Bacterial infection of GI I

Question 1

Diarrhea

Answer 1

• 3+ loose or liquid stools per day-usually result of probs in small intestine

Question 2

Gastritis
gastroenteritis
enteritis
enterocolits
colitis

Answer 2

Gastritis- inflammation of the stomach

gastroenteritis- inflammation of stomach and intestines-nausea, vomiting, or diarrhea and ab pain

enteritis-inflammation of the intestines; usually small intestine

enterocolits-inflammation of the mucosa of the large and small intestine

colitis- inflammation of the large colon

Question 3

dysentery

Answer 3

dysentery- inflammatory disorder of GI tract often associated with blood and pus in the feces
pain, fever and abdominal cramps
results usually from prob in LARGE intestine

Question 4

what should you expect to see in stool that is infected by inflammatory bacteria

Answer 4

• leukocytes and fecal occult (not visible blood) and blood

Question 5

in what hrs of digestion do performed (already made toxins) toxins work? Toxins produced after ingested? when adhered, grew and then release toxin.

Answer 5

1-8 hr
8-16
16 + hrs

Question 6

what are the two types of bacterial food poisoning

Answer 6

1) Toxins produced by bacteria BEFORE food consumed
2) large numbers of spores ingested, spores germinate in intestine and vegetative bacteria make toxins- no implied adherence/colonization to GI tract

Question 7

symptoms of bacterial food poisoning

Answer 7

• diarrhea, vomiting, both

- no fever

Question 8

four bacteria that cause bacterial food poisoning

Answer 8

s. aureus
c. botulinum
c. perfingens
bacillus cereus

Question 9

staphylococcus aureus
type:
spores?
how does it cause disease?
symptoms
inflammation?
time
pathogenesis
treatment

Answer 9

type: Gram pos cocci
spores? no
how does it cause disease? performed toxin
symptoms- severe vomiting, diarrhea, and ab pain
inflammation? no
time 1-8 hrs post consumption
pathogenesis- heat stable
treatment-supportive

Question 10

Clostridium botulinium
type:
spores?
how does it cause disease?
symptoms
inflammation?
time
pathogenesis
Mechanism

Answer 10

type: gram pos rod
spores? yes
how does it cause disease? botulinium toxin by preformed toxin
symptoms: early- onset of vomit, diarrhea, ab pain (1-8 h post ingestion)/8-16 hrs post late- flaccid paralysis and progressive muscle weakness and respiratory arrest
inflammation? no
time- 1-8/8-16- late
pathogenesis- ingest preformed toxin and large numbers of spores form and germinate the intestine to produce toxin
mechanism- acts as a neuromuscular nerve junction signaling blocker- blocks Ach from binding and muscle stim is blocked

Question 11

clostridium botulinium found where?
complications of infection
treatment

Answer 11

• found in home canning
• patient survives- lingering weakness and sypnea up to year after primary disease
• treatment- supportive therapy, IV antitoxin administration

Question 12

floppy baby syndrome

Answer 12

infant botulism
occurs between birth and 6 mo
germination of C. botulinium spores in intestines with toxin production
usually found when infants given honey
milder and lower mortality than adult botulism

Question 13

clostridium perfringens
type:
spores?
how does it cause disease?
symptoms
inflammation?
time
pathogenesis
treatment

Answer 13

type: gram pos rod
spores? yes
how does it cause disease? mediated by C. Perfringens enterotoxin (toxins produced in the body)
symptoms? diarrhea and ab cramps 8-16 h post-ingestion and lasts for 24 h
inflammation? NO
time- 8-6 hrs post ingestion
pathogenesis- associated with contaminated meat products/gravies held below recommended temps
treatment- supportive

Question 14

Bacillus Cereus
type:
spores?
Inflammation?
what are the two forms?

Answer 14

type: gram pos rod
spores: yes
inflammation- no
Forms: emetic (vomiting) form and diarrheal form

Question 15

Diarrheal form of B. cereus
implicated food-
cause of disease-
onset of symptoms-
enterotoxin vs heat-

Answer 15

implicated food- meats and vegis
cause of disease-toxin made in intestine
onset of symptoms- 8-16 hrs post ingestion
enterotoxin-heat liable (dies in heat)

Question 16

emetic form of B. cereus
implicated food-
cause of disease-
onset of symptoms-
enterotoxin vs heat-

Answer 16

implicated food- Rice (improperly stored) (cereus sounds like cereal and that is a grain and so is rice)
cause of disease-preformed toxin
onset of symptoms- 15 min-8h
enterotoxin vs heat- heat-stable
-spores survive cooking, bacteria multiply and make heat-stable enterotoxin that is not inactivated upon reheating

Question 17

treatment for B. cereus

Answer 17

• supportive

Question 18

Helicobacter pylori

how does it infect

Answer 18

• attracted to chemostatic substances HEMIN AND UREA of the stomach’s epithelium and it’s mucus that lines it
• recruits and inactivates inflammatory cells and also releases urease that cleaves urea, producing NH3 that neutralizes stomach acid in its vicinity
• H pylori cytotoxin and ammonia from urease cause destruction of mucus-producing cells, exposing the underlying connective tissue to stomach acid

Question 19

Diagnosis and treatment of of H. pylori

type of bacteria and what does it cause

Answer 19

urea breath test or biopsy
antibiotics and proton pump inhibitor- to control acid
gram neg rod
causes stomach ulcers

Question 20

listeria monocytogenes

type, oxygen and traits

Answer 20

• gram pos
• facultative anaerobe
• key traits: wide growth range *1C-45C
• resistant high salt concentrations
• wide pH range

Question 21

why would you find listeria monocytogenes in processed food? what type of food would you see it the most?

Answer 21

• processed food often have a lot of salt in them to kill bacteria but listeria monocytogenes is resilient to high salt conc.
• food- processed meat and raw vegis

Question 22

symptoms of listeria monoytogenes for
healthy people
immunocompromised
pregnant women

Answer 22

healthy adults- usually asymptomatic but may have fever, nausea, diarrhea

immunocompromised pt- Bacteremia (fever, chills and malaise)
or Meningitis and encephalitis- fever, headache, stiff neck, vomiting and confusion

pregs- fever with no obvious infection =blood culture- may tx to neonate

20-50% mortality rate and significant neuro sequelae in survivors

Question 23

what occurs if a neonate is infected by listeria monocytogenes

Answer 23

• granulamatosis infantiseptica- pyogenic granulomas distributed over the whole body
• meningitis
• encephalitis
• pre mature birth, abortion or still-birth

Question 24

how does listeria monogenes work

Answer 24

-adherence and induced uptake via internalin-A
-internalized into endocytic vacuole
-acidification of vacuole/phagosome activated listeriolysin O- disrupts vacuole membrane to allow for escape to the cytosol
int A -> LLO -> ACT A-> blood (CNS)

Question 25

how does listeria monogenes replicate

Answer 25

• replicates in host cell cytosol and does so via Act A mediated actin polymerization and spreads to neighboring cells and blood stream
• disseminated infection-liver, spleen, CNS

Question 26

what is the best method for diagnosing listeria monocytogenes

Answer 26

• NOT microscopy because too little bacteria

- instead use culture of cerebral spinal fluid and blood via cold enrichment selection (will grow in fridge)

Question 27

treatment and prevention of listeria monocytogenes

Answer 27

beta lactam or trimethyoprim-sulfamethoxazole

prevention- no vaccine- properly cook animal pdts including ready to eat meats and wash raw vegis