We are Not Alone

They are in the air we breathe... In our food... On our skin...

-on everything we touch.

They are...

microorganisms

What are microorganisms? (also called microbes)

plants animals Microbes are small living plants or animals most of which are not visible to the naked eye. diseaseinfection Some microbes cause disease or infection. “good” organisms Many microbes are “good” organisms that help keep balance in the environment and the body.

What microbes lack in size, they make up in number. On the average human, there are about 100 trillion microbes.

Good vs. Bad Microorganisms: Microorganisms that cause disease (germs) are referred to as pathogens. Yeah, I’m bad.

Microorganisms that are harmless or beneficial are called nonpathogens.

Most microbes are considered beneficial or harmless. 87% beneficial organisms 10% opportunists Pathogens 3%

The role of good microorganisms Marine & freshwater microbes form the basis of the food chain in oceans, lakes, and rivers.

Soil microbes help break down wastes.

Humans and other animals depend on bacteria in their intestines for digestion and synthesis of vitamins including: vitamin B (for metabolism) vitamin K (for blood clotting)

Microorganisms have many commercial applications They are used in synthesis of chemical products such as: acetone enzymes alcohol organic acids many drugs

They are used in the food industry for producing: vinegar pickles cheese green olives alcoholic beverages yogurt bread

Main Classes of Pathogenic Organisms: 1)Bacteria simple one-celled organisms At home within “climate” of human body compose largest group of pathogens 2)Fungi: yeasts & molds Plant-like organisms that live on dead organic matter Grow best in dark, damp places

3) Viruses - smallest microbes acellular particles (not a complete cell) 4) Protozoa one-celled animals often found in decayed materials & contaminated water 5) Helminths parasitic worms caused by larval & egg infestations

Bacterial Infections

Impetigo highly contagious bacterial infection

Extensive case of impetigo on underarm of baby.

Fetal Tetanus (note severe muscle contractions) Due to toxin production as a result of bacterial infection.

Diphtheria Note swelling in neck

Diphtheria membrane

Cellulitis An acute bacterial inflammation of connective tissue.

Lymes Disease hallmark “bulls-eye” lesion

Tiny deer tick vector that transmits lymes disease.

Fungal Infections

Candidiasis: Oral Thrush

Oral Thrush: tongue

Candidiasis of Skin Typical red, slightly most lesions.

Nail Fungus

Black Hairy Tongue

Cutaneous Fungal Infection: Tinea Versicolor Note: hypopigmented fungal lesions

Cutaneous Fungal Infection: Ringworm

Cutaneous Blastomycosis: Hand & Wrist

Subcutaneous Blastomycosis: Manifested by subcutaneous abscesses in upper chest

Chromomycosis Deep fungal infection with granulomatous lesions.

Viral Infections

Viral Infection: Verruca Vulgaris (Wart)

Herpes Type I: Oral Herpes

More Oral Herpes healing stage

Neonatal Herpes Premature infant born with classic “cigarette burn” pattern of HSV infection.

Poliomyelitis (also called infantile paralysis) Note: deformed right leg

Iron Lung: used by polio victims

Varicella (Chickenpox with oral involvement)

Measles (rubeola) Rash usually begins on face and spreads to trunk and extremities.

Mumps: Note edema to cheeks and neck

Viral Hepatitis Severely distended abdomen (ascites). Secondary complication from hepatitis.

Parasitic & Protozoan Infections

Leishmaniasis (protozoan systemic disease) Severe nodular, disfiguring lesions transmitted by sand fly

Dracunculiasis (Fiery Dragon Worm) Found just under skin of human host. Causes blisters at site of infestation.

Ulceration from worm.

A fiery dragon worm emerges from leg.

Elphantiasis (filariasis)

Elphantiasis affecting left leg and genitals

Intestinal helminthes cause infestations in intestinal tract and abdominal organs such as the liver and spleen. Always in pairs.

Helminthes which have infested the liver. hepatomegaly and ascites

Intestinal Roundworms Mass of 800 worms removed from child’s ileum during autopsy

Loa Loa eye worm infestation in conjunctiva

Loa loa being extracted from under conjunctivia.

Hydatid cyst formed by tiny tapeworm that migrated to brain.

Summary Microbes are microscopic organisms About 100 trillion microbes live on the average human “Bad” microbes are pathogens About 3% of microorganisms are pathogenic Main classes of pathogenic microbes include: bacteria, fungi, viruses, protoza, & helminths

That’s all folks.