Construction of P. aeruginosa PA14 deletion mutant strains.

The pMQ30 vector (Table S3) was used to generate the P. aeruginosa PA14 ΔkatA, ΔkatB, ΔkatA ΔkatB, and ΔdbpA mutant strains. The pMQ30-katA, pMQ30-katB, and pMQ30-dbpA deletion constructs were built using homologous recombination of the PCR products made with the respective “KO” primers (listed in Table S4) with the XbaI restriction enzyme-digested pMQ30 in yeast as previously reported (61). Plasmid integrants were isolated on LB agar supplemented with gentamicin and nalidixic acid, followed by counterselection on sucrose medium. Deletion mutants were confirmed by PCR with respective “conf.” primers (Table S4), followed by sequencing. Coculture was conducted as described above with the confirmed P. aeruginosa PA14 deletion mutant strains.