BIOL 209 1st Edition Lecture 20 Outline of Last Lecture I. Question/Answer’sII. Acquisition of Drug ResistanceIII. Infectious DiseasesIV. Human Microbiome: our normal microfloraV. Koch’s PostulatesOutline of Current Lecture I. Question/Answer’sII. DefintionsIII. InfectionIV. Sources of DiseaseCurrent LectureI. Question/Answer’sA. Where do pathogens come from? Humans, animals, soil & waterB. Why are many enveloped viruses more sensitive than non-enveloped viruses? Losing the membrane makes it less infectiousII. DefintionsA. Virulence: ability to cause disease – factors include pathogen characteristics that enhance infectionsB. True pathogen: presence always associated with diseaseC. Opportunistic pathogens: not typically associated with disease1. Ability to cause disease depends on location in host OR host resistance (immune function)D. Obligate: requires host cells for growthE. Facultative: can grow without a hostF. Zoohotic: can grow in animals and humansG. Vector: (mosquito) pathogen can be transmitted from one organism to another by a carrier (living)H. Epidemiology: understanding distribution/spread of disease in order to estimate risk & develop preventative measures1. Identifying a pattern of disease: who, where, when…III. InfectionA. Pathogen entry, adhesion, (invasion*), multiplication, transmission1. Not all pathogens are invasiveB. Pathogens can:1. Alter host cell functionThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.2. Damage tissue3. Stimulate a system – wide host immune response (fever)IV. Sources of DiseaseA. Resevoirs 1. Living – human and animal (zoohotic)2. Non-living – inanimate (soil and water)B. Sources: carriers who are asymptomatic (either before illness or as chronic carriers), or have no infection but are passive carriers – direct & indirect transmissionC. Carriers1. Biological – pathogen grows in vector2. Physical – no growth of pathogen within vectorD. Mode of transmission is related to survival characteristics of the pathogen1. High resilience (endospores) – moderate resilience (cysts, non-enveloped virus, some bacterial mycobacterium, staphylococcus) – least resilience (enveloped virus, most vegetative bacteria, protozoan trophozoites)a. Indirect or direct (high resilience) usually direct (least
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