Group B Streptococcus (GBS) Colonization and Disease among Pregnant Women: A Historical Cohort Study. Infect Dis Obstet Gynecol. 2019;2019:5430493. [PMID: 30853787 PMCID: PMC6378061 DOI: 10.1155/2019/5430493]

Adolescent Pregnancy: A Comparative Insight into the Prevalence and Risks of Obstetric Complications in a Polish Cohort

Background: Adolescent pregnancy is associated with increased risk of both maternal and neonatal complications. Common maternal complications include anemia, hypertensive disorders, and a higher incidence of infections, including Group B Streptococcus (GBS). Additionally, adolescents are at increased risk for gestational diabetes and postpartum hemorrhage. Neonatal complications often involve low birth weight, prematurity, and an increased likelihood of neonatal intensive care unit (NICU) admission. Objectives: This study aims to assess and compare the prevalence of obstetric complications between adolescent and older pregnant women. Methods: This retrospective study investigates obstetric outcomes in adolescent pregnancies, analyzing data collected from 1 January 2016 to 30 June 2024. This study included 902 participants, of whom 224 were adolescents. The variables were categorized into maternal, birth, and neonatal characteristics. Results: Adolescent patients demonstrated a significantly higher prevalence of Group B Streptococcus (GBS) infection, affecting 25.89% of this group. Adolescent patients reported 17.86% nicotine use during pregnancy, a rate significantly higher than that of older age groups (p < 0.001). Additionally, adolescent pregnancies were associated with the highest mean blood loss during delivery, averaging 500 mL during vaginal birth and 1050 mL during cesarean section, leading to a higher incidence of blood transfusions (3.13%, p = 0.021). Newborns from adolescent pregnancies had the lowest mean birth weight (3199 g) and length (53.6 cm). Neonatal complications were more frequent in this group, affecting 20.09% of newborns, with a significantly higher rate of admission to intensive care units (2.68%, p = 0.008). These findings underscore the need for targeted interventions and more proactive management strategies to address the specific challenges faced by this population.

Gestational diabetes as a risk factor for GBS maternal rectovaginal colonization: a systematic review and meta-analysis

BACKGROUND

Maternal rectovaginal colonization by group B Streptococcus (GBS) increases the risk of perinatal GBS disease that can lead to death or long-term neurological impairment. Factors that increase the risk of rectovaginal GBS carriage are incompletely understood resulting in missed opportunities for detecting GBS in risk-based clinical approaches. There is a lacking consensus on whether gestational diabetes mellitus (GDM) is a risk factor for rectovaginal GBS. This systematic review and meta-analysis aims to address current conflicting findings and determine whether GDM should be clinically considered as a risk factor for maternal GBS colonization.

METHODS

Peer-reviewed studies that provided GDM prevalence and documented GBS vaginal and/or rectal colonization in women with and without GDM were included in this analysis. From study inception to October 30, 2023, we identified 6,275 relevant studies from EMBASE and PUBMED of which 19 were eligible for inclusion. Eligible studies were analyzed and thoroughly assessed for risk of bias with a modified Newcastle-Ottawa Scale that interrogated representativeness and comparability of cohorts, quality of reporting for GDM and GBS status, and potential bias from other metabolic diseases. Results were synthesized using STATA 18 and analyzed using random-effects meta-analyses.

RESULTS

Studies encompassed 266,706 women from 10 different countries, with study periods spanning from 1981 to 2020. Meta-analysis revealed that gestational diabetes is associated with a 16% increased risk of rectovaginal GBS carriage (OR 1.16, CI 1.07-1.26, P = 0.003). We also performed subgroup analyses to assess independent effects of pregestational vs. gestational diabetes on risk of maternal GBS carriage. Pregestational diabetes (Type 1 or Type 2 diabetes mellitus) was also associated with an increased risk of 76% (pooled OR 1.76, CI 1.27-2.45, P = 0.0008).

CONCLUSIONS

This study achieved a consensus among previously discrepant observations and demonstrated that gestational diabetes and pregestational diabetes are significant risk factors for maternal rectovaginal carriage of GBS. Recognition of GDM as a risk factor during clinical decisions about GBS screening and intrapartum antibiotic prophylaxis may decrease the global burden of GBS on maternal-perinatal health.

To evaluate the performance of simultaneous amplification and testing assay for group B Streptococcus detection: comparison with real-time PCR and ddPCR assays

BACKGROUND

To evaluate the performance of simultaneous amplification and testing (SAT) assay for the detection of group B Streptococcus (GBS) in maternal vaginal and perianal swabs compared with real-time polymerase chain reaction (RT-PCR).

METHODS

We obtained vaginal and perianal swabs from 1474 pregnant women at the Obstetrics and Gynecology Hospital of Fudan University (Shanghai, China) between April 2023 and June 2023. Vaginal and perianal swabs were collected at 35-37 weeks of gestation. Swabs were tested for GBS simultaneously by using the SAT assay and RT-PCR, and a comparative analysis (kappa coefficient) was performed. Furthermore, we conducted additional droplet digital PCR (ddPCR) tests to confirm the results when there were controversial results between SAT and RT-PCR. In addition, we compared the limit of detection, technical specificity, repeatability and reproducibility of SAT-GBS with those of routine RT-PCR assays.

RESULTS

In our study, the detection rate of clinical GBS according to the SAT assay was 11.5% (169/1471). The SAT assay showed a sensitivity of 91.8%, a specificity of 99.9%, a diagnostic accuracy of 98.9%, a positive predictive value (PPV) of 99.4% and a negative predictive value (NPV) of 98.8%. The kappa value between RT-PCR and SAT was 0.917.

CONCLUSIONS

This SAT assay for the detection of group B Streptococcus is not only easy to perform but can also detect GBS sensitively and specifically and may be used in the regular molecular diagnosis of GBS infection among pregnancies.

Outcomes of Moderately Preterm Infants of Insulin-Dependent Diabetic Mothers

OBJECTIVE

Little is known about the hospital outcomes of moderately preterm (MPT; 29 0/7-33 6/7 weeks gestational age) infants born to insulin-dependent diabetic mothers (IDDMs). We evaluated characteristics and outcomes of MPT infants born to IDDMs compared with those without IDDM (non-IDDM).

STUDY DESIGN

Cohort study of infants from 18 centers included in the MPT infant database from 2012 to 2013. We compared characteristics and outcomes of infants born to IDDMs and non-IDDMs.

RESULTS

Of 7,036 infants, 527 (7.5%) were born to IDDMs. Infants of IDDMs were larger at birth, more often received continuous positive pressure ventilation in the delivery room, and had higher risk of patent ductus arteriosus (adjusted relative risk or aRR: 1.49, 95% confidence interval [CI]: 1.20-1.85) and continued hospitalization at 40 weeks postmenstrual age (aRR: 1.55, 95% CI: 1.18-2.05).

CONCLUSION

MPT infants of IDDM received more respiratory support and prolonged hospitalizations, providing further evidence of the important neonatal health consequences of maternal diabetes.

KEY POINTS

· Little data are available on moderate preterm infants of IDDMs.. · MPT infants of IDDMs need more respiratory support.. · Longer neonatal intensive care unit stays among MPT infants of IDDMs..

Association between Group B Streptococcus and Clinical Chorioamnionitis by Gestational Week at Delivery-A Multicenter Cohort Study

OBJECTIVE

 In the era of group B Streptococcus (GBS) screening and intrapartum antibiotic prophylaxis (IAP), GBS colonization has been associated with a lower risk of chorioamnionitis, possibly due to a protective effect of IAP. We sought to confirm this finding and assess whether this association varies by gestational week at delivery.

STUDY DESIGN

 We performed a retrospective cohort study of term (37.0-42.6 weeks), singleton parturients with known GBS status who delivered from 2005 to 2021 at two academic medical centers in Israel. We excluded patients who underwent planned cesarean, out of hospital birth, or had a fetal demise. Patients received GBS screening and IAP for GBS positivity as routine clinical care. The primary outcome was a diagnosis of clinical chorioamnionitis as determined by the International Classification of Diseases 10th Revision code, compared between GBS-positive and -negative groups, and assessed by gestational week at delivery.

RESULTS

 Of 292,126 deliveries, 155,255 met inclusion criteria. In total, 30.1% were GBS positive and 69.9% were negative. GBS-positive patients were 21% less likely to be diagnosed with clinical chorioamnionitis than GBS-negative patients, even after controlling for confounders (1.5 vs. 2.2%, adjusted odds ratio: 0.79, 95% confidence interval: 0.68-0.92). When assessed by gestational week at delivery, there was a significantly greater difference in rates of clinical chorioamnionitis between GBS-positive versus GBS-negative groups with advancing gestational age: 1.5-fold difference at 38 to 40 weeks, but a twofold difference at 42 weeks. The risk of clinical chorioamnionitis remained stable in the GBS-positive group, but increased significantly in the GBS-negative group at 41- and 42-week gestation (2.0 vs. 2.9%, p < 0.01 at 41 weeks; up to 3.9% at 42 weeks, p < 0.01).

