Microbio Lecture 17
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- Causative agent of Anthrax?
- Bacillus anthracis, G+, spore forming rod
- Transmission of Anthrax?
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- spores germinate on contact with human tissues
- violin bows, leather jackets, bioterrorism - Types of anthrax (3):
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- Pulmonary/inhalation: Woolsorter's disease (worst kind)
- Gastrointestinal: consumption of contaminated meat
- Cutaneous (inoculation of spores into skin) - Pathogenicity of Anthrax?
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- thick capsules on cells hard to phagocytose
- produce 3 types of toxins that work together to kill host
1. Edema factor (EF): convert ATP to cAMP and causes swelling
2. Protective antigen (PA): helps bacteria bind human cells
3. Lethal factor (LF): causes death of human cells - Symptoms of Anthrax?
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- bloody black fluid results from tissue destruction
1. Pulmonary leads to blood infection with hemorrhaging; initial symptoms are common cold, is fatal
2. GI- violent dysentery: 25-60% fatal
3. Cutaneous: black crusted lesions, death is rare unless infection gets to blood - Treatment and Prevention of Anthrax?
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- Penicillin
- cipro and doxycycline used if bacteria is resistant to penicillin
- Prevent by burying in lime or incineration
- Vaccinate with Cell free filtrate of B. anthracis - 6 shots in 18 months - Causative agent of Tetanus?
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Clostridium tetani, G+, anaerobic spore former
- found in intestines of many animals - Transmission of Tetanus?
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animal bites, rusty nails, broken glass, body piercing
- feces excreted in soil, soil introd. to wound, anaerobic environ. spurs vegetative growth - Pathogenicity of Tetanus:
- Toxins are produced (Tetanospasmin), inhibits relaxation pathway following muscle contraction. Toxin spreads not bacteria
- Symptoms of Tetanus (3):
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rapid developing muscle stiffness, reduced breathing
1. Trismus: lockjaw, clenched teeth, jaw muscle spasm
2. Risus Sardonicus: grinning caused by facial spasms
3. Opisthotonus: arching of back - Treatment of Tetanus:
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dark quiet rooms, sedatives, antitoxin and antibiotics
- vaccinate with DTaP - tetanospasmin toxoid requires boosters - Three different types of plagues: the agent and the vector.
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Causative agent for all: Yersinia Pestis, G- rod, bipolar staining like safety pin
Sylvatic: vector= fleas from ground squirrels, prarie dogs, wild rodents
Urban plague: rats- Xenopsylla cheopsis (rat fleas)
Pneumonic plague: person to person airborne droplets- death in 2 days: 100% mortality - Causative agent of Bubonic plague?
- Yersinia pestis, G- rod
- Transmission of Bubonic Plague?
- Xenopsylla cheopsis: rat flea, bites different animals; and airborne droplets from humans
- Pathogenicity of Bubonic plague?
- Blood disease- bacteria multiply in blood stream and localize in lymph nodes.
- Symptoms of Bubonic plague?
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Buboes: hemorrhaging and swelling in lymph nodes
Rosies: hemorrhaging on skin resultin in dark purplish spots - Treatment of Bubonic plague:
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antibiotics (Erythromycin, streptomycing)
Vaccinate with deat Y. pestis for high risk professions like forest rangers - What is Septicemic plague?
- Yersinia pestis; bacilli overwhelms circulatory system; 50% mortality rate
- Causative agent of Lyme disease?
- Borrelia burgdorferi, G- microaerophilic spirochete
- Transmission of Lyme disease?
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Ticks are vectors:
Ixodes scapularis: deer ticks in NE and MW
Ixodes pacificus: woodrat tick in W - Pathogenicity of Lyme disease?
- Human picks up infected ticks. Tick penetrates skin and eats blood meal and efecates into wound depositing spirochetes.
- Symptoms of Lyme disease? (3 stages)
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1. Early localized: Erythema chronicum migrans: does not itch, flu like symptoms; bullseye rash
2. Early disseminated: joint pain- irreversitble arthritis
3. Late chronic: headaches, loss of muscle tone, losing hearing and vision, damage to CVS and NS, mortality rate not high - Treatment of Lyme disesase?
- tetracycline or penicillin at early localized stage
- Causative agent of Rocky Mountain Spotted Fever?
- Rickettsia rickettsii
- Transmission of Rocky Mountain Spotted Fever?
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Ticks:
Dermacentor andersonii: wood tick
Dermacentor variabilis: dog tick
Amblyomma: tick - Pathogenicity of R. Mtn. Spotted Fever?
- Tick defecates into host and transmits agent
- Symptoms of Rocky Mtn. spotted fever?
- high fever, spotted rash: starts as Macules (pink spots), then as Papules (pimples showing small blood vessel damage), then Maculopapular rash from extremities to trunk
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Treatment of Rocky Mtn. Spotted Fever?
Diagnosis? -
Tetracycline, chloramphenicol
- Diagnose with Weil-Felix test (agglutination) serum w/ Proteus OX19- Abs agglutinate with O polysaccharide on Proteus just like Rickettsiae - Mortality rate of Rocky Mtn. Spotted Fever?
- 75% if not diagnosed early
- Causative agent of typhus?
- Rickettsiae prowazekii
- Transmission of Typhus?
- Pediculus: head/body lice
- Pathogenicity of Typhus?
- infected lice defecates into host and transmits agent
- Symptoms of Typhus?
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-maculopapular rash (trunk to extremities) REVERSE of ricketssiae ricketsii
- 104 F fever causes hallucinations/delerium - Treatment of Typhus, Diagnosis, and Prevention?
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- tetracycline, chloramphenicol
- good hygiene needed
- Weil-Felix test