Partnership for Environmental Education and Rural Health (PEER)

Supported by the National Institutes of Health ORIP

Living With BugsDr. Ian Tizard

Director of Schubot Exotic Bird Health Center

Professor of Immunology and Pathobiology

*What is a Microbe?*Definition: A microbe is a

microscopic, single-celled organism. *Also called “germs” or “bugs”

*Microbes are everywhere!!!*They are on every surface

*What sort of microbes?

*Bacteria (Mainly) *Molds (Fungi)*Viruses

Colorful!

BACTERIUM

VIRUS

*Lets focus on bacteria*Bacteria are single celled

organisms*They feed on organic matter*They can survive for a long time and even grow on many surfaces*What surfaces?

Walls, floors, plants animals, clothes*How about body surfaces?

Bacteria on a Human Tongue(seen in a colored scanning electron micrograph)

GERMS CAUSE DISEASE

*…….but they are also essential if we are to survive!!!

OUR MICROBIOME

*Within us are:*Ten thousand bacterial species*Bacterial cells outnumber our own cells 10 to 1.*They weigh about 3 pounds – the same as our brain!

*The surfaces of your body

*The skin*The respiratory tract*The intestine

*ALL OF THESE SURFACES ARE INHABITED BY SPECIALIZED BACTERIAL POPULATIONS!

*Skin Microbe

s

*YOUR SKIN*Several hundred different bacterial species live there permanently*They differ between different skin sites*They cause your sweat or your feet to smell*Washing does not remove them*They protect you against other invaders*They do not invade your body (until you die!)

*A word about washing!

*Washing only removes the most superficial bacteria.*Many bacteria live deep in your skin

where they cannot be reached.*That is why surgeons wear gloves in

addition to washing their hands.*Hand washes do not completely sterilize

your skin

*Wounds*Infection

OUCH!!

*Washing*Sunbathing*Disinfectants

Bacteria can penetrate and liveIn the upper layers of theskin as well as your sweat glands

I like sunbathin

g!

*YOUR INTESTINE

*Contains many billions of bacteria*There are more bacteria in your intestine than cells in your body*They help digest some foods*They provide some essential vitamins*They keep your defenses in tip-top condition*They control your weight*They influence the development of some diseases

*The Rumen

*Stomach System-Ruminant

* Cecum of Horse“Blind Pouch”

Cecum

Small Intestine (Ileum) entering large intestineSmall Intestine-Duodenum

Large Intestine

*Your intestinal bacteria keep your

immune defenses in top condition

*They constantly stimulate the immune system.*They are needed for its proper

development.*In effect there is a constant conversation

between your intestinal bacteria and your immune system.*When an animal dies the intestinal

bacteria are free to invade the body!

*ALLERGIES?*Allergies and the hygiene hypothesis*Why do we have an “allergy epidemic”?*Because we are “too clean”*Some intestinal bacteria suppress allergies*Living on a farm reduces allergy problems

*The problem with antibiotics

*Antibiotics get rid of disease-causing germs – but cause collateral damage!*Antibiotics can change the microflora so

that obesity results*Antibiotics can change our gut flora so

that allergies develop.*By age 18, the average American child

will have received 10-20 courses of antibiotic treatment.

*OBESITY*The intestinal bacteria of fat people are different from those in skinny people!*Are the bacteria in obese people “more efficient” than those in skinny people?*“Cause or effect”

*OTHER DISEASES*Arthritis*Heart Disease*Tuberculosis*Other intestinal diseases*Diarrhea

Birds get

arthritis, too!

*Can we change our intestinal

microflora?*Probiotics are live bacteria that can colonize our intestines and promote health.*Yoghurt containing live Lactobacillus is a

great example of a probiotic.*The dose of bacteria eaten determine

whether their effect is long or short.

*Mouth and Teeth

*Commonplace Interaction

*Saliva has natural bacterial defenses*Teeth hygiene gets rid of bad germs

*Tooth decay*Systemic infection

We’re glad we

don’t have teeth!

*RESPIRATORY TRACT*Lots of bacteria up your nose

*Quite a few in your lungs as well*Maybe cause disease in some people*Chronic coughing or sneezing

He should cover his

mouth when he coughs!

*Sneezing or Coughing

A natural defense mechanism to remove foreign material including

mucus from your airways.

*IN SUMMARY!

We are covered with bacteria.They have the potential to do harm or good.We should consider ourselves to be, not isolated individuals but mixed colonies of creatures.

*The Superorganism

Our bodies together with our associated

bacteria working together for the

common good