scholarly journals Group B Streptococcus cpsE Is Required for Serotype V Capsule Production and Aids in Biofilm Formation and Ascending Infection of the Reproductive Tract during Pregnancy

2021 ◽  
Author(s):  
Kristen Noble ◽  
Jacky Lu ◽  
Miriam A. Guevara ◽  
Ryan S. Doster ◽  
Schuyler A. Chambers ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Reproductive Tract ◽  
Group B Streptococcus ◽  
Ascending Infection ◽  
Capsule Production ◽  
Group B

scholarly journals A hemolytic pigment of Group B Streptococcus allows bacterial penetration of human placenta

2013 ◽  
Vol 210 (6) ◽  
pp. 1265-1281 ◽  
Author(s):  
Christopher Whidbey ◽  
Maria Isabel Harrell ◽  
Kellie Burnside ◽  
Lisa Ngo ◽  
Alexis K. Becraft ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Amniotic Fluid ◽  
Preterm Labor ◽  
Group B Streptococcus ◽  
Dependent Manner ◽  
Microbial Infection ◽  
Amniotic Cavity ◽  
Protein Toxin ◽  
Ascending Infection ◽  
Group B

Microbial infection of the amniotic fluid is a significant cause of fetal injury, preterm birth, and newborn infections. Group B Streptococcus (GBS) is an important human bacterial pathogen associated with preterm birth, fetal injury, and neonatal mortality. Although GBS has been isolated from amniotic fluid of women in preterm labor, mechanisms of in utero infection remain unknown. Previous studies indicated that GBS are unable to invade human amniotic epithelial cells (hAECs), which represent the last barrier to the amniotic cavity and fetus. We show that GBS invades hAECs and strains lacking the hemolysin repressor CovR/S accelerate amniotic barrier failure and penetrate chorioamniotic membranes in a hemolysin-dependent manner. Clinical GBS isolates obtained from women in preterm labor are hyperhemolytic and some are associated with covR/S mutations. We demonstrate for the first time that hemolytic and cytolytic activity of GBS is due to the ornithine rhamnolipid pigment and not due to a pore-forming protein toxin. Our studies emphasize the importance of the hemolytic GBS pigment in ascending infection and fetal injury.

scholarly journals Bacterial Hyaluronidase Promotes Ascending GBS Infection and Preterm Birth

mBio ◽  
2016 ◽  
Vol 7 (3) ◽  
Author(s):  
Jay Vornhagen ◽  
Phoenicia Quach ◽  
Erica Boldenow ◽  
Sean Merillat ◽  
Christopher Whidbey ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Molecular Mechanisms ◽  
Group B Streptococcus ◽  
Placental Tissue ◽  
In Utero ◽  
Hyaluronidase Activity ◽  
Healthy Women ◽  
Ascending Infection ◽  
Underlying Mechanisms ◽  
Group B

ABSTRACT Preterm birth increases the risk of adverse birth outcomes and is the leading cause of neonatal mortality. A significant cause of preterm birth is in utero infection with vaginal microorganisms. These vaginal microorganisms are often recovered from the amniotic fluid of preterm birth cases. A vaginal microorganism frequently associated with preterm birth is group B streptococcus (GBS), or Streptococcus agalactiae . However, the molecular mechanisms underlying GBS ascension are poorly understood. Here, we describe the role of the GBS hyaluronidase in ascending infection and preterm birth. We show that clinical GBS strains associated with preterm labor or neonatal infections have increased hyaluronidase activity compared to commensal strains obtained from rectovaginal swabs of healthy women. Using a murine model of ascending infection, we show that hyaluronidase activity was associated with increased ascending GBS infection, preterm birth, and fetal demise. Interestingly, hyaluronidase activity reduced uterine inflammation but did not impact placental or fetal inflammation. Our study shows that hyaluronidase activity enables GBS to subvert uterine immune responses, leading to increased rates of ascending infection and preterm birth. These findings have important implications for the development of therapies to prevent in utero infection and preterm birth. IMPORTANCE GBS are a family of bacteria that frequently colonize the vagina of pregnant women. In some cases, GBS ascend from the vagina into the uterine space, leading to fetal injury and preterm birth. Unfortunately, little is known about the mechanisms underlying ascending GBS infection. In this study, we show that a GBS virulence factor, HylB, shows higher activity in strains isolated from cases of preterm birth than those isolates from rectovaginal swabs of healthy women. We discovered that GBS rely on HylB to avoid immune detection in uterine tissue, but not placental tissue, which leads to increased rates of fetal injury and preterm birth. These studies provide novel insight into the underlying mechanisms of ascending infection.

scholarly journals Group B streptococcus exploits vaginal epithelial exfoliation for ascending infection

2018 ◽  
Vol 128 (5) ◽  
pp. 1985-1999 ◽  
Author(s):  
Jay Vornhagen ◽  
Blair Armistead ◽  
Verónica Santana-Ufret ◽  
Claire Gendrin ◽  
Sean Merillat ◽  
...  
Keyword(s):  
Group B Streptococcus ◽  
Ascending Infection ◽  
Group B

Spectrum of Changes Seen With Placental Intravascular Organisms

2018 ◽  
Vol 22 (3) ◽  
pp. 229-235 ◽  
Author(s):  
Pawel T Schubert ◽  
Deidre Mason ◽  
Roosacelis Martines ◽  
Marlene Deleon-Carnes ◽  
Sherif R Zaki ◽  
...  
Keyword(s):  
Bacterial Infection ◽  
Bacterial Infections ◽  
Fetal Death ◽  
Group B Streptococcus ◽  
Congenital Infection ◽  
Neonatal Morbidity ◽  
Chorionic Villi ◽  
Congenital Infections ◽  
Ascending Infection ◽  
Group B

