Clin Med Infectious Disease 1

infection

The process in which an organism has a parasitic relationship with a host

Prions

Corrupted proteins that are folded abnormally

What happens when prions and normal proteins come in contact?

Normal folded proteins (PrPc), prion causes a chain reaction of abnormally folded proteins (PrPsc).

Abnormal folded chain of proteins leads to dysfunction

What do Prions cause?

Transmissible Spongiform Encephalopathies

Transmissible Spongiform Encephalopathies

Uncurable, fatal chronic degenerative disease of brain

Examples of Transmissible Spongiform Encephalopathies

Cruetzfeldt-Jakob Disease and Kuru

How are prions transmitted

Coming into contact with infected tissue

What would be examples of infected tissue causing prions?

Ingesting animal brain, blood products, or contaminated surgical instruments

Are viruses living or non-living?

Non-living

Viruses characteristics

Subcellular, made of only nucleic acids and proteins, and they are obligate intracellular parasites (can only replicate in a host)

Viruses spread

Inject the contents through the tails. Causing infection and dysfunction.

Virus

Do we typically use traditional antibiotics for a virus? If not, what do we use?

No, we use anti-virals

Bacteria characteristics

Single celled, cell wall, grow independently (most of the time), grown on a culture medium (most), contain both RNA and DNA. They have no nucleus.

Bacteria is classified by

Morphology - shapes

Colony types

Gram staining (+/-) - be able to see with stain

Aerobic/anaerobic

Facultative - anaerobic without oxygen

Obligate - harmed by oxygen

Shape of bacilli

Long, oblong, look like Cheeto puffs

Bacilli

Shape of spirochetes

Spiral-like or worm

Spirochetes

Shape of cocci

Sphere or circle

Colonization

The grouping together

Streptococci

In strings/strands

Associated with strep

Staphylococci

clumps

Associated with staph infections

Cocci

Streptococci

Mycoplasma Characteristics

No cell wall, Grow on culture medium, smaller, DNA and RNA, Creates ATP and proteins independently

What does mycoplasma cause?

Atypical pneumonia or STI

Rickettsiae Characteristics

Obligate intracellular parasites - unstable cell membrane, and cannot be grown on traditional culture media

Insect and animal vectors

Cell wall

DNA and RNA

Create ATP and Protein Independency

What does Rickettsiae cause?

Rocky Mountain spotted fever and typhus

Chlamydia Characteristics

Obligate intracellular parasites - can't make ATP by itself

Cell wall

Create Protein independency

Need Host for ATP

DNA and RNA

What does Chlamydia cause?

STI and pneumonia

Fungi Characteristics

Cell wall

Nuclear membranes

Yeast vs. molds

What does fungi cause?

infections in skin, GI, GU tracts

Protozoa Characteristics

Motile, Single celled organisms, Nucleus

What does protozoa cause in the US?

Giardia and trichomonas

What does protozoa cause in developing countries?

Malaria, sleeping sickness, amebiasis, leishmaniasis