Group B Streptococcus  -hemolysin/Cytolysin Breaches Maternal-Fetal Barriers to Cause Preterm Birth and Intrauterine Fetal Demise in Vivo

Randis, Tara M.; Gelber, Shari E.; Hooven, Thomas A.; Abellar, Rosanna; Akabas, Leor H.; Lewis, Emma L.; Walker, Lindsay B.; Byland, Leah M.; Nizet, Victor; Ratner, Adam J.

doi:10.1093/infdis/jiu067

Cited by 110 publications

(135 citation statements)

References 36 publications

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…Remarkably, 47 of the 63 NH/NP strains originated from invasive diseases, including bacteremia and meningitis. These results suggest that ␤-h/c pigment production is not critical for GBS virulence although numerous in vitro and in vivo studies using cellular or animal models indicated that greater ␤-h/c pigment production is associated with increased virulence (10)(11)(12)(13)(14)(15)18). The pathogenicity of GBS is multifactorial and combines the expression of several factors to result in an overall virulence phenotype that may vary for each isolate (42).…”

Section: Discussionmentioning

confidence: 94%

“…This ␤-h/c has a central role in balancing the pro-and anti-inflammatory responses of the infected host and is necessary to breach the epithelial and endothelial barriers and the phagolysosome membrane (10)(11)(12)(13)(14)(15). Remarkably, the GBS ␤-h/c is unique among Gram-positive pathogens and its production is linked to that of a characteristic orange-to-red pigment.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Molecular Characterization of Nonhemolytic and Nonpigmented Group B Streptococci Responsible for Human Invasive Infections

et al. 2016

View full text Add to dashboard Cite

h Group B Streptococcus (GBS) is a common commensal bacterium in adults, but is also the leading cause of invasive bacterial infections in neonates in developed countries. The ␤-hemolysin/cytolysin (␤-h/c), which is always associated with the production of an orange-to-red pigment, is a major virulence factor that is also used for GBS diagnosis. A collection of 1,776 independent clinical GBS strains isolated in France between 2006 and 2013 was evaluated on specific medium for ␤-h/c activity and pigment production. The genomic sequences of nonhemolytic and nonpigmented (NH/NP) strains were analyzed to identify the molecular basis of this phenotype. Gene deletions or complementations were carried out to confirm the genotype-phenotype association. Sixty-three GBS strains (3.5%) were NH/NP, and 47 of these (74.6%) originated from invasive infections, including bacteremia and meningitis, in neonates or adults. The mutations are localized predominantly in the cyl operon, encoding the ␤-h/c pigment biosynthetic pathway and, in the abx1 gene, encoding a CovSR regulator partner. In conclusion, although usually associated with GBS virulence, ␤-h/c pigment production is not absolutely required to cause human invasive infections. Caution should therefore be taken in the use of hemolysis and pigmentation as criteria for GBS diagnosis in routine clinical laboratory settings. S treptococcus agalactiae, or group B Streptococcus (GBS), is aGram-positive bacterium that is usually an asymptomatic member of the human intestinal and vaginal microbiota. However, GBS is also the leading cause of neonatal sepsis and meningitis in developed countries (1-3) and an emerging pathogen in adults, mostly in the elderly (4, 5). Neonatal infections occur predominantly during delivery by inhalation or ingestion of contaminated secretions of the mother's vagina. Rapid invasive infections may follow, with a mortality rate of up to 10% during the first week of life (early-onset disease [EOD], age of 0 to 6 days) or during the first 3 months of life (late-onset disease [LOD], age of 7 to 89 days). Systematic GBS screening prior to delivery and intrapartum antibiotic prophylaxis have efficiently reduced EOD but not LOD (6), highlighting the need to further improve the diagnosis and treatments.GBS is an extracellular pathogen and one of its characteristics is the secretion of a potent ␤-hemolysin/cytolysin (␤-h/c) (7-9). This ␤-h/c has a central role in balancing the pro-and anti-inflammatory responses of the infected host and is necessary to breach the epithelial and endothelial barriers and the phagolysosome membrane (10-15). Remarkably, the GBS ␤-h/c is unique among Gram-positive pathogens and its production is linked to that of a characteristic orange-to-red pigment. This dual and specific ␤-h/c and pigment phenotype is routinely used in clinical settings to identify GBS isolates (16,17).It was initially proposed that the GBS protein CylE was, in fact, ␤-h/c and that the pigment was a distinct carotenoid-like molecule (18,19). However, it was rece...

show abstract

Section: Discussionmentioning

confidence: 94%

mentioning

confidence: 99%

Molecular Characterization of Nonhemolytic and Nonpigmented Group B Streptococci Responsible for Human Invasive Infections

