Table 2.

Virulence characteristics of the serotype K1 and K20 strains.

		Virulence determinant#
Strain	Hypermucoviscous phenotype*	Aerobactin (iucA)	Yersiniabactin (irp2)	Salmochelin (iroB)	Enterobactin (entB)	Allantoin Metabolism (allS)	Iron-uptake system (kfu)
K1	+	+	+	+	+	+	+
K20	–	+	+	+	+	–	+

Note.

^*Identified by string test.²

^#Detected by PCR.^10,11