dental anaerobes

Question 1

why is aspirate of pus better than swabs especially for anaerobes

Answer 1

swabs can get exposed to air

increased volume of pus better preserves anaerobe

Question 2

what transport medium is necessary for anaerobe swab

Answer 2

amies transport medium

Question 3

is clostridium gram negative or positive

Answer 3

gram positive

Question 4

does clostridium form spores

Answer 4

yes

Question 5

is clostridium is primary or secondary pathogen

Answer 5

primary pathogen. can infect healthy organism

Question 6

what toxin does clostridium perfringens produce

Answer 6

alpha toxin lecithinase

Question 7

what agar plate to use to differentiate clostridium perfringen from other clostridium species

Answer 7

nagler plate test. lecithinase break down lecithin, form opacity surrounding colony

Question 8

clinical manifestations of clostridium perfringens

Answer 8

clostridium cellulitis, gas gangrene is clostridial myonecrosis, food poisoning (diarrhea)

Question 9

how to treat gas gangrene caused by clostridium perfringens

Answer 9

benzylpenicillin. hyperbaric oxygen in severe cases to kill the anaerobes.

Question 10

symptoms of gas gangrene

Answer 10

skin discolouration, fluid bleb, muscle necrosis, crepitation due to gas, x ray radiolucency

Question 11

what is pigbel

Answer 11

clostridial necrotising enteritis found in undercooked pork

Question 12

characteristic histological appearance of clostridium perfringens

Answer 12

box car. subterminal clostridial spore

Question 13

where is spore of clostrium tetani located

Answer 13

terminally. drumstick appearance

Question 14

what toxin does clostridium tetani produce and what is its effect

Answer 14

tetanospasmin which causes spastic paralysis

Question 15

what bacteria can cause trismus and risus sardonicus

Answer 15

locked jaw, affected smile.

clostridium tetani

Question 16

how does clostridium tetani infect tissues

Answer 16

unlike perfringens, bacteria does not spread through out tissues. produces toxins that spread through blood stream

Question 17

how to treat clostridium tetani

Answer 17

tetanus immunoglobulin and antibiotics. prevention using toxoid vaccine

Question 18

how does clostridium botulinum infect host

Answer 18

preformed toxin that blocks release of acetyl choline at neuromuscular junctions

Question 19

manifestation of clostridium botulinum

Answer 19

flaccid paralysis

Question 20

how to detect clostridium difficile

Answer 20

cytotoxicity assay using tissue culture technique, antibody based test, GDH enzy,e test (glutaraldehyde dehydrogenase uniquely associated with c difficile), PCR for toxin

Question 21

which bacteris is uniquely associated with GDH

Answer 21

clostridium difficile

Question 22

clinical manifestation of c difficile

Answer 22

pseudomembranous colitis, can progress to toxic megacolon whereby so much of mucosa is damaged, the colon stops moving and gas accumulates

Question 23

how can clostridium difficile progress

Answer 23

self limiting, or may become fulminant ie severe sudden onset

Question 24

how to treat CDAD

Answer 24

vancomycin first line, metronidazole second line

Question 25

most anaerobes are sporing or non sporing

Answer 25

non sporing. only clostridium sporing

Question 26

oral non sporing anaerobes usually sensitive to what antimicrobial

Answer 26

penicillin as majority do not produce penicillinase vs majority of GIT anaerobes that do produce penicillinase

Question 27

what bacteria can cause halitosis

Answer 27

non sporing anaerobes wich give off volatile compounds

Question 28

what kind of bacteria are tannerella forsythia, prevotella intermedia, porphyromonas gingivalis

Answer 28

gram negative anaerobic rods strongly linked to periodontal disease

Question 29

what kind of bactera are bacteroides ie b fragilis

Answer 29

gram negative anaerobic rod, found mainly in gut

Question 30

what bacteria causes necrotising ulcerative gingivitis aka vincents infection aka trench mouth

Answer 30

fusobacterium nucleatum + oral treponemes (spirochetes)

Question 31

is actinomyces gram positive or negative? aerobic or anaerobic?

Answer 31

gram positive microaerophilic rod

Question 32

bacteria with branching. what bacteria is this?

Answer 32

actinomyces

Question 33

what bacteria responsible for progression of small carious lesions

Answer 33

actinomyces

Question 34

what antimicrobial is actinomyces resistant to. what should you treat it with

Answer 34

resistant to metronidazole. treat with penicillin.

Question 35

what bacteria responsible for aggressive periodontitis

Answer 35

aggregatibacter (capnophilic gram positive rod) also causes infective endocarditis

Question 36

what toxin does aggregatibacter produce

Answer 36

leukotoxin. jp2 clone overproduces leukotoxin, raising risk of aggressive periodontitis

Question 37

how to treat dento alveolar infection

Answer 37

drain pus --> remove source --> antibiotics in selected cases, usually not needed

Question 38

what is ludwig angina

Answer 38

bilateral infection of sublingual, submandibular spaces. mixed endogenous infection. usually secondary to dental/post extraction infection. may spread to brain and cause brain abscess