Parasites

Microbiology CH 12

Parasite

An organism that lives completely at the expense of another organism called the host

Host

An organism which harbors a parasite and provides the parasite with living conditions and nutrition

Definitive host

A host where the parasite lives its complete life cycle; reproduces and lives its entire life in the host

Intermediate host

A host that harbors a parasite for only part of its life cycle

Cyst

A survival structure formed by some species of protozoans and helminths; analogous to an endospore in bacteria

Vector

An organism that harbors pathogenic organisms and can transfer the pathogens to infect other organisms

Usually arthropods

Mycology

The study of fungi

Mycosis

An infection caused by fungi

Protozoans

Free-living, unicellular organisms

Some are commensals, some are parasites

4 categories based on their motility (movement)

Apicomplexans motility

No movement (intracellular parasites)

Mastigophorans motility

Flagella

Sarcodines motility

Pseudopods

Ciliates motility

Cilla

What is the most common species of pathogenic yeast?

Candida Albicans

Helminths

Flatworms and roundworms

Flatworms

Flat, leaf-shaped bodies

Live in lungs, liver, intestines, blood

Tapeworms

In raw pork, beef, and fish

Grow mostly in intestines

Can grow to 50 feet long

Can migrate to other areas of the body such as liver, lungs, and brain

Roundworms

Can be free-living in soil

Arthropods (insects)

Act as vectors, which carry pathogenic microbes

Some cause symptoms themselves

Arthropod borne diseases

Body & pubic lice, fleas, and flies

Lyme disease symptoms

Fever, headache, fatigue, skin rash

Can usually be treated with 2 weeks of antibiotics

Yeasts

Round or oval one-celled fungi