Bacterial GI 2 Flashcards
When you suspect shigella and you want to send specimens to the lab, what must you do?
Get the sample on a plate Quickly!
What is the reservoir of C.diff in nosocomial outbreaks?
Asymptomatic carriers of c. Diff
Is salmonella incidence increasing or decreasing?
Increasing
Will you be sick for a long time after consuming the toxins of staphylococcus, B. Cereus, or C. Perfringens?
No, these are short duration, since no additional growth of the organism or production of the toxin will occur
How long after eating food infected by the heat stable preformed toxin of staphylococcus will you start having N/V, diarrhea, cramps and acute salivation?
1-6 hours…fast!
Which strain of salmonella leads to food poisoning?
Salmonella typhimurium
What kinds of symptoms will you have if you ingest the preformed toxin of bacillus cereus?
Beautiful projectile vomiting only 1-5 hours after eating the contaminated food
🍚
Is salmonella normal gut flora?
It is in birds and other animals!!!
Is the infectious dose of shigella high or low?
Very low, don’t need much
Do state authorities keep track of serotypes of salmonella
Yes
Is it possible to have disease with colonization of staph?
Yes, because just ingestion of the heat stable preformed toxin in foods will cause disease
Which patients need special care for salmonella poisoning?
AIDS patients
Are the eggs you buy at Safeway pasteurized?
Yes
What is an example of a physician-induced disease?
C. Diff causing pseudomembranous colitis
How do you treat shigella?
Fluid replacement
Antibiotics might help shorten the course and eliminate carriers, but there are lots of resistant strains
Is c.diff part of the normal flora?
It is in about 10% of people who are asymptomatic !
What are the 4 species of shigella and which two are most prevalent in the US
Group A- S. dysentariae-WORST ONE HUS CAUSING
Group B- S. flexneri
Group C- S. boydii
Group D- S. sonnei
Flexneri and sonnei are most common in US
(I don’t know if we need to know this)
Can you detect the staph toxin in foods?
No, there is nothing off about the smell/taste/appearance
How is shigella spread?
Person to person
Does shigella cause a fever?
Yes
What organism causes problems when you cook meat inadequately to kill spores, then leave it out, allowing the spores to germinate?
Clostridium perfringens
Will antibiotics help you if you have staphylococcal food poisoning/.
No. This is an intoxication from Enterotoxin A
What should you suspect if you see blood, mucus, PMNs and RBCs in someone’s feces?
Shigella
Is staphylococcal food poisoning directly communicable from person to person?
No
What are some complications of shigella?
Reiters syndrome in HLA-B27 people
Hemolytic Uremic syndrome (HUS) if you have Shigella dysentariae since it produces shiga toxin
What kind of a sample is ideal to send to the lab if you suspect shigella?
Blood-tinged flecks of mucus
When do we see the most salmonella infections?
Summer and fall
How do you diagnose salmonella?
Culture a sample of the food that made them sick
Stool sample
Blood cultures
Fluorescent Antibody tests allow for serological confirmation
What should you be very suspicious of if someone starts hardcore vomiting 1-5 hours after eating?
Bacillus cereus
What is the source of staphylococcus toxin in foods?
Humans
What food is associated with staphylococcal food poisoning
Custard-filled baked goods
Also canned foods, processed meats, potato salad
What are the two forms of bacillus cereus disease?
- Emetic form- preformed toxin is ingested
2. Diarrheal form- ingestion of large numbers of vegetative cells
How do you treat salmonella?
Supportive care, fluid/electrolytes
AIDS patients get a little extra love
How do humans get salmonella?
Food contamination
What kind of symptoms will you get with shigella?
Ranges from moderate diarrhea to severe dysentery
Starts with fever, cramps, vomiting, and watery diarrhea, and then can progress to dysentery in severe forms: blood, mucus, and PMNs in stools
What is the 2nd leading cause of food borne disease?
Staphylococcus
What is the best way to prevent shigella
Hand washing. Especially kids
How do you get clostridium perfringens?
Grossly contaminated meat/poultry that was left out after cooking that wasn’t enough to destroy spores!
What is the difference between shiga toxin and shiga-like toxin?
They are biochemically identical
Do we see shigella in regions with modern plumbing and good sanitation?
Yes
What organism is associated with eating spores in rice?
Bacillus cereus
Which microbe might get passed to you from your pet dog, cat, or turtle?
Salmonella
How do you prevent bacillus cereus?
Promptly refrigerating all grain foods after cooking
What is the specific preformed heat-stable toxin produced by staphylococcus that makes you vomit and shit
Enterotoxin A
Tolerates boiling for 30 minutes!
Do you need a high or low dose to get clostridium perfringens?
High dose
Does C.diff always cause pseudomembranous colitis?
No it may just cause diarrhea/cramping or it can cause a severe colitis, but without a pseudomembrane
How long does clostridium perfringens type A illness last?
Complete recovery in one day
Since our eggs are pasteurized, does that mean that the yolk is sterile and safe to eat raw?
No, since the chicken may be infected by salmonella, and it will get in there before it even lays the egg
Why do we see more salmonella these days?
Food processing changes-large scale facilities increase risk of massive common source outbreaks
Changing consumer preferences for fresh food items, including salad ingredients (tomatoes) has led to mosre cases by cross contamination by consumers or at the factory by equipment or water supplies with poop in them
Changes in animal husbandry
What is a predisposing factor to C.diff infection?
Disruption of normal gut flora
What is the reservoir for shigella?
Humans
What is the “pseudomembrane” in PMC?
An elevated yellowish plaque over inflamed mucosa. Its a fibrin mesh of necrotic cells, PMNs, monocytes, and RBCs