CONCLUSION

 In a large multicenter cohort with universal GBS screening and IAP, GBS positivity was associated with a lower risk of chorioamnionitis, driven by an increasing rate of chorioamnionitis among GBS-negative patients after 40 weeks.

KEY POINTS

· GBS positivity and IAP may be associated with lower risk of chorioamnionitis.. · GBS-positive patients were less likely to be diagnosed with chorioamnionitis.. · This difference increased with advancing gestational age after 40 weeks..

Microorganism-derived extracellular vesicles: emerging contributors to female reproductive health

Extracellular vesicles (EVs) are cell-derived nanoparticles that carry small molecules, nucleic acids, and proteins long distances in the body facilitating cell-cell communication. Microorganism-derived EVs mediate communication between parent cells and host cells, with recent evidence supporting their role in biofilm formation, horizontal gene transfer, and suppression of the host immune system. As lipid-bound bacterial byproducts, EVs demonstrate improved cellular uptake and distribution in vivo compared to cell-free nucleic acids, proteins, or small molecules, allowing these biological nanoparticles to recapitulate the effects of parent cells and contribute to a range of human health outcomes. Here, we focus on how EVs derived from vaginal microorganisms contribute to gynecologic and obstetric outcomes. As the composition of the vaginal microbiome significantly impacts women's health, we discuss bacterial EVs from both healthy and dysbiotic vaginal microbiota. We also examine recent work done to evaluate the role of EVs from common vaginal bacterial, fungal, and parasitic pathogens in pathogenesis of female reproductive tract disease. We highlight evidence for the role of EVs in women's health, gaps in current knowledge, and opportunities for future work. Finally, we discuss how leveraging the innate interactions between microorganisms and mammalian cells may establish EVs as a novel therapeutic modality for gynecologic and obstetric indications.

Interstate Practice Variation and Factors Associated with Antibiotic Use for Suspected Neonatal Sepsis in the United States

OBJECTIVE

This study aimed to estimate national time trends of overall and statewise antibiotic utilization (AU) rates for suspected neonatal sepsis (SNS) in the United States.

STUDY DESIGN

In this cross-sectional study, we used retrospective linked birth cohort and vital records data from the Centers for Disease Control and Prevention Wide-ranging ONline Data for Epidemiologic Research database for the years 2016 to 2020 and analyzed data containing antibiotic use for SNS. The primary outcome was proportional national and state-specific AU rates per 1,000 live births during the birth hospitalization. Secondary outcomes included overall trends and association between maternal education, race, sex, chorioamnionitis, mode of delivery, gestational age at birth, Apgar's scores, and insurance status with antibiotics exposure for SNS among newborns. Contingency tables, two-tailed t-test, and chi-square for independence tests were performed with statistical significance set at p < 0.05.

RESULTS

For a birth cohort of >18 million, 2.2% of infants received antibiotics during birth hospitalization nationwide. There were wide variations in AU among U.S. states and territories, whereas overall treatment rates decreased by 16.1% (95% confidence interval [CI]: 15.2-17.0; p < 0.001). Compared with White newborns, Black newborns had higher AU rates (odds ratio [OR]: 1.33; 95% CI: 1.32-1.34), and Asians had the lowest rates (OR: 0.96; 95% CI: 0.95-0.97). There was a significant difference in mean AU rates by race (p < 0.001). Chorioamnionitis at birth significantly increased the odds for AU (OR: 14.5 ;95% CI: 14.4-14.6), although AU rates for chorioamnionitis showed a significant downward trend (OR: 0.52; 95% CI: 0.50-0.53) during the study period.

CONCLUSION

Our findings suggest that there has been a gradual decline in AU for SNS in more than a third of states in last 5 years. While risk-based management approaches achieve widespread implementation, state- and nationwide quality improvement collaborates might have contributed to the relative decline in antibiotic use in newborns. Further studies are warranted to understand factors related to practice variation in the management of SNS in the United States KEY POINTS: · Early and prolonged use of antibiotics can lead to altered gut microbiome and adverse long-term neonatal outcomes.. · There is considerable clinical practice variation in antibiotic-prescribing practices for suspected neonatal sepsis.. · This cross-sectional study reports the differences in neonatal antibiotic usage patterns by region and maternal factors.. · Antibiotic use should be limited to newborns at high risk of infection and proven sepsis.. · Judicious use of antibiotics can be promoted by following evidence-based approaches to sepsis risk assessment..

Vaginal and Rectal microbiome changes following administration of a multi-species antenatal probiotic: A randomized control trial

The gut and vaginal microbiome undergo changes during pregnancy which may be protective or harmful to the birthing person. Probiotics have been found to cause protective changes to the gut and vaginal microbiomes, with the potential to improve perinatal outcomes. This randomized control trial compares the vaginal and rectal microbiomes before and after an antenatal probiotic or placebo intervention, with a diverse group of pregnant people and a special focus on racial disparities. The vaginal and rectal microbiomes reveal non-significant increased Lactobacillus in the probiotics group, with a greater increase in participants who identified as Black. Potential implications and future study are discussed.

Antimicrobial Resistance Profile of Group B Streptococci Colonization in a Sample Population of Pregnant Women from Romania

Group B Streptococcus (GBS) represents one of the leading causes of life-threatening invasive disease in pregnant women and neonates. Rates of GBS colonization vary by region, but studies on maternal GBS status are limited in Romania. This study aims to identify the prevalence of colonization with GBS and whether the obstetrical characteristics are statistically associated with the study group's antimicrobial susceptibility patterns of tested GBS strains. This observational study was conducted between 1 May and 31 December 2021 at The Department of Obstetrics and Gynecology at Elias University Emergency Hospital (EUEH) in Bucharest, Romania. A total of 152 samples were positive for GBS and included in the study according to the inclusion criteria. As a result, the prevalence of colonized patients with GBS was 17.3%. GBS isolated in this population had the highest resistance to erythromycin (n = 38; 25%), followed by clindamycin (n = 36; 23.7%). Regarding the susceptibility patterns of tested strains to penicillin, the 152 susceptible strains had MIC breakpoints less than 0.06 μg/μL. The susceptibility patterns of tested strains to linezolid indicated three resistant strains with low levels of resistance (MICs ranging between 2 and 3 μg/μL). Multidrug resistance (at least three antibiotic classes) was not observed. In conclusion, although GBS naturally displays sensitivity to penicillin, the exact bacterial susceptibility testing should be performed in all cases where second-line therapy is taken into consideration for treatment. We acknowledge the need for future actions to limit multidrug-resistant bacteria.

Oral Probiotic Supplementation in Pregnancy to Reduce Group B Streptococcus Colonisation (OPSiP trial): study protocol for a double-blind parallel group randomised placebo trial

INTRODUCTION

Group B streptococcus (GBS), or Streptococcus agalactiae, remains a leading cause of neonatal morbidity and mortality. Canadian guidelines advise universal maternal screening for GBS colonisation in pregnancy in conjunction with selective antibiotic therapy. This results in over 1000 pregnant individuals receiving antibiotic therapy to prevent one case of early-onset neonatal GBS disease, and over 20 000 pregnant individuals receiving antibiotic therapy to prevent one neonatal death. Given the growing concern regarding the risk of negative sequela from antibiotic exposure, it is vital that alternative approaches to reduce maternal GBS colonisation are explored.Preliminary studies suggest some probiotic strains could confer protection in pregnancy against GBS colonisation.

METHODS AND ANALYSIS

This double-blind parallel group randomised trial aims to recruit 450 pregnant participants in Vancouver, BC, Canada and will compare GBS colonisation rates in those who have received a daily oral dose of three strains of probiotics with those who have received a placebo. The primary outcome will be GBS colonisation status, measured using a vaginal/rectal swab obtained between 35 weeks' gestation and delivery. Secondary outcomes will include maternal antibiotic exposure and urogenital infections. Analysis will be on an intention-to-treat basis.

PATIENT OR PUBLIC INVOLVEMENT

There was no patient or public involvement in the design of the study protocol.

ETHICS AND DISSEMINATION

This study protocol received ethics approval from the University of British Columbia's Clinical Research Ethics Board, Dublin City University and Health Canada. Findings will be presented at research rounds, conferences and in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT03407157.

Gestational diabetes augments group B Streptococcus infection by disrupting maternal immunity and the vaginal microbiota

Group B Streptococcus (GBS) is a pervasive perinatal pathogen, yet factors driving GBS dissemination in utero are poorly defined. Gestational diabetes mellitus (GDM), a complication marked by dysregulated immunity and maternal microbial dysbiosis, increases risk for GBS perinatal disease. Using a murine GDM model of GBS colonization and perinatal transmission, we find that GDM mice display greater GBS in utero dissemination and subsequently worse neonatal outcomes. Dual-RNA sequencing reveals differential GBS adaptation to the GDM reproductive tract, including a putative glycosyltransferase (yfhO), and altered host responses. GDM immune disruptions include reduced uterine natural killer cell activation, impaired recruitment to placentae, and altered maternofetal cytokines. Lastly, we observe distinct vaginal microbial taxa associated with GDM status and GBS invasive disease status. Here, we show a model of GBS dissemination in GDM hosts that recapitulates several clinical aspects and identifies multiple host and bacterial drivers of GBS perinatal disease.

