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Medical Microbiology > Anaerobes > Flashcards

Flashcards in Anaerobes Deck (29):
1

Treatment of anaerobic infections

Penicillin, Penicillin+betalactamase inhibitor, 2nd generation cephalosporins, carbapenems

2

Which are second generation cephalosporins?

Cefuroxime, cefoxitin, cefotetan.

3

What organism causes pseudomembranous colitis?

C. Difficile

4

Characteristics of C. diff.

Gram positive anaerobic spore-forming bacillus.

5

What is C. diff resistant to?

Many many antibiotics including beta lactams, clindamycin, cephalosporins, perhaps fluoroquinolones.

6

Diagnosis of C. diff?

EIA toxin assay, PCR.

7

Toxin A

Enterotoxin, causes neutrophil chemotaxis.

8

Toxin B

Cytotoxin, causes tight cell junctions to fail. Increases permeability of the intestinal wall to cause diarrhea.

9

Worst possible complication of C. diff?

Toxic megacolon and septic shock.

10

How to treat C. diff?

Metronidazole and oral vancomycin, fecal transplant therapy.

11

Clostridium perfringens gram stain?

Positive rod, but doesn't hold it well at all.

12

C. perfringens plate?

Double zones of hemolysis

13

Where is C. perfringens from?

GI tract flora.

14

C perfringens alpha toxin

Mediates hemolysis, vascular permiability and tissue destruction

15

Diseases caused by C. perfringens

Gas Gangrene, cellulitis, emphasematous cholesystitis, food poisoning (spores and heat labile toxin).

16

How to treat C. perfringens?

Penicillin

17

C. tetani causes...?

Spastic paralysis because of decreased GABA.

18

How can C. tetani survive in soil?

Terminal spores.

19

C. Botulinum causes...

Flaccid paralysis due to AB toxin

20

How can somebody be infected with C. botulinum?

Improperly canned foods, spore contamination of honey

21

Most common gram negative anaerobe to cause disease?

Bacteroides fragilis

22

Characteristics of bacteroides fragilis?

Capsule, tolerant of oxygen due to catalase and SOD.

23

Which organism causes sulfur granules?

Actinomyces.

24

How does Actinomyces appear under the microscope?

Gram positive and branching. Anaerobic only.

25

Nocardia nova appearance under a microscope?

Stains w/ a modified acid fast stain. Gram positive beaded branching bacilli. Anaerobic and aerobic

26

How to treat novocardia nova?

With TMP-SMZ

27

Mycobacterium fortuitum

Grows much faster than MTB, can retain a gram stain and often grows in contaminated water supply. Treat w/ macrolides+beta lactams.

28

Corynebacterium diptheriae appearance

Gram positive bacillus that produces an exotoxin

29

How does diptheria cause death?

Causes thickening and toughening of pharyngeal membranes.