Transcriptional profiles of walK/clpP associated vancomycin-intermediate S.aureus (CBX144). unidentified

The aim is to know transcriptional profile change in laboratory-developed vancomycin-intermediate S.aureus (VISA). Four pair comparisons were performed: 1) Vancomycin-susceptible N315LR5P1 vs its vancomycin-intermediate derivative LR5P1-V3, 2) N315LR5P1 vs gene-replacement hVISA strain LR5P1walK*, 3) N315LR5P1 vs gene-replacement hVISA strain LR5P1clpP*, 4) N315LR5P1 and double gene replacement VISA strain LR5P1walK*clpP*. RNA extraction and microarray hybridization was performed as described in Ref.1 VISA strain LR5P1-V3 is developed by exposing vancomycin-susceptible MRSA strain N315LR5P1 to vancomycin with gradual increment of vancomycin concentration. Two mutations in genes walk and clpP were identified in LR5P1-V3 compared to N315LR5P1, and the gene-replacement strains were generated by introducing the mutated walK or/and clpP (denoted as walk* and clpP*), respectively. The RNA extraction and microarray hybridization was performed as described in Ref.1.