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overview of anaerobe
ch 42
Question | Answer |
---|---|
predominantly do not grow in the presence of | O2 |
reservoir Clostridium botulinum and C. tetani | soil and environment |
similarities of Bacillus spp and Clostridium spp differences between the 2 | same : make spores, difference: respiration. Bacillus is facultative anaerobe and Clostridium is an anaerobe |
Most anaerobes are | normal flora |
reservoir of pathogenic anaerobes is | soil and water |
outdoor anaerobes make | spores |
most anaerobes gain access to a sterile site as a result of | disruption of an anatomic barrier |
infection originating in a hospital | nosocomial |
Clostridium difficile is a significant example of this transmission type | nosocomial |
outdoor anaerobes reside in | soil, vegetation, GI tract of mammals |
Species that produces potent and lethal toxins, can be used in biowarfare. | Clostridium |
poisoned by O2, gather at the bottom of the tube | obligate anaerobe |
clostridium 5 characteristics | gram + rods, obligate anaerobes, cat neg, form spores, differentiated by shock spore test |
Ethanol shock spore isolation | ethanol is added to a culture 1 hr before innoculating on anaerobic plate. Ethanol has no effect on spores. |
following ethanol shock spore test clostridium endospores | germinate on innoculation |
spores are produced only what condition | anaerobic conditions |
Clostridium species are widespread in nature because | endospores |
In human and animals clostridium is normal flora of | GI tract |
C. perfringes gram stain | Gram pos rod with spores |
C. perfringes virulence | exotoxins |
C. perfringes toxin mediated destruction of tissue after traumatic introduction, commonly called or | gas gangrene or myonecrosia |
C perfringes causes food intoxication from foods like rice that are reheated over and over. Illness is not from the infection its from the toxin. | Food poisoning |
C. perfringes on BAP shows | B hemolysis |
C. botulinum gram stain and cultivation | Large fastidious spore forming rods |
C botunlinum virulence factor | neurotoxin |
what 3 infections / diseases does C. botulinum produce? | food borne botulism, infant botulism, wound botulism |
botulism from spores, found in canned foods (no O2), not food poisoning. Absorption of the toxin leads to flaccid paralysis. | foodborne botulism |
Occurs when the organism produced the toxin after it has colonized GI tract of infants -honey, powdered milk, dust - all nonpastuerized sources | infant botulism |
Botulism that occurs when C. botulinum produces the toxin from an infected wound site. | wound botulism |
Produces toxins A and B that may cause diseases from self-limiting diarrhea to severe, life threatening pseudomembranous colitis (PMC). | Clostridium difficile |
persistance and spread in hospitals of C. difficile from | spores |
in C. difficile overgrowth of intestinal flora in patients on antibiotics | antibiotic resistance |
specimen used in C. difficile culture and toxin assays | fresh stool |
C. difficile can be plated to 2 types of agar | Cycloserine cefoxitin fructose agar (CCFA) and Anaerobic blood agar |
Appearance of mo - Large, motile, spore forming rod terminal spores give appearance of a drumstick. | C. tetani |
virulence in C. tetani | tetanospasmin (neurotoxin) |
action of tetanospasmin | disrupts nerve impulses to the muscles. |
Clostridium difficult to grow due to extreme oxygen sensitivity | tetani |
Treatment for tetanus | debridement, antimicrobials, antitoxin and vaccination (dpt) |
except for food intoxication, clostridium is 100% fatal if | untreated |