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194 Cards in this Set

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What are the NANB viral heps technically?
C, E, G, SEN, TTT, maybe others
What is the most common type of new pathogen? Why?

Emerging pathogen: 3 examples?

Re-emerging pathogens: 3 examples?
Virus - simpler/smaller genome, quicker adaptations

new, never before seen pathogen
Ebola, Chikungunya virus, Granulobacter bethesdensis in CGD patients

previously seen pathogens, thought gone:
Influenza H5N1 avian flu, measles, Ecoli O157:H7 (spinach), salmonella (peanut butter)
Common features of viral hepatitis?

Lab findings?
RUQ abd pain, nausea, anorexia, fatigue, fever, jaundice, hepatomegaly

elevated liver enzymes, bilirubin in blood/urine, Alk Phos, LDH
4 m/o infant presents with watery diarrhea, vomiting x 24 h. no PO intake, appears dehydrated:

Morphology?

Which group most common?

Why is its habitat unique?
Rotavirus

dsRNA, Reoviridae

A

more common in temperate climates, circulates in winter months
HAV:
1. Family of viruses?
2. stable or unstable in environment?
3. acute, chronic infection? asymptomatic, symptomatic?
4. Transmission? Where?
5. single outbreak or community?
6. Vaccine? Who gets which kind?
1. picornaviridae, +ssRNA, one serotype worldwide (enterovirus group)
2. stable in environment
3. acute, asymptomatic infections in kids, adults quick onset "infectious hepatitis"
4. fecal-oral, crowded, poor hygiene
5. community outbreaks
6. inactive vaccine for children. killed vaccine for the military, travelers to endemic regions, high risk groups. of infection.
List from CDC of re-emerging pathogens? (5)
• Staphylococcus aureus
• Clostridium difficile
• Enterovirus 71
• Group A Streptococcus
• Mumps virus
Hep A pathogenesis? (incubation as well)

definitive dx of acute infection?

definitive dx of past infection?

Tx of HAV?
intestine --> hepatocytes (replication) --> feces- incubation- 30 days
acute infection, >14 y/o

anti-HAV IgM - acute infection

anti-HAV IgG - past infection

no antiviral tx, vaccinations, children @ 1 y/o, travelers
What two bacterias cause a syndrome clinically indistuishable from typhoid fever?
camplylobacter fetus
yersinia enterocolitica
HBV:
1. Family?
2. Transmission?
3. How is the liver damaged?
4. When do clinical signs show up?
5. Who gets the active vaccine?
6. Who gets the passive vaccine?
1. hepaDNA viridae, enveloped (partially) dsDNA
2. blood/semen, to liver
3. Damage to liver cells is immune mediated (due to release of toxic substances from infiltrating mononuclear cell and cytotoxic T-lymphocytes (CTLs)
4. When liver damage ensues clinical signs occur
5. children, infants, high-risk
6. health care workers
3 reasons why re-emerging pathogens come back?
develop resistance
decline in vaccination rates
re-assortment from other species
Hep B:
General serum marker of infection: why?
Recovery/immunity to HBV by itself vs found with other Abs:
Marker of acute infection:
Marker of past/chronic infection:
active replication:
general: HBsAg- surface is what body sees first "s"
Recovery/immunity: anti-HBsAb (alone = vaccination) (with other Ab's = recovery)
acute: anti-HBc IgM
chronic: anti-HBc IgG
active replication: HBeAg, HBV-DNA
What age group is most commonly affected?

What makes Rotavirus so hardy?

What binds to glycolipids on the membrane of villus epithelial cells?
6-24 mo.

no membrane, can remain for days on surfaces, wide pH survival, relatively resistant to cleaning/disinfectants

capsid
Serum findings in active infections of Hep B?

Serum findings in recovery?

Serum findings in chronic persistent?

Chronic active?
HBsAg, anti-HBcAg IgM

anti-HBsAg, anti-HBcAg IgG

HBsAg, anti-HBcAg IgG, anti-HBeAg

HBsAg+, HBeAg, HBcAg IgG, DNA Pol.
What are the criteria for viral eradication?
1. humans critical for transmission (no non‐human reservoir)
2. sensitive and specific diagnostic tools exist
3. effective intervention is available
Which hepatitis often co-infects with Hep B?

What type of virus?

risk group?

Serologic dx? Which ones are more likely in chronic vs acute?
Hep D

ssRNA, unclassified

IVDA's and partners

anti-HDV IgM (high in chronic) also found in acute, anti-HDV IgG (late in acute), HDV Ag
H. pylori was officially "discovered" by:

How?

Habitat?
Marshall, Warren

Marshall ate a H. pylori cx - exhibited symptoms of gastritis

exclusively human gastric mucosa
Hep C:
Family, type of virus?

animal reservoir?

