The <i>pch</i> and <i>ptsP</i> Mutants Are Preferentially Permeabilized and Killed by SP-A

<div><p>(A) Fluorescence of a cleavage-activated phosphatase substrate ELF97 was examined in the presence or absence of 50 μg hSP-A for a period of 60–90 min. Human SP-A (hSP-A) preferentially permeabilized LPS mutant <i>wbpL,</i> but not the parental wild-type PA01. The <i>wbpL</i> strain was used as positive control for membrane permeability. The difference in membrane permeabilization between <i>wbpL</i> mutant and PA01 was significant from the 28^th min onward. *<i>p</i> < 0.05.</p><p>(B) A mutant strain <i>STMG2A7</i> that is virulent in both SP-A^+/+ and SP-A^−/− mice was as resistant to SP-A-mediated membrane permeabilization as the parental wild-type PA01.</p><p>(C–D) Membrane permeability of the STM mutant <i>pch</i> and <i>PA06331</i>, a <i>P. aeruginosa</i> strain which is deleted in all of the structural genes required for pyochelin biosynthesis (<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.0010031#ppat-0010031-t001" target="_blank">Table 1</a>.). The difference in membrane permeabilization between the mutants against wild-type PA01 was significant from the 35^th and 18^th min onward for mutant strains <i>pch</i> and <i>PA06331</i>, respectively. *<i>p</i> < 0.05.</p><p>(E–F) Membrane permeability of the STM mutant <i>ptsP</i> and the Δ<i>ptsP,</i> a <i>P. aeruginosa</i> strain with a nonpolar, inframe deletion of the <i>ptsP</i> gene. The difference in membrane permeabilization between the mutants against wild-type PA01 was significant from the 29^th and 28^th min onward, for mutant strains <i>ptsP</i> and Δ<i>ptsP</i>, respectively. *<i>p</i> < 0.05.</p>