Two Novel Point Mutations in Clinical Staphylococcus aureus Reduce Linezolid Susceptibility and Switch on the Stringent Response to Promote Persistent Infection
Figure 2
Microarray transcriptional analysis of SCV strain JKD6229 and parental strain JKD6210.
A) Results of microarray transcriptional analysis of JKD6229 (SCV) compared to JKD6210 (MRSA). Up-regulated genes (in red) are differentially up-regulated in JKD6229 compared to the parent strain JKD6210, and the down-regulated genes (in green) are differentially down-regulated in JKD6229 compared to JKD6210. The heat map analysis highlights the proportion of each cluster of orthologous groups (COG) functional group [70] that is differentially regulated in the array analysis. This clearly demonstrates global transcriptional changes in the SCV strain, affecting genes from all COG groups. J is associated with translation, ribosomal structure and biogenesis; K is related to transcription; L is related to replication, recombination and repair; B is related to chromatin structure and dynamics; D is related to cell cycle control, cell division, chromosome partitioning; V is related to defence mechanisms, T is related to signal transduction mechanism; M is related to cell wall, membrane and envelope biogenesis; N is related to cell motility; U is related to intracellular trafficking, secretion, and vesicular transport; O is related to posttranslational modification, protein turnover, chaperones; C is related to energy production and conversion; G is related to carbohydrate transport and metabolism; E is related to amino acid transport and metabolism; F is related to nucleotide transport and metabolism; H is related to coenzyme transport and metabolism; I is related to lipid transport and metabolism; P is related to inorganic ion transport and metabolism; Q is related to secondary metabolites biosynthesis, transport and catabolism; R and S are function unknown or general function prediction only categories. B) Anti-capsule type 5 immunoblot of serial dilutions of crude capsule extracts from JKD6210, JKD6229, and control strains Newman (Cap5 positive) and P1 (Cap8 positive), demonstrating a marked increase in capsule production in the SCV strain JKD6229, consistent with the microarray transcriptional profiles.