Enterobacteriaceae

Question 1

Enterobacteriaceae

Answer 1

• gram negative rods

- facultative anaerobes (oxidase negative)

Question 2

Species of Enterobacteriaceae

Answer 2

• E. coli
• Salmonella
• Shigella
• Klebsiella

Question 3

Opportunistic diseases

Answer 3

• Cause disease in healthy people
• Septicemia
• Pneumonia
• Meningitis
• Urinary tract infections

Question 4

Pneumonia

Answer 4

• Klebsiella pneumoniae
• respiratory disease
• prominent capsule

Question 5

Urinary tract infection

Answer 5

• Fecal contamination
• Proteus spp
• urease (degrades urea)
• alkaline urine

Question 6

Gastrointestinal diseases

Answer 6

• E. coli
• Salmonella
• Shigella
• Yersinia entercolita

Question 7

Not Enterobacteriaceae

Answer 7

• campylobacter

- helicobacter

Question 8

Excreted in feces E. coli

Answer 8

• Lactose positive
• not usually identified
• common in the healthy intestine

Question 9

Excreted in feces Shigella, Salmonella, Yersinia

Answer 9

• Lactose negative

- Identified

Question 10

Serotypes (antigens)

Answer 10

• O (lipopolysaccharide) O1-O181
• H (flagellar) H1-H56
• K (capsular) 60

Question 11

Enterotoxigenic E. coli ETEC

Answer 11

-acts in the small intestine
-“travellers diarrhea” watery diarrhea non bloody stools
-vomiting
-cramps
-nausea
-fever
-diagnose by immunoassay for ST or PCR
-

Question 12

EPEC diagnose

Answer 12

-adherence to human HeLa or Hep-2 cells, presence of plasmid-encoded pili

Question 13

Enteroaggregative E.coli EAEC

Answer 13

-Acts on small intestine

Question 14

EAEC symptoms

Answer 14

• watery diarrhea
• vomiting
• dehydration
• low-grade fever
• aggregative adherence of rods

Question 15

EAEC diagnose

Answer 15

-by adherence to human Hep-2 cells, the presence of plasmid

Question 16

Enterohemorrhagic E. coli EHEC

Answer 16

• usually O157:H7
• contaminated meat, water, unpasteurized milk, veggies
• verotoxin Stx-1 and Stx-2 blocks protein synthesis
• hemolysins

Question 17

EHEC symptoms

Answer 17

• hemorrhagic
• initial watery diarrhea followed by bloody
• few leukocytes
• little no fever
• hemolytic anemia
• low platelets

Question 18

Enteroinvasive E. coli EIEC

Answer 18

-acts in large intestine

Question 19

EIEC symptoms

Answer 19

• fever
• cramps
• watery diarrhea
• bloody stools

Question 20

EIEC diagnose

Answer 20

-by plaque assay inhuman HeLa cells (cant be distinguished from shigella species)

Question 21

Treatment: gastrointestinal disease

Answer 21

• Fluid replacement

- Antibiotics NOT used unless systemic infection

Question 22

Salmonella

Answer 22

• 2000 antigenic types
• genetically single species
• disease category determines the serovar

Question 23

Salmonellosis (gastroenteritis)

Answer 23

-uncomplicated case
-no antibiotic therapy
-S. enteritidis
=the common salmonella infection
=no human reservoir
=nausea
=vomiting
= non-bloody stool

Question 24

Typhoid fever symptoms

Answer 24

• enteric fever
• most severe in salmonella disease
• rare in the US
• 10-14 day incubation period
• increased fever
• followed by GI symptoms

Question 25

Salmonella typhi

Answer 25

- human reservoir - contaminated food - contaminated water supply - poor sanitary conditions

Question 26

S. typhi

Answer 26

- Vi (capsular) antigen | - protective antibodies are made

Question 27

S. typhi therapy

Answer 27

- antibitics (essential) | - vaccine (inefective)

Question 28

Shigella

Answer 28

- bacterial dysentery - shigellosis - bloody feces - intestinal pain

Question 29

Shigella relevant species

Answer 29

- S. flexneri - S. boydii - S. sonnei

Question 30

Shigellosis

Answer 30

- humans only reservoir - mostly young children - unwashed hands - epithelial cell damage

Question 31

Shinga toxin

Answer 31

-enterotoxin -cytotoxic -inhibits protein synthesis =lyses 28S rRNA

Question 32

Treatment shigellosis

Answer 32

-manage dehydration -patient respond to antibiotics =diseas duration diminished