Microbiology Exam

• -Showing microbes cause disease:
• Pasteur-silkworm disease
• -How we determine which microbe cause specific disease.
• Robert Koch--established Koch's Pastulates, procedure determing cause of a specific infectous disease.

• -You cannot grow microbes into a artifical culture.
• -pathogen will only cause disease in humans.
• (H.I.V) can't use humans as test animals.
• -Disease cycle takes to long
• -Can't observe symptoms objectively.

Study of how disease 'move" in a population.

• Present in population at all times (low level).
• Ex: common cold, bladder infection

• Increased for confined period of time, in a confined area (in one particular area)
• Ex: Swine Flu

• Worldwide epidemic
• Ex: AIDS

• -Concentrate on "Notifiable diseases."
• -Can have significant impact on public health.
• -Reported to:
• County Public Health then to
• State Public Health to
• Center of Disease Control (CDC) to
• World Health Organization (WHO)

• The bodies rapid response:
• -Fever, chilis, aches, redness, swelling, rash, diarrhea.

• Response that take llonger, but necessary for a cure:
• -Antibody production
• -Killing of infected host cells
• Targeted to a specific microbe
• Long-term protection
• -Memory cells that are produced "remember" that microbe and when exposed agian the memory cells "kick in" and rapidly eliminate microbes.

Make protection by vaccine possible. Vaccine microbial afntigen is given to the patient for the immune response make memory cells.

Fluid is removed from the blood vessel to tissues (carring nutrients) to lymph vessels (drainage system) to lymph nodes (containg phagocytic wbc's) filtering debris and mivrobe and fluid then back to the blood.

Mostly due to an increase in the number of phagocytic wbc's(responding to infection)

All are formed from blood cell steam cells.

Mature in the thymus

Mature in the bursa tissue (bone marrow)

Y shaped proteins each tip can attach to a antigen

Enhances phagocytosis and reduce number of infectious units to be dealt with by trapping the bacteria.

• Blocks adhesion of bacteria and viruses to mucosa by coating with antibodies.
• OR
• Blocks active site of toxin (molecule).

Only kills the bacteria (cell lysis). Complement binds with antibodies to help lysin the bacteria.

Disruption of cell by complement/reactive protein attracts (antibodies) phagocytic and other defensive immune system cells.

• Infectious dose- number of microbes needed to establish infection in 50% of the population.
• Bact. #1-ID50=20 cells
• (will establish infection; few cells)
• Bact. #2-ID50=10,000 cells
• ID50 measures pathogencity ability of microbes to establish infection.

• Lethal dose- number of microbes needed to kill 50% of population.
• LD50 measures virulent- degree of pathogencity- how well microbes can cause series problems in host.

• -Microbe has a rapid rate of reproduction can establish infection (as immune sys. starts to get activated)
• -Tuberculosis (very slow grower) in a healthy patient-immune sys. get rid of it before it can establish infection.

• (non-specific)Not targeted againsts anyone microbe invader
• (innate)born with these defenses
• Mostly responsible for symptoms!

• (specific)targeted against specific microbe
• (acquired)acquire defense only when invaded

• 1. Skin-microbes enter through breaks.
• 2. Clotting-closes breaks in skin (scab)
• 3. Normal flora-crowd out and out-compete pathogens.
• 4. Cilia escalator-move debris and microbes.
• 5. Bodily fluids- tears, salivia, stomach acid
• -tears contain an enzyme that degrades peptidoglycan
• 6. Fever (wbc's respond to microbes by producing "pyrogens" (fire generate)
• -fever stimulates wbc's
• "impairs activity of microbes"
• 7. Leukocytes (wbc's)
• -Non-specific phagocytosis of invading microbes-Neutophils are first to arrive, esp. in bacterial infections.
• 8. Inflammatory response
• Symptoms-if localized redness, and swelling, and pain
• -If body-wide may have rash, aches, and swelling in joints.

• 1. Microbe engulfed- now within membrane sac (phagosome)
• 2. Membrane of phagosome fuses with membrane of lysosome (containing digestive enzymes)
• 3. Becomes phagolysosome (digestive enzyme digest microbe)
• 4. Phagolysome fuses with outer cell membrane to release waste materials.

• immature neutorphils (not fully functional; soldiers being trained)
• Hi- band count patient is fighting a significant infection. (band forms not mature yet) also called LEFT SHIFT.

Mature neutrophils (fully functional).

• 1. Antigen-presenting cells
• Many: monocytes/macrophage
• 2. T-lymphocytes (T-cells)
• Mature in thymus
• 3. B-lymphocytes (B-cells)
• Mature in the bursa (bone marrow)

• most prevalent
• -can cross placenta
• -last 2-3 months
• (baby's immune response begins to activate ~ 2-3 months)

Found in serum and colosterum,... breast mild.

Immunoglobulin= antibodies

• Artificial infections
• Vaccines natigens given artificially Goal; making memory cells against that antigen.

• -whole cells/viruses- killes not used a lot
• -live vaccine use (weakened microbe) not used a lot
• -Toxoids (toxins-altered so there not toxic but give immunity)
• Ex. tetanus, diptheria
• -cell/viral parts or proteins
• Ex. step pneumoniae vaccine= capsule material
• Hep B b vaccine= protein from hep b

Large portion of population immune disease is not as likely to move through population

Get ag and get immune response

Get antibody to a pathogen

• Natural Active: immunity get sick (get antigen) naturally get immune response
• Natural Passive: mom baby (thru placentaor via breast milk)
• Artificial Active: vaccines
• Artificial Passive: IgG= ab shots= anti hep a antibodies

Using antimicrobials still need your immune response

• infects and kills a number of cells but esp. Helper T-cells.
• (serious impaiment of specific responses more susceptible to infecton

• Impair immune response on purpose: Tissue transplant reduce rejection against new tissue (immune resp.)
• Reduce inflammation respons (allergies, inflammation in lungs)