Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004610 (bacteremia)
 13,199 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bacteremia frequently occurs after dental treatment. Periodontal inflammation may influence the incidence, magnitude and duration of bacteremia. The presence of circulating oral bacteria or bacterial components may induce cytokine synthesis in blood cells, which may contribute to the development or exacerbation of atherosclerosis. The present study tested the hypothesis that bacteremia occurring after scaling in periodontitis patients results in altered plasma levels of cytokines. Twenty periodontitis patients were subjected to scaling. Blood samples at baseline and at 0.5, 10 and 30 minutes postscaling were examined for bacteremia whereas baseline and eight-hour postscaling blood samples were examined for the levels of IL-1beta, TNF-alpha, IL-6, IL-8, IL-10 and IL-12p70. IL-6 levels were significantly increased eight hours after scaling, while IL-8 was significantly decreased. No systematic changes occurred in the levels of IL-1beta, TNF-alpha, IL-10 and IL-2p70. IL-6 levels may be increased while IL-8 may be decreased due to scaling, which may have implications for general health.
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PMID:Increased plasma levels of IL-6 in bacteremic periodontis patients after scaling. 1690 Dec 99

Intra-abdominal abscesses are a potential source of recurrent or residual infection after surgical intervention for secondary peritonitis. The development of therapies requires a model which combines low mortality with the formation of persisting abscesses and which is also suitable to study the local inflammatory response. Male Wistar rats were injected intraperitoneally with a mixture of sterile rat faeces, increasing doses of E. coli (10(4)-10(8) cfu/ml) and a fixed dose of B. Fragilis (10(4) cfu/ml). After one h a laparotomy was performed and the peritoneal cavity was debrided. Blood samples were taken under anaesthesia after 6 and 24 h. Abdominal fluid samples were collected (by laparotomy) after 24 and 72 h. The rats were killed after 5 days and the abdomen was inspected for abscesses. Mortality was 90% in the two groups with the highest doses of E. coli and 30% in those with the two lowest doses. In the latter groups all surviving rats but one showed intraabdominal abscesses and bacteremia was encountered frequently, especially after 24 h in the 10(5) cfu E. coli group. The groups receiving 10(4)-10(6) cfu E. coli showed similar plasma IL-6 concentrations after 6 h which were lowered significantly after 24 h. No circulating TNF-alpha was found. Considerable concentrations of TNF-alpha, IL-6, IL-1beta, and IL-10, were found in the peritoneal fluid after 24 h but no differences were observed between the contro groups and those receiving 10(4)-10(6) cfu E. coli. At 72 h cytokine levels were reduced significantly and remained the highest in the animals dosed with 10(6) cfu E. coli. The present model is suitable to study the mechanisms involved in, and prevention of, intra-abdominal abscess formation after surgical treatment of generalized peritonitis.
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PMID:A peritonitis model with low mortality and persisting intra-abdominal abscesses. 1696 63

Bacterial super-infection of influenza patients is the primary cause of excess mortality during influenza pandemics, with Staphylococcus aureus (S. aureus) having the highest fatality rate. The cotton rat (Sigmodon hispidus) is an excellent model for both influenza and S. aureus pathogenesis, and therefore a potential tool to model co-infection. We compared physiologic and pathologic changes in cotton rats infected with both S. aureus and influenza A/Wuhan/359/95 (H3N2), with animals infected with each pathogen alone. Co-infected cotton rats demonstrated significantly higher mortality, lower temperatures on 2 and 3 days post-inoculation (p.i.), higher levels of bacteremia and pulmonary bacterial load 4 days p.i., and worse pathology 7 days p.i. Early indicators of exacerbated disease coincided with higher pulmonary mRNA levels for IL-1beta, IL-6, IL-10 and IFNy, supporting the idea that these may contribute to disease severity. Our results demonstrate that the cotton rat is a good model of influenza and S. aureus co-infection, with increased mortality and hypothermia as well as prolonged bacterial duration indicative of synergistic disease that may be the result of increased induction of both pro- and anti-inflammatory cytokines.
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PMID:Co-infection of the cotton rat (Sigmodon hispidus) with Staphylococcus aureus and influenza A virus results in synergistic disease. 1768 46

Apoptosis of CD4(+) T cells and T(H)2 polarization are hallmarks of sepsis-induced immunoparalysis. In this study, we characterized sepsis-induced adaptive immune dysfunction and examined whether improving T-cell effector function can improve outcome to sepsis. We found that septic mice produced less antigen-specific T-cell-dependent IgM and IgG(2a) antibodies than sham-treated mice. As early as 24 hours after sepsis, CD4(+) T cells proliferated poorly to T-cell receptor stimulation, despite normal responses to phorbol myristate acetate and ionomycin, and possessed decreased levels of CD3zeta. Five days following immunization, CD4(+) T cells from septic mice displayed decreased antigen-specific proliferation and production of IL-2 and IFN-gamma but showed no difference in IL-4, IL-5, or IL-10 production. Treatment of mice with anti-GITR agonistic antibody restored CD4(+) T-cell proliferation, increased T(H)1 and T(H)2 cytokine production, partially prevented CD3zeta down-regulation, decreased bacteremia, and increased sepsis survival. Depletion of CD4(+) T cells but not CD25(+) regulatory T cells eliminated the survival benefit of anti-GITR treatment. These results indicate that CD4(+) T-cell dysfunction is a key component of sepsis and that improving T-cell effector function may be protective against sepsis-associated immunoparalysis.
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PMID:Treatment with GITR agonistic antibody corrects adaptive immune dysfunction in sepsis. 1769 Feb 55

