Bacteriology and Oral Diseases; pptx 2

how do you stain Mycobacteria

using a a acid-fast stain

why does Dr. Kadouri not like calling the capsule the "Exopolysaccharide capsule" or "glycocalyx"?

because the capsule isn't always completely made of sugar

Both gram-positive and gram negatives can produce capsules

True

what is a capsule on a bacteria

a very thick structure, that is primarily composed of sugar, that surrounds and is (firmly)anchored to the cell

do all bacteria have a capsule?

No, only some

what does the capsule do?

protects the cell in adverse conditions

what are adverse conditions?

an environment that is not advantageous or may hinder the bacteria

does the bacteria need the capsule to grow?

No, they can grow without it

what is virulence?

ability to cause disease

What is pathogenicity?

ability of a microorganism to cause disease

what kind of stain is used to see the capsule

India ink

is the capsule charged?

No, it is not charged

How does India ink work?

It stains everything except for the capsule because of their charge

how does the capsule help the bacteria in terms of conflicts with the immune system

It makes the bacteria stealthy

does the capsule cover the LPS

yes, it completly encapsulates the bacteria

What is extracellular polymeric substance (EPS)?

A glycocalyx that helps cells in a biofilm attach to their target environment.

What role does EPS play in biofilms?

It helps cells in a biofilm attach to each other.

What are biofilms?

ability of bacteria to attach to surfaces, a community of microorganisms attached to a surface and is imbedded in the EPS

slime layer

usually associated to biofilms, basically the EPS

full structure of gram-positive bacteria (inner to outer)

1. inner cell membrane

2. Thick peptidoglycan cell wall

3. S-layer (yes or no)

4. capsule (yes or no)

5. EPS (yes or no)

full structure of gram-negative bacteria (inner to outer)

1. inner cell membrane

2. periplasmatic space

3. thin peptidoglycan cell wall

4. outer cell membrane

5. S-layer (yes or no)

6. capsule (yes or no)

7. EPS (yes or no)

Do bacteria need the EPS to survive?

No, it does not need it to survive

How does the EPS benefit bacteria

it helps them survive in adverse conditions

Is the EPS a virulent factor?

It depends on the bacteria, e.g. teeth bacteria need to attach to form a cavity so it needs it for attachments (making it a virulence factor)

other functions of EPS

nutrient trap, carbon storage, very sticky, attachment to surfaces

in what ways does the EPS protect the bacteria

acts a physical barrier, chemical barrier, protection from phagocytosis, protection from viruses

What is the only virulent factor of Streptococcus pneumoniae?

The capsule

What serious condition can Streptococcus pneumoniae cause?

Meningitis

What type of infections can Streptococcus pneumoniae cause besides meningitis?

Lung infections and ear infections

How many different types of capsules does Streptococcus pneumoniae have?

90+ different capsules

what happens if you run Streptococcus pneumoniae in the lab multiple times?

it looses its capsule cause it "doesn't need it anymore"

What type of bacteria is Streptococcus pyogenes?

Gram-positive

What is the main virulence factor of Streptococcus pyogenes?

Hyaluronic acid capsule

What disease does Streptococcus pyogenes cause that is characterized by a sore throat?

Strep throat

What infection can result from Streptococcus pyogenes and affects the ear?

Ear infection

What condition caused by Streptococcus pyogenes involves red patches due to an immune response to a toxin?

Scarlet fever

What serious condition can occur from prolonged untreated infection with Streptococcus pyogenes?

Rheumatic fever

what happens in the body due as a result of

Rheumatic fever

antibodies being produced for hyaluronic acid causing it to attack the bacteria and our own cells

What is childbed fever?

an infection of Streptococcus pyogenes acquired by mothers during childbirth and transmitted between them by doctors

Who is known as the Savior of Mothers?

Ignaz Philipp Semmelweis

What practice did Ignaz Philipp Semmelweis instruct his students to follow before entering the delivery room?

Wash their hands

What observation did Semmelweis make about fever in women during childbirth?

Fever often affected women delivered by medical students coming straight from the autopsy or dissecting rooms.

what happened to Semmelweis?

committed to an asylum and died at the age of 47 from infection

What type of bacteria is Bacillus anthracis?

Gram positive bacteria

Does Bacillus anthracis produce spores?

Yes, it produces spores

What disease does Bacillus anthracis cause?

Anthrax

What is unique about the capsule of Bacillus anthracis?

It is made of amino acids instead of polysaccharides

What type of toxin does Bacillus anthracis produce?

