microbiology ch 13, actinomycetes, clostridia, bacillus Flashcards Preview

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Flashcards in microbiology ch 13, actinomycetes, clostridia, bacillus Deck (17):
1

2 important genera of actinomycetes?

actinomyces, nocardia

2

Actinomyces

major component of dental plaque, Femal genital tract

3

Actinomyces isralii

major agent of human actinomycosis, has yellowish sulfur granules, colonies appear as bread crumbs or molars, sensative to penicillin and amoxicillin

4

where are the infections for israelii usually found?

60-65% are in cervicofacial region
10-20% are abdominal
some are thoracic

5

Nocardia

cause nocardiosis in humans

6

clostridia in general

gram positive spore forming bacilli found in soil, water, decaying animal and plants

7

clostridia welchii

spores are in soil, vegetative cells in colon and vagina

8

what does c welchii cause?

gas gangrene, good poisening

9

what toxin does c welchii make?

alpha toxin- lyses phospholipids of eukaryotic cell membranes

10

whats the name of the test that uses egg yolk to neutralize the alpha toxin?

naglers reaction

11

clostridium tetani

Intestinal tract of herbivores, spores in soil, look like drumstick,

12

c. tetani toxiins

tetanospasmin- potent neurotoxin from vegatative cells
tetanolysin- haemolytic toxin

13

what do the toxins cause?

trismus( lockjaw), risus sardonicus ( facial muscle spasm), opisthotonos( arching body)

14

how do the toxins cause these?

blocks inhibitory mediators at spinal synapses

15

clostridium difficile

faeces of adults and kids, up to 25% of common antibiotic associated diarrhoea is from C difficile

16

bacillus anthracis

• spores can survive for years – humans accidental hosts and can cause anthrax
• infection causes septicemia and death

17

bacillus cereus

causes food poisening especially in reheated infected rice