W2 - Clinical Bacteriology (Escherichia coli)

Colon Bacillus

Escherichia coli (E. coli) is also known as \_______

Escherichia coli

The number one cause of UTI

Normal stools

Escherichia coli:

Normal GIT flora so found in \________

Fecal contamination

Escherichia coli:

It is used as the primary marker of \________

\++- -

Escherichia coli:

IMVIC reaction result

K/A

Escherichia coli:

TSI result

a.) Nephropathogenic E. coli/ Uropathogenic E. coli
b.) Diarrheagenic/ Enterovirulent E. coli

Two serotypes of E. coli

Nephropathogenic E. coli/ Uropathogenic E. coli

What E. coli serotype is the cause of UTI?

Diarrheagenic/ Enterovirulent E. coli

What E. coli serotype is the cause of diarrhea?

Community-acquired UTI

E. coli is regarded as the number one cause of \_______

Enterotoxigenic E. coli (ETEC)

It can cause profuse/severe watery diarrhea that is cholera like due to production of toxin

Enterotoxigenic E. coli (ETEC)

Diarrhea produced can be called turista, traveler's diarrhea, or Montezuma's revenge

Enteroinvasive E. coli (EIEC)

It can cause bloody diarrhea that is Shigella like due to its ability to invade the bowel mucosa

Enteropathogenic E. coli (EPEC)

Non-toxigenic and non-invasive but can cause diarrhea in infants / infantile diarrhea

Enteropathogenic E. coli (EPEC)

Watery diarrhea with mucus but no blood, nosocomial

Enteroaggregative E. coli (EAEC)

It can cause acute & persistent diarrhea in children and adults

Enteroaggregative E. coli (EAEC)

It causes watery diarrhea, actual pathogenic mechanism is not known

Enteroaggregative E. coli (EAEC) and Diffusely Adherent E. coli (DAEC)

It causes persistent pediatric diarrhea

Diffusely Adherent E. coli (DAEC)

This constitutes the 6th group in the diarrheagenic E. coli

Diffusely Adherent E. coli (DAEC)

It can cause diarrhea in otherwise healthy patients

Enterohemorrhagic E. coli (EHEC) or Verotoxic E. coli (VTEC) or Shiga toxin Producing (STEC)

It can cause severe blood diarrhea due to its ability to produce neurotoxin called verotoxin

EHEC

E. coli 0157:H7 is categorized as \________

EPEC

E. coli 0111 is categorized as \________

E. coli 0157:H7

It is associated with eating poorly cooked meat in particular hamburgers

Enterohemorrhagic E. coli (EHEC) or Verotoxic E. coli (VTEC) or Shiga toxin Producing (STEC)

It can cause Hemolytic Uremic Syndrome (HUS)

Sorbitol Macconkey Agar (SMAC) and MUG test

What test/media are used to detect EHEC?

Colorless colonies

E. coli 0157:

Sorbitol Macconkey Agar (SMAC) result

Negative

E. coli 0157:

MUG test result

Lactose

MAC:

Fermentable/carbohydrate

Crystal violet

MAC:

Inhibitor

Phenol Red

MAC:

Indicator

Pink to Purple

MAC:

Lactose positive result

Colorless

MAC:

Lactose negative result

Sorbitol

SMAC:

Fermentable/carbohydrate

Crystal violet

SMAC:

Inhibitor

Neutral Red

SMAC:

Indicator

Pink to purple

SMAC:

Sorbitol positive result

Colorless

SMAC:

Sorbitol negative result

Pink-purple colonies

All E. coli serotypes are lactose (+) so on Mac Conkey agar, all can develop \_______

E. coli 0157:H7

All E. coli serotypes are sorbitol (+) except \________

MUG Test

Test used to characterize verotoxin producing E. coli

𝛃-D-glucuronidase

MUG Test:

It is used to detect the ability of the organism to produce the enzyme \__________

4-methylumbelliferyl-𝛃-D-glucuronide

What substrate is used in MUG disk in performing MUG testing?

Electric Blue fluorescence

MUG Test:

Positive result

No fluorescence

MUG Test:

Negative result

Yellow

E. coli 0157:H7:

Colorimetric assay result

Yellow

What is the positive result in the MUG Test? (choices does not include electric blue or none of the above)

Electric blue fluorescence

What is the positive result in the MUG Test? (choices include both blue and yellow; did not specify if colorimetric)