Transmission? 90% of who will get this?

commonly causes _________ infections.

leading cause of ______________.
Flavivirus, +ssRNA

humans, chimps

injection, needle stick, sexual, 90%- drug users

chronic

liver transplantation
What gives the influenza A virus the ability to replicate?
Markers found in blood?
8 strands, which allows for many changes
HA- hemagglutanin
NA- neuraminidase
What are the "serum transmitted" Hep viruses?
B and D
S/S of Rotavirus?
Pattern of when occuring and where?
Mortality from what?

malabsorption of what?
smelly poops, fever, nausea, diarrhea, watery diarrhea WITHOUT LEUKOCYTES, fever
- circulates in winter months "winter diarrhea" starts SW in Autumn, ends NE in Spring
dehydration

fat, lactose
HBV Ag or anti found from (acute infection)...
a. 4-24 weeks
b. 6-32 weeks
c. 32+ weeks
d. 6+ weeks
a. HBsAg
b. IgM anti-ABc
c. Anti-Hbs
d. Total anti- HBc
What is antigenic drift? What pressures it?

What is antigenic shift?
Which drift/shift is pandemic?
point mutations in serotype - antigens pressure (in mammals)

whole gene change/rearrangement - species jumping (shift) H1N1
Factors that promote progression/severity of Hep C:

Ability to clear virus depends on ______ response.
EtOH, age, HIV, male, HBV

T-cell (CD4, CD8)
What are the three types of clinical "manifestation" labels for salmonella...
1. Enteritis
2. Septicemia
3. Enteric fever-
Which hepatitis is not person-person transmitted?
Type of virus?
Related to what virus?
Best way to prevent Hep E infection?
Hep E
NANB hep virus ,non-eveloped RNA genome
similar to Calciviruses
watch for contaminated H2O
T/F: H5N1 is easily transmitted person-person.

_________ has high death rates in sub-Saharan Africa due to low vaccination.

199 people infected in 2006 with _________ from eating bad spinach:
F

Measles

E. coli O157:H7
Name the type of virus for the following...
a. AKA infectious hepatitis
b. replicates via RNA intermediate
c. High risk sexual drug abusers
a. HAV- Hep A
b. HBV- Hep B
b. HDV- Hep D
What virus can cause either respiratory or GI diseases?

Morphology?

transmission?

Where does it attack?
adenovirus

dsDNA, non-enveloped

droplets, fecal-oral, poorly chlorinated H2O,
attacks mucoepithelial cells of conjunctiva, repiratory tract, GI, GU, leads to decreased absorption of Na and H20
Types of HBV chronic infections?

Incubation period?

More likely to develop chronic infection at what age?
Chronic persistent- can still transmit but not symptomatic
Chronic active- symptomatic hepatitis

- 100 days (about)

- 0-5 yrs old
Recently this virus has been seen on the rise with 8,383 cases in California in 2010...
Pertussis
For Acute HBV infections at what times would you see...
a. HBeAg
b. Anti- HBe
a. 4-12 weeks
b. 12+ weeks
What causes amoebic dysentery?

Most common dissemination?

S/S of acute and chronic?

What stage is often ingested?
Entamoeba histolytica

Liver abscess

acute: dysentery, abd pain, mucosal necrosis
chronic: acute S/S, + quadrinucleate cysts in feces

cysts
1. needs HBV as a helper to code its surface protein

2. Worrisome of mortalities in pregos
1. Hep D

2. hep E
What should you not use on O157:H7 patients? (2)

Bacteria found in Hershey's chocolate in Canada, 2006:

One major complication from Salmonella poisoning?

Which emerging pathogen has the mosquito as a vector?
Abx, anti-diarrheals

Salmonella

Reiter's syndrome (can't see, can't pee, can't go out with me)

Chikungunya virus
How does Hep D create Super-infection vs. coinfection...
Which is usually acute vs. chronic?
Co-infection usually acute- D got while getting B

Super- usually chronic after already having B you get D
People on a cruise develop GI symptoms with abd cramps, main symptom is vomiting, also diarrhea, malaise, HA. Disease lasted for 2-3 days:

what age groups does it affect more?

any blood/leukocytes in stool?
caliciviruses - Norwalk virus, Norwalk-like

adults, children > 4 y/o

No blood or leukocytes
For superinfection of HDV how do you prevent?

How do you cure/prevent coinfection
stop shitty behavior to prevent developing super infection

- Coinfection if you cure B you cure D
What type of virus is chikungunya and what family is it?
What is it similar to?
Symptoms?
Vector?
Alpha virus- Togaviridae family

(+)ssRNA genome

- joint pain, rash, other similar viral reactions

Joint pain
What serology studies find for Hep E?
anti- HEV IgG, anti HEV IgM, viral detection
Which clinical manifestation of salmonella am I describing...
a. risk higher in pediatric, geriatric and immunocompromised gets in blood
b. 6-48 hrs after ingestion, nausea, abdominal cramp, vomiting, non-bloody diarrhea (last 2 days-1 week)
c. 10-14 days after ingestion, rose spots
d. most common
a. septicemia
b. enteritis
c. enteric fever
d. enteritis
What is the diagnostic process for HCV?
1. anti- HCV first with ELISA
2. Confirm with RIBA test for RNA specific for Hep C
3. HCV PCR qualitative- (reverse transcriptase) to find out if presentand quantitative to find out how much present
Bacteria only seen in chronic granulomatous disease CGD patients, used for vinegar production, Gram(-) rod:
Granulobacter bethesdensis
Where are caliciviruses often found?

