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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Streptococcus agalactiae (group B streptococcus, GBS) is the major pathogen of neonatal sepsis. In some newborns, GBS sepsis may have a severe course, including septic shock with a high mortality rate, whereas other newborns are colonized with GBS on their surfaces without any clinical signs of bacterial infection. The reason for this discrepancy is far from clear. We sought, in this study, to compare cytokine expression in cord blood mononuclear cells after stimulation with GBS strains isolated from newborns with sepsis, and strains isolated from newborns without any symptoms of invasive infection. Cord blood mononuclear cells were incubated with either heat-killed bacteria of different strains or lipopolysaccharide, respectively. After 6 and 24 h, cells were harvested and cytokine mRNA-expression was analyzed by reverse-transcriptase PCR. Likewise, supernatants were tested for IL-6 and tumor necrosis factor-alpha concentrations by enzyme immunoassay. When comparing IL-6 and tumor necrosis factor-alpha secretion, there were significantly higher IL-6 levels after stimulation with sepsis than with colonizing isolates. Likewise, mRNA expression of IL-6, IL-1 beta, and IL-12p40 was significantly higher after stimulation with sepsis isolates. This was also true when normalizing to cytokine expression after stimulation with lipopolysaccharide. These findings indicate that the different clinical pictures in response to GBS, either septic infection or colonization, might reflect strain-specific properties. If the respective characteristics can be defined, it might become possible to distinguish by molecular methods potentially "dangerous" from "harmless" strains. Moreover, our findings underline the essential role of these cytokines in the pathogenesis of neonatal GBS sepsis.
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PMID:Different cytokine expression in cord blood mononuclear cells after stimulation with neonatal sepsis or colonizing strains of Streptococcus agalactiae. 1132 54

Group B streptococcus is a possible cause of chorioamnionitis, endometritis and urinary tract infections in pregnant woman. Maternal risk factors and the vertical transmission of GBS and neonatal GBS infection occur through the following fever during labor, the rupturing of membranes more than 18 hours before delivery, prematurity and chorioamnionitis. GBS can induce early-onset neonatal disease (sepsis, meningitis or pneumonia) during the first week of life and late-onset neonatal infection (leptomeningitis) within the first 12 weeks of life. Numerous strategies for preventing neonatal group B streptococcal infection were investigated: 1) the treatment of GBS-colonized women during the third trimester of pregnancy did not prove to be effective because it does not reduce maternal colonizzation rates at delivery; 2) the neonatal universal post-partum prophylaxis with penicillin G was ineffective and increased neonatal mortality due to penicillin-resistant bacterial infection; 3) the intrapartum maternal chemoprophylaxis with penicillin G or ampicillin in GBS-colonized women, in women with risk factors, or in women with both GBS colonization and risk factors. The latter strategy proved to be the most effective because it reduces the risk of early-onset GBS infection by 75% and 95% when associated with post-neonatal prophylaxis. To date, there are no guidelines on the management of the asymptomatic neonate whose mothers have been treated with chemopropylaxis intra-partum.
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PMID:[Prophylaxis of group B beta-hemolytic streptococcal infections]. 1142 3

Of the 6,060 consecutive live births delivered at the University Maternity Unit of Guadeloupe (French West Indies) during a 30-month period, 635 newborns (10.4%) presented with meconium stained (MS) amniotic fluid, of which 595 (94%) received bacteriological screening at birth (light MS, n = 543; thick MS, n = 52). Thirty (5%) of MS newborns had a bacteraemia (n = 13, group B streptococcus, GBS), and 128 (21.5%) a bacterial positive gastric aspirate (n = 54, GBS). Sixty-six newborns among MS babies needed tracheal suctioning (11%) in the delivery room for meconium inhalation. Among these 595 screened MS newborns, 286 (48%) presented clinical signs of postmaturity at birth, having therefore an explanation for their MS condition. For the other MS newborns without the postmaturity explanation, we experienced twofold increased risk of neonatal sepsis (OR 1.88 for bacteraemia and 2.61 for external carriage p < 0.02, Chi square) as compared with their MS postmature counterparts. We conclude that when meconium stained deliveries are associated with postmaturity signs, one may not need to initiate prophylactic antibiotic treatment at birth unless they present with other traditional risk factors for neonatal sepsis such as intrapartum fever and prolonged rupture of membranes.
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PMID:Evaluation of neonatal sepsis screening in a tropical area Part III: Neonatal sepsis in meconium stained deliveries. 1167 9