Very aggressive toxin

What type of bacteria is Streptococcus mutans?

Gram-positive bacteria

What dental condition does Streptococcus mutans produce?

Caries (tooth decay)

What does Streptococcus mutans need to attach itself to the enamel of teeth?

A biofilm/EPS

What is the composition of the EPS produced by Streptococcus mutans?

A sugar known as glucan (long chains of glucose)

why is eating a lot of sugar beneficial to Streptococcus mutans

it ferments it to produce acid and can grow its EPS

What type of bacteria is Staphylococcus aureus?

Gram-positive

What is a characteristic feature of Staphylococcus aureus's cell wall?

Very thick peptidoglycan

What is the composition of the thick EPS in Staphylococcus aureus?

Poly-N-acetylglucosamine

What types of infections can Staphylococcus aureus cause?

is the cause of MANY infections; Skin infections, food poisoning, eye infections, etc.

what does the Poly-N-acetylglucosamine EPS do for Staphylococcus aureus

attachment to tissues and cells, attachment to biomaterials, forms a Biofilm, Protection from antimicrobial killing and protection from phagocytosis

how do we make vaccines for some bacteria

inject the capsule into a person and they will start producing antibodies for that bacteria's capsule

Haemophilus influenzae

causes meningitis, ear infections, lung infections

conjugated vaccine

a vaccine consisting of the desired antigen and other immunogenetic proteins

streptococcus pneumoniae bacteria

extremely deadly, inflammation in brain

what is the HIB vaccine for?

Haemophilus influenzae type B

what is the PCV13 vaccine for?

streptococcus pneumoniae

what is worse, viral or microbial meningitis?

microbial

DPT vaccine

Combination vaccine for diphtheria, pertussis, tetanus.

tetanus

gram-positive, lives in soil

pertussis (whooping cough)

pertussis

Do archaea have peptidoglycan like bacteria?

no, they have pseudopeptidoglycan

is the structure for archaea cell wall also NAG and NAM?

No, it is NAG and NATM

is the cross link for archaea the same as bacteria?

no, it is not a β1,4 it is a β1,3

T/F: Pseudopeptidoglycan will be broken apart by lysozymes

False

What is the surface layer (s-layer)?

Extracellular portion of the cell envelope commonly found in archaea and some bacteria.

How does the surface layer (s-layer) differ from slime layers?

It is not the same as slime layers.

What is the composition of the surface layer (s-layer)?

It is not made of polysaccharides.

Where is the surface layer (s-layer) located in relation to the capsule?

It is below the capsule.

What is the structure of the surface layer (s-layer)?

It is made of crystallized proteins.

What is one function of the surface layer (s-layer)?

It protects the cell.

what are membrane proteins?

proteins that are anchored to the membrane

what is the function of membrane proteins in bacteria

-transport, glucose and nutrients in

-secretion, toxins

-sensing, transmit signal into cell for bacteria to sense density in environment

-attachment

-toxins

-enzymes

T/F porins can e found in gram-positive bacteria

False, porins are only found in gram-negative bacteria

What are porins?

protein channels that span the outer membrane

what is the role of porins?

proteins that permit small molecules to pass through the outer membrane into the periplasmatic space

are porins compound specific?

Some are and others aren't

what method do compounds use to go through a porin?

Diffusion

what size does a molecule have to be to pass through porins?

<1500 Daltons or 1.5 kDa

what is the size of a typical sugar?

a couple hundred Daltons

what is the size of a amino acid?

120 Daltons

can enzymes pass through porins?

No, they are too large and need to use a different transport method

why are lysozymes only effective in gram-positive bacteria?

Due to the peptidoglycan being exposed in gram+ bacteria; lysozymes cant reach the peptidoglycan in G- bacteria due to them not being able to go through the porins

T/F You can find porins in in mitochondria and chloroplasts in humans

True

what are the different transporter systems used in bacteria?

-Simple transport

-Group translocation

-The ABC System

how does simple transport work?

uses a protein gradient to transport, does not require ATP, compound is not modified

how does Group transport work?

Requires ATP, the compound gets phosphorylated as is passes through the channel

How does the ABC system work?

Requires ATP, compound is not modified

Lactose permease

transports lactose across cell membrane, example of simple transporter

how does lactose permease work?

the protein has a V shape in the cell membrane, lactose binds to it, changing its conformation, flipping the V inwards, allowing it into the cell

substance that goes through group translocation

glucose

what happens to glucose after it goes through group translocation

the glucose goes through a cascade of proteins and gets phosphorylated