DSA slides from McGowan Flashcards
bacteria from chicken
salmonella
campylobacter
shifella
Undercooked hamburger
EHEC (O157:H7 E coli)
Fried rice
Bacillus Cereus
Potato salad, mayo, or cream pastries
Staph Aureus
Eggs
Salmonella
Lunch meat and soft cheeses
Listeria
Raw seafood
Vibrio!
-or norwalk, campylobacter
Staph aureus
water diarrhea
- rapid onset
- preformed enterotoxins
Bacillus Cereus
- preformed enterotoxins
- comiting
- rapid onset
- rapid resolution
- fried rice
- watery diarrhea
Clostridium perfringens
- preformed enterotoxins
- watery diarrhea
- crampy abd pain
- rapid onset
- rapid res
- beef, ham, poultry, legumes, gravy: heat resistant spores inadequately cooked
Shigella
- shiga toxin
- usually children (daycare)
- BLOODY diarrhea
- Fecal leukocytes
Tx Shigella
BIsmuth, ampicillin, fluoroquinolone, or trimethoprim/sulfamethoxazole
Complications of Shigella
- respiratory compliants and seizures (children)
- post infectious complications: REACTIVE ARTHRITIS AND HUS
Which Shigella is the most common species in the united states?
Shigella sonnei
Salmonella Typhimurium
- fram negative, non-lactose fermenting, motile, rod-shaped, bacteria
- Watery->bloody diarrhea
- fever
- Ingests contaminated food (eggs, poultry)
- animal exposure: reptiles
- Increased risk with sickle cell pts
- Stool culture is lactose (-) motile
Are Abx indicated for Salmonella Typhimurium?
no!
-course of illness may be prolonged by it
What are complications of Salmonella typhimurium?
reactive arthritis, endocarditis, septic arthritis, osteomyelitis
Salmonella Typhi
- travel
- lives only in humans
- Typhoid fever: 103-104
- *rose spots rash
- Dx: samples of stool or blood
Tx of salmonella typhi
Fluoroquinolones (becoming resistant), ceftriaxone, and azithromycin
Campylobacter Jejuni
- Bloody diarrhea
- Guillian Barre syndrome
- Gram negative curved rod
- Spiral shaped, oxidase +, motile with flagellum
Tx of campylobacter
supportive
-NO ABX NEEDED
Vibrio cholerae
- O1 and O139 variants
- Toxin production
- watery rice water diarrhea (profuse)
- Curved/comma shaped, anaerobic gram- bacilli with flagellum
- waterborne illness (saltwater)
- Raw oysters (seafood)
- underdeveloped nations
Tx of vibrio cholerae?
- rehydration/electrolyte replacement
- in africa and India
Vibrio Parahemolyticus
Cytotoxin production
- Non-O1 and non O139 variants
- cause seafood associated diarrhea
- bloody diarrhea*
Vibrio Vulnificus
Gram negative bacillus
- warm shallow, coastal salt water*
- seafood
- open wound in water
- Bullous skin lesions
What kinds of patients are really in trouble if they have Vibrio Vulnificus?
Immunocompromised patients and
-especially cirrhosis patients
Aeromonas Hydrophila
- Gram (-), non- spore forming rod, facultative anaerobic bacteria, motile with flagellum
- FRESHWATER environments or bracksih water
- Eating fish or shellfish
- necrotizing fasciitis
- 2 types: Cholera like (non bloody), and Bloody mucoid stools
- scuba divers that swallow small amounts of fresh water and then have gastroenteritis
Tx of Aeromona Hydrophila
Ampicillin
Most common cause of Travelers diarrhea
ETEC
-affects small intestine
Ppl who go to russia and people who go camping a lot will get….
Giardia-associated diarrhea
Where is cyclospora found?
visitors to Nepal
What patients will have travelers diarrhea due to a Norwalk virus?
ppl who just went on a cruise ship
What kind of Diarrhea does ETEC give you?
the watery kind
What complication is much more likely to happen in EHEC than in shigella?
HUS
-tx with abx
Yersinia Enterocolitica
- Higher risk in Iron-overload syndromes*, diabetes, and preexisting GI disorders
- bloody diarrhea
- Clinically indistinguishable form salmonella or shigella
- can mimic appendicitis*
Complications of Y. enterocolitica?
rash, reactive arthritis, and hemochromatosis*
Tx of yersinia
supportive
Listeria Monocytogenes
- preggos
- non-bloody diarrhea
- confirm Dx by blood culture
- deli meaths
- can multiply at refrigerator temps
- meningoencephalitis
Clostridium dicifile
- Anaerobic, gram +, spore forming bacillus
- cytotoxin production
- watery diarrhea
- Pseudomembranes on colonic mucosa
- PCR for toxin (A and B)
- wash hands with soap and water**
Tx of Clostridium dificile?