While it is known that risk of death from sepsis is higher in patients with pre-existing chronic kidney disease its mechanism is unknown. To study this we established a two-stage mouse model where renal disease was first induced by folic acid injection followed by sub-lethal cecal ligation and puncture to induce sepsis. Septic mice with pre-existing renal disease had significantly higher mortality, serum creatinine, vascular permeability, plasma vascular endothelial growth factor (VEGF) levels, bacteremia, serum IL-10, splenocyte apoptosis and more severe septic shock when compared to septic mice without pre-existing disease. To evaluate the contribution of vascular and immunological dysfunction, we treated the folate-septic mice with soluble Flt-1 to bind VEGF and chloroquine to reduce splenocyte apoptosis. These treatments together resulted in a significant improvement in kidney injury, hemodynamics and survival. Our study shows that the sequential mouse model mimics human sepsis frequently complicated by pre-existing renal disease and might be useful in evaluating preventive and therapeutic strategies.
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PMID:Pre-existing renal disease promotes sepsis-induced acute kidney injury and worsens outcome. 1882 99

During relapsing fever borreliosis, a high pathogen load in the blood occurs at times of peak bacteremia. Specific IgM Abs are responsible for spirochetal clearance so in absence of B cells there is persistent high-level bacteremia. Previously, we showed that B cell-deficient mice persistently infected with Borrelia turicatae produce high levels of IL-10 and that exogenous IL-10 reduces bacteremia. This suggested that IL-10 helps reduce bacteremia at times of high pathogen load by a B cell-independent mechanism, most likely involving innate immunity. To investigate this possibility, we compared B. turicatae infection in RAG2/IL-10(-/-) and RAG2(-/-) mice. The results showed that IL-10 deficiency resulted in significantly higher bacteremia, higher TNF levels, and early mortality. Examination of the spleen and peripheral blood showed markedly increased apoptosis of immune cells in infected RAG2/IL-10(-/-) mice. Neutralization of TNF reduced apoptosis of leukocytes and splenocytes, increased production of IFN-gamma by NK cells, increased phagocytosis in the spleen, decreased spirochetemia, and rescued mice from early death. Our results indicate that at times of high pathogen load, as during peak bacteremia in relapsing fever borreliosis, IL-10 protects innate immune cells from apoptosis via inhibition of TNF resulting in improved pathogen control.
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PMID:IL-10 helps control pathogen load during high-level bacteremia. 1864 46

Dendritic cells (DCs) are professional APCs that direct both cellular and humoral immune responses. Escherichia coli K1 causes meningitis in neonates; however, the interactions between this pathogen and DCs have not been previously explored. In the present study, we observed that E. coli K1, expressing outer membrane protein A (OmpA), was able to enter, survive, and replicate inside DCs, whereas OmpA(-) E. coli was killed within a short period. Opsonization of OmpA(+) E. coli either with adult or cord serum did not affect its survival inside DCs. Exposure of DCs to live OmpA(+) E. coli K1 prevented DCs from progressing in their maturation process as indicated by failure to up-regulate costimulatory molecules, CD40, HLA-DR, and CD86. The distinct DC phenotype requires direct contact between live bacteria and DCs. The expression of costimulatory molecules was suppressed even after pretreatment of DCs with LPS or peptidoglycan. Furthermore, the suppressive effects of OmpA(+) E. coli on DCs were abrogated when the bacteria were incubated with anti-OmpA Ab. The inhibitory effect on DC maturation was associated with increased production of IL-10 as well as TGF-beta and decreased production of IL-6, TNF-alpha, IL-1beta, and IL-12p70 by DCs, a phenotype associated with tolerogenic DCs. These results suggest that the subversion of DC functions may be a novel strategy deployed by this pathogen to escape immune defense and persist in the infected host to reach a high degree of bacteremia, which is crucial for E. coli to cross the blood-brain barrier.
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PMID:Outer membrane protein A expression in Escherichia coli K1 is required to prevent the maturation of myeloid dendritic cells and the induction of IL-10 and TGF-beta. 1868 58

