GI Infections 8

Question 1

_________ replicates in the phagosome

Answer 1

salmonella

Question 2

what are the antigens that can be found with Salmonella?

Answer 2

O antigen (cell wall) 
H antigen (flagellar) 
Capsular Vi (virulence) antigen

Question 3

________ is part of the commensal organisms of cows, cats, dogs (pets), etc

Answer 3

campylobacter

Question 4

what are some complications of salmonella infection?

Answer 4

• cardiovascular
• CNS
• pulmonary
• reactive arthritis (also seen with shigella infection)
• oesteomyelitis
• hepatobiliary

Question 5

GBS is a unilateral/bilateral ascending/descending paralysis and starts at the lower/upper extremities

Answer 5

GBS is a bilateral ascending paralysis that starts at nth slower extremities and is frequently preceded by mild respiratory or intestinal infection

Question 6

salmonella invades the _______ and _____ after attaching to the SI epithelia

Answer 6

M cells of Peyer’s patches and enterocytes (PAI encoded)

Question 7

travelers to ______, _____, or ______ are usually the only people that we see enteric fever in; what vaccines would you give them?

Answer 7

Asia, Mexico, or India

- oral live attenuated OR IM for Vi capsular polysaccharide antigen

Question 8

what are the toxins produced by V. parahemotlyticus?

Answer 8

• enterotoxin (watery diarrhea)

- hemolysin (later get bloody diarrhea)

Question 9

recurrent salmonella _______ (one of the three clinical manifestations of salmonella) is considered an AIDS defining

Answer 9

septicemia

Question 10

the antibodies raised against he LPS of campylobacter strains cross react with _________ leading to GBS

Answer 10

the GM1 gangliosides in the myelin sheath of the nerve

Question 11

Yersinia enterocolytica infection is common in kids of age _______ and adults with exposure to ________

Answer 11

kids < 7 years old and adults where there are outbreaks in daycares

Question 12

what are three types of vibrio vulnificus infections?

Answer 12

• acute gastroenteritis from eating raw or uncooked shellfish
• necrotizing wound infection can occur in injured skin exposed to contaminated water
• invasive sepsis can occur after an immunocompromised person eating raw or undercooked shellfish

Question 13

what are some risk factors for acquiring yersinia enterocolytica

Answer 13

• contaminated food: raw/undercooked pork and beef, eggs, milk, raw seafood
• contact with infected animals

Question 14

sources of infection for NON cholera vibrio include ______

Answer 14

shellfish and seawater; (cholera vibrio source of infection include food and contaminated water)

NON cholera vibrio: virbrio parahemolyticus and vibrio vulnificus

Question 15

of all the enterobacteriaceae, which 2 organisms are NON motile?

Answer 15

Klebsiella and Shigella
(all the rest are motile)

YES PECKSS
Yersinia
Escerichia
Serratia

Proteus 
Enterobacter 
Citrobacter
Klebsiella 
Shigella
Salmonella

Question 16

salmonella is acid ______

Answer 16

labile; so when the pH of the stomach ↑ then the person is at risk for developing salmonella infection

shigella is acid stable

Question 17

temperature can be selective for which inflammatory diarrhea causing organism?

Answer 17

campylobacter; no growth at 25C but can grow at 3C and 42-43C

Question 18

a characteristic presentation of patients with NON cholera vibrio infection is _______

Answer 18

wound infection

Question 19

in enteric fevers, _____ cultures are positive after the 1-2nd week and _____ cultures are positive from the 2nd week and onwards but negative before that

Answer 19

blood cultures is positive from 1-2nd week

stool cultures are positive from 2nd week and onwards

Question 20

vibrio species are grown on _______ agar and how would you differentiate between cholera and parahemolyticus and vulnificus?

Answer 20

• TCBS agar and SUCROSE is the differentiating agent because cholera is it is the only one that is sucrose positive while the other two are not

Question 21

what is a feature that is unique to salmonella in differentiating it from shigella?

