Post on 10-May-2015
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)
Microbes are small living plantsplants or animalsanimals most of which are not visible to the naked eye.
Some microbes cause diseasedisease or infectioninfection.
Many microbes are “good” “good” organismsorganisms 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%
opportunistsPathogens 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:
acetoneenzymes
alcohol
organic acids
many drugs
They are used in the food industry for producing:
vinegarpickles
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 water5) 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)
Elphantiasisaffecting 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.