Prevention of Group B Streptococcal Early-Onset Disease in Newborns: ACOG Committee Opinion, Number 797

Spatial profiling of the placental chorioamniotic membranes reveals upregulation of immune checkpoint proteins during Group B Streptococcus infection in a nonhuman primate model

Background

Preterm birth is a leading cause of neonatal mortality, which is often complicated by intrauterine infection and inflammation. We have established a nonhuman primate model of Group B Streptococcus (GBS, Streptococcus agalactiae) infection-associated preterm birth. Immune checkpoints are modulators of the immune response by activating or suppressing leukocyte function and are understudied in preterm birth. The objective of this study was to spatially profile changes in immune protein expression at the maternal-fetal interface during a GBS infection with a focus on immune checkpoints.

Methods

Twelve nonhuman primates (pigtail macaques, Macaca nemestrina) received a choriodecidual inoculation of either: 1) 1-5 X 108 colony forming units (CFU) of hyperhemolytic/hypervirulent GBS (GBSΔcovR, N=4); 2) an isogenic/nonpigmented strain (GBS ΔcovRΔcylE, N=4); or, 3) saline (N=4). A Cesarean section was performed at preterm labor or 3 days after GBS infection or 7 days after saline inoculation. Nanostring GeoMx® Digital Spatial Profiling technology was used to segment protein expression within the amnion, chorion, and maternal decidua at the inoculation site using an immuno-oncology panel targeting 56 immunoproteins enriched in stimulatory and inhibitory immune checkpoint proteins or their protein ligands. Statistical analysis included R studio, Kruskal-Wallis, Pearson and Spearman tests.

Results

Both inhibitory and stimulatory immune checkpoint proteins were significantly upregulated within the chorioamniotic membranes and decidua (VISTA, LAG3, PD-1, CD40, GITR), as well as their ligands (PD-L1, PD-L2, CD40L; all p<0.05). Immunostaining for VISTA revealed positive (VISTA+) cells, predominantly in the chorion and decidua. There were strong correlations between VISTA and amniotic fluid concentrations of IL-1β, IL-6, IL-8, and TNF-α (all p<0.05), as well as maternal placental histopathology scores (p<0.05).

Conclusion

Differential regulation of multiple immune checkpoint proteins in the decidua at the site of a GBS infection indicates a major perturbation in immunologic homeostasis that could benefit the host by restricting immune-driven pathologies or the pathogen by limiting immune surveillance. Protein expression of VISTA, an inhibitory immune checkpoint, was upregulated in the chorion and decidua after GBS infection. Investigating the impact of innate immune cell expression of inhibitory immune checkpoints may reveal new insights into placental host-pathogen interactions at the maternal-fetal interface.

Pre-labour Rupture of Membranes at Term in Women With Gestational Diabetes and the Risk of Neonatal Hypoglycemia

OBJECTIVES

The management for improving maternal and neonatal outcomes of women with gestational diabetes mellitus (GDM) arriving at the delivery ward with pre-labour rupture of membranes (PROM) has not been elucidated. We tested the hypothesis that prolonged PROM in women with GDM would result in higher rates of neonatal hypoglycemia.

METHODS

We retrospectively enrolled women with diet or insulin-controlled GDM who presented with spontaneous clear PROM. Each woman was allocated into one of two groups based on the PROM-delivery time: <18 hours (group 1) and ≥18 hours (group 2). The primary outcome was the incidence of neonatal hypoglycemia, defined as glucose <40 mg/dL (2.2 mmol/L) within 24 hours of birth.

RESULTS

We ultimately analyzed 631 cases of GDM (6.7%), 371 with PROM-delivery <18 hours, and 260 with PROM-delivery ≥18 hours. The incidence of neonatal hypoglycemia did not differ between the two groups, reaching 7.3%. Women in group 2 were at increased risk of both cesarean delivery (20% vs. 12.4%, P < 0.01) and maternal chorioamnionitis morbidity (6.5% vs. 1.3%, P < 0.001).

CONCLUSIONS

In a sub-group of women with GDM, a PROM-delivery time ≥18 hours is not associated with higher rates of neonatal hypoglycemia, but higher rates of chorioamnionitis and cesarean delivery were noted. Therefore, we suggest consideration for early delivery when managing women with GDM and PROM.

Early-onset group B streptococcal infections in five Nordic countries with different prevention policies, 1995 to 2019

BackgroundNeonatal early-onset disease caused by group B Streptococcus (GBS) is a leading cause of infant morbidity. Intrapartum antibiotic prophylaxis (IAP) is effective in preventing early-onset GBS disease, but there is no agreement on the optimal strategy for identifying the pregnant women requiring this treatment, and both risk-based prophylaxis (RBP) and GBS screening-based prophylaxis (SBP) are used.AimThe aim of this study was to evaluate the effect of SBP as a public health intervention on the epidemiology of early-onset GBS infections.MethodsIn 2012, Finland started the universal SBP, while Denmark, Iceland, Norway and Sweden continued with RBP. We conducted an interrupted time series analysis taking 2012 as the intervention point to evaluate the impact of this intervention. The incidences of early- and late-onset GBS infections during Period I (1995-2011) and Period II (2012-2019) were collected from each national register, covering 6,605,564 live births.ResultsIn Finland, a reduction of 58% in the incidence of early-onset GBS disease, corresponding to an incidence rate ratio (IRR) of 0.42 (95% CI: 0.34-0.52), was observed after 2012. At the same time, the pooled IRR of other Nordic countries was 0.89 (95% CI: 0.80-1.0), specifically 0.89 (95% CI: 0.70-1.5) in Denmark, 0.34 (95% CI: 0.15-0.81) in Iceland, 0.72 (95% CI: 0.59-0.88) in Norway and 0.97 (95% CI: 0.85-1.1) in Sweden.ConclusionsIn this ecological study of five Nordic countries, early-onset GBS infections were approximately halved following introduction of the SBP approach as compared with RBP.