Neonatal Group B Streptococcus Disease

Group B Streptococcus (GBS) is an important cause of neonatal sepsis in term and preterm infants. Because GBS colonizes human genitourinary and gastrointestinal tracts, a significant focus of neonatal GBS disease prevention is to interrupt vertical transmission of GBS from mother to infant during parturition. Routine antepartum GBS screening in pregnant women, as well as widespread use of intrapartum antibiotic prophylaxis, have aided in overall reductions in neonatal GBS disease during the past 3 decades. However, neonatal GBS disease persists and may cause mortality and significant short- and long-term morbidity among survivors. Herein, we highlight contemporary epidemiology, microbial pathogenesis, and the clinical presentation spectrum associated with neonatal GBS disease. We summarize obstetric recommendations for antenatal GBS screening, indications for intrapartum antibiotic prophylaxis, and considerations for antibiotic selection. Finally, we review national guidelines for risk assessment and management of infants at risk for GBS disease.

Prevalence of early neonatal sepsis and positive maternal culture for group B beta-hemolytic Streptococcus

OBJECTIVE

The aim of this study was to evaluate the prevalence of early neonatal sepsis in pregnant women with a positive culture for group B beta-hemolytic Streptococcus in a middle-income city in Southeastern Brazil.

METHODS

A retrospective cohort study was conducted, involving singleton low- and high-risk pregnancies in whom group B beta-hemolytic Streptococcus cultures were evaluated between 35 and 37 weeks of gestation using vaginal and anal swabs. A specific medium (Todd-Hewitt) was used for culturing. The pregnant women were divided into two groups based on positive (n==201) and negative (n==420) cultures for group B beta-hemolytic Streptococcus.

RESULTS

The maternal colonization rate by group B beta-hemolytic Streptococcus was 32.3%. The prevalence of early neonatal sepsis was 1.0% (2/201) among patients with a positive group B beta-hemolytic Streptococcus culture and 1.9% (8/420) among patients with a negative culture. Among the patients who underwent adequate prophylaxis, crystalline penicillin G was used in 51.9% (54/104), followed by cefazolin in 43.3% (45/104), ampicillin in 3.8% (4/104), and clindamycin in 1.0% (1/104). A model that included prematurity (p==0.001) proved to be an independent risk predictor of early neonatal sepsis [χ2 (1)==15.0, odds ratio: 16.9, 95% confidence interval: 4.7-61.6, p<0.001, Nagelkerke R2==0.157].

CONCLUSION

The prevalence of a positive culture for group B beta-hemolytic Streptococcus was high. However, the prevalence of early neonatal sepsis was low in pregnant women with both positive and negative group B beta-hemolytic Streptococcus cultures and in pregnant women with a positive culture who underwent both adequate and inadequate antibiotic prophylaxis. Prematurity proved to be an independent predictor of early neonatal sepsis, considering the entire study population.

Group B Streptococcus and Perinatality in the South of Tunisia: Epidemiology, Serotype Distribution, and Antibiotic Susceptibility

INTRODUCTION

In the lack of updated Tunisian epidemiological data, we sought to describe the epidemiology of Group B Streptococcus (GBS) in pregnant women and newborns.

MATERIALS AND METHODS

A retrospective analysis of GBS neonatal invasive infections and a cross-sectional study evaluating the prevalence of maternal GBS colonization were conducted. GBS isolates were tested for antimicrobial susceptibility, serotyped, and assessed for the appurtenance to the hypervirulent ST17 clone.

RESULTS

Of 98 neonates with GBS, early-onset GBS disease (EOD) comprised 83.7 and 16.3% were late-onset GBS disease (LOD). The prevalence of maternal GBS colonization was 27%. All GBS isolates were susceptible to penicillin. Serotype III predominated (42.6%) for neonatal invasive infections. GBS isolates belonging to the ST17 sequence type were found only as serotype III.

CONCLUSION

This study documents the frequency of GBS EOD, the high rate of maternal GBS colonization, and the predominance of the hypervirulent clone type III/ST17 in infants.

Association between intrapartum antibiotic prophylaxis for Group B Streptococcus colonization and clinical chorioamnionitis among patients undergoing induction of labor at term

BACKGROUND

Rectovaginal colonization with Group B Streptococcus during pregnancy has historically been shown to be associated with an increased risk of clinical chorioamnionitis and peripartum infectious morbidity.

OBJECTIVE

Newer observational data in the era of intrapartum antibiotic prophylaxis suggest a possible reversal of this association; however, it is unclear if this is related to differences in labor management for those with and without Group B Streptococcus colonization. We therefore sought to assess the association between intrapartum antibiotic prophylaxis for Group B Streptococcus colonization and clinical chorioamnionitis within the context of a randomized induction of labor trial with a standardized labor protocol.

STUDY DESIGN

We performed an exploratory secondary analysis of a randomized trial of patients undergoing term induction at a tertiary care center. Patients received third trimester Group B Streptococcus screening and intrapartum antibiotic prophylaxis as routine care. Group B Streptococcus detection was performed using a carrot broth-enhanced subculture to Group B Streptococcus Detect approach (Hardy Diagnostics, Santa Maria, CA). Labor management was protocolized per the trial. Patients with unknown Group B Streptococcus status or who did not receive intrapartum antibiotic prophylaxis, if indicated, were excluded. The primary outcome was diagnosis of clinical chorioamnionitis, compared between patients who received intrapartum antibiotic prophylaxis for known Group B Streptococcus positive status (by culture, history, or Group B Streptococcus bacteriuria) and those who were Group B Streptococcus negative and did not receive intrapartum antibiotic prophylaxis. Secondary outcomes included postpartum endometritis, wound infection, a composite maternal peripartum infectious morbidity, and neonatal outcomes.

RESULTS

A total of 491 patients were enrolled in the trial. Of these, 466 had a known Group B Streptococcus status and received or did not receive intrapartum antibiotic prophylaxis accordingly and were included in this analysis: 292 (62.7%) were Group B Streptococcus negative and did not receive intrapartum antibiotic prophylaxis, and 174 (37.3%) were Group B Streptococcus positive and received intrapartum antibiotic prophylaxis. The majority of patients were Non-Hispanic Black (78.1%) and nulliparous (59.7%). There were no differences in demographic, clinical, induction or labor characteristics between groups. Patients who were Group B Streptococcus positive had a 49% lower rate of clinical chorioamnionitis (8.1% vs 14.7%, odds ratio, 0.51; P=.03) and a lower rate of peripartum infectious morbidity (8.1% vs 15.8%, odds ratio, 0.47; P=.02) compared to those who were Group B Streptococcus negative. Infants born to patients who were Group B Streptococcus positive were significantly less likely to be admitted to the neonatal intensive care unit (3.4% vs 15.1%, P<.001).

CONCLUSION

Although Group B Streptococcus colonization has historically been considered a risk factor for clinical chorioamnionitis, in the era of universal antibiotic prophylaxis for Group B Streptococcus positive patients, our findings support the point that intrapartum antibiotic prophylaxis for Group B Streptococcus positivity is associated with lower rates of clinical chorioamnionitis and peripartum infectious morbidity among patients undergoing induction with protocolized labor management. These findings demonstrate that intrapartum antibiotic prophylaxis for Group B Streptococcus may protect against perinatal infectious morbidity, a phenomenon that warrants further investigation.

Association between glycemic control and group B streptococcus colonization among pregnant individuals with pregestational diabetes

PROBLEM

Pregestational diabetes increases the risk of group B streptococcus (GBS) colonization in pregnancy. Whether glycemic control is associated with differences in this risk is unknown. We examined the association between glycemic control and GBS colonization among pregnant individuals with pregestational diabetes.

METHOD OF STUDY

A retrospective cohort of pregnant individuals with pregestational diabetes at a tertiary care center. The exposure was glycemic control, measured as hemoglobin A1c (A1c) at >20 weeks and assessed categorically at thresholds of <6.5% and <6.0%, and secondarily, as a continuous percentage. The outcome was maternal GBS colonization. Multivariable logistic regression was used and adjusted for age, parity, race, and ethnicity as a social determinant, body mass index, type of diabetes, and gestational age at A1c assessment.

RESULTS

Among 305 individuals (33% Type 1, 67% type 2), 45.0% (n = 140) were colonized with GBS. Individuals with an A1c < 6.5% were half as likely to be colonized with GBS compared with those with a A1c ≥ 6.5% (38.8% vs. 53.9%; adjusted odds ratio, AOR: 0.55; 95% CI: 0.33-0.91). Results were unchanged at an A1c threshold of <6.0% (35.7% vs. 48.5%; AOR: 0.60; 95% CI: 0.36-0.98). Individuals with a higher A1c as a continuous measure (%) were more likely to be colonized (AOR: 1.57 per 1%; 95% CI: 1.25-1.97).

