Microbe-Human

  • Heomoniphilus aegyptious- pink eye- infectious agents that enters the skin

  • syhillus- spirochetes corkscrew right through the skin- urogenital portal if entry- penetrate an unbroken surface- can cross the placenta

  • TORCH (Toxoplasmosis, other diseases, rubella, cytomegalovirus, herpes-simplex); a group of infections that doctors screen for in pregnant women because they can cause problems for the developing baby.

  • smaller infectious dose(ID)= greater virulence

  • Antiphagocytic factors: leukocidens(toxic to WBC; produced by streptococcus and staphylococcus), extracellular surface layer(like capsule makes it difficult for phagocytes to engulf them), and some can survive inside phagocytes after ingestion (ex. mycobacterium)

  • Extracellular enzymes- secreted enzymes by pathogens that break down and inflict damage on tissues or dissolve host defense barriers

    • Mucinase, keratinase, collagenase, hylauroniase, coagulase (cause blood to clot), kinase(break down clot)

  • Toxigenicity: the power to produce toxins

  • Toxinoses: variety of diseases caused by toxigenicity

  • Toxemias: toxinoses in which the toxin is spread by the blood from the site of infection (tetanus and diphtheria)

  • Intoxication: toxinoses caused by ingestion of toxins (botulism)

  • Endotoxin: causes fever, gram-negative bacteria, lyse

  • Exotoxin: unstable with heat, gram-neg and pos, secreted from a live cell

  • Necrosis: accumulates damage leads to cell and tissue death

  • Damage can be caused by excessive host response

  • Focalized infection: A focalized infection is one that begins in a specific area of the body but has the potential to spread or produce effects in distant sites; produces a toxin.

  • Syndrome- when a disease can be ibdefied or defined by a certain complex of signs and symptoms

  • Fever is a sign

  • Signs of Inflammation: Edema(swelling caused by excess fluid trapped in body’s tissues), Granulomas and abscesses, lymphadentis(inflammation of lymph nodes), lesion(site of infection or disease)

  • Leukocytosis- increased amount of WBCs

  • Leukopenia- decrease in amount of WBCs

  • Septicemia: general state in which microorganisms are multiplying in the blood and are present in large numbers

  • Bacteremia/viremia: microbes are present in the blood but are not necessarily multiplying

  • Persistence of microbes- latency: a dormant state; the microbe can periodically become active and produce a recurrent disease like heroes simplex, hepatitis B, AIDS; sequelae: long term or permanent damage to tissues or organs

  • Progression of infection: incubation(initial exposure to microbe), prodromal(starting to get sick), invasion/acute please(height of infection), convalescence(getting better), recovery-where you’re done or continuation- where you’re chronic carriers

  • Convalescence is the period after an illness where the body recovers, while convalescent carriers are individuals who are still able to transmit a pathogen during this recovery phase. In contrast, chronic carriers harbor and can transmit a pathogen for a long, indefinite period, such as months or years, after their initial infection.

  • Vector: a live animal that transmits an infectious agent from one host to another- majority are anthropods

  • Biological vector: vector is infected and pathogens are internal

  • Mechanical vector: vector js not infected, passive carriers, pathogens are external

  • Zoonosis- infectious indigenous to animals but naturally transmissible to humans- we’re dead end host usually; example: influenza which are transmissible person to person but not dead end

  • Horizontal transmission: disease is spread through a population from one infected individual to another

  • Vertical transmission: transmission from parent to offspring through ovum, sperm, placenta or milk

  • Fomite: Inanimate object that harbors and transmits pathogens- things people touch a lot and pass around like doorknob or phone; is direct transmission

  • Air as a vehicle

  • Droplet nuclei- tiny dried particles that remain in the air after larger respiratory droplets evaporate; airborne and indirect transmission

  • Aerosols: any suspension of tiny solid or liquid particles in air.