Self-collection of samples for group B streptococcus testing during pregnancy: a systematic review and meta-analysis

BACKGROUND

Sample self-collection for reproductive tract infection diagnosis has been found to offer greater convenience, privacy, autonomy, and expanded access to testing in non-pregnant adults. This review aimed to determine whether sample self-collection is as accurate as provider-collection for detection of group B streptococcus colonisation in pregnancy and whether a strategy of self-collection compared to provider-collection might improve maternal and neonatal health outcomes.

METHODS

We searched CINAHL Plus, Medline, EMBASE, Maternity and Infant Care Database, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews in June 2022. Eligible studies compared self-collected and provider-collected samples taken from the same participants or participants randomised to either self-collection or provider-collection for reproductive tract infection testing using the same test and testing method in pregnant individuals. We included trials and observational studies. Reviewers assessed risk of bias using the QUADAS-2 checklist and independently extracted data. Sensitivity and specificity for group B streptococcus colonisation of self-collected compared to provider-collected samples were pooled using a bivariate, random-effects, meta-analytic model. This review was registered with PROSPERO (CRD42023396573).

RESULTS

The search identified 5909 references, of which eleven diagnostic accuracy group B streptococcus studies were included (n = 3269 participants). No studies assessed the effects of self-collection in pregnancy on health outcomes. All studies had high or unclear risk of bias. Pooled sensitivities of self-collected samples for group B streptococcus detection were 82% (95% CI: 66-91%; I2 = 68.85%) in four trials (n = 1226) and 91% (95% CI: 83-96%; I2 = 37.38%) in seven non-randomised studies (n = 2043). Pooled specificities were 99% (95% CI: 98-99%; I2 = 12.08%) and 97% (95% CI: 94-99%; I2 = 72.50%), respectively.

CONCLUSIONS

Self-collected samples for group B streptococcus detection in pregnancy had high specificity compared to provider-collection, but lower sensitivity, particularly for included trials. Studies investigating the effect of self-collection on health outcomes, and further higher quality trials comparing accuracy of self-collection to provider-collection, are required.

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.

Time to reconsider antibiotic prophylaxis in women with prolonged rupture of membranes: The trend of Enterobacteriaceae in peripartum infections

OBJECTIVE

The proportion of neonatal early-onset sepsis (EOS) by gram-negative bacteria has increased. The authors examined bacterial distribution in the amniotic membrane cultures of women with peripartum fever (PPF) and related perinatal outcomes.

METHODS

This retrospective study covered the period 2011 to 2019. The primary outcomes were Enterobacteriaceae-positive birth culture rates in women with PPF and the trend of ampicillin resistance. Maternal and neonatal outcomes were compared between women with group B Streptococcus (GBS) and Enterobacteriaceae-positive isolates. Bacterial distribution was also compared according to rupture of membrane (ROM) duration.

RESULTS

Among 621 women with PPF, the positive birth culture rate was 52%. Increasing prevalences of ampicillin-resistant Enterobacteriaceae (81%) were noted. Positive birth cultures were associated with maternal bacteremia (P = 0.017) and neonatal EOS (P = 0.003). Prolonged ROM ≥18 h was associated with increased risk for Enterobacteriaceae-positive cultures, while intrapartum ampicillin and gentamicin were associated with lower risk. Enterobacteriaceae-positive compared with GBS-positive birth cultures were associated with adverse maternal and neonatal outcomes.

CONCLUSION

Positive birth cultures were related to maternal bacteremia and neonatal sepsis. Adverse outcomes were more prevalent among women with Enterobacteriaceae-positive versus GBS-positive birth cultures. Prolonged ROM is a risk factor for Enterobacteriaceae-positive birth cultures among women with PPF. Antibiotic prophylaxis treatment for prolonged ROM should be reconsidered.

Placental Streptococcus agalactiae DNA is associated with neonatal unit admission and foetal pro-inflammatory cytokines in term infants

Streptococcus agalactiae (Group B Streptococcus; GBS) is a common cause of sepsis in neonates. Previous work detected GBS DNA in the placenta in ~5% of women before the onset of labour, but the clinical significance of this finding is unknown. Here we re-analysed this dataset as a case control study of neonatal unit (NNU) admission. Of 436 infants born at term (≥37 weeks of gestation), 7/30 with placental GBS and 34/406 without placental GBS were admitted to the NNU (odds ratio (OR) 3.3, 95% confidence interval (CI) 1.3-7.8). We then performed a validation study using non-overlapping subjects from the same cohort. This included a further 239 cases of term NNU admission and 686 term controls: 16/36 with placental GBS and 223/889 without GBS were admitted to the NNU (OR 2.4, 95% CI 1.2-4.6). Of the 36 infants with placental GBS, 10 were admitted to the NNU with evidence of probable but culture-negative sepsis (OR 4.8, 95% CI 2.2-10.3), 2 were admitted with proven GBS sepsis (OR 66.6, 95% CI 7.3-963.7), 6 were admitted and had chorioamnionitis (inflammation of the foetal membranes) (OR 5.3, 95% CI 2.0-13.4), and 5 were admitted and had funisitis (inflammation of the umbilical cord) (OR 6.7, 95% CI 12.5-17.7). Foetal cytokine storm (two or more pro-inflammatory cytokines >10 times median control levels in umbilical cord blood) was present in 36% of infants with placental GBS DNA and 4% of cases where the placenta was negative (OR 14.2, 95% CI 3.6-60.8). Overall, ~1 in 200 term births had GBS detected in the placenta, which was associated with infant NNU admission and morbidity.