Most common transmission?

What causes "winter vomiting disease"?

How do you dx?
water - shellfish, contaminated food, lakes

contaminated food

Noroviruses

by exclusion, R/O everything else, cup like hollows under microscope, Amplification of the viral genome from stool samples by RT-PCR is the mainstay of diagnosis
1.1 Slutty Drugged Waitress Test show:
– HAV IgG: positive
– HAV IgM: negative
– HBsAg: positive
– Anti-HBsAg: negative
– Anti-HBcAg IgM: positive
– HBeAg: positive
– Anti-HBeAg: negative
– Anti-HCV: negative
Start with A's and then go C and then B
HAV IgG- not active then skip B
See- Anti-HCV neg so no Hep C
See "M" for HBV meaning she has acute infection, then others are used to confirm... but keep CHRONIC IN MIND IF PERSON IS DIRTY WHORE
35 y/o, traveled to Bangladesh, fever, diarrhea, G(-) rod, non-lactose, motile, H2S+:

30 y/o, sudden onset fever,abd pain, watery diarrhea; eaten crabs, diffuse abd tenderness:
Salmonella typhi

V. parahemolyticus, halophilic species (high salt)
1.2 Six month follow up of slutty waitress with normal liver enzymes
– HBsAg: positive
– Anti-HBsAg: negative
– Total Anti-HBcAg: positive
– Anti-HBcAg IgM: negative
– HBeAg: negative
– Anti-HBeAg: postive
more like chronic peristent not active, but can still transmit infections
H.pylori
Infections are associated with _______ conditions in childhood.

______% of the developed world is colonized.

___ out of 10 peptic ulcers due to H. pylori infection
crowded, low socioeconomic status

70-90%

9/10
1.3 Two years later of dirty waitress:
– HAV: IgG positive
--HAV IgM: negative
– HBsAg: positive
-Anti HBsAg: negative
– Total Anti-HBcAg: positive
– Anti-HBcAg IgM: negative
– HBeAg: positive
– HBV DNA: positive
– Anti-HDV IgM: positive
– Anti-HCV: negative
now she has D most likely superinfection
25 y/o on vacation in Mexico; abrupt watery diarrhea, abd cramps, fever/chills; no RBC's, WBC's, parasites in stool:

20 y/o, extensive purpuric rash, oliguria, weakness; bloody diarrhea, RBC's, no parasites, ate a hamburger:
ETEC, probably EAEC

EHEC, E. coli O157:H7
What pathogens cause enteric disease in AIDS patients/immunosuppressed?

37 y/o homosexual male, vomiting, diarrhea, cramping, abd pain, no blood in stool, no leukocytes, intranuclear inclusions with halo:
CMV, HSV, HIV

CMV
30 y/o in hospital, watery diarrhea, abd pain, N/V; on ampicillin 5 d.

What else might you see?
C. difficile

Pseudomembranous colitis
This bacteria is motile non-lactose fermenter, H2S+,
salmonella
19 y/o, abd cramps, bloody diarrhea, afrbile, ate undercooked chicken, occult blood +, G- S-shaped rods, microaerophilic:

15 y/o, ate fried rice, cramping/vomiting:
C. jejuni

B. cereus, type I (emetic, heat stable)
What groups are most at risk for CMV infection?

transmission of CMV?
high income - 50%
low income - 85%
homosexuals - 95%

sexual, urine contact, transfusion/transplantation
E. histolytica:
Characteristic histology finding?

Diagnostic requirement?

Treatment?
NO cysts, trophozoites + RBC's
3 stool tests - trophozoites + RBC's

mild: iodoquinol,paromomycin
moderate: Met, tinidazole
Severe/extraintestinal: *Met*, dehydroemetine
Review:
DsRNA, 10-11 segments, non-enveloped:

domestic/wild animals, outbreaks in closed environments - camps, cruises, schools:

- look like a star in electron microscope, cause diarrhea in kids <5 yrs
Rotavirus

Norwalk virus

astrovirus
Growth on MacConkey usually means?
If it is clear growth vs. pink?
Growth is usually G-
If clear it mean non-lactose fermenting
serotypes 40,41 associated with diarrhea in infants:

most common cause of viral GE in industrialized countries, "winter vomiting disease":

"summer diarrhea", often community outbreaks:
Adenovirus

Norovirus

Norwalk virus
Morphology of H. pylori?

Converts urease to __________.

Pathology?
G-, microaerophilic, spiral/corkscrew shape, up to 7 flagella

ammonia, CO2

local tissue/mucosal injury, increased gastrin, HCl
affects immunocompromised, highest risk in homosexuals and low-income:

vaccine approved in 2006, mortality due to dehydration:
CMV

Rotavirus
Gram-negative bacilli, non-motile, non-lactose fermenter, survives in cytoplasm
Transmission?
Shigella

- 4 F's: food, fingers, feces, flies
What viruses may be seen in healthy GI tracts without infection?
CMV, HSV, HIV
Giardiasis:
Organism?

Prevalence is high with _________.


