Enterobacteriaceae 1 Flashcards
All members of the Enterobacteriaceae are:
Gram (-), Rods, ferment glucose to acid and gas
Over 90 species of Enterobacteriaceae have been discovered with _____ genera.
30
What is the habitat for Enterobacteriaceae?
Gastrointestinal tract, soil, and water
Are Enterobacteriaceae pathogenic or non-pathogenic?
can be either
Do Enterobacteriaceae grow readily on Blood Agar and MacConkey Agar?
Yes
The three major pathogens of the family Enterobacteriaceae are?
E. coli, Salmonella serotypes, Yersina spp.
The opportunistic pathogens of Enterobacteriaceae include:
Proteus species, Klebsilla pneumoniae, Enterobacter aerogenes
How do lactose fermenting enterobacteria present on MacConkey Agar? Give two examples of this class of bacteria
Pink colonies, Examples: E. coli and Klebsiella
What does it mean for a bacteria to be “coliform”?
It means they are Lactose-fermenting Enterobacteria
How do non-lactose fermenting enterobacteria present on MacConkey Agar? Give the two examples (discussed in class)
Colorless colonies, Examples: Salmonella and Yersinia
T/F Enterobacteria can either be Major pathogens, Opportunistic pathogens, or Non-pathogens
TRUE
E. coli is a facultative anaerobe, what does this mean?
Can grow with or without the presence of oxygen.
What is the normal habitat for E coli?
Lower small intestine and colon of warm blooded animals (intestinal commensal)
What is the most common aerobic species in feces?
E. coli
What does it mean for a pathogen to have O, K, and H antigens? Which Enterobateriaceae fits this description?
O - cell wall. K - capsule. H - flagella. E. coli
What are the predisposing factors for E. coli infection?
-age -immune status -nature of diet -heavy exposure to pathogenic strains
Colonization of the mammalian intestinal tract from the environs shortly after birth via fecal–oral route is a general characteristic of what pathogen?
E. coli
How can we classify E. coli?
Intestinal Pathogenic (IPAC). (has 4 subclasses) or Extraintestinal Pathogenic E. coli (ExPAC)
What class of E. coli causes the following? •Causes diarrhea in humans, principally in children. •Also, implicated to cause diarrhea in rabbits, pigs and dogs
IPAC: Enteropathogenic (EPEC)
What type of E. coli is described by the following? •Also referred to as ‘Cholera like’. •Causes hypersecretory diarrhea.
IPAC: Enterotoxigenic (ETEC)
Which type of IPAC is described by the following? •Cause bacteremia or septicemia. •Mostly seen in poultry.
Enteroinvasive (EIEC)
What type of IPAC is described by the following? •Recognized as a cause of serious food borne illness. •Produce Shiga toxin(s). •Serotype O157:H7
Enterohemorrhagic (EHEC ), Shiga toxigenic (STEC), or Verotoxigenic (VTEC), Also referred to as ‘Shigella like’.
E. coli serogroup O157:H7 may be associated with __________ in humans
Hemorrhagic enteritis and hemolytic uremic syndrome (Hamburgers!)
What type of E. coli cause septicemia, mastitis, and infections of the uterus, urinary tract, and air sacs (in chickens)?
Extraintestinal Pathogenic E. coli (ExPAC )
Urinary tract infections in dogs and cats are called
Urinary Pathogenic E. coli (UPEC)
E. coli infections in poultry (respiratory) are sometimes called
Avian Pathogenic E. coli (APEC)
What is the function of the cell wall (soma) (O) of E. coli in terms of its antigenic characteristic?
-endotoxin production -major importance in septicemic infections
The antigenic characteristic of E. coli’s capulse (K) is?
-adhesion -protection against phagocytosis
What are the three major routes of E. coli infection?
-ingestion -inhalation -direct infection
What is the route of transmission for enteric disease causing E.coli strains?
Oral route - once establishing in the small intestinal mucosa via pili they produce enterotoxins
How are neonates exposed to E. coli?
Neonatal animals are either exposed at birth in the vagina or very shortly after birth when they suckle. Also, feed and water contaminated with feces.