dxtxpx
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A gp of 25 businessmen celebrated New Year's Day party. In addition to alcoholic refreshments and a wide assortment of cooked foods, the feast included fresh oyesters and clams. On Jan2, 23 of them began to experience GI illnesses which included diarrhea(86%), nausea (82%), abdominal cramps (65%), fever (56%) and vomiting (35%). In most cases the illnesses lasted 15-17 hours. The affected men ate only the mollusks. BActeriologic cultures taken from the mollusks produced significant colony # of Gm negative rods including E coli, Vibrio parahemolyticus, and Clostridium perfingens
I) A low moleuclar weight protein enterotoxin, comprising part of bacterial spore is produced by
a) Clostridium perfingens
b) E coli
c) Campylobacter jejuni
d) Shigella dysenteriae
e) Salmonella typhi
II) The halophilic nature and tendency to induce diarrhea, following colonization of intestinal tract, makes which of the following organisms a primary candidate for causing illness described in the men?
a) Clostridium perfringens
b) Vibrio parahaemolyticus
c) Campylobacter jejuni
d) Bacillus cereus
e) Salmonella typhi
III) High levels of E coli recovered from shellfish samples is indicative of
a) Normal enviormental conditions
b) Improper storage of shellfish
c) Sewerage pollution of shellfish beds
d) Shellfish eating patterns
e) poor sample collecting procedures
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| peekay
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1- C. difficle
2-c -jejuni
3- improper storage of shell fish
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| dxtxpx
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Answers are
I) a [Clostiridum perfingens]
II) b [Vibrio parahemolyticus]
III)c [sewerage pollution of shellfish beds]
Public health dept. in most states closely regulate the sale of shellfish. Some guidlines include tagging and tracing of such foods esp those crossing interstate lines. Gastroenteritis is not always traced to specific causative agent, but rather several potential pathogens
A variety of bacterial, viral and parasitic pathogens are associated with consumption of raw shellfish. Serratia sp are not normally associated with high salt conditions of shellfish-associated diseases, but rather nosocomial infections.
Clostridum perfingens is a spore forming bacterium. The enterotoxin is associated with the spore wall. It is released during germination.
Many Vibrio organisms are water-borne. They have a high tolerance to sea water, this they are commonly isolated from shellfish and fish. Dis results from colonization of bacteria in intestines and release of exotoxins. Diarrheal infections caused by Vibrio parahemolyticus respond to antibiotic therapy which also diminshes the likelihood of secondary infections and shortens the duration of diarrhea. Tetracycline, ampicillin and chloramphenicol are among the drugs used for this purpose
The abruptness of sx following consumption of foods imply the presence, in the foods, of significant toxin. However, rapid colonization of GIT and toxin production are characteristics of certain bacteria as V parahemolyticus. Improper storage and extended shipping intervals may provide additional favorable conditions for bacterial growth and toxin production. high colony counts for E coli are indicative of fecal contamination. The waters of shellfish collection may have been polluted with human sewage
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| bactitech
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One comment - Clostridium perfringens is a gram POSITIVE rod. This statement:
"BActeriologic cultures taken from the mollusks produced significant colony # of Gm negative rods including E coli, Vibrio parahemolyticus, and Clostridium perfingens"
is therefore ambiguous. :-(.
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Clinical Microbiology since 1974
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| Malaysian
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Bactitech(I really am useless in micro. thats why I ask a million and one questions from you(I hope you don't mind).......have you grown vibrio cholarae and the parahemolyticus in your lab. before and if so what has your expereince been like?
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| bactitech
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I have seen V. parahemolyticus in a survey. This organism is also used to QC the TCBS media that helps to recover Vibrio sp. I have never seen V. cholerae, although a lab I worked at formerly isolated it and it was confirmed by the health department/CDC (first one I've heard of in this area in 30 years). Vibrios grow yellow on TCBS. Most enterobacteriaceae are inhibited. Here's a great page and picture:
http://service.merck.de/microbiology/tedisdata/pr...
Any colony that grows yellow on this medium MUST be identified to r/o Vibrio, as nothing much else will grow. They are oxidase positive.
If this organism is suspected, be SURE to let the laboratory know, as TCBS is NOT set up routinely. Labs that do stool cultures are, however, required to keep it on hand. Take a GOOD travel history. I would suspect that labs on either coast set this medium up a lot more often than we do inland.
I saw a movie back in 1970 when I took pathogenic micro in college. It showed a cholera outbreak in India. Those images have stuck with me ever since. It is a horrible disease. These people literally lose most of their body fluids and electrolytes within hours. The dehydration is extremely profound. The treatment was to put them on cholera cots, measure the output, and put the same amount back in through IV's. This obviously only worked if it was started fast enough. The people were lying in rows on a beach somewhere. Many were so dehydrated they were unresponsive. Obviously there's no time to do cultures in cases like this.
Cholera was endemic in this country before water purification was common. We are extremely lucky that our water supply is, for the most part, good.
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Clinical Microbiology since 1974
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