PCR analysis of FZBAN and FZBHarpin. (A) Validation of FZB42AN (FAN, DnprE DnprA, deficient in neutral and alkaline protease). Left: N, negative control (double distilled water); P, 844-bp fragment from the Km-containing plasmid; FAN 2 and FAN5, presence of the Km resistance cassette in two FZB42AN isolates. Right: N, negative control (double distilled water); P, 1,438-bp fragment from the Spec-containing plasmids; FAN 2 and FAN5, respectively, presence of the Spec resistance cassette in the two FZB42AN isolates. (B) Validation of FZBHarpin (FZBH, nprE::hpa1 nprA::hpa1). Lanes from left to right: presence of the spec resistance gene (1,438 bp) in FZB42Harpin, presence of the hpa1 gene (813 bp) in FZB42Harpin, presence of the his-tagged hpa1 gene (844 bp) in FZB42Harpin, and presence of the km resistance gene (880 bp) in FZB42Harpin.