sensitive strain
Sequencing libraries were prepared using the Illumina genomic DNA library prep kit according to the manufacturers recommendations (Illumina, CA) with several modifications (PMID: 19582764). In brief, DNA was sheared by sonication to an average fragment length of 200 bp. Illumina adapters were blunt-end ligated and libraries were amplified by PCR and purified using Ampure (Agencourt) beads at a DNA:bead ratio of 1:0.9. Each sample was sequenced in a single lane on an Illumina GAII platform, yielding 6.6 and 4.9 million 76 bp reads for strain A and strain G respectively (30-35x average genome coverage).