Enterobacteriaceae Flashcards
Enterobacteriaceae
- gram negative rods
- facultative anaerobes (oxidase negative)
Species of Enterobacteriaceae
- E. coli
- Salmonella
- Shigella
- Klebsiella
Opportunistic diseases
- Cause disease in healthy people
- Septicemia
- Pneumonia
- Meningitis
- Urinary tract infections
Pneumonia
- Klebsiella pneumoniae
- respiratory disease
- prominent capsule
Urinary tract infection
- Fecal contamination
- Proteus spp
- urease (degrades urea)
- alkaline urine
Gastrointestinal diseases
- E. coli
- Salmonella
- Shigella
- Yersinia entercolita
Not Enterobacteriaceae
- campylobacter
- helicobacter
Excreted in feces E. coli
- Lactose positive
- not usually identified
- common in the healthy intestine
Excreted in feces Shigella, Salmonella, Yersinia
- Lactose negative
- Identified
Serotypes (antigens)
- O (lipopolysaccharide) O1-O181
- H (flagellar) H1-H56
- K (capsular) 60
Enterotoxigenic E. coli ETEC
-acts in the small intestine
-“travellers diarrhea” watery diarrhea non bloody stools
-vomiting
-cramps
-nausea
-fever
-diagnose by immunoassay for ST or PCR
-
EPEC diagnose
-adherence to human HeLa or Hep-2 cells, presence of plasmid-encoded pili
Enteroaggregative E.coli EAEC
-Acts on small intestine
EAEC symptoms
- watery diarrhea
- vomiting
- dehydration
- low-grade fever
- aggregative adherence of rods
EAEC diagnose
-by adherence to human Hep-2 cells, the presence of plasmid
Enterohemorrhagic E. coli EHEC
- usually O157:H7
- contaminated meat, water, unpasteurized milk, veggies
- verotoxin Stx-1 and Stx-2 blocks protein synthesis
- hemolysins
EHEC symptoms
- hemorrhagic
- initial watery diarrhea followed by bloody
- few leukocytes
- little no fever
- hemolytic anemia
- low platelets
Enteroinvasive E. coli EIEC
-acts in large intestine
EIEC symptoms
- fever
- cramps
- watery diarrhea
- bloody stools
EIEC diagnose
-by plaque assay inhuman HeLa cells (cant be distinguished from shigella species)
Treatment: gastrointestinal disease
- Fluid replacement
- Antibiotics NOT used unless systemic infection
Salmonella
- 2000 antigenic types
- genetically single species
- disease category determines the serovar
Salmonellosis (gastroenteritis)
-uncomplicated case
-no antibiotic therapy
-S. enteritidis
=the common salmonella infection
=no human reservoir
=nausea
=vomiting
= non-bloody stool
Typhoid fever symptoms
- enteric fever
- most severe in salmonella disease
- rare in the US
- 10-14 day incubation period
- increased fever
- followed by GI symptoms