CONCLUSIONS

Pregnant individuals with pregestational diabetes with worse glycemic control were at an increased risk of GBS colonization. Further study is needed to understand if improved glycemic control leads to lower risk of GBS colonization.

Near-term pregnant women in the Dominican Republic experience high rates of Group B Streptococcus rectovaginal colonization with virulent strains

Maternal colonization with Group B Streptococcus (GBS) is an important cause of stillbirth, prematurity, and serious infection and death in infants worldwide. Resource constraints limit prevention strategies in many regions. Maternal GBS vaccines in development could be a more accessible prevention strategy, but data on geographic variations in GBS clones are needed to guide development of a broadly effective vaccine. In the Dominican Republic (DR), limited data suggest that pregnant women experience GBS colonization at rates among the highest globally. We aimed to determine the prevalence of maternal rectovaginal GBS colonization and describe clonal characteristics of colonizing strains in the DR. A cross-sectional study assessed rectovaginal GBS colonization in 350 near-term pregnant women presenting for routine prenatal care at an urban tertiary center in the DR. Rectovaginal samples were tested with chromogenic Strep B Carrot Broth and cultured for confirmatory whole-genome sequencing. In a secondary analysis, participants' demographics and histories were assessed for association with GBS colonization. Rectovaginal GBS colonization occurred in 26.6% of women. Serotypes Ia, Ib, II, III, IV, and V were detected, with no one serotype predominating; serotype III was identified most frequently (21.5%). Virulent and emerging strains were common, including CC17 (15.1%) and ST1010 (17.2%). In this first characterization of maternal GBS serotypes in the DR, we found high rates of rectovaginal colonization including with virulent and emerging GBS strains. The serotypes observed here are all targeted by candidate hexavalent GBS vaccines, suggesting effective protection in the DR.

Determinants of Gastrointestinal Group B Streptococcus Carriage in Adults

Background

Streptococcus agalactiae (Group B Streptococcus, GBS) is a commensal Gram-positive bacterium found in the human gastrointestinal and urogenital tracts. Much of what is known about GBS relates to the diseases it causes in pregnant people and neonates. However, GBS is a common cause of disease in the general population with 90% of GBS mortality occurring in non-pregnant people. There are limited data about the predisposing factors for GBS and the reservoirs in the body. To gain an understanding of the determinants of gastrointestinal GBS carriage, we used stool samples and associated metadata to determine the prevalence and abundance of GBS in the gut microbiome of adults and find risk factors for GBS status.

Methods

We used 754 stool samples collected from adults in Wisconsin from 2016-2017 to test for the prevalence and abundance of GBS using a Taqman probe-based qPCR assay targeting two GBS-specific genes: cfp and sip. We compared the microbiome compositions of the stool samples by GBS status using 16S rRNA analysis. We compared associations with GBS status and 557 survey variables collected during sample acquisition (demographics, diet, overall health, and reproductive health) using univariate and multivariate analyses.

Results

We found 137/754 (18%) of participants had detectable GBS in their stool samples with a median abundance of 104 copies per nanogram of starting DNA. There was no difference in GBS status or abundance based on gender. Beta-diversity, Bray-Curtis and Unweighted UniFrac, was significantly different based on carrier status of the participant. Prior to p-value correction, 59/557 (10.6%) survey variables were significantly associated with GBS carrier status and 11/547 (2.0%) variables were significantly associated with abundance (p-value<0.05). After p-value correction, 2/547 (0.4%) variables were associated with GBS abundance: an increased abundance of GBS was associated with a decreased frequency since last dental checkup (p<0.001) and last dental cleaning (p<0.001). Increased GBS abundance was significantly associated with increased frequency of iron consumption (p=0.007) after p-value correction in multivariate models.

Conclusions

GBS is found in stool samples from adults in Wisconsin at similar frequencies as pregnant individuals screened with rectovaginal swabs. We did not find associations between risk factors historically associated with GBS in pregnant people, suggesting that risk factors for GBS carriage in pregnancy may differ from those in the general population. We found that frequency of iron consumption and dental hygiene are risk factors for GBS carriage in Wisconsin adults. Given that these variables were not assayed in previous GBS surveys, it is possible they also influence carriage in pregnant people. Taken together, this work serves as a foundation for future work in developing approaches to decrease GBS abundance in carriers.

Interspecies Interactions within the Host: the Social Network of Group B Streptococcus

Group B Streptococcus (GBS) is a pervasive neonatal pathogen accounting for a combined half a million deaths and stillbirths annually. The most common source of fetal or neonatal GBS exposure is the maternal microbiota. GBS asymptomatically colonizes the gastrointestinal and vaginal mucosa of 1 in 5 individuals globally, although its precise role in these niches is not well understood. To prevent vertical transmission, broad-spectrum antibiotics are administered to GBS-positive mothers during labor in many countries. Although antibiotics have significantly reduced GBS early-onset neonatal disease, there are several unintended consequences, including an altered neonatal microbiota and increased risk for other microbial infections. Additionally, the incidence of late-onset GBS neonatal disease remains unaffected and has sparked an emerging hypothesis that GBS-microbe interactions in developing neonatal gut microbiota may be directly involved in this disease process. This review summarizes our current understanding of GBS interactions with other resident microbes at the mucosal surface from multiple angles, including clinical association studies, agriculture and aquaculture observations, and experimental animal model systems. We also include a comprehensive review of in vitro findings of GBS interactions with other bacterial and fungal microbes, both commensal and pathogenic, along with newly established animal models of GBS vaginal colonization and in utero or neonatal infection. Finally, we provide a perspective on emerging areas of research and current strategies to design microbe-targeting prebiotic or probiotic therapeutic intervention strategies to prevent GBS disease in vulnerable populations.

Enhanced Vulnerability of Diabetic Mice to Hypervirulent Streptococcus agalactiae ST-17 Infection

Streptococcus agalactiae (Group B Streptococcus, GBS) is the leading cause of neonatal sepsis and meningitis but has been recently isolated from non-pregnant adults with underlying medical conditions like diabetes. Despite diabetes being a key risk factor for invasive disease, the pathological consequences during GBS infection remain poorly characterized. Here, we demonstrate the pathogenicity of the GBS90356-ST17 and COH1-ST17 strains in streptozotocin-induced diabetic mice. We show that GBS can spread through the bloodstream and colonize several tissues, presenting a higher bacterial count in diabetic-infected mice when compared to non-diabetic-infected mice. Histological sections of the lungs showed inflammatory cell infiltration, collapsed septa, and red blood cell extravasation in the diabetic-infected group. A significant increase in collagen deposition and elastic fibers were also observed in the lungs. Moreover, the diabetic group presented red blood cells that adhered to the valve wall and disorganized cardiac muscle fibers. An increased expression of KC protein, IL-1β, genes encoding immune cell markers, and ROS (reactive oxygen species) production was observed in diabetic-infected mice, suggesting GBS promotes high levels of inflammation when compared to non-diabetic animals. Our data indicate that efforts to reverse the epidemic of diabetes could considerably reduce the incidence of invasive infection, morbidity and mortality due to GBS.

Long-term Risk of Epilepsy Following Invasive Group B Streptococcus Disease in Neonates in Denmark

Importance

The risk of epilepsy after neonatal invasive Group B Streptococcus (iGBS) disease, particularly iGBS sepsis, is poorly understood.

Objective

To examine the association between neonatal iGBS (sepsis or meningitis) and long-term risk of epilepsy, stratified by sex, prematurity, and maternal socioeconomic position (SEP).

Design, Setting, and Participants

This population-based cohort study was conducted in Denmark with an inclusion period from 1997 through 2017 and follow-up until the end of 2018. A general population comparison cohort was randomly sampled and matched up to 10:1 to the exposed cohort. Linkage between Danish national registers were applied for data collection. Participants were infants aged 0 to 89 days. The general population comparison cohort was matched by sex, the child's year and month of birth, and gestational age. SEP was defined by maternal income and education.

Exposure

Hospital-diagnosed iGBS (sepsis or meningitis) during the first 89 days after birth.

Outcomes and measures

Epilepsy was defined by International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes and/or prescription codes for antiepileptic drugs using Danish medical registry data. Cumulative risk (CR) of epilepsy was calculated by treating death as a competing event. Cox proportional hazards regression was used to estimate hazard ratios with 95% CIs. Effect modification by sex, prematurity, and maternal SEP was assessed on an additive scale.

Results

A total of 1432 children (792 [55.3%] boys; 1126 [78.6%] with gestational age ≥37 weeks) were identified with iGBS disease: 1264 with sepsis and 168 with meningitis. In the comparison cohort, there were 14 211 children (7869 [55.4%] boys; 11 260 [79.2%] with gestational age ≥37 weeks). The overall (0 to 22 years) CR of epilepsy was 3.6% (95% CI, 2.6%-5.0%) in children with iGBS disease and 2.3% (95% CI, 1.9%-2.7%) in the comparison cohort. The overall CR of epilepsy for iGBS meningitis was 15.1% (95% CI, 8.9%-22.8%) and 2.2% (95% CI, 1.4%-3.4%) for iGBS sepsis. The adjusted hazard ratio for epilepsy in children with iGBS disease was 2.04 (95% CI, 1.46-2.85). Being a boy, born premature, or born to a mother belonging to a low SEP group was associated with an increased risk of epilepsy in later childhood.