Fetal bacterial infections are a common cause of fetal/neonatal morbidity and mortality. The pathologic correlates of congenital bacterial infection include acute chorioamnionitis, acute villitis, and acute intervillositis. The strength of the association of congenital bacterial infection differs among these pathologies. Acute chorioamnionitis results usually from an ascending infection, and damage to the fetus is thought to be cytokine driven rather than damage secondary to bacteremia. Acute villitis is strongly associated with fetal sepsis due to congenital infections. A much less common variant on acute villitis pattern has been described with additional presence of bacteria in the fetal capillaries of the chorionic villi. We describe the spectrum of bacteria that would induce this unique pattern. The histological archives were searched from 2 institutions for cases with intravascular bacteria present in the villous capillaries of the placenta. Thirteen cases were identified, of which 11 cases had acute chorioamnionitis and all cases showed an acute villitis. Eight cases had Escherichia coli identified and 3 cases had Group B Streptococcus. All cases were associated with fetal death. In 9 cases, the mother showed signs of a significant infection including 1 maternal death. We conclude that finding intravascular bacteria is a serious complication of congenital infection with serious fetal and maternal sequela.

scholarly journals Downregulation of Ribosomal Contents and Kinase Activities Is Associated with the Inhibitive Effect on the Growth of Group B Streptococcus Induced by Placental Extracellular Vesicles

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 664
Author(s):  
Jing Gao ◽  
Yunhui Tang ◽  
Xinyi Sun ◽  
Qiujing Chen ◽  
Yiqian Peng ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Reproductive Tract ◽  
Biological Activities ◽  
Group B Streptococcus ◽  
Female Reproductive Tract ◽  
E Coli ◽  
Resistance To Antibiotics ◽  
Cell Energy ◽  
Group B ◽  
Cellular Components

Background: Like many other cell types, the human placenta produces large amounts of extracellular vesicles (EVs). Increasing evidence has shown that placental EVs contribute to the regulation of maternal immune and vascular systems during pregnancy via the transfer of their cargos. In this study, we investigated the effect of placental EVs on the growth of opportunistic pathogens that commonly colonise the female reproductive tract. Methods: Gram-positive bacterium Group B Streptococcus (GBS) and Gram-negative bacterium Escherichia coli (E. coli) were treated with placental EVs that were collected from placental explant cultures, and the growth, susceptibility, and resistance to antibiotics of the bacteria were measured. In addition, comparative proteomics analysis was also performed for the GBS with or without exposure to placental EVs. Results: When treated with placental micro-EVs or nano-EVs, the GBS growth curve entered the stationary phase earlier, compared to untreated GBS. Treatment with placental EVs also inhibited the growth of GBS on solid medium, compared to untreated GBS. However, these biological activities were not seen in E. coli. This attenuative effect required interaction of placental EVs with GBS but not phagocytosis. In addition, the susceptibility or resistance to antibiotics of GBS or E. coli was not directly affected by treatment with placental EVs. The proteomic and Western blotting analysis of GBS that had been treated with placental EVs suggested that the downregulation of cellular components and proteins associated with phosphorylation and cell energy in GBS may contribute to these attenuative effects. Conclusion: We demonstrated the attenuative effect of the growth of GBS treated with placental EVs. Downregulation of cellular components and proteins associated with phosphorylation and cell energy may contribute to the physiological changes in GBS treated with placental EVs.

scholarly journals The antimicrobial activity of zinc against group B Streptococcus is strain-dependent across diverse sequence types, capsular serotypes, and invasive versus colonizing isolates

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Jamisha D. Francis ◽  
Miriam A. Guevara ◽  
Jacky Lu ◽  
Shabir A. Madhi ◽  
Gaurav Kwatra ◽  
...  
Keyword(s):  
Reproductive Tract ◽  
Group B Streptococcus ◽  
Antimicrobial Properties ◽  
Zinc Toxicity ◽  
Capsular Type ◽  
Zinc Stress ◽  
Wide Range ◽  
Invasive Infections ◽  
Group B ◽  
Sequence Types

Abstract Background Streptococcus agalactiae or Group B Streptococcus (GBS) is an encapsulated gram-positive bacterial pathobiont that commonly colonizes the lower gastrointestinal tract and reproductive tract of human hosts. This bacterium can infect the gravid reproductive tract and cause invasive infections of pregnant patients and neonates. Upon colonizing the reproductive tract, the bacterial cell is presented with numerous nutritional challenges imposed by the host. One strategy employed by the host innate immune system is intoxication of bacterial invaders with certain transition metals such as zinc. Methodology Previous work has demonstrated that GBS must employ elegant strategies to circumnavigate zinc stress in order to survive in the vertebrate host. We assessed 30 strains of GBS from diverse isolation sources, capsular serotypes, and sequence types for susceptibility or resistance to zinc intoxication. Results Invasive strains, such as those isolated from early onset disease manifestations of GBS infection were significantly less susceptible to zinc toxicity than colonizing strains isolated from rectovaginal swabs of pregnant patients. Additionally, capsular type III (cpsIII) strains and the ST-17 and ST-19 strains exhibited the greatest resilience to zinc stress, whereas ST-1 and ST-12 strains as well as those possessing capsular type Ib (cpsIb) were more sensitive to zinc intoxication. Thus, this study demonstrates that the transition metal zinc possesses antimicrobial properties against a wide range of GBS strains, with isolation source, capsular serotype, and sequence type contributing to susceptibility or resistance to zinc stress.

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