Micro lecture 6 infections and disease

Symbosis

Means “to live together”

Types of Symbosis

Mutalism , Commensalism, Parasitism & Pathogen

Mutalism

Both benefit, meaning you benefit from microoranisms living in you, Whether its living in you or protection from pathogens. It also helps with digesting food and balancing PH.

Commensalism

No harm or benefit

Parasitism

Causes harm

Pathogen

is a parasitism.

Normal Flora

It can be Bacteria, Fungi, Protozoa that lives in you.'

Most are commnsual (Such as staph epi)

Some are mutal such as ecoli in the intestine and bascillus in the vahinal tract .

Candidad albicans is harmless

How normal flora become opportunistic pathogens

Immune suppersions: Any kind of common cold, stress,drinking alchol,aids,cancer,chemo etc. that lowers the immnue system.

Changes in the normal flora

Broad spectrum in antibiotics lower normal flora in the vaginal tract, then increase in getting a yeast infection. C diff can grow

Normal flora in an unsual place

E. coli belongs in the intestine, but when it gets in urinary tract you get a uti. (Bad when gets into urinary tract)

What are other normal floras?

Diet changes, & hormonal changes

Infection

Is the movement of microbes into the host, that is not apart of the normal flora. '

exposure to microbes, contamination.

Microbes not members of the normal flora get into the body by the way of :

Food and drink (diarhea), air,sex and Arthropods.

FYI: Arthropods are insect bites and arachinds bite and inject you w alot of pathogens.

Portals of the entery into the host are the

Skin.

Skin

outer layer is thick with dead cells that form a barrier.

Psthogens

enter the skin by hair or sweat glands. Abrasions, cuts & scapes.

Parasitic worm larvae

go through the skin.

Fungi

is ring worm.

Mucous membrane

are thin mosit and alive. They have easy portal of entery and are more hospitable.

• Respitory tract

• Urinary tract

• reproductive tract

• gastrointestinal tract

• conjunctiva (is pink eye & gram negative)

Placenta

Some pathogens can cross the placenta. If you get it while prego it will cause spontaneous abortion, birth defects and premature birth.

The parental route

puncture beneath the skin and mucous membrane

• happens by penetrating the skin with things such as a nail,thorn,dog-cat vite, instect bite. Any of these are parental route.

Nature of diseases

Disease is known as morbidity.

• any change from a state of health

Manifestation of disease

Only patients can feel or you feel. Nobody can disproof you feel bad(ill).

symptoms subjective

only patient can feel

signs objective

Fever, rash, throwing up

syndromes are groups of signs and symptoms

enough signs to get diagnosed by Dr.

Asymptomatic or subclinical

No signs or symptoms

Epitology

The cause of disease

Koch’s postulates

1.) every case of disease you find the same pathogen or agent.

2.)Then grow and isolate on other medias

3.)Inject into healthy host, gets same disease.

4.) Then reisolate.

Nature of incetious disease

the question is what causes the disease, whts the ability?

• Pathogencity

• The ability the organism to cause disease.

• Virulence

The degree of pathogencity

or how sick can it make you

Patterns of infection: Localized infection

its found in one place

Systemic infection

is when you dont take care if the infection and gets into your blood or lymph system then goes to other organs.

mixed infection

2 or more pathogens w infection

primary infection

is the 1st pathogen example (Common flu)

Secondary infection

when it gets worse example (causing pnemonia)

Acute

Comes on fast ans lasts a short time

chronic

comes on slow and lasts along time

Subacute

between chronic and acute

Virulence factors

allows pathogens to cause infection.

Adhension factors

attached to you to attach to host.

types of adhesion

• Bacteria, Pilli or Fimbrae

• Protozoa discs

• Worms/ hook and suckers and some may have teeth called scolex.

extracellular enzymes

Degrage specific molecules to enable bacteria to invade deeper tissue.

Hyluronidase

Digest hydlaronic acid between cells. Then bacteria produce hyluronidase and collagenase. Bacterua invase deeper tissue.

Collagensase

Uses your serum protiens to make a clot and can hide,grow, reproduce from immune system.

Kinase

breaks down clot and dissolves by releasing bacteria.

Phospholipases & lipases

• Lipases break down antibacterial lipids into the skin.

• membrane is made up of phospho. some og these pathogens sit out and make a chain of them and produce phos.

• They then break down the bilayer and allows to go through tissue & cells

Toxins

Alot of these organisims ctreate some kind of toxins that make you sick.

Exotoxins

screted by the organisms

cytotoxins

Kill Cells

Neurotoxins

Inhibit neurons

enterotoxin

Affect intestine & causes diarrhea/vommiting.

Endotoxins

from the gram negative bacteria.

Lipid A portion of the Lipopolysaccharide

Fever,Shock, Rash , —» eventually leas to death.

Antiphagocytes properties

Capluses -inhibits phagocytoses bcus it cannot hold on. It is very big and slimmy.

FYI- some are made up of hyloronic acid

Immune system dies not recall as foreign

Some capluses neutralzie the enzymes in lysosomes.

Pathogens are not broken down and live in phagocytes.

Five stages of the infeciton

• Incubation period

• Prodromal period

• Illness

• Decline

• Convalescenes

Incubation period

no signs or symptoms

prodormal period

Vague, general symptom/starting to feel bad

illness

actual sickness,most severe signs & symptoms

Decline

Feel a bit better declinging signs and symptoms

Convalescenes

no signs or symptioms ; tissue repaired

Reservoirs of pathogenic organisms

• Animal reserviors - zoonosis or zootonic (found in animals)

• Human reserviors -Human to human Symptomatic or asymptomatic

• Nonliving reserviors - soil,water food

Transmission of infectious disease

• Contact trasnmission ‘ direcr human to human of any kind such as ( kissing,hugging sex)

• direct transmisson

• indirect transmission

• fomites; any object where pathogen an live for a ehile

• droplet transmission ; small droplets of spit and can contain pathogens (1 meter or less)

Veichle transmission

carries much farther than a few ft away from the body

Airborne transmission

can spread, greater than 1 meter and can last a long time in air . Usually in dust or aerosols.

Waterborne transmission

diseases that got in water called feccal route

vector transmission

any insect or arachind that transmit dissease.

• Example mosqioto bits cow, we eat cow w mosquito bite and transmits into human.

• ( Arachind = mosqiotes, tics, spiders, insects)

Epidemiology

Occurance of disease incidence rate and the prevlance

prevalence

= old cases + new cases/people at risk

noncommunicable

does not go from human to human