41 PA14 genes required for virulence in a <i>C. elegans</i> infection based killing model.

<p>The ratio of nematode survival on mutant PA14 to that on wild-type PA14 (mutant LT₅₀/WT LT₅₀) is presented for 41 mutants identified after three rounds of screening as well as for the known virulence-attenuated mutants, <i>lasR</i> and <i>pilA</i>. The time to 50% death (LT₅₀) was calculated using a non-linear regression based on the Hill equation (Prism 5.0). 100–150 animals were tested in each experiment. Error bars represent the SEM of the ratios derived from at least two different experiments (lack of error bars indicates that the mutants for known virulence factors <i>gacA</i>, <i>ptsP</i> and <i>vfr</i> were tested only once). Red bars depict the ratio of the LT₅₀ of <i>lasR</i> or <i>pilA</i> to WT PA14. The <i>lasR</i> and <i>pilA</i> mutants were generated previously (see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002813#s4" target="_blank">Materials and Methods</a>); there are no alleles of <i>lasR</i> or <i>pilA</i> in the NR library. The number of alleles tested with an avirulent phenotype is indicated by a number below the graph: 1 indicates that a single allele was tested but that there exist multiple alleles in the master transposon library, S indicates only a single allele was available in the library. Genes that are predicted to be in operons are indicated (Y = yes, N = no). Genes in a single operon are represented in the same color and an underline designates that other genes within the same operon were tested for their role in virulence.