BIOL 211 Lecture Notes - Lecture 18: Koch'S Postulates, Microbiological Culture, Immune System
Document Summary
Overcrowding & sanitary conditions [*usually #1 reasons for human sickness*] Primary pathogen: have ability to penetrate host defenses. Opportunistic pathogen: cause disease only in compromised host. Break in tissue allows organism to access new site. Loss of other microflora allows organism to bloom. Acute: illness is short term because the pathogen is eliminated by host defenses; person is usually immune to reinfection. Chronic: illness persists over a long period of time. Incubation illness convalescence latency recurrence. Latent: illness may recur if immunity weakens. Bacterial pathogenicity: ability to invade tissues, mechanisms of colonization, ability to bypass/overcome host defense mechanisms, production of extracellular substances that aid in invasion, ability to produce toxins, production of endotoxins (cell associated, production of exotoxins (released from cells) Microbial infection: colonization: establishment of pathogen @ appropriate portal of entry (encounter entry) Adherence = digestive tract, respiratory tract, urogenital tract, conjunctiva: invasion: production of invasins, evasion from host defenses: establishment.
