Fig 3. The lipoteichoic acid pathway is crucial for fitness of USA300-TCH1516 but is dispensable in MW2.

(A) Tn-Seq data for the LTA pathway genes, with sequencing reads from insertions in the plus strand in purple and minus strand in teal. The reads were calculated by summing two replicate Tn-Seq experiments, only including data from transposon constructs that contained a transcriptional terminator. The data were normalized to each other by non-zero means normalization prior to plotting. The x-axis is expressed in kilobases. The y-axis is expressed on a log₁₀ scale and is truncated to 500 reads. (B) Growth on agar plates for wild-type (WT) and ΔugtP strains confirms that USA300-TCH1516 is more sensitive to ugtP deletion than MW2 is. (C) Growth on agar plates of wild-type and ΔltaS strains confirms that ltaS is dispensable in MW2 at both 30°C and 37°C. Arrow highlights a suppressor mutant growing in the USA300 spot. (D) Western blot of LTAs produced by 4S5 (known to not produce LTAs), wild-type MW2, and MW2 P_tet-ltaS confirms that MW2 P_tet-ltaS does not produce LTAs unless expression of the exogenous copy of ltaS is induced.