Conclusion

In this population-based cohort study of 1432 neonates, iGBS disease was associated with a higher incidence of epilepsy in later childhood, notably after meningitis. Premature birth, sex, and low maternal SEP modified the association.

High Glucose Promotes Inflammation and Weakens Placental Defenses against E. coli and S. agalactiae Infection: Protective Role of Insulin and Metformin

Placentas from gestational diabetes mellitus (GDM) patients undergo significant metabolic and immunologic adaptations due to hyperglycemia, which results in an exacerbated synthesis of proinflammatory cytokines and an increased risk for infections. Insulin or metformin are clinically indicated for the treatment of GDM; however, there is limited information about the immunomodulatory activity of these drugs in the human placenta, especially in the context of maternal infections. Our objective was to study the role of insulin and metformin in the placental inflammatory response and innate defense against common etiopathological agents of pregnancy bacterial infections, such as E. coli and S. agalactiae, in a hyperglycemic environment. Term placental explants were cultivated with glucose (10 and 50 mM), insulin (50–500 nM) or metformin (125–500 µM) for 48 h, and then they were challenged with live bacteria (1 × 105 CFU/mL). We evaluated the inflammatory cytokine secretion, beta defensins production, bacterial count and bacterial tissue invasiveness after 4–8 h of infection. Our results showed that a GDM-associated hyperglycemic environment induced an inflammatory response and a decreased beta defensins synthesis unable to restrain bacterial infection. Notably, both insulin and metformin exerted anti-inflammatory effects under hyperglycemic infectious and non-infectious scenarios. Moreover, both drugs fortified placental barrier defenses, resulting in reduced E. coli counts, as well as decreased S. agalactiae and E. coli invasiveness of placental villous trees. Remarkably, the double challenge of high glucose and infection provoked a pathogen-specific attenuated placental inflammatory response in the hyperglycemic condition, mainly denoted by reduced TNF-α and IL-6 secretion after S. agalactiae infection and by IL-1β after E. coli infection. Altogether, these results suggest that metabolically uncontrolled GDM mothers develop diverse immune placental alterations, which may help to explain their increased vulnerability to bacterial pathogens.

Evaluating the cost-effectiveness of testing pregnant women for penicillin allergy

INTRODUCTION

True penicillin allergy is rare and is commonly incorrectly reported. In fact, less than five percent of patients who report a penicillin allergy will have a currently active clinically-significant IgE- or T-cell-mediated hypersensitivity when appropriately tested. Penicillin is the agent of choice for intrapartum antibiotic prophylaxis to reduce the risk of group B streptococcus early-onset disease in the newborn. Inaccurate penicillin allergy status may lead to inappropriate antibiotic use, as most alternative drugs are more expensive and broader spectrum than penicillin. Penicillin allergy testing has been found to be safe in pregnancy and cost-effective in other patient populations.

OBJECTIVE

To evaluate the cost-effectiveness of penicillin allergy testing and appropriate antibiotic treatment (test then treat strategy) compared to usual care among pregnant women.

METHODS

We developed a decision tree to evaluate the cost of providing appropriate care via a test then treat strategy for pregnant women who report a penicillin allergy, compared to usual care.

RESULTS

Using the test then treat strategy the additional cost to ensure appropriate care for all pregnant women who report a penicillin allergy, was $1122.38 per person. Adopting a test then treat strategy increased the number of appropriate antibiotic use from 7,843/10,000 to 10,000/10,000 simulations.

CONCLUSION

Our results show that a test then treat strategy for pregnant women who report a penicillin allergy is a good-value intervention.

Advances towards licensure of a maternal vaccine for the prevention of invasive group B streptococcus disease in infants: a discussion of different approaches

Group B streptococcus (Streptococcus agalactiae, GBS) is an important cause of life-threatening disease in newborns. Pregnant women colonized with GBS can transmit the bacteria to the developing fetus, as well as to their neonates during or after delivery where infection can lead to sepsis, meningitis, pneumonia, or/and death. While intrapartum antibiotic prophylaxis (IAP) is the standard of care for prevention of invasive GBS disease in some countries, even in such settings a substantial residual burden of disease remains. A GBS vaccine administered during pregnancy could potentially address this important unmet medical need and provide an adjunct or alternative to IAP for the prevention of invasive GBS disease in neonates. A hurdle for vaccine development has been relatively low disease rates making efficacy studies difficult. Given the well-accepted inverse relationship between anti-GBS capsular polysaccharide antibody titers at birth and risk of disease, licensure using serological criteria as a surrogate biomarker represents a promising approach to accelerate the availability of a GBS vaccine.

Transmission of Group B Streptococcus in late-onset neonatal disease: a narrative review of current evidence

Group B streptococcus (GBS) late-onset disease (LOD, occurring from 7 through 89 days of life) is an important cause of sepsis and meningitis in infants. The pathogenesis and modes of transmission of LOD to neonates are yet to be elucidated. Established risk factors for the incidence of LOD include maternal GBS colonisation, young maternal age, preterm birth, HIV exposure and African ethnicity. The mucosal colonisation by GBS may be acquired perinatally or in the postpartum period from maternal or other sources. Growing evidence has demonstrated the predominant role of maternal sources in the transmission of LOD. Intrapartum antibiotic prophylaxis (IAP) to prevent early-onset disease reduces neonatal GBS colonisation during delivery; however, a significant proportion of IAP-exposed neonates born to GBS-carrier mothers acquire the pathogen at mucosal sites in the first weeks of life. GBS-infected breast milk, with or without presence of mastitis, is considered a potential vehicle for transmitting GBS. Furthermore, horizontal transmission is possible from nosocomial and other community sources. Although unfrequently reported, nosocomial transmission of GBS in the neonatal intensive care unit is probably less rare than is usually believed. GBS disease can sometime recur and is usually caused by the same GBS serotype that caused the primary infection. This review aims to discuss the dynamics of transmission of GBS in the neonatal LOD.

Group B Streptococcus adaptation promotes survival in a hyperinflammatory diabetic wound environment

Diabetic wounds have poor healing outcomes due to the presence of numerous pathogens and a dysregulated immune response. Group B Streptococcus (GBS) is commonly isolated from diabetic wound infections, but the mechanisms of GBS virulence during these infections have not been investigated. Here, we develop a murine model of GBS diabetic wound infection and, using dual RNA sequencing, demonstrate that GBS infection triggers an inflammatory response. GBS adapts to this hyperinflammatory environment by up-regulating virulence factors including those known to be regulated by the two-component system covRS, such as the surface protein pbsP, and the cyl operon, which is responsible for hemolysin/pigmentation production. We recover hyperpigmented/hemolytic GBS colonies from the murine diabetic wound, which we determined encode mutations in covR. We further demonstrate that GBS mutants in cylE and pbsP are attenuated in the diabetic wound. This foundational study provides insight into the pathogenesis of GBS diabetic wound infections.

Is it safe and effective to administer COVID-19 vaccines during pregnancy? A systematic review and meta-analysis

OBJECTIVE

To evaluate the safety and efficacy of COVID-19 vaccines in pregnant women performing an updated meta-analysis.

METHODS

We searched PubMed, Cochrane Central, and SCOPUS from inception to March 2022. Outcomes of interest were incidence of adverse maternal, fetal and neonatal consequences pertaining to safety of the vaccines. Secondarily, we analyzed the number of SARS-CoV-2 infections, hospitalization for COVID-19, and admission to the I.C.U. for COVID-19 assessing effectiveness of vaccines. Results were pooled using a random effects model.

RESULTS

Ten observational studies (n=326,499) analyzing pregnant women were included. Our results suggest that COVID-19 vaccination prevents infection (OR: 0.56, 95% CI: 0.47, 0.67; P = <0.00001) and related hospitalizations (OR: 0.50, 95% CI: 0.31, 0.82; P = 0.006) effectively. It was also observed that vaccination does not change adverse outcomes in pregnancy, namely preeclampsia or eclampsia, stroke (four weeks of delivery), meconium-stained amniotic fluid, spontaneous vaginal delivery, operative vaginal delivery, cesarean delivery, postpartum hemorrhage, and blood transfusions. Furthermore, the vaccine was observed to be protective against neonatal COVID-19 I.C.U. admissions (OR: 0.85; 95% CI: 0.81, 0.90; P = <0.00001).

CONCLUSION

Our pooled analysis suggests that the COVID-19 vaccination in pregnant women prevents infection effectively and has no adverse outcomes. Future large-scale trials in a randomized fashion are needed to confirm our results.