Possible Rates of Detection of Neonatal Sepsis Pathogens in the Context of Microbiological Diagnostics in Mothers - Real World Data

Objective

The aim of this study was to identify the rate of detection of neonatal sepsis pathogens in maternal microbiological smears.

Study Design

This is a retrospective study conducted at a Level 1 perinatal center in the context of routine care from 2014 to 2019. For all premature infants and neonates with neonatal sepsis, the neonatal and maternal microbiological findings were examined to see if there was a match.

Results

During the study period, a total of 948 premature or newborn infants were identified as having a neonatal infection. Among all of the premature or newborn infants, 209 (22%) met the diagnostic criteria for neonatal sepsis; of these, 157 were premature births and 52 were full-term births. We evaluated the microbiological findings for these 209 mother and child pairs. No pathogens were detected in 27 out of 157 mothers of premature infants (17.1%) and in 31 out of 52 mothers of full-term infants (59.6%). In the premature infant group there were pairs with matching pathogens in 30 out of 130 cases (23.1%, 95% CI: 16.1-31.3), and in the full-term infant group there was a match in 4 out of 21 cases (19%, 95% CI: 5.4-41.9). The number needed to test to have a 90% probability of success for pathogen detection varies between 9 and 11 in the most favorable case and 26 and 32 in the least favorable case, depending on the evaluation method.

Conclusion

In cases of neonatal sepsis, the sepsis-causing pathogen was successfully detected through prior analysis of a maternal smear in 7% of full-term infants and in 19% of premature infants. The number needed to test was relatively high in all groups. The value of maternal smears for identifying neonatal sepsis-causing pathogens needs to be critically questioned.

Group B Streptococcus Rectovaginal Colonization and Resistance Patterns in HIV-Positive Compared to HIV-Negative Pregnant Patients

OBJECTIVE

The objective of our study is to determine if human immunodeficiency virus (HIV)-positive pregnant patients have a higher rate of group B streptococcus (GBS) rectovaginal colonization compared with HIV-negative pregnant patients.

STUDY DESIGN

Our study is a multi-site retrospective study performed at Ochsner Louisiana State University-Health Shreveport and Monroe campuses including patients who delivered between December 2011and June 2019. Rates of GBS rectovaginal colonization between HIV-positive pregnant patients were compared with a control group of HIV-negative patients. The control group was age and race matched in a 2:1 fashion. The primary outcome was to investigate rates of GBS rectovaginal colonization. Secondary outcomes included GBS culture antibiotic sensitivities, presence of GBS urinary tract infection, GBS positivity based on HIV viral load, and GBS positivity based on new vs established diagnosis of HIV. Continuous data were analyzed using an unpaired t-test, and categorical data were analyzed using a Chi-squared test. The probability level of <0.05 was set as statistically significant.

RESULTS

A total of 225 patients were included in the final analysis, 75 HIV-positive and 150 HIV-negative controls. Demographic differences were noted. HIV-positive patients were more likely to deliver preterm and were more likely to deliver via cesarean section. Our primary outcome showed no significant differences in incidence of GBS colonization between HIV-positive patients and control group (n = 31, 41.3% vs n = 46, 30.6%, p = 0.136). Antibiotic resistance patterns showed no significant difference between the two groups. There were no significant differences in GBS positivity based on HIV viral load.

CONCLUSION

Our study does not show a statistically significant difference in the incidence of GBS colonization between HIV-positive patients and HIV-negative controls.

KEY POINTS

· HIV-positive pregnant patients do not have an increased risk of GBS rectovaginal colonization.. · HIV-positive pregnant patients have similar rates of GBS colonization regardless of viral load.. · GBS antibiotic sensitivities are similar in HIV-positive and HIV-negative pregnant patients..

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.

Impact of antimicrobial stewardship interventions on peripartum antibiotic prescribing in patients with penicillin allergy

BACKGROUND

Beta-lactam antibiotics (eg, penicillins, cephalosporins, and carbapenems) are preferred for group B streptococcus prophylaxis, intra-amniotic infection, and cesarean surgical site infection prophylaxis. Non-beta-lactam alternatives are associated with inferior efficacy and contribute to higher rates of surgical site infection and longer lengths of stay. Most patients who report a penicillin allergy can tolerate penicillins without any adverse reaction. There are low rates of cross-reactivity between penicillins and other beta-lactams, including cephalosporins and carbapenems. Efforts to evaluate penicillin allergy and promote the use of beta-lactams are needed.

OBJECTIVE

This study aimed to evaluate whether an antimicrobial stewardship intervention improved the use of first-line antibiotics for peripartum indications in patients with a reported penicillin allergy, following updates to institutional guidelines.

