This
multiplex PCR assay allowed the identification of bla-SHV, blaTEM and blaCTX-M genes in a series of
clinical isolates of Enterobacteriaceae with previously characterised ESBL phenotype. The presence
of blaSHV, blaTEM and blaCTX-M genes was confirmed by partial DNA sequence analysis. Apparently,
the universal well-established CTX-M primer pair used here to reveal plasmid-encoded blaCTX-M
genes would also amplify the chromosomally located K-1 enzyme gene in all Klebsiella oxytoca strains
included in the study.