PO/IV metronidazole, ORAL vancomycin
Main complication with C. diff
Toxic Megacolon
-treat aggressively and surgery consult for colectomy
What is the most common cause of acute diarrhea in children <2 yo?
rotavirus
Rotavirus
- children <2yo
- watery diarrhea
- wagon-wheel appearance on electron microscopy
- Death can occur from dehydration
Tx rotavirus
supportive care
-vaccine available
Norwalk virus
- older children and young adults
- Watery diarrhea
- symptoms within 24-48 hours
- cruise ships*
Tx of rotavirus
supportive care
Adenovirus (40 and 41)
- children (2nd to rotavirus as most common)
- Fever
- Watery diarrhea and vomiting
- conjunctivitis
- Pharyngitis
- lasts about 10 days
- Virus can shed for months after symptom resolution
Tx of Adenovirus
Supportive care
Cytomegalovirus (CMV)
- rare cause
- immunosuppressed patients
- reactivation of previous infection
- fever, abdominal pain, bloody diarrhea
- dx by doing endoscopy with bx of ulcerated lesions using CMV specific stains
Entamoeba histolytica
-Most common cause of dysentery in the world***
-Flask shaped ulcer
-Can penetrate bowel and into portal circulation….. LIVER ABSCESSES
-Toxic megacolon or pneumatosis coli
-needs treatment even if asymptomatic
(most are asymptomatic carriers)
-Stool antigen (PCR for DNA)
-crowded living conditions
Tx of Entamoeba histolytica
metronidazole and paromomycin
Giardia Lamblia
- pear shaped, 4 flagella, 2 nuclei protozoan
- Fecal-oral
- Watery (malodorous) diarrhea
- Stool antigen detection
- get it from water or daycare or Russia
Tx of Giardia Lamblia
Metronidazole
Which one was associated with and overcrowded swimming pool?
Cryptosporidium
- you’re fine as long as you’re not immunocompromised
- resistant to chlorine treatment
- watery diarrhea (large volume >20L a day)
Strongyloides Stercoralis
nematode: roundworm
- bare feet on contaminated soil
- enters body through exposed skin
- Rhabditiform larvae in stool, eosinophils in stool
Tx of Strongyloides Stercoralis
Ivermectin
Cyclospora cayetanensis
- Produce (like veggies) from endemic areas
- Travel to endemic areas (tropics)
- Watery diarrhea
- oocysts are hard to kill
- detect oocysts in stool sample
Tx of cyclospora cayetanensis
Trimethoprim/sulfamethoxazole (TMP/SMX)
Cystoisospora belli (used to be Isospora belli)
- watery diarrhea
- tropics
- repeated stool exams and concentration procedures are recommended
- if stool examinations are negative, do an examination of duodenal specimens by bx
- oocysts can be visualized by modified acid fast stain
Tx of Cysoisopora belli
Bactrim DS (TMP/SMX)
Ascaris Lumbricoides
- hook worm
- Bowel obstruction
Diphyllobothrium latum
-fish tapeworm… from fish
Schistosoma mansoni
- most common cause of esophageal varices behind alcohol in africa
- fresh water snails
- blood stools, bladder cancer, liver cysts
Taenia solium
- pork tape worm, mostly asymptomatic
- rare serious cases of seizures and muscle or eye disease
Echinococcus granulosus
- dog tapeworm
- cysts in liver or lungs
- looks like free-flowing “hydatid sand” on CT
What does an increase in fecal lactoferrin mean?
there is an inflammatory process behind the diarrhea
What are the only 2 organisms that will give us fecal leukocytes but not necessarily bloody diarrhea?
Listeria and clostridium
What are the only 2 penetrating things that cause diarrhea?
Salmonella typhi, Y. enterocolitica
What 2 things gave us rapid onset diarrhea?
Staph aureus or b. cereus
if there is diarrhea >16 hours after eating potato or egg salad and there’s dysentery, what organism?
Shigella!
What do you not use in C diff or EHEC?
anti motility agents
-you just need to shit them out
What kind of sanitation does NOT work for norovirus and C. diff?
alcohol gels…. they are Irishmen, they can handle their alcohol
For travelers, is prophylaxis with abx recommended?
no
What are some characteristics about pathogens that typically affect the small bowel?
Presents with: large volume, watery, abd cramps, weight loss
- WBC’s absent in stools
- pain is mid abdomen or diffuse
- Dehydration/malabsorption
What pathogens typcally affect the small bowel?
Salmonella Vibrio cholerae ETEC EPEC Yersinia Rotavirus Norovirus CMV Adenovirus Giardia Cryptosporidium Cyclospora Clostridium perfringens Staph aureus Bacillus Cereus
What are some characteristics about pathogens that typically affect the large bowel?
Present with: frequency, small colume stools
- May be associated with: fever, blood or WBC’s in stool (inflammatory), Fecal leukocytes common*
- Location: lower abd or rectum (tenesmus)
What organsims typically affeect large bowel?
Campylobacter, salmonella shigella yersinia EIEC EHEC C diff Vibrio parahaemolyticus E. histolytica CMV Adenovirus Herpes simplex
What are people with hemochromatosis prone to?
invasive, even fatal enteric infection
- Vibrio and Yersinia infection
- should avoid raw fish
What are some common enteric pathogens in AIDS patients?
Mycobacterium CMV Adenovirus HSV Cryptosporidium Cystoisospora belli Microsporida Blastocystis hominis
