Micro 2.2: Gram Negative Battons Flashcards
Hate to do it to you but name all of enterobacteria and state what type this is
Bâtonnets Gram
- Escherichia coli
- Klebsiella
- Proteus
- Salmonella
- Shigella
- Yersinia
What is special about Gélose MacConkey
It is highly selective and gets rid of all gram positive bacteria as well as cocci gram negative
As such we get only batons gram negative
Which one of the enterobacteria are strictly aerobic
None of them enter a bacteria can grow in aerobic and anaerobic conditions
What is special about Pseudomonas aeruginosa
It is a strictly aerobic bacteria which means it needs oxygen and cannot grow in anaerobic conditions
What is special about Bacteroides
These ones in contrast to pseudomonas aeruiginosa can only grow in an anaerobic conditions
List the three entero bacterias that are part of the normal flora of the human:
Escherichia coli
Klebsiella pneumoniae
Proteus mirabilis
Name the Three enterobacteria that are not part of the normal microbiota and thus can cause diarrhea
Salmonella
Shigella
Yersinia
Certains E. coli peuvent causer de la diarrhée
What are lipopolysaccharides in terms of bacteria
Lipopoli saccharides or lps are Molecules that are part of** gram negative bacteria** found on the external membrane
They contain lipid A which is a super potent endotoxin
LPS is important in pathogenicity of bacteria as it can create a huge reaction in the host
True or false liposaccharides are a key part of Grand Negative bacteria and are found in the cytoplasmic membrane
False the cytoplasmic membrane is the same for all bacteria gram positive and gram negative it is the external membrane that contains the LPS
Membrane externe
Describe the difference between endotoxins and exotoxins
An endotoxin is something that is part of the structure of bacteria
They all have it just like all females have a uterus and all enterobacteria have an LPS
On the other hand an exotoxin is something that is produced by a bacteria is sort of like a toxic pp
Not all bacteria can produce it some can and some can’t
What is a endotoxin and why is it so toxic
How come we have so many gram negative bacteria in our colon and we’re not sick
Like we said an endotoxin is a part of a virus that is or bacteria that is shared with all other finally of bacteria
In our case it is a lipid a of the lps
The reason why it is not toxic in the large intestine is because it is not free there it is bound to the bacteria and as long as an endotoxin is bound to the bacteria it doesn’t cause anything it is the moment that it is laced from a immune cell that it causes an issue
For example when the traveling the bloodstream our immune system sees the bacteria and lices them releasing lipid a and then hell is loose
Write out the main manifestations of Escherichia coli
Infection urinaire
Infection intra-abdominale
Méningite (bébé < 1 mois)
Bactériémie (passage de la bactérie dans le sang)
What is the first thing that has to happen in order for E Coli to cause symptoms
It has to attach
Most or almost all bacteria will have some type of adhesion molecules whether it is Fibrin Pili or different adhesion molecules that they will use to attach to the host cell and then walk up to the destination
What is the main thing that E coli will lead to
Most of the time it generates diarrhea Through the fabrication of toxins the host cell and then walk up to the destination
What is the mode of disease causation for urinary infections of E coli
They use their pilly and Thimbre to attach to the walls and multiply
Important to note here that they do not produce toxins