Group A, B, C, and G Streptococcus Lancefield antigen biosynthesis is initiated by a conserved {alpha}-d-GlcNAc-{beta}-1,4-l-rhamnosyltransferase Glycobiology and Extracellular Matrices

In this study, using molecular and synthetic biology approaches, biochemistry, radiolabeling techniques, and NMR and MS analyses, we examined the role of GacB, encoded in the S. pyogenes GAC gene cluster, in the GAC biosynthesis pathway. We demonstrate that GacB is the first characterized α-d-GlcNAc-β-1,4-l-rhamnosyltransferase that synthesizes the committed step in the biosynthesis of the GAC virulence determinant. Importantly, the substitution of S. pyogenes gacB with the homologous gene from Streptococcus agalactiae (Group B Streptococcus), Streptococcus equi subsp. zooepidemicus (Group C Streptococcus), Streptococcus dysgalactiae subsp. equisimilis (Group G Streptococcus), or Streptococcus mutans complemented the GAC biosynthesis pathway. These results, combined with those from extensive in silico studies, reveal a common phylogenetic origin of the genes required for this priming step in>40 pathogenic species of the Streptococcus genus, including members from the Lancefield Groups B, C, D, E, G, and H. Importantly, this priming step appears to be unique to streptococcal ABC transporter–dependent RhaPS biosynthesis, whereas the Wzx/Wzy-dependent streptococcal capsular polysaccharide pathways instead require an α-d-Glc-β-1,4-l-rhamnosyltransferase. The insights into the RhaPS priming step obtained here open the door to targeting the early steps of the group carbohydrate biosynthesis pathways in species of the Streptococcus genus of high clinic...
Source: Journal of Biological Chemistry - Category: Chemistry Authors: Tags: Editors ' Picks Source Type: research

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A mother whose baby got meningitis because of Group B Strep says all pregnant women should be tested.
Source: BBC News | Health | UK Edition - Category: Consumer Health News Source Type: news
Authors: Esposito S, Principi N Abstract Introduction: Neonatal sepsis (NS) is a very severe condition that causes significant morbidity and mortality. The approach to NS is based on measures that can eliminate pathogens and overcome clinical manifestations derived from the immune process that follows pathogen invasion.Areas covered: To overcome the limits of antibiotic therapy and improve NS outcomes, measures chosen among those theoretically able to improve host defences or positively interfere with deleterious immune responses could be suggested. This paper discusses the mechanisms of action of these measures, w...
Source: Expert Review of Clinical Pharmacology - Category: Drugs & Pharmacology Tags: Expert Rev Clin Pharmacol Source Type: research
This study reports the in vitro antibacterial effect of the oleoresin from Copaifera officinalis Jacq. L. in natura (copaiba oil) and loaded into carbomer-hydrogel against planktonic and sessile cells of GBS. First, the naturally extracted copaiba oil was tested for the ability to inhibit the growth and metabolic activity of planktonic and sessile GBS cells. The time-kill kinetics showed that copaiba oil exhibited a dose-dependent bactericidal activity against planktonic GBS strains, including those resistant to erythromycin and/or clindamycin [minimal bactericidal concentration (MBC) ranged from 0.06 mg/mL to 0.12 mg/mL]....
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
The objective of this study was to evaluate the recommended practice of screening patients admitted preterm for group B streptococcal (GBS) colonization by comparing culture results between those who received antibiotics before culture and those who did not. Since many patients (e.g. those transferred from other facilities) receive antibiotics before screening culture specimens are obtained, false negative results might occur.
Source: American Journal of Obstetrics and Gynecology - Category: OBGYN Authors: Tags: IDSOG Abstract Source Type: research
To assess whether colonization with group B streptococcus (GBS) is associated with chorioamnionitis in an era of routine intrapartum antibiotic prophylaxis.
Source: American Journal of Obstetrics and Gynecology - Category: OBGYN Authors: Tags: IDSOG Abstract Source Type: research
The association between obesity and group B streptococcus (GBS) colonization remains to be fully defined, and has implications for antibiotic prophylaxis in an era of increasing obesity prevalence and severity. We estimated the association between maternal pre-pregnancy body mass index (BMI) and GBS colonization.
Source: American Journal of Obstetrics and Gynecology - Category: OBGYN Authors: Tags: IDSOG Abstract Source Type: research
To determine the rates of maternal GBS screening during pregnancy and to identify demographic characteristics associated with maternal GBS screening in Latin America.
Source: American Journal of Obstetrics and Gynecology - Category: OBGYN Authors: Tags: IDSOG Abstract Source Type: research
Abstract Early onset sepsis (EOS) in neonates is a serious disease with severe complications. The increased severity of EOS and risk of death for newborns in recent years means that continued monitoring to detect possible changes in pathogen etiology, disease severity and disease outcome is particularly important. We performed a retrospective study on early-onset infection among infants (birth weights>800 g) who were hospitalized in the Children's Hospital of Soochow University from Jan1, 2011 to Dec 31, 2017. Multivariable analysis was conducted to determine the significant predictors of mortality. The most fr...
Source: Japanese Journal of Infectious Diseases - Category: Infectious Diseases Authors: Tags: Jpn J Infect Dis Source Type: research
Although Streptococcus agalactiae is the leading causative agent of neonatal sepsis and meningitis, recently it is increasingly isolated from non-pregnant adults. The relation between its presence in the genitour...
Source: BMC Infectious Diseases - Category: Infectious Diseases Authors: Tags: Research article Source Type: research
CONCLUSION: Of infection-related stillbirth cases in a large U.S. cohort, E coli, GBS, and enterococcus species were the most common bacterial pathogens and CMV the most common viral pathogen. PMID: 31764728 [PubMed - in process]
Source: Obstetrics and Gynecology - Category: OBGYN Authors: Tags: Obstet Gynecol Source Type: research
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