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38 Cards in this Set
- Front
- Back
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free of microbes |
axenic |
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what prevents most microbes, and most antibiotics from entering the brain? |
blood brain barrier |
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how do pathogens access the CNS? |
-through the breaks in the bones and meninges -during medical procedures -by traveling from peripheral neurons to the CNS (leprosy) |
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causative agents of bacterial meningitis? (5) |
1) Haemophilus influenzae: leading cause prior to vaccine 2) Streptococcus pneumoniae: leading cause in adults 3) Streptococcus agalactiae: causes most cases of newborn meningitis (rare) *4) Neisseria meningitidis: causes outbreaks in colleges, most common cause 5) Listeria monocytogenes: causes disease in fetuses, pregnant women, and immunocompromised indivicuals from contaminated foods |
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-only genus of Gram negative cocci that regularly causes disease in humans-diplococci |
Neisseria |
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what two species of Neisseria are pathogenic to humans? |
-Neisseria gonorrhoeae -N. meningitidis: causes meningitis due to fimbriae, capsule, and LPS |
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symptoms of meningitis |
-mild: influenza-like upper respiratory infection -serious: sudden fiver, pounding headache and stiff neck due to inflammation -petechiae -can lead to encephalitis |
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diagnosis of meningitis |
spinal tap |
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treatment of meningitis |
intravenous antimicrobial drugs (Rifampin) |
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prevention of meningitis |
vaccine available for meningococcal meningitis (Menactra) |
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another name for leprosy |
Hansen's disease |
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causative agent for leprosy (hansen's disease) |
Mycobacterium leprae -only known pathogen to target nervous system |
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pathogenesis of leprosy (hansen's disease) |
-Mycobacterium leprae grows best in cooler regions of the body (30 degrees C in the PNS and skin) -bacteria will grow very slowly within phagocytes -armadillos are the only other known host |
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transmission of leprosy (hansen's disease) |
-person-to-person contact via respiratory droplets -through breaks in the skin |
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two kinds of leprosy |
-Tuberculoid leprosy -lepromatous leprosy |
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-non progressive.-patients have strong immune system -results in nerve damage and regions of skin that lose sensation |
tuberculoid leprosy |
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-progressive tissue destruction caused my multiplication of bacteria in skin, mucous membrane, and nerve cells -can result in loss of facial features, fingers, toes, etc |
lepromatous leprosy |
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diagnosis of leprosy (hansen's disease) |
-skin test with leprosy antigen -observation of acid-fast rods in tissue samples |
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treatment of leprosy |
-combination of antimicrobial drugs (sometimes lifetime) |
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prevention of leprosy (hansen's disease) |
-limiting exposure to the pathogen -prophylactic use of antimicrobial agents after exposure -BCG vaccine provides some protection |
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characteristics of Clostridium bacteria |
-gram positive, anaerobic, endospore-forming bacillus -lives in soil, water, and GI tracts of animals |
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causative agent for tetanus |
Clostridium tetani -gram positive, spore-former |
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transmission of tetanus |
-animal bites, rusty nails, broken glass, intravenous drug use, body piercing |
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where does tetanus come from? |
found in intestines of many animals -feces excreted into soil -soil introduced to wound anaerobic environment spurs vegetative growth |
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symptoms of tetanus (4) |
-rapid developing muscle stiffness, trismus: lockjaw risus sardonicus: permanent grinning opisthotonus: arching of back |
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treatment of tetanus |
sedatives, dark quiet rooms, antitoxin & antibiotics |
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Prevention of tetanus |
DTaP immunization: tetanospasmin toxoid, requires boosters |
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pathogenicity of tetanus (5) |
1) spore into body 2) gets into anaerobic place 3) spore germinates, grows vegetatively 4) transcribes and translates gene for tetanospasmin 5) tetanospasmin gets into system and seeks out nerve cells |
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mechanism of tetanus |
-tetanospasmin prevents the release of glycine (inhibitory NT) and other NTs needed to inhibit muscle contraction -blocks relaxation pathway that follows contraction |
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causative agent of botulism |
Clostridium botulinum -gram positive, anaerobic spore-former (fish, bird, cow intestines) |
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three forms of botulism |
1) food borne 2) infant 3) wound |
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course of infection in a baby for botulism (5) |
1) baby inhales or ingests Clostridium botulinum endospores 2) endospores germinate in anaerobic environment of intestinal tract. Vegetative cells grow, reproduce and release botulism toxin 3) toxin absorbed into blood and circulated 4) botulism toxin produces constipation and weak cry 5) toxin paralyzes muscles, including neck muscles and the diaphragm |
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symptoms of botulism |
-flaccid paralysis |
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pathogenicity of botulism |
botulism toxin blocks release of acetylcholine |
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applications of botulism -aligning eyes simultaneously -uncontrolled eyelid closure |
type A botulism can be used for -strabismus -blepharospasm |
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epidemiology of botulism |
-infant botulism more common form |
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treatment of botulism (3) |
-washing of intestinal tract to remove Clostridium -administration of botulism immune globulin (BIG) -antimicrobial drugs |
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prevention of botulism |
destroying endospores in contaminated food -heat foods to 90 degrees C for at least 10 years -infants under 1 year shouldn't consume honey |
