Expression levels of <i>S. aureus</i> A170 and A172 virulence factors.

<p>Acquisition of phage-resistance by A172 is accompanied by extensive alterations in virulence gene expression levels. Out of the 14 ORFs examined, 13 are significantly under-expressed, compared to the phage-sensitive strain A170. Bacteria were collected for transcriptional analysis during the exponential growth phase. SA0107 (<i>spa</i>, IgG binding protein A precursor); SA0112 (hypothetical protein, similar to cysteine synthase); SA0184 (hypothetical protein); SA039 (<i>geh</i>; glycerol ester hydrolase); SA1007 (α-haemolysin); SA1160 (<i>nuc</i>; thermonuclease); SA1898 (hypothetical protein, similar to SceD precursor); SA2097 (hypothetical protein, similar to secretory antigen precursor SsaA); SA2206 (<i>sbi</i>; IgG-binding protein SBI); SA2255 (oligopeptide transporter substrate binding protein); SA2406 (<i>gbsA</i>; glycine betaine aldehyde dehydrogenase gbsA); SA2459 (<i>ica</i>; N-glycosyltransferase); SAR216 (<i>groEL</i>; chaperonin GROEL); SAR2117 (<i>groES</i>; co-chaperonin GRES). ORFs numbers correspond to the <i>S. aureus</i> N315 genome sequence. Gene designations (when known) and proteins function are shown in parentheses.