STUDY DESIGN

This was a retrospective study of adult patients presenting for vaginal or cesarean delivery at 2 hospitals within a healthcare system. Patients received at least 1 dose of antibiotics for a peripartum indication between May 1, 2018, and October 31, 2018 (preintervention group) and May 1, 2020, to October 31, 2020 (postintervention group). The stewardship intervention bundle, which was implemented between March 2019 and April 2020, included updates to institutional antibiotic guidelines, reclassification of severe penicillin allergy, development of obstetrical prophylaxis and treatment order sets, promotion of allergy referral services, and establishment of a physician champion. The primary outcome was the composite rates of patients with reported penicillin allergy who received a preferred antibiotic for a peripartum indication. The secondary measures included maternal and neonatal outcomes.

RESULTS

A total of 192 patients with a history of documented penicillin allergy were evaluated (96 patients in the preintervention group and 96 patients in the postintervention group). Hives were the most commonly reported index symptom in both groups (40/96 [41.7%] vs 39/96 [40.6%]; P=.883). After stewardship interventions, there was a significant increase in the rate of preferred antibiotic use (33/96 [34.3%] vs 81/96 [84.3%]; P<.001). The effect was the greatest in patients with nonsevere allergy (14/76 [18.4%] vs 68/82 [82.9%]; P<.001). There was no difference in the rates of postpartum endometritis, 30-day readmission, 90-day surgical site infection, or neonatal early-onset sepsis between the pre- and postintervention groups. Of note, 1 patient in the postintervention group experienced itching, and another patient developed a rash, both of which resolved with medical management.

CONCLUSION

A comprehensive antibiotic stewardship intervention was associated with a 50% increase in the use of preferred antibiotics for peripartum indications in patients with penicillin allergy. Allergic reactions with first-line beta-lactams were minimal and manageable.

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.

Endometrial responses to bacterial and viral infection: a scoping review

BACKGROUND

The endometrium is a highly dynamic tissue that undergoes dramatic proliferation and differentiation monthly in order to prepare the uterus for implantation and pregnancy. Intrauterine infection and inflammation are being increasingly recognized as potential causes of implantation failure and miscarriage, as well as obstetric complications later in gestation. However, the mechanisms by which the cells of the endometrium respond to infection remain understudied and recent progress is slowed in part owing to similar overlapping studies being performed in different species.

OBJECTIVE AND RATIONALE

The aim of this scoping review is to systematically summarize all published studies in humans and laboratory animals that have investigated the innate immune sensing and response of the endometrium to bacteria and viruses, and the signaling mechanisms involved. This will enable gaps in our knowledge to be identified to inform future studies.

SEARCH METHODS

The Cochrane Library, Ovid Embase/Medline, PubMed, Scopus, Google Scholar, and Web of Science databases were searched using a combination of controlled and free text terms for uterus/endometrium, infections, and fertility to March 2022. All primary research papers that have reported on endometrial responses to bacterial and viral infections in the context of reproduction were included. To focus the scope of the current review, studies in domesticated animals, included bovine, porcine, caprine, feline, and canine species were excluded.

OUTCOMES

This search identified 42 728 studies for screening and 766 full-text studies were assessed for eligibility. Data was extracted from 76 studies. The majority of studies focused on endometrial responses to Escherichia coli and Chlamydia trachomatis, with some studies of Neisseria gonorrhea, Staphylococcus aureus, and the Streptococcus family. Endometrial responses have only been studied in response to three groups of viruses thus far: HIV, Zika virus, and the herpesvirus family. For most infections, both cellular and animal models have been utilized in vitro and in vivo, focusing on endometrial production of cytokines, chemokines, and antiviral/antimicrobial factors, and the expression of innate immune signaling pathway mediators after infection. This review has identified gaps for future research in the field as well as highlighted some recent developments in organoid systems and immune cell co-cultures that offer new avenues for studying endometrial responses to infection in more physiologically relevant models that could accelerate future findings in this area.

WIDER IMPLICATIONS

This scoping review provides an overarching summary and benchmark of the current state of research on endometrial innate immune responses to bacterial and viral infection. This review also highlights some exciting recent developments that enable future studies to be designed to deepen our understanding of the mechanisms utilized by the endometrium to respond to infection and their downstream effects on uterine function.

Determinants of microbial colonization in the premature gut

Abnormal microbial colonization in the gut at an early stage of life affects growth, development, and health, resulting in short- and long-term adverse effects. Microbial colonization patterns of preterm infants differ from those of full-term infants in that preterm babies and their mothers have more complicated prenatal and postnatal medical conditions. Maternal complications, antibiotic exposure, delivery mode, feeding type, and the use of probiotics may significantly shape the gut microbiota of preterm infants at an early stage of life; however, these influences subside with age. Although some factors and processes are difficult to intervene in or avoid, understanding the potential factors and determinants will help in developing timely strategies for a healthy gut microbiota in preterm infants. This review discusses potential determinants of gut microbial colonization in preterm infants and their underlying mechanisms.

Reduced Compared With Traditional Schedules for Routine Antenatal Visits: A Systematic Review

OBJECTIVE

To assess differences in maternal and child outcomes in studies comparing reduced routine antenatal visit schedules with traditional schedules.

DATA SOURCES

A search was conducted of PubMed, Cochrane databases, EMBASE, CINAHL, and ClinicalTrials.gov through February 12, 2022, searching for antenatal (prenatal) care, pregnancy, obstetrics, telemedicine, remote care, smartphones, telemonitoring, and related terms, as well as primary study designs. The search was restricted to high-income countries.

