Lecture 32Outline of Last Lecture 1. HypersensitivityOutline of Current Lecture 1. Infections2. InvasionsCurrent LectureTypes of InfectionsMixed- Poly microbial, more than one pathogenPrimary- Initial infection; Localized that led to systemicSecondary- Infection caused by different microbe other than caused by primaryAcute- Come on rapidly, usually short lived. SevereChronic- Progresses and persists over long period of timeLatent- Latency; Infectious agent lies quietly inside you, flares up time to timeCommunicable- Disease can be passed on, person to person- Contagious- Highly communicable. Host to host- Non-communicable- does not come up from host to host. Most are brought about by normal flora having some change that brings on pathogen in youVirulence Factors- Traits used to invade & establish themselves in host, determine degree of tissue damage that occurs—Severity of diseasePhagocytosis- Initial host responses- Invasions should be non-phagocytic - Exotoxins that kill phagocytes- Capsules (slime layers) makes phagocytosis difficultMore difficult to adhere to specific cells. Can also hide antigenic sites. Can allow formation of biofilms BSC 160 1nd EditionPathogenicity Island- 6 genes that make up 6 proteins for organism’s virulence (ability to get in)- Horizontal & vertical transfer of entire islands. Make organisms that weren’t pathogenic- pathogenic Bacillus anthracis- first microbe studied, first to be causative agent of disease.- Anthrax- Koch. Biological warfare. Gram+. Classic endospore former. - Facultative anaerobe- can survive with or without oxygen- Natural outbreaks. 1/100,000 people/year- More likely to get it thru diseased animals 3 forms of Anthrax- Cutaneous anthrax- create endospores in cuts in your skin. - Gastrointestinal anthrax- Eat spores: undercooked food. Diagnosis usually happens late bc of hidden lesion. Rare & often fatal- Inhalation anthrax- spores entering lungs. Frequently seen in people working with animals. Fever & chest pain. Hidden internal hemorrhaging Pathogenesis- Capsule: Protects from phagocytic attacks. Has series of toxinsTreating it? Susceptible to a lot of antibiotics, Sifero used prophylactically. By time diagnosis made, too late for antibiotics. Usually fatalBordetalla Pertussis- Know same as Anthrax- Disease - Forms- Pathogenesis- TreatmentStreptococcal diseases- Know disease, method of pathogenesis, treatment40,000 deaths annually from Strep PneumoniaS. pyogenes- Gram+, chain of cocci, not all are pathogenic. - Attack respiratory tract, pyogenes on skin, cellulitis-rapid death of skin cells- Can go deeper into blood, muscles, heart, bone- Left untreated, frequently fatalCatalase- fermentation through sugars. Complex growth requirements. Different Hemolysis patterns on blood agar.Strep Pneumonia: Most infectious disease in adults in US. Most healthy adults are somewhat resistant300,000 infections, 40,000 deaths. Microbe flexibleears, sinuses,
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