Everything Flashcards
Cite a gram+, anaerobic and spore-forming bacteria with oval-cylindrical terminal to sub-terminal spores
Clostridium botulinum
What is the T range for non proteolytic C. botulinum?
3.3 - 45C, optimum 30
What is the incubation time of foodborne botulism?
12 - 72h
Bacteria that infects low acid fruits and vegetables?
C. botulinum toxins A and B
Bacteria that infects fish?
C. botulinum toxin E
What is a bacteria other than STEC that produces Shiga toxin?
Shigella
What is the incubation time for Shigella foodborne infection?
1-7 days
What are the symptoms of Shigella foodborne infection?
Dysentery (bloody/with pus)
Severe abdominal pain
Fever
Rectal pain
What are the virulence factors of Shigella?
Shiga-toxin
Cell-to-cell spread
Damage to intestinal cells
What are the Shigella species?
Shigella flexneri
Shigella boydii
Shigella soneii
Shigella dysenteriae
Best temperature and pH of Shigella?
10-48 C
6 - 8
Which species cause foodborne Salmonellosis?
S. Typhimurium (everything)
S. Enteritidis (eggs)
What is the incubation time for Salmonellosis and how long does it last?
12-24 hours and it lasts 2-3 days
What does Salmonella attacks in Salmonellosis?
It attachs to the ileum, penetrate with aid of fimbrial adhesins in cell attachment and invades M cells of Peyer’s patches
What are the symptoms in Salmonellosis?
Headache, fever, chills, diarrhea
What are the subpsecies of Salmonella enterica?
arizonae
diarizonae
enterica
houtenae
indica
salamae
What is the temperature and pH range of Salmonella?
Mesophilic: 5.3 - 45
pH 6.6 - 8.2
Which strain of C. perfrigens produces enterotoxin?
Type A strain
What does C. perfringens attacks and how?
Small intestine (ileum)
Abrupt change of pH triggers sporulation on the villi
What is the incubation time of C. perfringens gastroenteritis?
8 - 24h
What is the duration time of C. perfringens gastroenteritis?
12 - 24h
What are the signature symptoms of C. perfringens gastroenteritis?
Diarrhea, gas, abdominal pain, vomiting
No fever and nausea
What is the minimum concentration of C. perfringens for the gastroenteritis?
At least 5x10^5 CFU/mL
What are the characteristics of Bacillus cereus?
Gram+, motile, aerobic, endospore forming rod
What is the optimum temperature and pH for B. cereus?
35 - 40 C
pH 4.9 - 9.3
Does B. cereus produce toxins?
Yes, two extra-cellular ones
Is B. cereus diarrheal syndrome caused by a toxin? If yes, which one?
Heat labile enterotoxin
Is B. cereus emetic syndrome caused by a toxin? If yes, which one?
Heat stable enterotoxin
What is the incubation time and duration of B. cereus diarrheal syndrome?
12-13h
Lasts 6-12h
In which foods can you get B. cereus diarrheal syndrome?
Starch based foods such a cereal, corn, flours
Which toxin does EaggEC produce?
Heat stable enterotoxin EAST1
How does EaggEC attacks?
The plasmid coded fimbriae is responsible for the aggregative expression and a specific outer membrane protein (OMP) is needed for adherence
How does ETEC attacks?
It attaches and colonizes the small intestine by a plasmid coded fimbrial colonization factor antigen (CFAs I, II, III, and IV)
Does ETEC produce toxins? If so, which ones
Heat stable (ST) and heat labile (LT)
How does EPEC attacks?
It adheres to the small intestine mucosa via plasmid-coded adherence factors (intimin-eaeA) and causes attachment-effacement lesions, destroying microbilli
What does EPEC cause?
Diarrhea
Does EPEC produce toxins? If yes, which ones
No
Does EIEC produce toxins? If yes, which ones
No
How does EIEC attacks?
It invades the colonic epithelial cells and spreads to adjacent cells like shigellae
What are the symptoms for EIEC infection?
Bloody diarrhea
Abdominal cramps
What does DAEC causes?
Diarrhea, mostly in kids with >12 years old
How does EHEC attacks?
It has chromosomal eaeA gene codes for intimin, an adherence factor protein
Does EHEC produce toxins? If yes, which ones
Shiga-like toxin (SLT)
What makes it possible for EHEC to attach to cells?
Plasmid coded fimbriae
Which toxins on EHEC are linked to which diseases?
Stx2 - hemorrhagic colitis
Stx1 - hemolytic uremic syndrome
What is the infection time and duration of EHEC infection?
3-4 days
Lasts 3-10 days
What are the EHEC infection symptoms?
Bloody diarrhea, severe abdominal pain, vomiting, kidney damage and failure
What are the other strains of STEC besides O157 that have a zero tolerance policy?
O26, O111, O103, O121, O45, and O145