False-positive detection of Group B Streptococcus (GBS) in chromogenic media (Strep B Carrot Broth) due to presence of Enterococcus faecalis in High Vaginal swabs

Introduction. Vaginal colonization of Group B Streptococcus (GBS) is associated with preterm births and neonatal sepsis. Thus routine screening of GBS in prenatal care is recommended.Hypothesis. Chromogenic media (carrot broth) aids in specific and rapid detection of GBS.Aim. To investigate the efficiency of Strep B Carrot Broth for detection of GBS in high vaginal swabs from pregnant women.Methods. In this study 201 vaginal swab samples were collected from pregnant women. Swabs were inoculated in chromogenic media (Strep B Carrot Broth). The positive and negative cultures were inoculated on blood agar and crome agar plates. The colonies were subjected to 16S rRNA sequencing and gene-specific PCR for confirmation. The Christie Atkins Munch Peterson (CAMP) and bile esculin agar (BEA) tests were used for biochemical confirmation. PCR was performed on genomic DNA isolated from uncultured vaginal swabs.Results. It was found that 20/201 (9.9 %) vaginal swab samples were positive in the Strep B Carrot Broth and 17/20 (85 %) and 19/20 (95 %) of these samples yielded colonies on blood agar and crome agar, respectively. Of the 181 carrot broth-negative samples, 1 (0.5 %) and 38 (20.9 %) yielded colonies on blood agar and crome agar plates, respectively. However, 16 s rRNA sequencing revealed that none of the 20 carrot broth-positive cultures were GBS and had sequence similarities to Enterococcus faecalis. This was also confirmed by using gene-specific PCR and BEA positivity. Furthermore, E. faecalis was detected by PCR in DNA isolated from 57 uncultured vaginal swabs samples, GBS could only be detected by PCR in four samples.Conclusion. Carrot broth-based culture can lead to false-positive detection due to the presence of E. faecalis. Thus GBS-positive results in carrot broth must be confirmed by the other molecular and biochemical tests before making a final diagnosis.

Adherence to screening and management guidelines of maternal Group B Streptococcus colonization in pregnancy

Aims

To investigate Group B Streptococcus (GBS) colonization in pregnancy; adherence to antenatal GBS screening and adherence to the intrapartum antibiotics protocol within two models of care (midwifery and non‐midwifery led).

Design

This retrospective quantitative study has employed a descriptive design using administrative health data.

Methods

Data from five maternity hospitals in metropolitan and regional Western Australia that included 22,417 pregnant women who gave birth between 2015 and 2019 were examined, applying descriptive statistics using secondary data analysis.

Results

The study revealed an overall GBS colonization rate of 21.7% with similar rates in the different cohorts. A lower adherence to screening was found in the midwifery led model of care (MMC, 68.76%, n = 7232) when compared with the non‐midwifery led model of care (NMMC, 90.49%, n = 10,767). Over the 5 years, screening rates trended down in the MMC with stable numbers in the counterpart. Adherence in relation to intrapartum antibiotic prophylaxis revealed discrepant findings between the study groups.

Conclusion

Adherence to screening and management guidelines of maternal GBS colonization in pregnancy is lower within the MMC when compared with the NMMC.

Impact

This is the first cohort study to describe the adherence to the recommended Western Australian GBS screening guidelines in the two different models of care. Findings may assist in the guidance and improvement of clinical protocols as well as the planning of clinical care in relation to GBS screening to reduce the risk of neonatal GBS infection.

Influence of Penicillin on Biofilm Formation by Streptococcus agalactiae Serotype Ia/CC23

Streptococcus agalactiae (Group B Streptococcus , GBS) is a major agent of perinatal infections. Biofilms have been associated with GBS colonization and disease, as well as with infection persistence and recurrence. Although GBS remains susceptible to beta-lactams, it is still unknown how sessile cells respond to these antibiotics. Here, we evaluated the effect of different concentrations of penicillin (3-48 mg/L) on in vitro biofilm formation by four GBS strains belonging to serotype Ia/clonal complexes23 that were recovered from the oropharynx or urine of pregnant women and were previously characterized as strong biofilm producers. All four GBS strains were fully susceptible to penicillin (minimum inhibitory concentration = 0.023 mg/L), but penicillin was not able to fully prevent biofilm formation by these GBS strains. Biofilms formed in the presence of penicillin had reduced biomasses and thickness, but they were still classified as strong. Penicillin significantly reduced the density of live cells, but higher penicillin concentrations did not lead to improved prevention of biofilm formation. Biofilms formed in the presence of penicillin had no channels or long cocci chains observed in penicillin-free biofilms. Overall, results highlight the concerning possible impacts of biofilm formation in penicillin-based treatment and preventive strategies of GBS infections, even when the bacterial strain involved is fully antibiotic-susceptible.

High rates of colonization and antimicrobial resistance of group B streptococcus highlight the need for vaccination even after implementation of guidelines for intrapartum antibiotic prophylaxis

INTRODUCTION

It is estimated that about 11-35% of pregnant women are colonized with Group B streptococcus. Intrapartum antibiotic prophylaxis (IAP) is the primary intervention to decrease the risk of infecting babies born to GBS colonized mothers.

METHODS

A total of 5,996 pregnant women, who received the Taiwanese universal GBS screening program from 2012 to 2020, were included in this study that investigated GBS colonization, antimicrobial resistance rates and their neonatal incidence of invasive GBS infection.

RESULTS

The average GBS colonization rate was 18.5%. Older age groups had higher colonization rates than younger age groups. Compared to Taiwanese, immigrant women from Indonesia had a greater positive rate. GBS isolated from Vietnamese women had significant greater resistance to clindamycin relative to Taiwanese women. Rates of resistance to erythromycin increase from 35.5% to 45.5% over the 9 years of measurements. The incidence of invasive GBS disease was about 0.6/1,000 (4/6,204) live births during the study.

CONCLUSIONS

Although relatively low incidence of invasive GBS diseases was observed after implementation of IAP, the colonization of GBS remains high and antimicrobial resistance of GBS is increasing. An effective GBS vaccine holds promise to be a solution for these issues.

Group B streptococcal infection of the genitourinary tract in pregnant and non-pregnant patients with diabetes mellitus: An immunocompromised host or something more?

Group B Streptococcus (GBS), also known as Streptococcus agalactiae is a Gram-positive bacterium commonly encountered as part of the microbiota within the human gastrointestinal tract. A common cause of infections during pregnancy, GBS is responsible for invasive diseases ranging from urinary tract infections to chorioamnionitis and neonatal sepsis. Diabetes mellitus (DM) is a chronic disease resulting from impaired regulation of blood glucose levels. The incidence of DM has steadily increased worldwide to affecting over 450 million people. Poorly controlled DM is associated with multiple health comorbidities including an increased risk for infection. Epidemiologic studies have clearly demonstrated that DM correlates with an increased risk for invasive GBS infections, including skin and soft tissue infections and sepsis in non-pregnant adults. However, the impact of DM on risk for invasive GBS urogenital infections, particularly during the already vulnerable time of pregnancy, is less clear. We review the evolving epidemiology, immunology, and pathophysiology of GBS urogenital infections including rectovaginal colonization during pregnancy, neonatal infections of infants exposed to DM in utero, and urinary tract infections in pregnant and non-pregnant adults in the context of DM and highlight in vitro studies examining why DM might increase risk for GBS urogenital infection.

Analysis of Susceptibility to the Antimicrobial and Anti-Biofilm Activity of Human Milk Lactoferrin in Clinical Strains of Streptococcus agalactiae With Diverse Capsular and Sequence Types

Group B Streptococcus (GBS) is one of the leading infection-related causes of adverse maternal and neonatal outcomes. This includes chorioamnionitis, which leads to preterm ruptures of membranes and can ultimately result in preterm or stillbirth. Infection can also lead to maternal and neonatal sepsis that may contribute to mortality. Currently, treatment for GBS infection include a bolus of intrapartum antibiotic prophylaxis to mothers testing positive for GBS colonization during late pregnancy. Lactoferrin is an antimicrobial peptide expressed in human breast milk, mucosal epithelia, and secondary granules of neutrophils. We previously demonstrated that lactoferrin possesses antimicrobial and antibiofilm properties against several strains of GBS. This is largely due to the ability of lactoferrin to bind and sequester iron. We expanded upon that study by assessing the effects of purified human breast milk lactoferrin against a panel of phenotypically and genetically diverse isolates of GBS. Of the 25 GBS isolates screened, lactoferrin reduced bacterial growth in 14 and biofilm formation in 21 strains. Stratifying the data, we observed that colonizing strains were more susceptible to the growth inhibition activity of lactoferrin than invasive isolates at lactoferrin concentrations between 250-750 µg/mL. Treatment with 750 µg/mL of lactoferrin resulted in differences in bacterial growth and biofilm formation between discrete sequence types. Differences in bacterial growth were also observed between capsular serotypes 1a and III. Maternally isolated strains were more susceptible to lactoferrin with respect to bacterial growth, but not biofilm formation, compared to neonatal sepsis isolates. Finally, high biofilm forming GBS strains were more impacted by lactoferrin across all isolates tested. Taken together, this study demonstrates that lactoferrin possesses antimicrobial and antibiofilm properties against a wide range of GBS isolates, with maternally isolated colonizing strains being the most susceptible.

Is Group B Streptococcus Colonization Associated with Maternal Peripartum Infection in an Era of Routine Prophylaxis?