METHODS OF STUDY SELECTION

Double independent screening was done in Abstrackr for studies comparing televisits and in-person routine antenatal care visits for maternal, child, health care utilization, and harm outcomes. Data were extracted into SRDRplus with review by a second researcher.

TABULATION, INTEGRATION, AND RESULTS

Five randomized controlled trials and five nonrandomized comparative studies compared reduced routine antenatal visit schedules with traditional schedules. Studies did not find differences between schedules in gestational age at birth, likelihood of being small for gestational age, likelihood of a low Apgar score, likelihood of neonatal intensive care unit admission, maternal anxiety, likelihood of preterm birth, and likelihood of low birth weight. There was insufficient evidence for numerous prioritized outcomes of interest, including completion of the American College of Obstetricians and Gynecologists-recommended services and patient experience measures.

CONCLUSION

The evidence base is limited and heterogeneous and allowed few specific conclusions. Reported outcomes included, for the most part, standard birth outcomes that do not have strong plausible biological connection to structural aspects of antenatal care. The evidence did not find negative effects of reduced routine antenatal visit schedules, which may support implementation of fewer routine antenatal visits. However, to enhance confidence in this conclusion, future research is needed, particularly research that includes outcomes of most importance and relevance to changing antenatal care visits.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42021272287.

The Detrimental Effects of Peripartum Antibiotics on Gut Proliferation and Formula Feeding Injury in Neonatal Mice Are Alleviated with Lactobacillus rhamnosus GG

Peripartum antibiotics can negatively impact the developing gut microbiome and are associated with necrotizing enterocolitis (NEC). The mechanisms by which peripartum antibiotics increase the risk of NEC and strategies that can help mitigate this risk remain poorly understood. In this study, we determined mechanisms by which peripartum antibiotics increase neonatal gut injury and evaluated whether probiotics protect against gut injury potentiated by peripartum antibiotics. To accomplish this objective, we administered broad-spectrum antibiotics or sterile water to pregnant C57BL6 mice and induced neonatal gut injury to their pups with formula feeding. We found that pups exposed to antibiotics had reduced villus height, crypt depth, and intestinal olfactomedin 4 and proliferating cell nuclear antigen compared to the controls, indicating that peripartum antibiotics impaired intestinal proliferation. When formula feeding was used to induce NEC-like injury, more severe intestinal injury and apoptosis were observed in the pups exposed to antibiotics compared to the controls. Supplementation with the probiotic Lactobacillus rhamnosus GG (LGG) reduced the severity of formula-induced gut injury potentiated by antibiotics. Increased intestinal proliferating cell nuclear antigen and activation of the Gpr81-Wnt pathway were noted in the pups supplemented with LGG, suggesting partial restoration of intestinal proliferation by probiotics. We conclude that peripartum antibiotics potentiate neonatal gut injury by inhibiting intestinal proliferation. LGG supplementation decreases gut injury by activating the Gpr81-Wnt pathway and restoring intestinal proliferation impaired by peripartum antibiotics. Our results suggest that postnatal probiotics may be effective in mitigating the increased risk of NEC associated with peripartum antibiotic exposure in preterm infants.

Antibiotic choice for Group B Streptococcus prophylaxis in mothers with reported penicillin allergy and associated newborn outcomes

OBJECTIVE

To evaluate the choice of antibiotic used for intrapartum Group B Streptococcus (GBS) prophylaxis in pregnant individuals with reported penicillin allergies compared to those without reported penicillin allergies and investigate whether there are associated differences in neonatal outcomes.

STUDY DESIGN

This retrospective cohort study included mother-infant dyads of GBS positive pregnant individuals who labored and delivered newborns ≥ 35 weeks of gestation at a high-volume urban hospital (2005-2018). The type of antibiotic administered to the mothers for GBS prophylaxis (beta-lactam prophylaxis defined as penicillin-class drug or cefazolin; alternative prophylaxis defined as vancomycin or clindamycin) was compared between those with a penicillin allergy documented in their medical record versus those who did not. Neonatal outcomes included number of postnatal blood draws, antibiotic administration, neonatal intensive care unit (NICU) admission, bacteremia, and hospital length of stay and were compared between groups. Bivariable and multivariable analyses were performed.

RESULTS

Of 11,334 mother-infant pairs, 1170 (10.3%) mothers had a penicillin allergy documented in their medical record. Of them, 49 (4.2%) received a penicillin, 259 (22.1%) received cefazolin, 449 (38.4%) received clindamycin, and 413 (35.3%) received vancomycin. Patients with a reported penicillin allergy were significantly more likely to receive alternative GBS prophylaxis compared to those without penicillin allergy (73.7% vs. 0.2%, p < 0.01). Neonates of patients who received alternative GBS prophylaxis were significantly more likely to undergo a postnatal lab draw compared to neonates of patients who received beta-lactam antibiotics (20.8% vs. 17.3%, OR 1.25 (95% CI 1.08-1.46)). This significant association persisted after adjusting for potential confounders (aOR 1.23, 95% CI 1.06-1.43). There were no other significant differences seen in other newborn outcomes.

CONCLUSION

Pregnant individuals who report a penicillin allergy were more likely to receive alternative antibiotics for GBS prophylaxis compared to those without a penicillin allergy. This was associated with an increased frequency of postnatal blood draws among neonates of mothers with a reported penicillin allergy. Administration of alternative intrapartum antibiotic prophylaxis with vancomycin or clindamycin is common in individuals with self-reported penicillin allergy, and maternal alternative antibiotic administration may impact neonatal care, particularly via increased lab draws.

