OBJECTIVE: To investigate the functional pathways enriched and differentially expressed genes (DEGs) in peripheral blood mononuclear cells (PBMCs) of patients with gram-positive and gram-negative sepsis. METHODS: Dataset GSE9960 obtained from NCBI GEO database containing PBMC samples from 16 non-infectious systematic inflammatory response syndrome (SIRS) patients, 17 gram-positive septic patients and 18 gram-negative septic patients were included in the study. Functional pathway annotations were conducted by gene set enrichment analysis and weighted gene co-expression network analysis. DEGs were filtered and master DEGs were then validated in PBMCs of gram-positive septic, gram-negative septic and non-infectious SIRS patients. RESULTS: The enriched gene sets in gram-positive sepsis and gram-negative sepsis were significantly different. The results indicated the opposite co-expression networks in SIRS and gram-negative sepsis, and the entirely different co-expression networks in gram-positive and gram-negative sepsis. Furthermore, we validated that CONCLUSIONS The results indicate that there are differences in the mechanism and pathogenesis of gram-positive and gram-negative sepsis, which may provide potential markers for sepsis diagnosis and empirical antimicrobial therapy.
Biomarkers/analysis* ; Gene Expression Profiling ; Gram-Negative Bacterial Infections/physiopathology* ; Gram-Positive Bacterial Infections/physiopathology* ; Humans ; Leukocytes, Mononuclear/pathology* ; Sepsis/physiopathology*

Stenotrophomonas maltophilia (previously named Xanthomonas maltophilia) is an aerobic, non-fermentive, Gram-negative bacillus that is wide spread in the environment. It was considered to be an organism with limited pathogenic potential, which was rarely capable of causing diseases in human other than those who were in debilitated or immunocompromised state. More recent studies have established that Stenotrophomonas maltophilia can behave as a true pathogen. Endocarditis due to this organism is rare, and only 24 cases of Stenotrophomonas maltophilia endocarditis have been reported in the medical literature. Most cases were associated with risk factors, including intravenous drug abuse, dental treatment, infected intravenous devices, and previous cardiac surgery. We present a case with two episodes of Stenotrophomonas maltophilia endocarditis after mitral valve prosthesis implantation, which was treated with antibiotics initially, and a combination of antibiotics and surgery later. To our knowledge, this is the first case of repetitive endocarditis due to Stenotrophomonas maltophilia.
Adult ; Anti-Bacterial Agents/*therapeutic use ; Bioprosthesis/adverse effects/*microbiology ; Endocarditis, Bacterial/*drug therapy/physiopathology ; Gentamicins/therapeutic use ; Gram-Negative Bacterial Infections/*drug therapy/physiopathology ; Heart Valve Prosthesis/adverse effects/*microbiology ; Humans ; Male ; Mitral Valve ; Recurrence ; Stenotrophomonas maltophilia/*drug effects ; Treatment Outcome ; Trimethoprim-Sulfamethoxazole Combination/*therapeutic use ; Vancomycin/therapeutic use