Enterobacteriaeae II

Question 1

How do Shigella differ from E. coli?

Answer 1

shigella: lactose NEG
ecoli: lactose POS

Shigella also does not produce gas and is non-motile (will not grow outside of stick in agar)

Question 2

How is Shigella transmitted

Answer 2

person to person via fecal oral

Question 3

What are the 5 Fs of shigella transmission?

Answer 3

food
flies
fingers
fomites
feces

Question 4

Who are the highest risk for shigella?

Answer 4

day care

male homosexuals

Question 5

Where does shigella replicate?

Answer 5

cytoplasm (gest in via phagocytic vacuole)

Question 6

How does Shigella attach and get into a cell?

Answer 6

via a virulent plasmid

Question 7

What is the clinical syndrome associated with shigella?

Answer 7

bacillary dysentery

ab cramps, tenesmus, pus/blood in stool

Question 8

What is the most common shigella?

Answer 8

shigella sonnei

Question 9

True or false: shigella need a low inoculum to cause disease

Answer 9

TRUE (fewer than 200 organisms)

Question 10

What infection is commonly contracted from snakes?

Answer 10

Edwardsiella tarda

Question 11

What are the clinical syndromes caused by E. tarda

Answer 11

gastroenteritis (watery diarrhea progressing to typhoid like with bloody diarrhea)

can be mistaken for salmonellosis and IBD (crohns)

Question 12

Where is salmonella found?

Answer 12

lower animals for nontyphoid strains

humans for typhi

Question 13

What are 5 characteristics of salmonella?

Answer 13

1) non-lactose fermenter
2) produces hydrogen sulfide (black)
3) transmission via improper food handling
4) found in humans and livestock
5) secondary person-to-person transmission

Question 14

What are 2 common sources of salmonella?

Answer 14

poultry and eggs

Question 15

What are 5 big clinical syndromes associated with salmonella?

Answer 15

1) asymptomatic carrier state
2) febrile gastroenteritis (most common)
3) enteric fever (typhoid caused by S. typhi - 4 week illnesst)
4) Septicemia (no major GI involvement, common in patients with underlying chronic problems)
5) Focal infections (osteomyelitis, meningitis, brain abscess, endocarditis)

Question 16

What are some clinical manifestations of salmonella enteric fever?

Answer 16

fever (temp-pulse dissociation), headache, rose spots, constipation)

Question 17

How do you diagnose positive salmonella bacteremia?

Answer 17

positive blood cultures

Question 18

What is the treatment for salmonella bacteremia?

Answer 18

third generation cephalosporin

Question 19

What is unique about the disease timeline of S. typhi?

Answer 19

lasts 4 weeks
first 2 - incubation/bacteremic (increasing fever)
last 2 - GI symptoms

Question 20

What are 2 important citrobacter syndromes?

Answer 20

nosocomial UTI and resp tracts of hospitalized patients

endocarditis

Question 21

What is C. koseri implicated in?

Answer 21

meningitis and brain abscess in neonates

Question 22

What does K. rhinoscleromatis cause?

Answer 22

chronic granulomatous disease involving mucosa of upper resp tract

Question 23

What does K. ozaenae cause?

Answer 23

atrophic rhinitis

Question 24

What does K. pneumoniae and K. oxytoca cause?

Answer 24

lobar pneumonia - destructive changes, necrosis, hemorrhage

Question 25

What are 2 key features of proteeae?

Answer 25

1) swarming (on blood agar)
2) Urease positive

also lactose neg

Question 26

What organism is known to produce highly alkaline urea which leads to renal calculi?

Answer 26

P. mirabilis

Question 27

What is a key feature of yersinia enterocolitica?

Answer 27

pinpoint colonies on macconkey at 24 h

Question 28

What organism is a huge reservoir for Yersinia enterocolitica for humans?

Answer 28

pigs

diarrhea after eating chitterlings