Streptococcus agalactiae (group B streptococcus [GBS]) is a leading cause of neonatal pneumonia, sepsis, and meningitis. Early-onset GBS pneumonia is characterized by marked pulmonary epithelial and endothelial cell injury. Innate proinflammatory responses to GBS infection that may contribute to the respiratory pathology include the synthesis and release of cytokines, prostaglandins, and nitric oxide (NO). The hypothesis that NO is directly induced in lung epithelial cells by invading GBS or indirectly induced by cytokines released by GBS-infected mononuclear cells was tested. A549 transformed human respiratory epithelial cells were directly cultured with GBS, cocultured with GBS-infected human mononuclear cells or purified macrophages, or exposed to conditioned culture medium from human mononuclear cells infected by GBS. The culture medium of A549 cultures was assayed for NO secretion, and the cell lysates were tested for presence of inducible nitric oxide synthase (iNOS) mRNA by reverse transcriptase PCR (RT-PCR). GBS-treated A549 cells neither secreted detectable NO nor expressed iNOS mRNA. GBS interaction with human mononuclear cells, however, stimulated release of soluble factors that readily induced iNOS mRNA expression and NO secretion by A549 cells. Inflammatory mediator-induced nitric oxide (NO) production by alveolar epithelium may exceed that of other lung cell types such as macrophages, and induction during GBS infection may play a significant role in pulmonary defense or free-radical-mediated lung injury.
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PMID:Cytokine responses to group B streptococci induce nitric oxide production in respiratory epithelial cells. 1174 62

Group B streptococcus (GBS; Streptococcus agalactiae) is the most common cause of neonatal and obstetric sepsis and is an increasingly important cause of septicemia in elderly individuals and immunocompromised patients. Ongoing surveillance to monitor GBS serotype distribution will be needed to guide the development and use of GBS conjugate vaccines. We designed sequencing primers based on the previously published sequences of the capsular polysaccharide (cps) gene clusters to further define partial cps gene clusters for eight of the nine GBS serotypes (serotypes Ia to VII). Subsequently, we designed and evaluated primers to identify serotypes Ia, Ib, III, IV, V, and VI directly by PCR and all eight serotypes (serotypes Ia to VII) by sequence heterogeneity. A total of 206 clinical GBS isolates were used to compare our molecular serotype (MS) identification method with conventional serotyping (CS). All clinical isolates were assigned an MS, whereas 188 of 206 (91.3%) were assigned a serotype by use of antisera. A small number of isolates (serosubtypes III-3 and III-4) showed different serotype specificities between PCR and sequencing, but the PCR results correlated with those obtained by CS. The overall agreement between the MS identification method and CS for isolates for which results of both tests were available was 100% (188 of 188 isolates). The MS identification method is a specific and practical alternative to conventional GBS serotyping and will facilitate epidemiological studies.
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PMID:Serotype identification of group B streptococci by PCR and sequencing. 1177 19

Neonatal bacterial sepsis is often characterized by a fulminant clinical course and highly elevated plasma levels of proinflammatory cytokines. To evaluate in vitro activation of the neonatal immune system by specific infectious stimuli, cord blood cells from healthy neonates were examined for expression of tumor necrosis factor-alpha (TNF-alpha), IL-1beta, IL-6, and IL-8 in response to Streptococcus agalactiae (GBS), lipopolysaccharide (LPS), and lipoteichoic acid (LTA). Cytokine-expression was compared in mononuclear cells from cord and adult peripheral blood. TNF-alpha and IL-6 levels in the supernatant of cord blood cell cultures were significantly higher after stimulation with heat-killed GBS (10(7)/mL) than with LPS (2 microg/mL) or LTA (2 microg/mL) (TNF-alpha: 2215 versus 267.5 versus 40 pg/mL, p = 0.001; IL-6: 9667 versus 4909 versus 919 pg/mL, p = 0.006). mRNA expression of TNF-alpha, IL-1beta, IL-6, and IL-8 was equally pronounced after stimulation with either GBS, LPS, or LTA in cord or adult blood cells at various times. A MAb directed against the monocyte receptor molecule CD14 did not inhibit the release of cytokines in cord blood mononuclear cells after stimulation with GBS. In summary, activation of cord blood cells by infectious stimuli is comparable to the adult immune response in terms of expression of proinflammatory cytokines. GBS in particular proves to be a potent activator of the neonatal immune system when compared with LPS and LTA. CD14 seems not to be a crucial molecule for activation of cord blood cells by GBS.
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PMID:Cytokine expression of cord and adult blood mononuclear cells in response to Streptococcus agalactiae. 1186 34

