Flashcards in EXAM #1: BACTERIAL INFECTIONS OF THE GI TRACT Deck (81):
What are the symptoms of Botulism poisoning?
2) Dry mouth
3) Blurred vision
4) Abd. sx
5) Progressive paralysis
What causes Botulism?
Improperly canned (non-acidic food)
When do the symptoms of Botulism start?
12-36 hours after ingestion
Is fever present in Botulinism?
No--only ingested toxin, NOT whole pathogen
What organism causes Botulinism?
List the characteristics of C. botulismsm.
What kind of toxin is the C. botulinum toxin?
A-B Bacterial toxin
What is the MOA of the C. Botulinum toxin?
1) B portion attaches to receptors on motor nerve endings
2) A portion enters nerve cell
3) Toxin blocks release of ACh
What causes Floppy Baby Syndrome?
C. Botulinum spore ingestion
What are the symptoms of Floppy Baby Syndrome?
Constipation followed by generalized paralysis
Where are C. botulinum spores and toxins identifiable in Floppy Baby Syndrome?
How is Botulsim treated?
What is a major adverse effect of Botulism antitoxin administration?
What are the characteristics of Clostridium difficile?
What does Clostridium difficile cause?
Antibiotic associated pseudomembranous colitis
What is the most common cause of nosocomial diarrhea?
How is Clostridium difficile transmitted?
What antibiotic was the first abx to cause pseudomembranous colitis?
What are the most common causes of pseudomembranous colitis today?
2nd and 3rd generation cephalosporins (only b/c they are the most frequently used)
What are pseudomembranes?
white-yellow plaques on the colonic mucosa
What is a severe complication of Clostridium difficile infection?
How do you tell the difference between adverse diarrhea with abx administration vs. Clostridium difficile?
Clostridium difficile toxin present in the stool
How is Clostridium difficile treated?
1) Withdraw antibiotic
2) Oral metronidazole* or vancomycin
3) Fluid replacement
What is Shigellosis?
Dysentery i.e. bloody diarrhea
List the characteristics of Shigella dysenteriae.
How does Shigella dysenteriae appear on MacConkey agar?
Colorless b/c non-lactose fermenting
How is Shigella dysenteriae distinguished from Salmonella?
1) Do NOT produce H2S
2) Non-glucose fermenting
What infective dose is required for Shigella dysenteriae infection? How does this compare to Salmonella?
Shigella dysenteriae= low
What type of diarrhea is seen with Shigella dysenteriae?
What is the typical symptom progression in Shigella dysenteriae infection?
1) Fever, abdominal cramping and diarrhea
- Watery diarrhea at first
- Bloody/ mucousy diarrhea
What strain of Shigella causes a much milder disease than Shigella dysenteriae?
What strain of Shigella is most common in the US?
What is the drug of choice to treat Shigella dysenteriae?
A fluoroquinolone i.e. Ciprofloxacin
What is the drug of choice for Shigella dysenteriae in kids?
What drugs are contraindicated in Shigella dysenteriae?
Why are Fluoroquinolones NOT used in kids?
Increased risk of tendinitis and tendon rupture, especially in kids
List the different infections caused by Salmonella species.
2) Typhoid fever
List the characteristics of Salmonella.
Gram negative rod
What antigens are associated with Salmonella?
What is the species of Salmonella most responsible for entercolitis?
What is the important host defense against Salmonella typhimurium ?
What does gastrectomy and use of antacids do to the infectious dose of Salmonella typhimurium ?
What disease is caused by Salmonella typhi?
Where does Salmonella typhi replicate?
Mononuclear phagocytes of the Peyer's Patches
After Salmonella typhi enters the GI tract, where does it go?
****Organism likes the gallbladder and can develop a carrier state there*****
What is the typical course of Salmonella in a healthy individual?
Non-bloody diarrhea that does NOT require medical care
What patient populations are at risk of life-threatening Salmonella infection?
What are the symptoms of Typhoid Fever?
1) Flu-like symptoms
2) Fever/ constipation
How is Salmonella Enterocolitis treated?
Fluid and electrolyte replacement
When are antibiotics indicated in Salmonella Enterocolitis?
Only in those at risk for septicemia
What drugs should be used to treat Salmonella enteric fever, septicemia, severe enterocolitis?
Ceftriaxone or ciprofolaxcin
What surgical procedure may be required to abolish the carrier state of Salmonella?
List the characteristics of E. Coli species.
Gram negative rod
What is the most common cause of traveler's diarrhea?
What is ETEC?
Enterotoxigenic E. Coli
What specific strain of E. coli is responsible for traveler's diarrhea?
What is the MOA of the ETEC toxin? What symptom does this toxin cause?
ETEC toxin is similar to the cholera toxin and causes a WATERY DIARRHEA
What type of diarrhea is seen in ETEC?
What is EIEC?
Enteroinvasive E. coli
What type of diarrhea is seen in EIEC?
Blood and pus in feces
What is EPEC?
Enteropathogenic E. coli
What does EPEC cause?
Chronic diarrhea in infants
What type of diarrhea is seen with EPEC?
Watery diarrhea containing mucous
What is EHEC?
Enterohemorrhagic E. coli
What toxins are seen in EHEC?
Shiga-Like Toxins 1 and 2 i.e. "SLT-I and SLT-II"
What are the symptoms of EHEC infection?
Severe disease with bloody diarrhea
What is an adverse effect of EHEC infection?
What is HUS?
Hemolyticuremic Syndrome characterized by:
1) Microangiopathic hemolytic anemia
3) Acute kidney injury
****This is the leading cause of acute renal failure in children worldwide*****
What antibiotics should be given to infants with E. coli infection?
How is traveler's diarrhea treated?
What type of diarrhea is "pathogmneomonic" for Cholera?
"Rice-water stool" i.e. severe watery diarrhea
Are neutrophils present in the stool of patients with Cholera?
What are the characteristics of Vibrio cholerae?
- Curved gram negative rod
- Tolerates strong alkaline conditions
- Tolerates high salt concentrations
What is the MOA of the Cholera toxin?
- AB subunit protein
- B-binds to receptors on microvilli
- A-activates adenylate cyclase (increases cAMP)
How is Cholera treated?
Rapid replacement of fluids and electrolytes
What are the characteristics of Campylobacter jejuni?
- Curved gram negative rod
How are severe Campylobacter jejuni infections treated?
Erythromycin or ciprofloxacin
What disease is caused by H. pylori?
What are the characteristics of H. pylori?
Short/ spiral shaped
What allows H. pylori to survive in that acidic environment of the stomach?
Urease enzyme that creates an alkaline microenvironment