Download Gastrointestinal Infectious Diseases

Gastrointestinal Infectious Diseases
Staphylococcus aureus- (G+ cocci)
Many strains are drug resistant (MRSA), most common nosocomial infection
Disease: most common bacterial “food poisoning”
Cramping, vomiting, diarrhea, nausea- 2 to 6 hour onset, 24 hour recovery
Caused by heat-stable enterotoxins…(implications???)
Transmission: typically meats, chicken, custards, cream pies (human nose/hands reservoir
to oral entry)
S. aureus can also causes:
Localized skin infections- folliculitis, boils, carbuncles
Systemic infections of organs- osteomyelitis
Kidney, liver, spleen abscesses
Endocarditis
ETC…
Clostridium perfringens- (G+ spore-forming bacilli)
Disease: mild food poisoning symptoms (very common) 8-16 hours after ingestion
Caused by an enterotoxin
Transmission: oral entry of spore-contaminated meats and vegetables
Clostridium botulinum- (human GI disease caused by 4 of 8 strains)
Disease: double vision, dizziness, muscle paralysis, respiratory distress
Cause- botulinum toxin (botox) interferes with neuromuscular junctions
70% mortality without supportive care, 10% with care
Transmission: oral entry of spores on veggies, fruits, occasionally meats and fish and
dairy
Clostridium difficile- (normal flora of ~5% population)
Disease: watery, foul diarrhea, sometimes bloody due to hemorrhaging of GI
Caused by toxin release
Overpopulation of C. difficile and toxin release occurs when enterics are
destroyed by course of antibiotics (often in hospital patients)
Transmission: oral-fecal, or normal flora
Listeria monocytogenes- (G+ bacilli)
Non-fastidious, resistant to heat, cold, pH extremes, salt
Disease: mild food poisoning symptoms, sore throat
Most harmful to pregnant women- spontaneous abortions
Fetus- meningitis, CNS damage
Transmission: typically dairy products, meats, poultry
Salmonella enteritidis- (G- bacilli) several strains known to cause disease
High quantity of inoculum
Disease: 6-24 hour onset of vomiting, diarrhea, fluid loss lasting for 2-5 days
Transmission: fecal contaminated food or water, primarily from reptiles and chickens
(but found in most animals)
Shigella sp.- (G- bacilli, several different species)
Low quantity of inoculum
Disease: Shigellosis- 2-3 day onset of watery or bloody diarrhea, Shiga toxin
Transmission: human reservoir, fecal contaminated food or water (or anything else)
Escherichia coli- (G- bacilli, over 150 known strains, most are normal flora of
mammals)
Only few strains pathogenic
Disease: mild to severe hemorrhagic GI disease (leading cause of infantile diarrhea)
Caused by variety of heat-stable and heat-labile toxins, attachment proteins for
colonization. Over-stimulation of fluid secretion in to GI lumen
Transmission: undercooked meats, unpasteurized milk, water (fecal-oral)
Campylobacter jejuni- (G- vibrio)
Becoming a very common GI pathogen
Disease: mild to severe diarrhea, fever, abdominal pain…bloody stool due to intestinal
perforation. 1 week to recovery.
Caused by a heat-labile toxin
Transmission: fecal material or contamination of water by cattle, chickens, turkey
Rotavirus- (RNA naked virus)
(most common gastroenteritis in infants and children worldwide)
Disease: infects epithelia of small intestine to cause watery diarrhea…dehydration! Kills
~2 million children each year worldwide.
Transmission: fecal contamination of water (virus pretty stable)
Vaccine pulled from market in 1998, new vaccine re-introduced in 2005.
Norovirus (aka Norwalk virus)- (RNA naked virus)
(may cause as much as ½ the gastroenteritis cases in U.S.)
Disease: 1-2 days nausea, vomiting, diarrhea
Transmission: fecal contamination of water and food (particularly seafood)
Giardia lamblia- (protozoan)
Low quantity of inoculum, chlorine resistant
Disease: 1-4 week incubation, 50% asymptomatic
Sudden-onset of watery, smelly diarrhea, cramps, foul-smelling flatulence
Transmission: fecal contaminated water (humans and other animals)
Raw veggies and fruits
Prevention and treatment: boil or filter water, quinacrine, metronidazole
Cryptosporidium sp.- (protozoan)
Low quantity of inoculum, chlorine resistant
Disease: often asymptomatic, mild watery diarrhea
Transmission: fecal contaminated water (various animals)