Community-acquired pneumonia (CAP) is associated with high morbidity and mortality, and Streptococcus pneumoniae is the most prevalent causal pathogen identified in CAP. Impaired pulmonary host defense increases susceptibility to pneumococcal pneumonia. S. pneumoniae may up-regulate Toll-like receptor (TLR)-2 expression and activate TLR-2, contributing to pneumococcus-induced immune responses. In the current study, the course of severe murine pneumococcal pneumonia after pulmonary TLR-2-mediated immunostimulation with synthetic macrophage-activating lipopeptide-2 (MALP-2) was examined. Intratracheal MALP-2 application evoked enhanced proinflammatory cytokine and chemokine release, resulting in recruitment of polymorphonuclear neutrophils (PMN), macrophages, and lymphocytes into the alveolar space in WT, but not in TLR-2-deficient mice. In murine lungs as well as in human alveolar epithelial cells (A549), MALP-2 increased TLR-2 expression at both mRNA and protein level. Blood leukocyte numbers and populations remained unchanged. MALP-2 application 24 hours before intranasal pneumococcal infection resulted in increased levels of CCL5 associated with augmented leukocyte recruitment, and decreased levels of anti-inflammatory IL-10 in bronchoalveolar lavage fluid. Clinically, MALP-2-treated as compared with untreated mice showed increased survival, reduced hypothermia, and increased body weight. MALP-2 also reduced bacteremia and improved bacterial clearance in lung parenchyma, as examined by immunohistochemistry. In conclusion, pulmonary immunostimulation with MALP-2 before infection with S. pneumoniae improved local host defense and increased survival in murine pneumococcal pneumonia.
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PMID:Immunostimulation with macrophage-activating lipopeptide-2 increased survival in murine pneumonia. 1893 26

Phagocytes of the reticuloendothelial system are important in clearing systemic infection; however, the role of the reticuloendothelial system in the response to localized infection is not well-documented. The major goals of this study were to investigate the roles of phagocytes in the reticuloendothelial system in terms of bacterial clearance and inflammatory modulation in sepsis caused by Pseudomonas pneumonia. Macrophages in liver and spleen were depleted by administering liposome encapsulated dichloromethylene diphosphonate (clodronate) intravenously 36 h before the instillation of Pseudomonas aeruginosa into the lungs of anesthetized rabbits. Blood samples were analyzed for bacteria and cytokine concentrations. Lung injury was assessed by the bidirectional flux of albumin and by wet-to-dry weight ratios. Blood pressure and cardiac outputs decreased more rapidly and bacteremia occurred earlier in the clodronate-treated rabbits compared with the nondepleted rabbits. Plasma TNF-alpha (1.08 +/- 0.54 vs. 0.08 +/- 0.02 ng/ml) and IL-8 (6.8 +/- 1.5 vs. 0.0 +/- 0.0 ng/ml) were higher in the depleted rabbits. The concentration of IL-10 in liver of the macrophage-depleted rabbits was significantly lower than in normal rabbits at 5 h. Treatment of macrophage-depleted rabbits with intravenous IL-10 reduced plasma proinflammatory cytokine concentrations and reduced the decline in blood pressure and cardiac output. These results show that macrophages in the reticuloendothelial system have critical roles in controlling systemic bacteremia and reducing systemic inflammation, thereby limiting the systemic effects of a severe pulmonary bacterial infection.
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PMID:Depletion of phagocytes in the reticuloendothelial system causes increased inflammation and mortality in rabbits with Pseudomonas aeruginosa pneumonia. 1902 78

The development of biomarkers able to predict the occurrence of nosocomial infection could help manage preventive strategies, especially in medical patients whose degree of acquired immunosuppression may be variable. We hypothesized that the NO fraction present in the airways (upper and lower) of critically ill patients under mechanical ventilation could constitute such a biomarker. We conducted an observational proof-of-concept study in a medical intensive care unit of a teaching hospital. Forty-five patients (26 men; 72 [25th-75th percentiles] years [56-82]; Simplified Acute Physiology Score II, 63 [50-81], 14 infected) under mechanical ventilation (>3 days) underwent on day 1 and day 3 of their stay: nasal and exhaled (partitioned in bronchial and alveolar sources) bedside NO measurements, determination of urine NO end products and plasma cytokine (IL-6, IL-10) concentrations, and Sequential Organ Failure Assessment score calculation. Nosocomial infection incidence was recorded during the 15 subsequent days. Fifteen patients (33%) acquired a nosocomial infection (16 infections, 15 ventilator-associated pneumonia and 1 bacteremia). Nasal NO was the only marker significantly different between patients with and without subsequent infection (day 1, 52 ppb [20-142] vs. 134 [84-203], P = 0.038; day 3, 98 ppb [22-140] vs. 225 [89-288], P = 0.006, respectively). Nasal NO fraction 148 ppb or less at day 3 had an 80% sensitivity, a 70% specificity, and an odds ratio of 2.7 (95% confidence interval, 1.9-3.8) to predict acquisition of nosocomial infection. Nonsurvivors had a higher IL-6 concentration on day 3 (P = 0.014), whereas their nasal NO fractions were not significantly different. Nasal NO seems to be a relatively sensitive and specific biomarker of subsequent nosocomial infection acquisition (at least for ventilator-associated pneumonia), which warrants confirmation in a multicenter trial.
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PMID:Prediction of nosocomial infection acquisition in ventilated patients by nasal nitric oxide: proof-of-concept study. 2016 Jun 67


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