Acute S/S?

Treatment?
Giardia intestinalis- "beaver fever"- not "Beiber fever" man if i ever saw t aht kid i would just punch him

poor water sanitation

explosive diarrhea, abd pain, smelly farts, greasy stools

DOC is Metronidazole, Oral rehydration
Which are the main viruses associated with gastroenteritis?
1. Caliciviruses
2. Rotaviruses
3. Adenoviruses
4. Astroviruses
5. SRSV (Small round structured) aka norwalk like
What are the two most common in US groups of shigella?
What is exotoxin?
How many cause infection?
S. Flexneri (Group B)
S. sonnei (group D)
- shiga toxin- 10-20 bacilli can cause
watery diarrhea also results from viral protein (NSP4) enterotoxin activity
– causes excess chloride secretion
Rotavirus
What is the preferred habitat of H. pylori?
exclusively human gastric mucosa (but can survive outside humans in feces and drinking water)
most important cause of gastroenteritis in infants and young children
Rotavirus
Where do Shigella attach and penetrate?
Some of the strands produce enterotoxin... what does this do with the shiga (exotoxin) toxin?
GI epithelial and M cells by using the host cells actin for transport
- cleave ribosomal RNA- causes host cell death and tissue destruction
Diagnosis of Rotavirus?
Viral antigen (VP6) detection from stool most common
– ELISA – rapid antigen detection
- Group A rotaviruses can be cultured in monkey kidney cells
Spore forming protozoa: *SPORE IN NAME*

Organisms?

S/S?

Transmission?

Who is mostly affected?
Cryptosporidium, Isospora/Cyclospora, Microsporidia

S/S: acute diarrhea in normal, chronic in immunocompromised

Transmission: fecal-oral
Usually affects immunocompromised
- well hydrated "Flagyl"- metronidazole
ROTA means?

2nd most common viral cause of gastroenteritis (all ages)
Right Out The Anus

adenovirus
Shigella
1. incubation period
2. symptoms
1. 36-72 hours
2. non-specific symptoms: fever (39°C), cramping abdominal pain, watery diarrhea after 48 hours, dysentery (bloody, mucous containing, small volume stools, pain upon defecation) ~2 days later
Incubation period: 8 to 10 days
• Transmission: Fecal-oral, fomite
• Signs: diarrhea for 5-12 days
• Population children, neonates
adenovirus
What bug is a major cause of chronic gastritis and duodenal ulcers?
H. pylori
Incubation period: Less than 24 hours
• Transmission: Fecal-oral, Community outbreak respiratory?
• Signs: Fever, nausea, (diarrhea sometimes)
• Duration: ~3 days
• Age effected: Adults & older children
• Seasonal?: most common in summer
Norwalk/Calciviruses (taxonomy is fucked up)
Difference between shigella and plesiomonas?
Plesiomonas oxidase positive
– Shigella is oxidase negative
A 37-year -old homosexual male with AIDS has vomiting, diarrhea, and severe cramping abdominal pain. What are the causes of vomiting and diarrhea in an immune compromised patient?
Bacteria, Virus, Parasite, Fungi possible?
– Bacteria- Shigella, Salmonella, Campylo, Mycobacterium
– Viruses- CMV, HSV, HIV
– Parasites- Cryptosporidia, microsporidia, isopora, giardia
- Fungi- Candida esophagitis
Cryptosporidiosis:
Infects what hosts?

S/S of Isospora and Cyclospora?

Lab Dx for these organisms?

Tx for C. parvum? Iso/Cyclo?
Crypto - cattle, livestock, *dogs*

Iso/Cyclo S/S: flu-like symptoms

Lab Dx: modified acid-fast stain

Tx for C. parvum: none, need to maintain immunity
Tx for Iso/Cyclo: Bactrim
HIV pt.
– no blood in stool
– no fecal leukocytes
– stool cultures did not reveal any bacterial pathogens
– O&P exam negative
– stool was negative for Adeno & Rotavirus antigen
some kind of virus, think CMV just cause he is a HIVite
Gram-negative, slender, curved or comma-shaped, microaerophillic, motile rods
campylobacter (jejuni) most common
You find a bug that is gram negative, microaerophilic, spiral/corkscrew shaped, has 7 flagella, and produces urease.... what do you think it is?
H. pylori
Leading cause of bacterial diarrheal illness in US
1. Incubation
2. What causes overt disease of it?
3. most common manifestation of this?
Campylobacter
1. 3-5 days after ingestions
2. if penetrates mucous layer and invades GI epithelial cells
3. watery diarrhea
Most common human helminthic infection?

Route of infection?

Manifestations?

DOC for Ascaris?
Ascaris lumbricoides

Ingestion, penetrate alveolar wall, ascend bronchi --> throat, swallowed

appendicitis, eosinophilic pneumonitis (Loeffler's Syndrome)

Albendazole
What special media and techniques are required to detect campylobacter?
Campy-BAP and Skirrow media
What are the 2 biggest virulence factors of H. pylori?
What are the main tests used to diagnose?
1.flagella and urease
2. rapid urease test, urea breath test, ELISA, stomach biopsy and culture
Aerobic gram negative found in domestic and farm animals presents often as appendicitis in the winter
yersinia enterocolitica
Hookworm found in US?