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Asymptomatic bacteruria should be treated to prevent the occurrence of symptomatic bacteruria as cystitis and pyelonephritis and to prevent its hazards on pregnancy outcomes. At the same time it should be known that asymptomatic bacteruria carries a great risk for development of pre-eclampsia, chorio-amnionitis and preterm delivery [18] [19] [20].…”

Section: Discussionmentioning

confidence: 99%

Fosfomycin Therapy for Non-Complicated Lower Urinary Tract Infections during Pregnancy: Tanta University Experience

Dawood¹,

Dawood²,

Nagla³

et al. 2017

OJOG

View full text Add to dashboard Cite

Objectives: To evaluate the efficacy, compliance, safety and economic cost for Fosfomycin trometamol and Nitofurantoin in uncomplicated lower urinary tract infections during pregnancy. Background: Nitofurantoin and Fosfomycin trometamol are recommended as the first-line agents for treatment of urinary tract infections (UTIs) in the latest guidelines endorsed by the Infectious Diseases Society of America (IDSA) and the European Society for Clinical Microbiology and Infectious Diseases (ESCMID). Fosfomycin is bactericidal and inhibits bacterial cell wall biogenesis and reduces bacterial adherence to uroepithelial cells. Fosfomycin has broad antibacterial activity against both Grampositive and Gram-negative pathogens, as Escherichia coli, Escherichia faecalis, and various Gram-negatives like Citrobacter and Proteus. Both Nitofurantoin and Fosfomycin are category B in pregnancy. Patients and Methods: This study was conducted at Tanta University Hospitals in the period from June, 1, 2015 to January, 1, 2017. Patients were recruited from outpatient clinics of Obstetrics and Gynecology and Urology Departments presenting with asymptomatic bacteruria or cystitis. Patients were allocated randomly into 2 groups: group I (n = 50 cases) received Fosfomycin therapy and group II (n = 50 cases) received Nitofurantoin therapy (n = 50 cases). After treatment, evaluation of patient symptoms, organism count, patient compliance and cost of treatment were done. Results: The enrolled patients were suffering from lower urinary tract infections; asymptomatic bacteruria (17 cases) or cystitis (83 cases). Ten patients were excluded. The demographic data of included patients were not significant for both groups. Complete relief (100%) of symptoms 5 days after start of treatment was noticed in Fosfomycin group while improvement of symptoms after 5 day-treatment was noticed in 86. 533difference in the reported side effects, (p-value = 0.003). Compliance was 38/38 (100%) in Fosfomycin group compared to 34/37 (91.89%) in Nitrofuantoin group (p-value = 0.001). Resistance was very minimal in Fosfomycin group where 1/38 case (2.63%) reported resistance for treatment compared to 8/37 cases (21.62%) in Nitofurantoin group (p-value = 0.001). Conclusion: Fosfomycin trometamine proved to be safe, effective, and has limited resistance. Moreover higher patient compliance and fewer side effects were recommending Fosfomycin to be a first choice drug for uncomplicated lower urinary tract infections during pregnancy at Tanta University.

show abstract

“…GBS also may contribute to birth asphyxia, prematurity and stillbirths; a recent systematic review estimated that GBS might account for up to 12% of stillbirths 21 . In vitro and animal data demonstrate that components of GBS are capable of disrupting critical maternal-fetal barriers during pregnancy resulting in tissue damage and inflammatory changes and thereby the potential to precipitate preterm labour [22][23][24][25] . However, it is more difficult to clearly establish this relationship in humans and the evidence currently is mixed 26 .…”

Section: Natural Infection a Disease Burden Gbsmentioning

confidence: 99%

Group B streptococcus and respiratory syncytial virus immunisation during pregnancy: a landscape analysis

Heath

Culley

Jones

et al. 2017

The Lancet Infectious Diseases

View full text Add to dashboard Cite

show abstract

Group B Streptococcus -hemolysin/Cytolysin Breaches Maternal-Fetal Barriers to Cause Preterm Birth and Intrauterine Fetal Demise in Vivo

Cited by 110 publications

References 36 publications

Molecular Characterization of Nonhemolytic and Nonpigmented Group B Streptococci Responsible for Human Invasive Infections

Molecular Characterization of Nonhemolytic and Nonpigmented Group B Streptococci Responsible for Human Invasive Infections

Fosfomycin Therapy for Non-Complicated Lower Urinary Tract Infections during Pregnancy: Tanta University Experience

Group B streptococcus and respiratory syncytial virus immunisation during pregnancy: a landscape analysis

Contact Info

Product

Resources

About