OBJECTIVE

This study aimed to assess whether colonization with group B streptococcus (GBS) is associated with maternal peripartum infection in an era of routine prophylaxis.

STUDY DESIGN

This study presented a secondary analysis of women delivering ≥37 weeks who underwent a trial of labor from the U.S. Consortium on Safe Labor (CSL) study. The exposure was maternal GBS colonization and the outcome was a diagnosis of chorioamnionitis, and secondarily, analyses were restricted to deliveries not admitted in labor and measures of postpartum infection (postpartum fever, endometritis, and surgical site infection). Logistic regression with generalized estimating equations was used accounting for within-woman correlations. Models adjusted for maternal age, parity, race, prepregnancy body mass index, pregestational diabetes, insurance status, study site/region, year of delivery, number of vaginal exams from admission to delivery, and time (in hours) from admission to delivery.

RESULTS

Among 170,804 assessed women, 33,877 (19.8%) were colonized with GBS and 5,172 (3.0%) were diagnosed with chorioamnionitis. While the frequency of GBS colonization did not vary by chorioamnionitis status (3.0% in both groups), in multivariable analyses, GBS colonization was associated with slightly lower odds of chorioamnionitis (adjusted odds ratio [AOR]: 0.89; 95% confidence interval [CI]: 0.83-0.96). In secondary analyses, this association held regardless of spontaneous labor on admission; and the odds of postpartum infectious outcomes were not higher with GBS colonization.

CONCLUSION

In contrast to historical data, GBS colonization was associated with lower odds of chorioamnionitis in an era of routine GBS screening and prophylaxis.

KEY POINTS

· Data in an era prior to routine group B streptococcus (GBS) screening and prophylaxis showed that maternal GBS colonization was associated with a higher frequency of maternal peripartum infection.. · In the current study, GBS colonization was associated with lower odds of chorioamnionitis in an era of routine GBS screening and prophylaxis.. · The results highlight potential benefits of GBS screening and intrapartum antibiotic prophylaxis beyond neonatal disease prevention, including mitigating the risk of maternal infectious morbidity..

Ruptured Renal Abscess From Streptococcus agalactiae Invasion in a Postpartum Female

Streptococcus agalactiae (Group B Streptococcus or GBS)is an exceptionally rare causative organism of a ruptured renal abscess. We report a case of this normally commensal organism causing a large ruptured renal abscess in a 17-year-old postpartum female. Although S. agalactiae is known to cause postpartum neonatal morbidity and mortality, it has rarely caused invasive infections in the last 20 years in adults. While this diagnosis often presents with nonspecific findings that can easily be overlooked during the postpartum period, the patient responded well to the established treatment of broad-spectrum antibiotics and a percutaneous drain.

Prevalence, serotype and antibiotic susceptibility of Group B Streptococcus isolated from pregnant women in Jakarta, Indonesia

Group B Streptococcus (GBS) is a bacterial pathogen which is a leading cause of neonatal infection. Currently, there are limited GBS data available from the Indonesian population. In this study, GBS colonization, serotype distribution and antimicrobial susceptibility profile of isolates were investigated among pregnant women in Jakarta, Indonesia. Demographics data, clinical characteristics and vaginal swabs were collected from 177 pregnant women (mean aged: 28.7 years old) at 29–40 weeks of gestation. Bacterial culture identification tests and latex agglutination were performed for GBS. Serotyping was done by conventional multiplex PCR and antibiotic susceptibility testing by broth microdilution. GBS colonization was found in 53 (30%) pregnant women. Serotype II was the most common serotype (30%) followed by serotype III (23%), Ia and IV (13% each), VI (8%), Ib and V (6% each), and one non-typeable strain. All isolates were susceptible to vancomycin, penicillin, ampicillin, cefotaxime, daptomycin and linezolid. The majority of GBS were resistant to tetracycline (89%) followed by clindamycin (21%), erythromycin (19%), and levofloxacin (6%). The serotype III was more resistant to erythromycin, clindamycin, and levofloxacin and these isolates were more likely to be multidrug resistant (6 out of 10) compared to other serotypes. This report provides demographics of GBS colonization and isolate characterization in pregnant women in Indonesia. The results may facilitate preventive strategies to reduce neonatal GBS infection and improve its treatment.

Diagnostic Performance of Various Methodologies for Group B Streptococcus Screening in Pregnant Woman in China

Maternal vaginal/rectal colonization of group B streptococcus (GBS) is a main risk for neonatal invasive infection. Efficient determination of GBS colonization in pregnant women is crucial. This study aimed to investigate the prevalence of GBS carriage and evaluate the diagnostic performance of six methodologies for GBS screening conducted in China, including blood agar plate, liquid chromogenic medium, and loop-mediated isothermal amplification (LAMP) without pre-enrichment, chromogenic agar plate with pre-enrichment, and GBS antigen detection without and with pre-enrichment in comparison with the standard reference method (Lim broth-enriched subculture with plating on 5% sheep blood agar). Vaginal/rectal swabs were collected from 1,281 pregnant women at 35–37 weeks of gestation. Of them, 309 were taken in triplicate, one for Lim broth-enriched subculture, one for blood agar plate, and the third for GBS antigen detection (Reagent W); 177 were acquired in duplicate, one for Lim broth-enriched subculture and the other for GBS antigen detection (Reagent H); 502 were obtained in duplicate, one for Lim broth-enriched subculture and the other for liquid chromogenic medium; 158 were collected in duplicate, one for Lim broth-enriched subculture and the other for LAMP; and 135 were inoculated in Lim broth-enriched for GBS antigen detection (Reagent W) and subculture with chromogenic agar plate and 5% blood agar plate. The overall prevalence of GBS carriage was 10.1% (130/1,281, 95% CI: 8.5–12.1%) according to the standard reference method. Compared with the standard reference method, the LAMP had excellent performance of sensitivity (100%, 95%CI: 83.4–100%), specificity (94%, 95%CI: 88.1–97.1%), and Yoden index (0.940); as well as the blood agar plate with sensitivity (81.5%, 95%CI: 61.3–93.0%), specificity (100%, 95%CI: 98.3–100.0%), and Yoden index (0.815). The other four methods were not sufficient to reach the threshold in terms of sensitivity or specificity compared to the standard reference method. Furthermore, for LAMP, results can be obtained within 0.5–1 h, while for blood agar plate, which needed 24–48 h, and further identification was required. Our data suggested that the performance of LAMP was highly comparable to the standard Lim broth-enriched subculture and LAMP is considered as an alternative for fast and accurate GBS screening.

Vaginal streptococcus B colonization is not associated with increased infectious morbidity in labor induction

INTRODUCTION

Labor induction rates are increasing and, in Finland today, one of three labors is induced. Group B streptococcus (GBS) is a bacterium found in 10%-30% of pregnant women and it can be transmitted to the neonate during vaginal delivery. Although GBS is rarely harmful in the general population, it is the leading cause of severe neonatal infections such as sepsis, pneumonia, and meningitis. In addition, GBS can cause maternal morbidity. Labor induction in GBS-positive women has not yet been investigated but concerns of infectious morbidity associated with balloon catheters have been raised.

MATERIAL AND METHODS

A historical cohort study of 1959 women undergoing labor induction by balloon catheter in Helsinki University Hospital, Finland, between January 1, 2014 and December 31, 2017. Women with viable singleton term pregnancy in cephalic presentation, unfavorable cervix (Bishop score <6), and intact amniotic membranes were included. GBS was screened by rapid qualitative in vitro test (XPert^® GBS) from vaginal and perineal culture upon admission for labor induction. All women testing positive received prophylactic antibiotics.

RESULTS

Of the women, 469 (23.9%) were GBS-positive. The rate of maternal intrapartum infection was 7.4%, being lower in the GBS-positive group compared with the GBS-negative group (4.7% vs 8.3%; p = 0.01). The rate of maternal postpartum infection was 3.9%, and the rate of neonatal infection was 3.3%, both being similar between the groups. Also, no difference in the rates of other adverse neonatal outcomes was seen. No GBS sepses occurred in the study. In multivariable logistic regression, rupture of membranes to delivery interval ≥12 hours was associated with maternal intrapartum and postpartum infection, as well as neonatal infection. Other risk factors for maternal intrapartum infection were GBS-negativity, nulliparity, prolonged pregnancy (≥41 weeks), and Bishop score <3 at the start of induction. Cesarean section was associated with postpartum endometritis, while nulliparity, gestational diabetes, and maternal intrapartum infection were associated with neonatal infection.

CONCLUSIONS

Regarding maternal and neonatal infectious morbidity, labor induction with balloon catheter appears safe in women colonized with GBS when prophylactic antibiotics are administered at the onset of labor or at membrane rupture.

