Lab 4Prepared bySamira FattahAssis. Lec.College of health sciences-HMU
commonly found in the lowerintestine.
MostE. colistrainsare harmless.
fecal-oral transmission is the major route through which pathogenic strains of the bacterium cause disease.
Rod-shapeGram negativeFacultative anaerobicMotile with peritrichous flagellaSome strains are encapsulated.
Laboratory diagnosis: Specimen: Urine. pus blood stoolCSFsputum
Microscope (gram stain):Gram negative rode shape bacteria.
On blood agar
E. coli appear as medium sized, smooth, round, grayish-white colonies on blood agar.
Some strains produce beta hemolysis.
On macConkey agarthe red color of the bacterial growth indicatesE. coliisable to ferment lactose.
On EMBFerment lactose.blue-black colonies with a greenish metallic sheen.
Oxidase testOxidase negative
Catalase testpositive Bubble formation
Escherichia coli motile Motility testEscherichia coliis highly motile and will show turbidity throughout the tube.
Klebsiella pneumoniaeNon motile
API test:indole test is +vegelatinase -veurease test veno H2O production
Serologic test For serotyping (Epidemiologic information)