Route of infection?

S/S?

DOC?
Necator americanus

filariform larva --> skin --> lungs --> swallowed --> intestine --> maturation, eggs in feces

+anemia, malnutrition, edema

DOC: infants - pyrantel pamoate, adults - meben/alben
This bacteria grows at 4 C and causes painful enlargement of mesenteric lymph
nodes
- daycare outbreats
yersinia enterocolitica
Strains of H. pylori producing expressing what gene and what toxin cause more intense tissue inflammation and induce IL-8 production?
1. Vacuolating cytotoxin (VacA)
2. Cytotoxin-associated gene (CagA)
ACT enterotoxin, mostly immunocompromised with water habitats
Aeromonas hydrophila
Which helminth completes its entire life cycle in humans?
(Strong with the force this one is)

Two life cycles?

S/S?

DOC?
Strongyloides stercoralis

Free-living - fecal oral
Parasitic - skin --> lungs --> throat --> swallowed

S/S: ground itch, pneumonitis, ulcers

DOC: albendazole, ivermectin
SSDC agar?
yersinia enterocolitica
What is the method of choice for diagnosing H. pylori infection?
Breath test?
urease test
Breath test is C14 unless prego than C13
small, curved Gram-negative rods with a
single flagellum, activates adenylate cyclase to increase cAMP
V. Cholerae
Whipworm:
2nd most common US whipworm?

Route of infection?

Egg shape?

DOC?
Trichuris trichiura

fecal-oral

Egg: barrel shape, 2 polar plugs

DOC: mebendazole, albendazole
How is V. Cholerae transmitted?
Colonizes what?
What toxins does it produce?
contaminated water or food (usually shellfish, crabs)
- small bowel
- cholera enterotoxin, mucinase, and endotoxin
What do normal flora of the GI tract do?
maintain health and normal function:
1. synthesize vit K
2. aid in nutrient absorption
3. conversion of bile pigments to bile acids
4. prevent colonization by pathogens
Caused by toxin; most often occurs in underdeveloped nations; commonly associated with consumption of raw oysters; comma shaped
V. cholerae
Pinworms:
Organism?

Why is this worm's habitat unique?

Route of infection?

Dx? (Got any tape)?

DOC?
Enterobius vermicularis

common in temperate regions, NOT TROPICAL

ROI: eggs hatch in perianal region, larva into GI tract

Dx: tape on ass, find eggs

DOC: albendazole
This bacteria produces an exotoxin that activates adenylate cyclase in the crypt cells. The increase in cyclic adenosine monophosphate (cAMP) activates Cl- secretory channels. Consequently, sodium and water accompany Cl- into the lumen, which results in an osmotic diarrhea.
V. cholerae
T of F. GI tract is sterile at birth.
True
organisms introduced in food, breast milk, etc
abrupt watery diarrhea "rice water" stools... of this bacterial toxin,
V. cholerae
Roundworms: (pets)
Commonly found in what animals?

Usually affects what organ?

Tx?

Prevention?
Dogs, cats

eye is usually affected (toxocara)

Tx: Albendazole, mebendazole

Prevention: treat pets, cover sandboxes, cook crustaceans well
What type of media do you need for vibrio cholera?
TCBS (thiosulfate- citrate bile salt-sucrose)
- cholera will show yellow and others (vibro only) will show green
major cause of chronic gastritis and duodenal ulcer
H.pylori
halophilic (salt-loving) and grows in
marine environments
– commonly found in raw or undercooked shellfish
• more common in Japan
V. parahaemolyticus
Trematodes - Flatworms
3 Schistosomiasis species? Where are they found?

Larval stage in what animals?

What organs do they like?

DOC?
mansoni - S. America, Arabia, Africa
haemotobium - Africa, India
japonicum - Asia

fresh water snails

M - liver portal system, H - bladder, K - sup. mesenteric veins

DOC - Praziquantel
What are the five E.coli's?
E- entero
toxigenic, pathogenic, hemorrhagic, invasive, aggregative
1. ETEC: Enterotoxigenic
2. EPEC: Enteropathogenic
3. EHEC: Enterohemorrhagic
4. EIEC: Enteroinvasive
5. EaggEC: Enteroaggregative (or EAEC)
H. Pylori
Shape?
Virulence factors?
Flagella?
How do they work?
a. microaerophilic- spiral/corkscrew shape
b. flagella and urease
c. 7
d. grow on surface of gastric epithelium cells, in the mucus layer
What are the five E.coli's?
E- entero
toxigenic, pathogenic, hemorrhagic, invasive, aggregative
1. ETEC: Enterotoxigenic
2. EPEC: Enteropathogenic
3. EHEC: Enterohemorrhagic
4. EIEC: Enteroinvasive
5. EaggEC: Enteroaggregative (or EAEC)
Tapeworms:
Host for: T. solium, T saginata, D. latum:

body structure?

Route of infection?

S/S?

