dental anaerobes Flashcards
why is aspirate of pus better than swabs especially for anaerobes
swabs can get exposed to air
increased volume of pus better preserves anaerobe
what transport medium is necessary for anaerobe swab
amies transport medium
is clostridium gram negative or positive
gram positive
does clostridium form spores
yes
is clostridium is primary or secondary pathogen
primary pathogen. can infect healthy organism
what toxin does clostridium perfringens produce
alpha toxin lecithinase
what agar plate to use to differentiate clostridium perfringen from other clostridium species
nagler plate test. lecithinase break down lecithin, form opacity surrounding colony
clinical manifestations of clostridium perfringens
clostridium cellulitis, gas gangrene is clostridial myonecrosis, food poisoning (diarrhea)
how to treat gas gangrene caused by clostridium perfringens
benzylpenicillin. hyperbaric oxygen in severe cases to kill the anaerobes.
symptoms of gas gangrene
skin discolouration, fluid bleb, muscle necrosis, crepitation due to gas, x ray radiolucency
what is pigbel
clostridial necrotising enteritis found in undercooked pork
characteristic histological appearance of clostridium perfringens
box car. subterminal clostridial spore
where is spore of clostrium tetani located
terminally. drumstick appearance
what toxin does clostridium tetani produce and what is its effect
tetanospasmin which causes spastic paralysis
what bacteria can cause trismus and risus sardonicus
locked jaw, affected smile.
clostridium tetani
how does clostridium tetani infect tissues
unlike perfringens, bacteria does not spread through out tissues. produces toxins that spread through blood stream
how to treat clostridium tetani
tetanus immunoglobulin and antibiotics. prevention using toxoid vaccine
how does clostridium botulinum infect host
preformed toxin that blocks release of acetyl choline at neuromuscular junctions
manifestation of clostridium botulinum
flaccid paralysis
how to detect clostridium difficile
cytotoxicity assay using tissue culture technique, antibody based test, GDH enzy,e test (glutaraldehyde dehydrogenase uniquely associated with c difficile), PCR for toxin
which bacteris is uniquely associated with GDH
clostridium difficile
clinical manifestation of c difficile
pseudomembranous colitis, can progress to toxic megacolon whereby so much of mucosa is damaged, the colon stops moving and gas accumulates
how can clostridium difficile progress
self limiting, or may become fulminant ie severe sudden onset
how to treat CDAD
vancomycin first line, metronidazole second line
most anaerobes are sporing or non sporing
non sporing. only clostridium sporing
oral non sporing anaerobes usually sensitive to what antimicrobial
penicillin as majority do not produce penicillinase vs majority of GIT anaerobes that do produce penicillinase
what bacteria can cause halitosis
non sporing anaerobes wich give off volatile compounds
what kind of bacteria are tannerella forsythia, prevotella intermedia, porphyromonas gingivalis
gram negative anaerobic rods
strongly linked to periodontal disease
what kind of bactera are bacteroides ie b fragilis
gram negative anaerobic rod, found mainly in gut
what bacteria causes necrotising ulcerative gingivitis aka vincents infection aka trench mouth
fusobacterium nucleatum + oral treponemes (spirochetes)
is actinomyces gram positive or negative? aerobic or anaerobic?
gram positive microaerophilic rod
bacteria with branching. what bacteria is this?
actinomyces
what bacteria responsible for progression of small carious lesions
actinomyces
what antimicrobial is actinomyces resistant to. what should you treat it with
resistant to metronidazole. treat with penicillin.
what bacteria responsible for aggressive periodontitis
aggregatibacter (capnophilic gram positive rod) also causes infective endocarditis
what toxin does aggregatibacter produce
leukotoxin. jp2 clone overproduces leukotoxin, raising risk of aggressive periodontitis
how to treat dento alveolar infection
drain pus –> remove source –> antibiotics in selected cases, usually not needed
what is ludwig angina
bilateral infection of sublingual, submandibular spaces. mixed endogenous infection. usually secondary to dental/post extraction infection. may spread to brain and cause brain abscess
