TSI agar = Triple Sugar Iron agar

Klebsiella

Escherichia coli

motile, gram -ve bacillus

facultatively anaerobic

ferment both lactose and glucose

grows well on blood, MacConkey, and eosin methylene blue (EMB) agar plates

(EMB agar is a selective and differential medium used to isolate and identify enteric pathogens from contaminated clinical specimens, in which lactose fermenting organisms bind to dye --> distinct green metallic sheen )

Most strains of E coli also demonstrate beta-hemolysis on blood agar

Pathogenesis:

Fimbrae, or pili (Type 1 fimbriae, P fimbriae, and S fimbriae), are one of the most important virulence factors expressed by E coli. They permit the adhesion of E coli to epithelial cells, uroepithelial cells, and enterocytes.

[P fimbrae = pyelonephritis-associated pili]

K for kids

Pseudomonas

Pseudomonas aeruginosa

gram -ve, motile rod

non-lactose fermentor;