Microbiology - Anerobes

Front 1

Why are anaerobic infections usually polymicrobic?

Back 1

they wait till the facultative anaerobes use up all the O2 then they flourish

Front 2

Why is O2 so toxic to anaerobes?

Back 2

They don't have catalase and superoxide dismutase.... the result is the accumulation of H2O2 and superoxide

they lack this "detoxifying" pathway

Front 3

What are the obligate anerobes?

Back 3

ABC's:
actinomyces, bacteriodes, clostridia

Front 4

Clostridia morphology?

Back 4

anerobic gram + spore-forming rods

Front 5

Size of clostridium spores?

Back 5

larger than the cell

Front 6

Gas gangrene group:

Back 6

perfringens, novyi, septicum

Front 7

Diseases caused by gas gangrene group?

Back 7

Gas gangrene, anaerobic cellulitis, food poisoning

Front 8

Virulence factors of the gas gangrene group:

Back 8

alpha toxin which distrupts cell membrane (most important,
theta toxin
enterotoxin

Front 9

What is alpha toxin?

Back 9

lechthinase that distrupts cell membrane

Front 10

what is theta toxin?

Back 10

hemolysin that alters cepilarry permeability

Front 11

What causes Clostridium spore generation?

Back 11

the low pH in healing wounds

Front 12

What is the pathogenesis of C. perfringens, novyi, septicum?

Back 12

myonecrosis due to muscle and tissue destruction and separation via gas production

Front 13

What is treatment for gas gangrene?

Back 13

debridement, penicillin, hyperbaric O2

Front 14

exhibits stormy fermentation

Back 14

lecithinase

Front 15

BAP double zone of hemolysis caused by?

Back 15

presence of multiple hemolysins

Front 16

death of tetanous caused by what?

Back 16

exhaustion and respiratory failure

Front 17

Acquisition of tetanous neonatorum?

Back 17

Contamination of umbilical cord with C. tetani

Front 18

How is food poisoning caused by C. perfringens?

Back 18

enterotoxin is produced by vegetative cells in intesting, casuing diarrhea and nausea 8-24 hrs after eating

Front 19

Virulence factor of C. tetani

Back 19

tetanospasmin - released when bacteira dies

Front 20

What does tetanospasmin do inthe body?

Back 20

goes to CNS via motor nerves and inhibits release of GABA/Glycine, resulting in muscle spasm

Front 21

Morphology of C Tetani?

Back 21

gram + tennis shaped rod (head = terminal spore) without a capsule

Front 22

is C. Tetani motile or nonmotile?

Back 22

motile

Front 23

Immunizations C. Tetani with what and when?

Back 23

toxoid (inactivated with formalin) at:
6 weeks, 1, 4, 10 yrs

Front 24

Treatment of C. Tetani?

Back 24

antitoxin, debridement, penicillin, and curare-like drugs

Front 25

When is antitoxin not needed if botulism is contracted?

Back 25

not needed for patients with immmunization/booster within 5 yrs of occurance

Front 26

Diseases caused by botulism?

Back 26

Flaccid paralysis, wound botulism, Infant botulism

Front 27

Incubation period of botulism?

Back 27

18-96 hrs

Front 28

Floppy baby?

Back 28

infant botulism

Front 29

Viurulence factor of botulism?

Back 29

destroyed by cooking but not stomach pH's. Toxin (which is phage-mediated) is released on death and autolysis

Front 30

Why are antibiotics bad for botulism?

Back 30

death of organism will cause release of more toxin

Front 31

What kinds of food will botulism flourish in?

Back 31

Spores will germinate on inadequately heated alkaline vegetables

Front 32

Action of botulism toxin?

Back 32

blocks ACh release at NMJ

Front 33

Cause of pseudomembranous colitis?

Back 33

C. difficile?

Front 34

Pathogenesis of C. difficile

Back 34

normally due to antibiotics, causing overgrowth. Toxin A and B released in stationary phase or after cell lysis allowing infiltratoin of pathogen.

Front 35

Treatment of C. difficile?

Back 35

discontinue antibiotics and substitute better drugs

Front 36

Outnumber all other bacteria in colon 10000:1

Back 36

bacteroides fragilis

Front 37

What is the common presentation of anaerobic causing disease?

Back 37

abscess formation

Front 38

mophology of B. fragilis?

Back 38

gram - rod, causes gram - infection in abdominal cavity

Front 39

morphology of actinomyces?

Back 39

filamentous gram + rod, normal oral flora

Front 40

How does actinomyces usually present?

Back 40

single organism after dental surgeyr

Front 41

#1 cause of infection in prosthetic joints? #2?

Back 41

1) propionibacterium acnes
2) S. epidermidis

Front 42

morphology of propionibacterium acnes?

Back 42

gram + rod in normal skin flora

Front 43

Peptostreptococcus causes what?

Back 43

pleuropulm disease, brain abscessins, OBGyne infections

Front 44

Lumy jaw caused by?

Back 44

actinomyces

Front 45

morphology of peptostrptococcus?

Back 45

gram + coccus