Microbiology 3

• Contain either DNA or RNA not both
• Need a host for replication
• Virions must be assembled before moving to a new host
• Acellular

nucleic acid and capsid proteins with the viral genome on the inside (single or double stranded DNA or RNA)

• Isometric - Polyhedral (20 sided) spherical
• Helical - Creates a protein tub with the nucleic acid on the inside
• Complex - Isometric top filled with DNA/RNA, helical body, base plate, tail fibers the helical shape acts as a needle and head acts as a syringe (usually naked)

nucleic acid and capsid proteins with the viral genome on the inside (single or double stranded DNA or RNA)

• By genome type (DNA or RNA, double or single stranded, single molecule or segmented)
• By virion shape (isometric, helical, complex)
• Presence or absence of envelope (naked or enveloped)

Making more viruses/virions (whole virus particle)

• Attachment - virus attaches by the spikes on the outside and looks for receptors on outside of host
• Entry - direct penetration, membrane fusion, endocytosis
• Synthesis - new manufacturing of particles
• Assembly & Release - everything for the virus is assembled and the cell either bursts or the virus pushes through the membrane to burst it

• Acute - Measles - Onset of infection, get sick, then get better and disease is gone
• Latent - Chicken Pox/Shingles - Onset of infection, get sick, then get better but disease hides and can be reactivated later
• Chronic - Hepatitis B/C - Onset of infection, get sick, get better but virus never leaves and you always shed it
• Slow - HIV/AIDS - Onset of infection, get sick, get better, slowly get sick again (as virus replicates in your t-cells) can take 10-20 years to get sick again

Prions are infectious proteins folded into wrong shape and can bump into good cellular cells and turn them to fold wrong (mad cow disease).

Can not do simple broth or plates as a virus has to replicate inside of a hose cell. A plaque with a bacterial lawn can be injected with a virus. Chicken eggs can also be injected with a virus as they are similar to humans and this is how a lot of vaccines are made.

• Innate - inherited, will always be on, non-specific
• Adaptive/Acquired - specificity, inducibility (can turn on or off), clonality, unresponsiveness to self, memory

Blood, erythrocytes, platelets, leukocytes (granulocytes - eosinophil, basophil, neutrophil / agranulocytes - lymphocytes, monocytes), dendritic cells, macrophages

• Platelets - involved in healing
• Eosinophil - defense against parasitic worms and allergic reactions
• Basophil - release of histamine, inflammation reactions
• Neutrophil - phagocytosis
• Lymphocytes - involved in adaptive immunity
• Monocytes - circulates, differentiate in tissue to macrophages & dendritic cells.
• Dendritic Cells - gather antigen & present to lymphocytes
• Macrophages - phagocytosis, signaling centers for rest of immune system

Skin, Saliva, Mucous Membrane, Normal Flora, Enzymes/Proteins

Quick and nonspecific

Phagocytosis, Inflammation, Fever

• Inflammation
• Fever - last response

• Calor - Heat
• Rubor - Redness
• Tumor - Swelling
• Dolor - Pain
• Loss of function (sometimes)
• Dilation of blood vessels
• Increased "leakiness" of blood vessels

Humoral & Cellular

• T-Cells:
• Cytotoxic T-Cells go after affected cells or ones that have changed their protein is CD-8
• Helper T-Cells target extracellular cells and their protein is CD-4

• B-Cells:
• Produce antibodies and have BCR's on their surface

T-Cells & B-Cells

• T-Cells - matures to a point in the bone marrow then goes to the thymus to finish maturing
• B-Cells - matures totally in the bone marrow

• T-Cells - recognize antigens presented by MHC molecules to recognize from a person or foreigner
• B-Cells - Turn into plasma cells & make antibodies

They each have certain receptors. Helper T-Cells have CD4, Cytotoxic T-Cells have CD8 and B-Cells have BCRs on their surface and make antibodies

Protein that binds to antigen

To identify and neutralize foreign objects

Its specific

• Neutralization - cover all receptors on a cell with antigens so virus/bacteria can not attach
• Opsonization (direct) - an antibody to attach to a bacterium & to get ready to eat
• Agglutination - a bunch of antibodies attach to different cells to help kill them off
• Antibody-dependent cellular cytotoxicity (ADCC) - a lymphocyte attaches to one of our cells that is different and natural killers are sent out

Both Cytotoxic T-Cells and Helper T-Cells go after an affected cell

Antigen presenting cells talks to T-Cells which activates a B-Cell. Somewhere else a B-Cell (or the same B-Cell) recognizes the bacteria. Both the T-Cell and B-Cell is activated.

Once a foreigner is seen the B-Cells can recognize it again and immediately start making antibodies without having to go through the process of being presented the antigen by the T-Cells

• Mutualism - both partners benefit (normal flora)
• Parasitism - one benefits at the expense of the other (worms living off our tissue)
• Commensalism - neither partner is benefiting/harmed or 1 may be benefiting but the other is not being effected

Organisms that can normally be found on surfaces of/in the body and usually do not cause us harm and can actually help us.

You get normal flora from your mother (when being born) and breathing

They are found everywhere in the body. Skin, gut, upper respiratory tract, upper and lower digestive tract, female/male urinary and reproductive systems, and eyes.

Humans, other animals, non-living reservoirs (water supplies, dust particles, food supply)

Any openings on the body (ears, eyes, nose, insect bite etc...) and placenta

Ability of a pathogen to produce and infectious disease

Ability to inflict damage on a host

Virulence factors contribute to the pathogenicity of an organism

• Primary Pathogen - will cause disease in healthy individuals
• Opportunistic Pathogen - will cause disease in only immunocompromised individuals

• 1) Organism must be present in every case of the disease
• 2) Organism must be grown in pure culture from the diseased host
• 3) The same disease must be produces when the organism is introduced into a susceptible hose
• 4) The organism must be recovered from an experimentally infected host

We can figure out what the actual organism is (by isolating it in different hosts), how long it takes to grow or cause illness, how it can be transfered

• Some organisms are human disease only and can not be given to another host (like HIV/AIDS)
• Can not isolate the organism (grow it in a lab)
• Some diseases are a combination of pathogens, environmental, or genetic factors

• Incubation Period - time between exposure & initial signs/symptoms
• Prodromal - vague, general symptoms (start feeling bad but don't know why)
• Illness - most severe signs & symptoms (where you'll go to the dr)
• Decline - declining signs & symptoms (getting better)
• Convalescence - no signs & symptoms (better)

How much damage is caused. Invasion, Adhesion, Evasion

virulence factors contribute to the pathogenicity (how much damage it can cause) of an organism

Allow for invasion, adhesion, evasion, cause damage

Toxins, Evasion (structures & strategies), and Extracellular Enzymes

The same as the entry (any opening of the body)

• Contact - (direct, indirect, and droplet)
• Vehicle - (environment, inanimate objects)
• Vector - A disease passed through another animal (mechanical - fly/roach and biological - mosquito)

• Incidence - number of new cases in a given area over a period of time
• Prevalence - total number of cases in a given year over a period of time
• Endemic - disease thats always present in an area
• Sporadic - Disease popping up randomly
• Epidemic - Sudden increase of a disease in an area
• Pandemic - Multiple epidemics

associates with hospital

• Endogenous - The infectious agent came from the patient itself
• Exogenous - The infectious agent came from the outside
• Iatrogenic - Procedure, devices, or material induced