[Recent research on the epidemiology and preventive strategies of neonatal group B Streptococcus infection in the latest decade]

Currently, the main strategy for preventing neonatal group B Streptococcus (GBS) infection is prenatal screening combined with intrapartum antibiotic prophylaxis, which has effectively reduced the incidence of neonatal GBS early-onset disease. However, the burden of GBS infection is still significant. The intrapartum antibiotic prophylaxis strategy has limitations such as inducing antibiotic resistance and inability to effectively prevent GBS late-onset disease. It is crucial to develop and evaluate other prevention strategies, while paying close attention to assessing penicillin allergy in pregnant women and how to prevent GBS infection in neonates with negative maternal GBS screening. In recent years, there has been some progress in GBS vaccines and related immunological research, and the use of specific vaccines is expected to significantly reduce GBS infection in neonates.

Penicillin allergy delabeling: Opportunities for implementation and dissemination

Although existing as a safety measure to prevent iatrogenic harm, unconfirmed penicillin allergy labels have a negative impact on personal and public health. One downstream effect of unconfirmed penicillin allergy is the continued emergence and transmission of resistant bacteria and their associated health care costs. Recognizing the consequences of inaccurate penicillin allergy labels, professional and public health organizations have started promoting the adoption of proactive penicillin allergy evaluations, with the ultimate goal of removing the penicillin allergy label when the allergy is disproved, also known as penicillin allergy "delabeling." A penicillin allergy evaluation includes a comprehensive allergy history often followed by drug challenge, sometimes with preceding skin testing. Currently, penicillin allergy delabeling is largely carried out by allergy specialists in outpatient settings. Penicillin allergy delabeling is performed on inpatients, albeit rarely, often at the time of need, as a point-of-care procedure. Access to penicillin allergy evaluation services is limited. Recent studies demonstrate the feasibility of expanding penicillin allergy evaluations and delabeling to internists, pediatricians, emergency medicine physicians, infectious diseases specialists, and clinical pharmacists. However, reducing the impact of mislabeled penicillin allergy will require comprehensive efforts and new investments. In this review, we summarize the current practices of penicillin allergy delabeling and discuss expansion opportunities for penicillin allergy delabeling as quality improvement.

Group B Streptococcus and the risk of perinatal morbidity and mortality following term labor

Streptococcus agalactiae (group B Streptococcus) colonizes the genital tract of approximately 20% of pregnant women. In the absence of intervention, approximately 1% of infants born to colonized mothers exhibit a clinical infection. This has led to implementation of screening and intervention in the form of intrapartum antibiotic prophylaxis in many countries, including the United States. However, screening has not been introduced in a substantial minority of other countries because of the absence of supportive level 1 evidence, the very large number needed to treat to prevent 1 case, and concerns about antimicrobial resistance. Optimal screening would involve rapid turnaround (to facilitate intrapartum testing) and report antibiotic sensitivity, but no such method exists. There is significant scope for a personalized medicine approach, targeting intrapartum antibiotic prophylaxis to cases at greatest risk, but the pathogen and host factors determining the risk of invasive disease are incompletely understood. Epidemiologic data have indicated the potential of prelabor invasion of the uterus by group B Streptococcus, and metagenomic analysis revealed the presence of group B Streptococcus in the placenta in approximately 5% of pregnant women at term before onset of labor and membrane rupture. However, the determinants and consequences of prelabor invasion of the uterus by group B Streptococcus remain to be established. The vast majority (98%) of invasive neonatal disease is caused by 6 serotypes, and hexavalent vaccines against these serotypes have completed phase 2 trials. However, an obstacle to phase 3 studies is conducting an adequately powered trial to demonstrate clinical effectiveness given that early-onset disease affects approximately 1 in 1000 births in the absence of vaccination.

Staphylococcal Resistance Patterns, blaZ and SCCmec Cassette Genes in the Nasopharyngeal Microbiota of Pregnant Women

Antimicrobial resistance in Staphylococcus spp. colonising the nasopharynx can create risk factors of therapeutic treatment failure or prophylaxis in pregnant women. Resistance is mostly encoded on plasmids (e.g., blaZ gene for penicillinase synthesis) or chromosomes (e.g., mecA and mecC for methicillin resistance). The mecA gene is part of the chromosomal mec gene cassette (SCCmec), which is also located on the plasmid. The disc diffusion method for the selected drugs (beta-lactams, fluoroquinolones, streptogramins, aminoglicosides, macrolides, oxasolidinones, tetracyclines and other groups) was used. PCR for blaZ, mecA and mecC genes and SCCmec cassette detection and typing were performed. S. aureus (54.4%) and S. epidermidis (27.9%) were the most prevalent and showed the highest diversity of resistance profiles. The blaZ, mecA and mecC genes were reported in 95.6%, 20.6% and 1.5% of isolates, respectively. The highest resistance was found to beta-lactams, commonly used during pregnancy. Resistance to a variety of antimicrobials, including benzylpenicillin resistance in blaZ-positive isolates, and the existence of a very high diversity of SCCmec cassette structures in all staphylococci selected from the nasopharyngeal microbiota of pregnant women were observed for the first time. Knowledge of the prevalence of antimicrobial-resistant staphylococci in the nasopharynx of pregnant women may be important for the appropriate treatment or prophylaxis of this group of patients.