Answer 21

Salmonella is H2S positive

Question 22

describe the biology of campylobacter

Answer 22

gram NEGATIVE, comma/small spiral shaped rods
motile
microaerophilic so it requires oxygen and co2 to grow
DOES NOT FERMENT GLUCOSE

OXIDASE POSITIVE

Question 23

can MacConkey’s agar be used to differentiate between Salmonella and Shigella?

Answer 23

NO because both are lactose NON fermenters and that is what is MacConkey’s agar differentiates with

Question 24

describe the rash that is occasionally seen in typhoid fever

Answer 24

transient, macular rash (rose colored) on the trunk

Question 25

what are some biochemical features of yersinia

Answer 25

- gram negative BIPOLAR staining coccobacili - ferments glucose and sucrose - catalase + - oxidase -

Question 26

contact with reptiles such as lizards, snakes, turtles or frogs has an increased risk for infection by _________

Answer 26

salmonella

Question 27

_______ metabolism is used to differentiate between cholera vibrio and non cholera vibrio

Answer 27

SUCROSE | v. cholera is sucrose positive

Question 28

is there an animal reservoir in enteric fever (typhoid/paratyphoid)

Answer 28

NO; (same with shigella)

Question 29

ingestion of raw/poorly cooked seafood is a common risk factor for infection by vibrio ________

Answer 29

parahemolyticus

Question 30

in diagnosing salmonellosis and the three different types, you would look at blood or stool cultures. When would you do one over the other? stool cultures for _______ is infrequently positive so you would do a blood culture for that

Answer 30

stool cultures for septicemias are infrequently positive so do a blood culture for salmonella caused septicemia

Question 31

of the enterobacteriaceae, which ones are lactose fermenters?

Answer 31

``` CEEK: Citrobacter enterobacter Escherichia Klebsiella ```

Question 32

cutluring on campylobacter selective media _______ agar and is oxidase ______ and catalase ______ is dialogistic of campylobacter

Answer 32

Skirrow agar; oxidase + and catalase +

Question 33

_________ is an associated complication of campylobacter infection due to ________

Answer 33

GBS due to antibodies raised against the LPS of campylobacter cross react with the GM1 gangliosides in the myelin sheet of the nerve leading to damage, loss of nerve conduction and paralysis

Question 34

secondary salmonella septicemia is due to ________ (organ)

Answer 34

secondary exposure to S. type in the gallbladder where they can replicate there for many years (gallbladder colonization)

Question 35

________ has bipolar staining when staining with ______ giving it a safety pin appearance

Answer 35

yersenia; wayson stain

Question 36

phagosome lysis is associated with _________

Answer 36

shigella

Question 37

what are the two types of typhoid vaccines?

Answer 37

- oral live attenuated | - IM for Vi capsular polysaccharide vaccine

Question 38

salmonellosis has 3 clinical manifestations:

Answer 38

- gastroenteritis - septicemia/bacteremia - enteric (typhoid) fever

Question 39

the most common reservoir of yersinia enterocolytica is ________

Answer 39

pigs

Question 40

describe the biology of salmonella:

Answer 40

gram negative rod motile DOES NOT ferment lactose

Question 41

Salmonella is diagnosed by plating on ________ agar which is selective due to ______

Answer 41

MacConkey agar which selects for lactose fermenters so wit will have pale colonies Salmonella (and Shigella is lactose NON fermenters)

Question 42

yersinia enterocolytica infection most commonly occurs in what part of the GI? What is the pathogenesis? It mimics ________

Answer 42

terminal ileum (invasion of M cells and then invades further mesenteric lymph nodes) and has chromosomal ST enterotoxin which ↑ cGMP mimics appendicitis

Question 43

vibrio vulnificus is commonly found in ________

Answer 43

Gulf of Mexico

Question 44

can you see muscle atrophy in GBS?

Answer 44

minimal atrophy because it progresses very quickly (hours to days) so no time for atrophy

Question 45

high mortality is associated in people with __________ and have been infected by vibrio vulnificus

Answer 45

underlying liver conditions

Question 46

________ cultures are better for diagnosis of salmonella caused enterocolitis

Answer 46

stool cultures; these are positive very soon after onset