A current review of pathogenicity determinants of Streptococcus sp

The genus Streptococcus comprises important pathogens, many of them are part of the human or animal microbiota. Advances in molecular genetics, taxonomic approaches and phylogenomic studies have led to the establishment of at least 100 species that have a severe impact on human health and are responsible for substantial economic losses to agriculture. The infectivity of the pathogens is linked to cell-surface components and/or secreted virulence factors. Bacteria have evolved sophisticated and multifaceted adaptation strategies to the host environment, including biofilm formation, survival within professional phagocytes, escape the host immune response, amongst others. This review focuses on virulence mechanism and zoonotic potential of Streptococcus species from pyogenic (S. agalactiae, S. pyogenes) and mitis groups (S. pneumoniae).

Streptococcus agalactiae: Sensitivity profile in pregnant women attending health units in northeastern Brazil

BACKGROUND

Group B Streptococcus agalactiae (GBS) is the main etiologic agent associated with early-onset neonatal sepsis, and of all newborns of parturients colonized by GBS, approximately 1%-2% develop invasive, early-onset disease. The risk of infection increases to 15.2% in premature neonates, to 10.7% when the parturient has chorioamnionitis or premature rupture of membranes for more than 24 h and to 9.7% if the mother has postpartum bacteremia. In addition to causing perinatal, neonatal and postnatal deaths, neonatal hospital infection is associated with high costs, as hospitalization is three times longer than in uninfected children. The identification of pregnant women colonized by GBS, through universal screening, associated with the adoption of appropriate antibiotics at the time of delivery are the most successful preventive measures.

AIM

To evaluate the sensitivity profile of GBS isolated from pregnant women attending Vitória da Conquista-BA.

METHODS

This is a cross-sectional study with a quantitative approach carried out in the municipality of Vitória da Conquista-Bahia between February 2017 and March 2018. The study population was composed of 210 pregnant women, with a gestational age of 32 to 40 wk, who were aged 18 years or older living in the urban area of the municipality of Vitória da Conquista. After a brief explanation about the research and obtaining a signed an informed consent form, data and vaginorectal swabs were collected from the women for GBS research. Examination of the samples in order to identify the presence of GBS was by culture on sheep blood agar and chromogenic agar for GBS and then, seeded on plates containing streptococcal culture medium and incubated for 18 h to 24 h at 35°C. The antimicrobial sensitivity profile of positive GBS samples was determined by the disk diffusion technique, according to the Clinical and Laboratory Standards Institute manual (2017). The data obtained were stored in a database using Microsoft Office Excel spreadsheets and a descriptive analysis was performed with the aid of the EPI-INFO statistical package (version 3.5.2).

RESULTS

Among the 210 pregnant women participating in the study, 38 (18.1%) had a positive GBS culture. All strains isolated from GBS were sensitive to 10 U penicillin, 10 µg ampicillin, 30 µg cefotaxime and 30 µg vancomycin. Seven strains (18.4%) resistant to clindamycin 2 µg and eight (21.1%) resistant to erythromycin 15 µg were found. Of these, six were concomitantly resistant to erythromycin and clindamycin, two resistant only to erythromycin and one resistant only to clindamycin. All nine GBS isolates that showed resistance to erythromycin and/or clindamycin showed negative results on the D-test. Two thirds of the isolates showed cMLSB phenotype and resistance only to erythromycin in specimens in this study (02), refers to strains with phenotype M and resistance to clindamycin (01) only with phenotype L.

CONCLUSION

Chemoprophylaxis for GBS in pregnant women, especially for those allergic to penicillin, should be guided by an antimicrobial susceptibility test as resistant GBS strains were reported in this study.

Group B streptococcal colonization: Prevalence and impact of smoking in women delivering term or near term neonates in a large tertiary care hospital in the southern United States

BACKGROUND AND HYPOTHESIS

The role of smoking as a risk factor for group B streptococcal (GBS) colonization in women during pregnancy has not been previously adequately explored. We hypothesized that women of term or near term neonates who smoked during pregnancy were more likely to have GBS colonization than their non-smoking counterparts.

METHODS

The electronic health records (EHRs) of a convenience sample of women delivering in an inner-city university tertiary care center were reviewed. The outcome variable of interest was maternal GBS colonization during pregnancy. The primary independent variable of interest was tobacco smoking during pregnancy, determined from the EHRs by the number of cigarettes smoked during gestation. Descriptive statistics were conducted and categorical data were compared by the Fischer's exact test. Multiple logistic regression analysis was further conducted to determine the independent impact of tobacco smoke exposure on GBS colonization.

RESULTS

The prevalence of maternal GBS colonization was 35% among the study population. In the univariate analyses, factors associated with maternal GBS colonization were tobacco smoking during pregnancy (P of trend <0.001), Race (P<0.001), maternal age <20 years (P = 0.006), low birthweight <2500 gm (P = 0.020), maternal drug use (P = 004), and gestational age <37 (P = 0.041). In a multiple logistic regression analysis, tobacco smoking during pregnancy remained the most significant predictor of GBS colonization. Women who smoked during pregnancy were more than twice more likely to be colonized than their non-smoking counterparts (OR = 2.6; 95% CI = 1.5-4.6; p<0.001). Maternal age was the only other significant predictor with younger mothers more than one and a half time more likely to be colonized than their older counterparts (OR = 1.65; 95% CI = 1.02-2.68; P = 0.04).

CONCLUSION

The prevalence of GBS colonization in this institution was consistent with recent national rates. Smoking and maternal age were identified as two independent risk factors for GBS colonization during pregnancy. Further studies are needed to confirm these findings.

Asymptomatic GBS bacteriuria during antenatal visits: To treat or not to treat?

Inconsistencies persist regarding the efficacy of treating asymptomatic group B Streptococcus bacteriuria in pregnant individuals with colony counts below 10 (100,000) CFU/mL. Despite these discrepancies, treatment still occurs. This article examines the role of screening and treatment, evidence-based guidelines, and practice patterns to provide clarification and resolve local practice disparities.

A Solution to Antifolate Resistance in Group B Streptococcus: Untargeted Metabolomics Identifies Human Milk Oligosaccharide-Induced Perturbations That Result in Potentiation of Trimethoprim

Adjuvants can be used to potentiate the function of antibiotics whose efficacy has been reduced by acquired or intrinsic resistance. In the present study, we discovered that human milk oligosaccharides (HMOs) sensitize strains of group B Streptococcus (GBS) to trimethoprim (TMP), an antibiotic to which GBS is intrinsically resistant. Reductions in the MIC of TMP reached as high as 512-fold across a diverse panel of isolates. To better understand HMOs' mechanism of action, we characterized the metabolic response of GBS to HMO treatment using ultrahigh-performance liquid chromatography-high-resolution tandem mass spectrometry (UPLC-HRMS/MS) analysis. These data showed that when challenged by HMOs, GBS undergoes significant perturbations in metabolic pathways related to the biosynthesis and incorporation of macromolecules involved in membrane construction. This study represents reports the metabolic characterization of a cell that is perturbed by HMOs.IMPORTANCE Group B Streptococcus is an important human pathogen that causes serious infections during pregnancy which can lead to chorioamnionitis, funisitis, premature rupture of gestational membranes, preterm birth, neonatal sepsis, and death. GBS is evolving antimicrobial resistance mechanisms, and the work presented in this paper provides evidence that prebiotics such as human milk oligosaccharides can act as adjuvants to restore the utility of antibiotics.

Prevalence of rectovaginal colonization by group B Streptococcus in pregnant women seen at prenatal care program of a health organization

Objective

To evaluate the prevalence of group B Streptococci in pregnant women of a corporate health program, as well as the epidemiological correlations.

Methods

This retrospective study used medical records of patients who participated of the prenatal care program at a private hospital in the city of São Paulo (SP), Brazil, from 2015 to 2016. Those who abandoned the program or had incomplete data in their medical records were excluded. Quantitative variables were described by means, standard deviations, median, minimal and maximal values. Parity and socioeconomic status were described by absolute frequency and percentages. We used logistic regression models in the software (SPSS) to analyze correlations of variables according to vaginal-rectal culture, considering a 95%CI and p-values. Variables were age, number of pregnancies, weight gain in pregnancy and gestational age at delivery.

Results

A total of 347 medical records were included, and after applying the exclusion criteria, 287 medical records composed the final sample. Patients’ age ranged between 17 and 44 years. Mean age was 30.6 years, 67 patients had positive result for group B Streptococcus (prevalence of 23.3%; 95%CI: 18.7-28.5).

Conclusion

Considering the high prevalence of group B Streptococcus in our service, the antibiotic prophylaxis strategy based on rectovaginal culture screening approach seems to be cost-effective.

Temporal development of the infant gut microbiome

The majority of organisms that inhabit the human body reside in the gut. Since babies are born with an immature immune system, they depend on a highly synchronized microbial colonization process to ensure the correct microbes are present for optimal immune function and development. In a balanced microbiome, symbiotic and commensal species outcompete pathogens for resources. They also provide a protective barrier against chemical signals and toxic metabolites. In this targeted review we will describe factors that influence the temporal development of the infant microbiome, including the mode of delivery and gestational age at birth, maternal and infant perinatal antibiotic infusions, and feeding method-breastfeeding versus formula feeding. We will close by discussing wider environmental pressures and early intimate contact, particularly between mother and child, as they play a pivotal role in early microbial acquisition and community succession in the infant.