DOC?
T. solium: pigs
T. saginata: cattle
D. latum: fish

scolex, proglottids + eggs

ROI: under-cooked meat

S/S: usually none, sometimes appendicitis, B12 deficiency

DOC: Praziquantel
What is the key to noting its an infection from bacteria in diarrhea?
fecal leukocytes with "left shift" meaning neutrophils PMNs are present
Explain how urease helps H. Pylori live in stomach
How do you diagnose?
converts urea to ammonia and CO2
- >5% bacterial total protein
= rapid urease test- looking for enzyme
Cholera-like toxin, *T*raveler's diarrhea:

adheres to small bowel, common in (Pint-sized) children:

Shiga-like toxin, O157:H7, inflammatory colitis:
ETEC

EPEC

EHEC
Echinococcus:
Unique about life cycle?

Characteristic manifestation?
Humans aren't really involved in life cycle, but can ingest the adult organism and be infected

Hydatid cysts
What are the many inflammatory gastroenteritis pathogens (8)?
– Salmonella sp.
– Shigella sp
– Vibrio parahaemolyticus
– EIEC
- EHEC
– Campylobacter sp.
– Yersinia enterocolitica
– Francisella tularensis
Other than urease and flagella what are four other virulence factors of H. Pylori?
1. phospholipases (breakdown host membranes)
2. adhesins (hook on)
3. protease- breaks down mucus layer
3. CagA (cytotoxin Associated Gene)-
4. VacA combined with CagA can cause intense tissue inflamation and IL-8 production
Shiga-like, but no toxin, invades colonic epithelium:

in colonic mucosa, +toxin, prolonged watery diarrhea:

Which ones are non-inflammatory/non invasive? (PAT)

InvAsive, inflammatory?
EIEC

EAEC

EPEC, EAEC, ETEC

EIEC, EHEC
Balantidiosis:
Organism?

Route of infection?

What animal has 20-100% prevalence?
Balantidium coli

ingestion of cysts

Pigs
Which of the bacterial causes of diarrhea is a lactose fermenting?
E. coli
Which cytokine is super involved with H.pylori infections?
IL-8
Salmonella sp.
habitat?
What pet is common?
Gram-negative rods, motile facultative anaerobes, non-lactose fermenting
S. typhi- humans GI
rest of Salmonells intestines of animals
- turtles (reptiles)
What helminth can migrate to your CNS and cause calcified cysts?
Cysticercosis-brain
caused by T. solium
SHIga-like?

Montezuma's Revenge?

ETEC affects what cell pathways?

What does that cause?
EHEC, EIEC

EAEC

more adenylate-cAMP, cGMP

more Cl- release, H2O follows
Pt. comes in to the clinic after he went crazy and ate his dog's poo about 15 years ago and felt he should confess... you feel a mass on his liver. turns out he's got them all over his liver... Dx? Tx?
Dx: Echinococcus granulosus (hydatidosis)
Tx: surgical removal of hydatid cysts, give Praziquantel w/ albendazole or meb)
What's unique about EPEC's attachment to the cell? (Princess on a Pedestal)

3 stages: stick to mucosa, biofilm formation, cytotoxin, intestinal cell damage:
attaching and effacing - EPEC injects tir receptor, binds to intimin, rearranges actin in the cell --> pedestal, bacteria on top

EAEC
Pt. presents w/ severe bloody diarrhea and RUQ pain after coming back from swimming tour in third-world countries. Stool sample reveals cysts w/ 4 nuclei and trophozoites containing RBC's. Dx? Tx?
Dx: E. histolytica (amebiasis)
Tx: Metronidazole followed by paromomycin
Normally salmonella enteridis infections show what symptoms? What cells do they invade?
What symptoms does salmonella typhi (or paratyphi) show ?
Enteridis- fever, abdominal pain, and diarrhea
• invades intestinal epithelial cells
– inflammatory diarrhea

Typhi- fever, nonproductive cough, bloody diarrhea, abdominal pain, skin develops small rose-colored macules (rose spots)
Pt. presents w/ foul-smelling EXPLOSIVE diarrhea, bloating. Hx reveals he went hiking a week ago and drank from the beautiful streams. Dx? Tx?
Dx: Giardiasis
Tx: Metronidazole or Tinidazole
Has 3 stages: mucosal adherence, *biofilm*, cytotoxin/intestinal cell damage

Why is pathogenic E. coli pink on MacConkey's agar?

What E. coli are related to S(HI)gella?
EAEC

lactose fermenter

EHEC, EIEC
Immunocompromised Pt. presents w/ severe watery diarrhea after visiting a local farm to pet the animals. Stool sample reveals cysts on acid-fast stain. Dx? Tx?
Dx: cryptosporidium
Tx: symptomatic
Since this type of bacteria is sensitive to gastric acid how does it invade?
- attach to gastric epithelial cells in small intestine and colon
--->bacterial type III secretory system to inject bacterial proteins into host cells
- eventually makes tunnel from bacterial cell to cause bacteria to flood in
Pt. presents w/ appendicitis and eosinophilic pneumonitis. They got back from a tropical year-long trip. Stool sample reveals ovoid eggs. Nothing else remarkable. Dx? Tx?
Dx: Ascaris lumbricoides
Tx: Albendazole or Mebendazole
EHEC usually affects what systems?

