mechanisms of pathogencity

Mutualism

Both parties benefit

Parasitism

One party benefits, while other is at expense of the other

Dysbiosis

Imbalance of microbiome, allows pathogens to be able to attach to binding sites thus causing infection (C diff, yeast, thrush)

Aids in digestion; breaks down fiber, protection against pathogens; covers binding sites for pathogens to attach, produces tons of vitamins and nutrients

How does microbiome benefit us?

Immunocompromised

Immune system is weak; being sick, malnourished, cancer, diseased etc. can cause this

symptoms

ONLY patient can experience and feel (nausea, pain, numbness etc.)

Signs

Things that can be MEASURED or be VISIBLY seen (fever, rash, pus, swelling, blood pressure etc.)

Primary infection

Very FIRST infection that you get Ex: you get COVID

Secondary infection

You get covid, you get so sick you inhale a bacteria, getting susceptible to ANOTHER infection and you end up getting pneumonia

Pathogenicity

Ability to cause disease

Virulence

Signs and symptoms; the level of the disease (how bad is it?)

Primary pathogen

Gets into body, attaches to tissue, it will cause disease

Opportunistic pathogen

If given the opportunity; gets into somewhere it’s not supposed to be, will have the opportunity to cause disease (staph, E. coli)

Virulence factors

Something pathogen posses/enhancements that makes the disease worse

Toxins, chemicals (gases, acids), slime layers, capsules, Fimbriae

What are some virulence factors?

Infectious dose

number of microbes to establish infection

Bacterial/viral load

Amount of bacteria that is expelled out of a sick persons body

Carriers

You have the disease but you don’t feel/know you have it, you are a spreader

Incubation period

Time between actual infection and onset illness

Illness

Signed and symptoms of disease that are apparent

Convalescence

Time it takes to get better; recovery time

Localized infection

Stays in one place

Systemic/disseminated infection

Spreads throughout body

In the blood

What does -emia mean?

First is exposure, then adhesions, attach to cell receptors, then colonization (multiply)

How do pathogens establish infections?

They have to enter a wound, or can break down mucosa cells

How do bacteria invade mucous membranes and skin?

Through wounds, by a vector, through pore/follicle, mucosa etc.

What ways can pathogens invade our immune system?

Indirect damage

Damage caused by hosts immune response

Direct damage

Damage to the host that is caused by microbe or substance that microbes directly secrete

Endotoxin

Only gram negative have this (lipid A)

Exotoxin

Released/exit when die, any cell can have this

A-B toxins

A is to in, B is attached to glucose and opens channels letting A in

Membrane damage toxins

Damages plasma membranes

Superantigens

Toxins when released causes cytokine storm

Exofoliatin

Binds to Areolar CT and destroys them causing Scalded skin syndrome (is in Staph)

Syncytium

Body of host cells fuse to form one big multinucleated cell complex