Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
25 Cards in this Set
- Front
- Back
|
what type of organism is Clostridium perfringens?
|
Gram (+ve)
Spore forming rod anerobic |
|
|
what food borne illness symptom is it know for worldwide?
|
Diarrheal disease
|
|
|
what are the symptoms of Tpye A C.perfringens foodborne illness?
|
Bloating & gas
Profuse diarrhea w/abdominal cramps little or no vomiting few cases of fever/headache |
|
|
what is the incubation period of C.perfringens?
|
8 - 22 hours
Median = 12hours |
|
|
Clostridium is known as a "ubiquitous Organism" what does this mean?
|
It is found everywhere in the environment.
Human reservoir animal food vehicle fly vector Soil & dust |
|
|
How many types of C.perfringens are known & what are they?
|
Five(5)
A, B, C, D, E |
|
|
what causes illness in Closrtidium perfringens?
|
the enterotoxin
|
|
|
Do spores give rise to new spores directly?
|
the answer is no, the spores form vegetative cells which multiply then sporulate into more spores
|
|
|
what is the sequence of events which lead to C.perfringens outbreak?
|
1)growth of cells in food (germination)
2)food consumed and sporulation occurs in Intestine 3)spores form vegetative cells & divide /& produce toxin |
|
|
why is reheating considered the last line of defense in preventing C.perfringens outbreak?
|
the vegetative stage will be killed off.
|
|
|
why are large chunks of meat the food vehicles for C.perfringens outbreaks rather than thin meats such as hamburgers?
|
takes longer to cool, thus allowing for growth
more anaerobic environment in large chunks of meat. |
|
|
what laboratory test was developed by the MOH in ontario to ID enterotoxin in faeces?
|
ELISA test
|
|
|
what are some other Lab diagnostic tests methods to ID C.perfringens as the causitive agent?
|
1)look at the number of spores in faeces 10*6 spores /gram of faeces
2)10*5 cells of C.P/g of food if available to test 3)serotype same amoung victims 4)match of serotypes in victims faeces & food |
|
|
what is the Rabbit ileal test?
|
researchers tool to ID if bacterinm produces an enterotoxin
|
|
|
What are the most common factors contributing to outbreaks of Clostridium perfringens?
|
Inadequate Storage - 46.1%
Improper heating - 38.5% |
|
|
what is the optimum temperature range for Clostridium perfringens?
|
37 - 45 degrees C
NB may double in 8-10 mins @45 C |
|
|
what temperature is considered normal for C.perfringens growth?
|
20 - 50 C
|
|
|
what is the best way to kill off C.perfringens?
|
refrigeration of food source is best way
|
|
|
what is the pH range for growth for C.perfringens?
|
5.5 - 8.5
|
|
|
What is the Eh for C.perfringens?
|
will grow b/w -200 and +320mV
prefers negative values anaerobe |
|
|
what happens to C.perfringens @ -17.7C?
|
tends to be preserved at this temperature.
|
|
|
where are the spores of C.perfringens most found?
|
Muscle & internal Organs of food animals:
pigs cattle sheep rats |
|
|
How does the enterotoxin exert its action?
|
breaks down the brush border of the microvilli
resulting in a net flow of water into sm Intestine giving rise to diarrhea |
|
|
what are the diagnostic clues for C.perfringins?
|
Severe lower abdominal pain
Diarrhea Absence of fever & headache little vomiting , w/nausea sometimes Incubation period: 8-23 hours Shortest IP 1 hour |
|
|
what difference in terms of an outbreak helps to determine whether Samonella is responsible or C.perfringens?
|
with Samonella the source might be a carrier
but with C.perfringens the problem is inadequate cooling of meat. |