Complications? (E-*H*-E-C)

Which bacteria do you AVOID ABX use? Why?
large bowel - necrosis, neutrophils
kidneys - shiga toxin

hemorrhagic colitis, HUS

EHEC - kills bacteria --> more toxin released
8-yr-old female presents w/ diarrhea, wt loss, anemia, distended abdomen, and itchy rash on planter surface of L foot. Stool sample reveals some eggs. Dx? Tx?
Dx: Hookworm (Necator americanus)... be careful as larvae look like strongyloides
Tx: Albendazole or Mebendazole
What are the three non invasive Ecolis
What does that mean?
do not see fecal WBCs
• ETEC
• EPEC
• EAggEC
Pt. presents w/ steatorrhea, vomiting, malabsorption syndrome, skin lesion on foot. Stool sample was negative, but enterotest (string test) was positive. Dx? Tx?
Dx: Strongyloides stercoralis
Tx: Ivermectin po
What are the 2 invasive E. Coli's
• EIEC
• EHEC
10-yr-old male presents w/ slightly bloody diarrhea, lower abdominal pain, tenesmus, and rectal prolapse. Stool sample reveals barrel-shaped eggs. Dx? Tx?
Dx: whipworm (trichuris trichuria)
Tx: Mebendazole
Name E.coli with each...
a. traveler's diarrhea
b. No toxin produced; adheres to apical surface, flattens villi, prevents absorption,
c. elaboration of cytotoxin which damages interstinal cells
d. infants < 6 months
a. ETEC
b. EPEC
c. EAggEC
d. EPEC
7-yr-old male presents w/ "my booty itch at night". You pull out the scotch tape b/c you suspect what? Tx?
Dx: Pinworms (enterobius vermicularis)
Tx: Mebendazole
What is the difference between the labile and stabile toxins of ETEC?
a. LT- A in cytoplasm ADP-ribosylates GTP-binding protein,
stimulates adenylate cyclase-cAMP system
b. ST- binding stimulates intracellular cGMP levels, stimulates chloride ion secretion and/or inhibition of NaCl adsorption
Little child presents w/ unilateral cataracts and retinitis. He enjoys playing w/ "scruffy the dog" all day everyday during the summer and sharing food with him. Found some eggs in the stool. Dx? Tx?
Dx: Toxocara canis (or cati)
Tx: Albendazole or Mebendazole
Name the E. Coli with
a. Tir and Intimin – causes actin re-arrangement and pedestal formation
b. Typically, food-borne transmission (e.g., uncooked hamburger); (O157:H7)
c. avoid antibiotics with this type
a. EPEC
b. EHEC
c. EHEC
Which Schistosoma species lives in your venous plexuses of the bladder?
S. hematobium
To isolate EHEC what are the special tests in addition to MacConkey plates?
1. Sorbitol must be included in the medium- inability to ferment sucrose
2. ELISA detection of Shiga Toxins 1 and 2 (Verotoxins) in stool specimens
Which schistosoma species lives in your portal system of the liver and small venules of the colon and lower ileum?
S. mansoni
This bacteria major risk in maternal infection during pregnancy
– neonatal sepsis and meningitis follow amniotic fluid infection
listeria monocytogenes
Which schistosoma species lives in your superior mesenteric veins draining the SI?
japonicum
Pt. presents w/ inflammation of spleen and liver, fever, chills, abd pain. He just got back from spending a year in the carribean. Stool revealed eggs w/ an obliquely oriented "tail." Dx? Tx?
Dx: schistosomiasis (mansoni)
Tx: Praziquantel
Carrier state common in tropical countries often without disease
• Causes dysentery and GI bleeding in susceptible hosts
• May mimic GI carcinoma
-perforate mucosa and disseminate widely
Entamoeba histolytica
This is mostly found in the SE US and can penetrate the foot. How much blood does it drink?
What positive can we come up with on these?
What sign may we see in myocardium?
hookworm - Necator Americanus
- drinks .2ml of blood causes anemia
- secrete anticoagulant and do not reproduce inside
- "tiger stripes" in myocardium
What is the flag sign in hair and what bug is it associated with?
- due to anemia possibly caused by necator Americanus (hook worm)
What type of worm do you do the "scotch tape" test for?
Pinworm (enterobius vermicularis)
most common cause of epileptic seizures from people that come from tropics
cysticercosis
"Beaver Fever" with severe non‐invasive diarrhea after drinking water fresh from rocky mountain stream
Giardia lamblia
Larvae hatch in the gut, then migrate through tissue to the lung – are swallowed, then mature in the gut
• Eggs are passed through in the feces, where they may infect another human via fecal‐oral
contamination
Ascaris lumbricoides- intestinal round worms
larvae hatch in small intestine and make way into the cecum where they live as adults which may cause anal- prolapse
Whipworm – Trichuris trichiuria
Brain cysts and seizures think...
taenia solium (cysticercosis)
Liver cysts think
echinococcus granulosus
Portal hypertension thinking (parasite)

hematuria, bladder cancer
schistosoma mansoni

schistosoma haematobium
Microcytic anemia
necator americanus
Perianal pruritus
enterobius
Name the three parasites that migrate to lungs are coughed up and swallowed into the GI to grow to adults...
How does each of the three cause problems?
Diagnosed?
1. Ascaris lumbricoides (egg/eosinophils in feces)- eggs injected
2. Necator Americanus (eggs eosinophil in feces)- larvae penetrate skin
3. Strongyloides stercorous (filiarform passed)- larvae penetrate skin
Normal flora in the GI tract synthesize _________ and help to convert ______. May also enhance. _____

Describe bacterial interference.