Risk Stratification to Support Antibiotic Stewardship and Breastfeeding Exclusivity in a Military Treatment Facility

OBJECTIVE

To safely reduce unnecessary antibiotic exposure in neonates exposed to chorioamnionitis and inadequately treated Group B Streptococcus (GBS) using the early-onset sepsis (EOS) calculator for risk stratification and a 36-hour antibiotic duration.

DESIGN

Evidence-based quality improvement initiative.

SETTING/LOCAL PROBLEM

Obstetric service at a midsized military treatment facility with approximately 2,000 births annually and no standard process for neonatal EOS risk assessment.

PARTICIPANTS

Clinical nurse specialist, physicians, nursing leadership, unit-level nursing champions, and nurses assigned to the mother-baby and labor and delivery units.

INTERVENTION/MEASUREMENTS

An interdisciplinary working group created a protocol to institute an EOS risk assessment calculator, a note for the electronic heath record, and interdisciplinary education for all staff providing care to neonates in our facility.

RESULTS

Before implementation of the EOS calculator, 97.6% of neonates exposed to chorioamnionitis or inadequate maternal GBS treatment received antibiotics; after implementation, the mean rate dropped to 32%. Exclusive breastfeeding rates before discharge in neonates exposed to chorioamnionitis or inadequate maternal GBS treatment also increased during this time, from 40% to a mean of 89%. After implementation, there were no readmissions to our institution for culture-proven sepsis within 14 days of discharge.

CONCLUSION

Multidisciplinary team-led implementation of the EOS calculator and of shortened antibiotic duration were associated with safely reduced antibiotic exposure in well-appearing neonates exposed to chorioamnionitis and GBS. In addition, dramatically improved rates of exclusive breastfeeding at discharge were observed in this population.

Group B Streptococcus in Pregnancy

To decrease risk of early-onset neonatal sepsis from group B streptococcus (GBS), pregnant patients should undergo screening between 36 0/7 and 37 6/7 weeks' gestation. Patients with a positive vaginal-rectal culture, GBS bacteriuria , or history of newborn with GBS disease should receive intrapartum antibiotic prophylaxis (IAP) with an agent targeting GBS. If GBS status is unknown at time of labor, IAP should be administered in cases of preterm birth, rupture of membranes for >18 hours, or intrapartum fever. The antibiotic of choice is intravenous penicillin; alternatives should be considered in cases of penicillin allergy depending on allergy severity.

Antimicrobial Photodynamic Inactivation: An Alternative for Group B Streptococcus Vaginal Colonization in a Murine Experimental Model

BACKGROUND

Streptococcus agalactiae, referred to as Group B Streptococcus (GBS), is a prominent bacterium causing life-threatening neonatal infections. Although antibiotics are efficient against GBS, growing antibiotic resistance forces the search for alternative treatments and/or prevention approaches. Antimicrobial photodynamic inactivation (aPDI) appears to be a potent alternative non-antibiotic strategy against GBS.

METHODS

The effect of rose bengal aPDI on various GBS serotypes, Lactobacillus species, human eukaryotic cell lines and microbial vaginal flora composition was evaluated.

RESULTS

RB-mediated aPDI was evidenced to exert high bactericidal efficacy towards S. agalactiae in vitro (>4 log10 units of viability reduction for planktonic and >2 log10 units for multispecies biofilm culture) and in vivo (ca. 2 log10 units of viability reduction in mice vaginal GBS colonization model) in microbiological and metagenomic analyses. At the same time, RB-mediated aPDI was evidenced to be not mutagenic and safe for human vaginal cells, as well as capable of maintaining the balance and viability of vaginal microbial flora.

CONCLUSIONS

aPDI can efficiently kill GBS and serve as an alternative approach against GBS vaginal colonization and/or infections.

Group B streptococcus in obstetrics: unsolved problems

For several decades, among all possible pathogens of neonatal infections, group B streptococcus has been one of the leading positions. Sepsis, meningitis, and pneumonia are among the most common clinical manifestations of neonatal infection associated with group B streptococcus. In this review, our goal was to analyze the literature demonstrating a worldwide approach to the prevention of vertical transmission of group B streptococcus from mother to child. When writing the review, scientific publications of foreign and domestic authors from the PubMed database were studied. The review considers the drugs of choice for intranatal antibiotic prophylaxis, and their pharmacodynamic, and pharmacokinetic features. The analysis details the problem of the growth of resistance of group B streptococcus to antibacterial drugs. The antimicrobial activity of lactoferrin was noted at a minimum inhibitory concentration of 500 μg/ml. The presented review also reflects the protective and therapeutic effects of oral intake of probiotics containing Lactobacillus acidophilus, Lactobacillus salivarius, Lactobacillus rhamnosus GR-1, and Lactobacillus reuteri RC-14 . Based on the analysis, it can be concluded that penicillin G and ampicillin have the most pronounced bactericidal effect against group B streptococcus. At the same time, the most common side effects of β-lactam penicillins include an allergic reaction with the possible development of anaphylactic shock. Given this, the antibiotics of the first-line reserve group include cefazolin, clindamycin, and vancomycin. At the same time, it is important to take into account the decrease in the therapeutic concentration of clindamycin with a change in the alpha-1-acid glycoprotein in the blood of the mother and fetus, the nephrotoxic effect of vancomycin and the cross-a llergic reaction of cefazolin with antibiotics of the penicillin group. A promising direction in solving the problem of group B streptococcus is the development of new strategies for the prevention of perinatal infection of the fetus and newborn based on a more detailed study of the effects of lactoferrin and probiotics.

