Pathogenic organisms

Viruses

Classified by shape, nucleic acid type (DNA & RNA), and method of reproduction (Multiplying)

Viruses

Invade host cells, take nutrients & produce more virus particles

Viruses

Microscopic, intracellular parasites that consist of a nucleic acid (DNA & RNA) core with a protein coat

Prions

Cause rare, degenerative disorders of the nervous system such as BSE (bovine spongiform encephalopathy)

Prions

Pathogenic protein molecules

Pathogenesis

Convert normal proteins to abnormal proteins, causing abnormal functions that produce disease; may be passed on to offspring

Creutzfeldt-Jakob Disease

Cellular Prion Proteins (normal proteins) high concentration in the brain

Creutzfeldt-Jakob Disease

proteins convert to prions causing tiny bubbles in brain cells – holes (“spongiform”)

Creutzfeldt-Jakob Disease

Affects the nervous system

Creutzfeldt-Jakob Disease

confusion, memory loss, loss of coordination, behavioral changes, muscle twitches, visual disturbances, gait difficulty, coma

Creutzfeldt-Jakob Disease Prevention

Sterilization of medical equipment, Many counties have strict guidelines for mgmt of infected cows & for what they are fed

Bacteria

Tiny cells without nuclei

Bacteria

Secrete toxins, parasitize host cells, or form colonies

Gram positive bacteria

Stain purple

Gram negative bacteria

don’t stain

Fungi

Simple organisms similar to plants but lacking chlorophyll

Fungi

Parasitize on tissue on/near skin and mucous membrane

Yeast

Small single-celled fungi

Molds

Large multicellular fungi

Fungal/myotic infections

Often resist treatment

Protozoa

Large, one celled organism

Protozoa

DNA organized in nucleus

Protozoa

may infest human fluids and Parasitize or destroy cells

Protozoa

Categorized by the way they move

Pathogenic animals

Large, complex multicellular organisms

Pathogenic animals

Parasitize/damage human tissues or organs

Pathogenic animals

Nematodes (roundworms), Platyhelminths (flatworms and flukes), Arthropods

Types of Arthropods

Parasitic mites, ticks, lice, fleas, Biting or stinging wasps, bees, mosquitoes, spiders

Arthropods

often vectors (Organism that spreads disease to another organism