Bacterial antigenic challenge presents a difficult fight for the neonatal immune system, and they have a smaller arsenal of weapons to fight bacterial infections than adults and older children. The baby's own systemic inflammatory response may have detrimental effects on several organs and longer lasting effects on the developing brain. Neurodevelopmental outcomes after maternal chorioamnionitis are worse than neonates without a contaminated intrauterine environment, regardless of gestation age and the baby's culture results. Successes with intrapartum antibiotic prophylaxis decreasing rates of GBS sepsis and maternal chorioamnionitis, have heartened care providers and parents. These results demonstrate the advances possible when specific diseases are made a national health priority, and good clinical trial work is applied to clinical practice.
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PMID:Neonatal sepsis: evaluation and management. 1212 92

Group B streptococcus (Streptococcus agalactiae) or GBS is the most common cause of neonatal sepsis and meningitis in the United States. One important risk factor for infants who acquire GBS is maternal colonization. Colonization rates have been estimated in various studies to be between 15% and 35% of pregnant women. Colonization rates for black women have also been shown to be higher than for non-blacks. Local data were collected and compared to those of other studies. Of the pregnant women in this study overall, 22.76% tested positive for GBS. Black women were colonized by GBS (35.71%) significantly more often than non-black women (19.84%; G = 8.9729, p < 0.00274). Generalized linear models were used to examine age and race. Both maternal age and the interaction of maternal race and age as predictors of infection were ruled out, leaving only race as a significant predictor of colonization.
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PMID:The incidence of group B streptococcus in the vaginal tracts of pregnant women in central Alabama. 1277 51

Streptococcus agalactiae (Group B Streptococcus: GBS) is the major causative agent of neonatal sepsis. Neonates at risk for GBS infections are empirically administered broad-spectrum antibiotics for at least 48 h pending blood culture results. A rapid assay to expedite detection of GBS would facilitate initiation of specific antibiotic therapy. Conversely, expeditious proof of absence of infection will avoid unnecessary antibiotic use. Using the LightCycler, we evaluated a hybridization probe polymerase chain reaction (PCR) assay to detect GBS-specific cfb gene target DNA sequence in blood specimens. Both sensitivity and specificity of the real-time PCR assay was 100%. The assay demonstrated 100% specificity when tested against 26 non-GBS bacteria. This method is capable of detecting as few as approximately 100 copies or 10 pg of GBS genomic DNA. This real-time PCR method is rapid, sensitive, and specific for the detection of GBS in neonatal blood samples and holds great promise in its utility in the diagnostic laboratory.
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PMID:Evaluation of a real-time fluorescent PCR assay for rapid detection of Group B Streptococci in neonatal blood. 1538 Feb 73

Streptococcus agalactiae (GBS) is a causative agent of sepsis and meningitis in newborns and diseases in pregnant women and nonpregnant adults. Various approaches, including both nongenetic and genetic techniques, are currently used for the study of epidemiology of GBS infections. In the present paper the different methods of molecular epidemiology of GBS infections are reviewed, and several novel approaches are introduced. The advantages and disadvantages of molecular methods are discussed and compared with traditional serotyping technique. The possible use of the molecular approaches for identification of different genetic lineages in GBS as well as for identification and control of the epidemiologically actual clones is discussed.
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PMID:Molecular epidemiology of group B streptococcal infections. 1553 3


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