3 common pathogens of acute infectious diarrhea:
Vitamin K, bile pigments --> acids, mucus production

normal flora compete w/ pathogens for nutrients in GI

Salmonella, Shigella, Campylobacter
3 mechanisms of bacterial pathogenicity in GI:

Why is intoxication unique?

What organism associated with Antibio-associated diarrhea?
intoxication, infection, antibio-associated

don't need to ingest bacteria- just toxin, no fecal leukocytes found

C. diff
Intoxication: 4 major organisms?

Inflammatory response or not?

Which bacteria is anaerobic?
– Clostridium perfringens
– Clostridium botulinum
– Staphylococcus aureus
– Bacillus cereus

NOT inflammatory

C. perfringens
1. anaerobic, G+, spore forming bacilli, boxcar shaped:
2. Transmission?
3. Problem?
4. enterotoxin targets what?
1. C. perfringens
2. meats, gravy, some vegetables
3. -part of normal flora as well
4. ion transport into intestine, which causes membrane to be more permeable, water follows, leaky membranes
1. How many organisms of C. perfringens are pathogenic?
2. S/S of clostridium intox?
3. characteristic on anaerobic blood agar?
1. > 10^5 food or 10^6 organisms/g stool
2. watery diarrhea, cramping <24 h, NO FEVER
3. zone of double hemolysis
1. anaerobic, G+, spore forming rods, from home-canned vegetables/products, honey:
2. Virulence factor?
3. Action of toxin?
1. C. botulinum
2. Botulinum toxin (neurotoxin)
3. prevents Ach release, muscle contraction failure, flaccid paralysis
1. What C. botulinum antigens are pathogenic? (4)
2. ____ protects against stomach acids, and ____ blocks Ach release.
3. S/S when does it manifest??
1. A,B (bind),E,F
2. B - stomach, A - blocks Ach release
3. (1-2 days to travel to target center.) blurred vision, dry mouth, constipation, abd pain, flaccid paralysis
1. Most common cause of intoxication in U.S.?

2. morphology?

3. virulence factor?

4. What kinds of food?
1. S. aureus

2. G+ cocci in "grape" clusters

3. heat-stable enterotoxin

4. Creamfilled deserts, mayonnaise, dairy products, high salted foods
Where does S. aureus bind to?

S/S?

Most potent membrane damaging toxin in S. aureus?
emetic reflex center --> projectile vomiting

vomiting, little/no diarrhea, NO FEVER, symptoms p 1-4 h. ingestion

alpha-toxin
aerobic G+ spore forming bacilli, central spores:

Major food associated with B. cereus:
Bacillus cereus

rice- think chinese buffets
Two types of toxins for B. cereus? Where do they act?

Which B. cereus toxin is heat-stable, which is heat-labile?
emetic eneterotoxin (Type I)- 2-3 hrs after ingestion

diarrheal enterotoxin (Type II) - intestinal epithelium - stimulates adenylate cyclase/cAMP --> fluid accumulation (10-14 hrs after)

I - stable, II - labile
1. Treatment for intoxication reactions generally?

2. How do you treat botulism, why is it different?
1. supportive care - fluids, hydration, electrolytes

2. - botulism differs because it is neural toxin.
-monitor cardiac, respiratory - antitoxin (A,B,E)
describe how bacteria cause diarrhea by infection
pathogenesis due to:
– colonization and/or
– toxin production and/or
– tissue invasion
most implicated food products are meats & gravy dishes
– sometimes vegetables
c. botulinum
8 antigenic types of S. aureus enterotoxin?
– SEA, B, C1-3, D, E, H
Bacteria associated w/ Dairy
Campylobacter, salmonella
Bacteria associated w/Eggs
Salmonella
Bacteria associated w/Meats
C. perfringens, B. Cereus, Campylobacter, Salmonella
Bacteria associated w/Ground Beef
EHEC
Bacteria associated w/poultry
campylobacter
Bacteria associated w/ pork
C. perfringens, yersinia enterocolitica
Bacteria/ virus associated w/ seafood
astrovirus and vibrio sp
Bacteria/ virus associated w/ oysters
calicivirus and vibrio
Bacteria associated w/ veggies
C. perfringens
Bacteria associated w/ mayo, salads with highly processed foods and cream puffs
Staph aureus
Bacteria associated w/ Rice Starch
Starch/Rice- B. Cereus enterotoxin I (Heat stabile)
Bacteria associated w/ Canned foods, honey, for children under 1
C. Botulinum