Figure 1.
Effect of antibiotics on bacterial load in A/J mice.
The bacterial loads in the (A) Kidney and (B) Blood from A/J mice after intraperitoneal infection with S. aureus (6×106 CFU/g, strain USA300), and treatment with linezolid (L) or vancomycin (V) (25 mg/kg). Infected mice were sacrificed as follows: 2 hpi S. aureus; 24 hpi S. aureus; 24 hpi S. aureus with linezolid or vancomycin. Each symbol represents one mouse. P-values were obtained by F-test. The error bars correspond to the standard error of mean (SEM) and the dashed line correspond to the mean value. Values of P<0.05 were considered significant.
Figure 2.
Effect of antibiotics on in vivo toxin production.
In vivo level of (A) Panton Valentine Leukocidin (PVL, µg) (B) and Alpha-toxin (ng) in the serum of A/J mice after 24 h of intraperitoneal (ip) infection with S. aureus (6×106 CFU/g, strain USA300), and treatment with linezolid or vancomycin (25 mg/kg) at 2 h was measured using ELISA. P-value was obtained by unpaired t-test. The error bar corresponds to the standard error of mean (SEM). Values of P<0.05 were considered significant.
Figure 3.
Effect of antibiotics on pro-inflammatory cytokines.
Level of (A) IL-1beta (pg/ml), (B) IL-6 (pg/ml), and (C)TNF-alpha (pg/ml) from the serum of A/J mice without infection, with 2 hours post infection (hpi) with S. aureus (6×106 CFU/g, strain USA300), and 24 hpi with and without antibiotic treatment as labeled was measured using ELISA. P-value was obtained by unpaired t-test. The error bar corresponds to the standard error of mean (SEM). Values of P<0.05 were considered significant.
Figure 4.
Unsupervised hierarchical clustering analysis of mouse blood microarray data.
Each colored row in the heat map represents the gene expression value for a probe and each column represents a sample. The color conventions are as follows: red indicates over-expressed transcripts, blue represents under-expressed transcripts. Time of analysis post-infection are marked as follows: green rectangles indicate 0 hpi, purple rectangles indicate 2 hpi, and orange rectangles indicate 24 hpi (with and without antibiotic treatment).
Figure 5.
Comparisons of differentially expressed genes in mice with the appropriate treatment.
(A) Effect of linezolid and vancomycin on host, (B) Effect of linezolid and vancomycin on host with S. aureus infection, and (C) Effect of S. aureus infection on host immune response. Venn diagrams indicate the number of genes unique to each comparison pair and the number of genes common to each comparison pair (overlapped).
Table 1.
Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the differentially expressed genes in each comparison groups.