give rise to antibiotic resistance for the pathogens as pathogens that are not killed by the antibiotic are the resistant ones. They can reproduce and replicate this trait identically which makes them harder to kill.
Examples of normal flora in your mouth
Streptococcus pneumoniae
Streptococcus pyogenes
What agar plates does the mouth flora grows best on?
Blood agar plates. Pyogenes have complete haemolysis (beta) and pneumoniae have partial haemolysis (alpha)
Examples of normal flora on skin and nose
Staphylococcus epidermidis
Staphylococcus aureus
What agar plate(s) does the normal flora for skin and nose grow on?
Nutrient Agar plates
Mannitol Salt agar plates
What makes the MSA special?
It is used for selective growth as the agar plate is 7.5% sodium chloride. This plate also have an indicator that can detect whether the organism is fermenting in the presence of mannitol. When an organism does ferment on mannitol, it lowers the pH of the agar which results in a color change from the indicator
Example of fastidious organism
Streptococcus pneumoniae. It only grows on blood agar plates and nutrient agar plates shows no signs of growth of this organism. This is because blood agar plates contains nutrients that only the blood would have which differs from the nutrient agar plates
Which streptococcus is more dangerous?
Streptococcus pyogenes. When it goes to our throat it can cause strep throat or sore throat. It can also cause more severe diseases like scarlet fever. Beta-haemolysis is more associated with pathogenicity
One health concept
A concept that states that the use of antimicrobials in agriculture impacts on human pathogens. meaning that many human disease originate form their environment
