TABLE 3

Interpretation algorithm for the Escherichia coli sequence type 648 complex (STc648) multiplex PCR assay

InterpretationTarget gene/allele (band size)
gyrB87 (143 bp)icd96 (297 bp)uidA (508 bp)
STc648++
Non-STc648 E. coli with gyrB87 (or related allele), not icd96++/−a
Non-STc648 E. coli with icd96 (or related allele), not gyrB87++/−a
Non-STc648 E. coli without gyrB87 or icd96+
Indeterminateb+++
Indeterminatec
  • a Absence of uidA band implies uidA-negative E. coli (non-STc648).

  • b Expect uidA to be absent for STc648 (this result was not encountered among the validation set strains).

  • c Possibly represents uidA-negative E. coli, non-E. coli, no template DNA, or PCR failure (this result was not encountered among the validation set strains).