Maternity care provider acceptance of a future Group B Streptococcus vaccine - A qualitative study in three countries

INTRODUCTION

There are vaccines in clinical trials that target the bacterium Group B Streptococcus (GBS). When approved, GBS vaccines will be intended for administration to pregnant women to prevent infection in their infants. The success of any vaccine will depend on its' uptake in the population. Experience with prior maternal vaccines, e.g. influenza, Tdap and COVID-19 vaccines, teaches us that acceptance of vaccines, especially if novel, is challenging for pregnant women, and that provider recommendation is a key driver of vaccine uptake.

METHODS

This study investigated attitudes of maternity care providers towards the introduction of a GBS vaccine in three countries (the United States (US), Ireland, and the Dominican Republic (DR)) with different GBS prevalence and prevention practices. Semi-structured interviews with maternity care providers were transcribed and coded for themes. The constant comparative method, and inductive theory building were used to develop conclusions.

RESULTS

Thirty-eight obstetricians, 18 general practitioners and 14 midwives participated. There was variability in provider attitudes towards a hypothetical GBS vaccine. Responses ranged from enthusiasm to doubts over the need for a vaccine. Attitudes were influenced by perceived additional benefits of a vaccine over current strategy and confidence in the safety of vaccines during pregnancy. Knowledge, experience and approaches to GBS prevention differed geographically and according to provider type, and influenced how participants assessed the risks and benefits of a GBS vaccine.

CONCLUSION

Maternity care providers are engaged in the topic of GBS management and there is opportunity to leverage attitudes and beliefs that will support a strong recommendation for a GBS vaccine. However, knowledge of GBS, and of the limitations of current prevention strategies vary among providers in different regions, and between different provider types. Targeted educational efforts with antenatal providers should focus on highlighting safety data the potential benefits of vaccination over current strategies.

Antibiotics in Labor and Delivery

Infections are common in obstetric care and often require specific antibiotics, depending on the infection site and prevailing organisms. Summaries of antibiotic recommendations and treatment algorithms are provided for the following conditions: routine labor, group B streptococcus prophylaxis, preterm prelabor rupture of membranes, operative vaginal delivery, cesarean delivery, obstetric anal sphincter lacerations, chorioamnionitis, postpartum endometritis, infections of the urinary tract, and bacterial endocarditis prophylaxis.

Management of the Pregnant Patient with Beta-Lactam Allergy

PURPOSE OF REVIEW

We review the literature and discuss the logistics of testing pregnant patients for penicillin allergy.

RECENT FINDINGS

As in the general population, pregnant patients commonly report a penicillin allergy, but most patients are able to tolerate penicillin. Avoidance of beta-lactams in pregnancy is associated with increased morbidity: longer hospitalizations, more frequent infections, and more complications. Penicillin allergy testing is safe in pregnant patients, and obstetricians are eager for allergists to offer this procedure to their patients. As allergists, we can improve our patients' health outcomes by offering penicillin allergy testing in our practices. The protocols for testing both with and without skin testing in pregnant patients have been studied, and future studies will continue to clarify the safety and efficacy of penicillin allergy delabeling in pregnant patients.

Tackling Neonatal Sepsis-Can It Be Predicted?

(1) Background: Early signs of sepsis in a neonate are often subtle and non-specific, the clinical course rapid and fulminant. The aim of our research was to analyse diagnostic markers for neonatal sepsis and build an application which could calculate its probability. (2) Methods: A retrospective clinical study was conducted on 497 neonates treated at the Clinical Department of Neonatology of the University Children's Hospital in Ljubljana from 2007 to 2021. The neonates with a diagnosis of sepsis were separated based on their blood cultures, clinical and laboratory markers. The influence of perinatal factors was also observed. We trained several machine-learning models for prognosticating neonatal sepsis and used the best-performing model in our application. (3) Results: Thirteen features showed highest diagnostic importance: serum concentrations of C-reactive protein and procalcitonin, age of onset, immature neutrophil and lymphocyte percentages, leukocyte and thrombocyte counts, birth weight, gestational age, 5-min Apgar score, gender, toxic changes in neutrophils, and childbirth delivery. The created online application predicts the probability of sepsis by combining the data values of these features. (4) Conclusions: Our application combines thirteen most significant features for neonatal sepsis development and predicts the probability of sepsis in a neonate.

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.

Molecular Epidemiology of Group B Streptococcus Isolates from Pregnant Women with Premature Rupture of Membranes in Fuzhou, China

Objective

This study investigated the molecular epidemiology of Group B Streptococcus (GBS) in pregnant women with premature rupture of membranes (PROM) in Fuzhou region of China as a source of clinical reference.

Methods

GBS isolates were obtained from pregnant women with PROM. All isolates were genotyped, serotyped, and tested for drug-resistance and virulence genes using PCR and DNA sequencing. Antibiotic susceptibility testing was performed using the Vitek^® 2 automated system.

Results

Among the 140 GBS isolates, seventeen sequence types (STs) were identified, of which ST19 (20.0%) was the most prevalent, followed by ST862, ST10, and ST12. Three clonal complexes (CC19, CC10 and CC1) were identified. The predominant serotype was III (45.7%), followed by V (23.6%), Ib (18.6%), Ia (7.1%), and II (3.6%). The prevalence of multidrug resistance was 72.8% (102/140). All isolates were susceptible to penicillin G, ampicillin, quinupristin, linezolid, vancomycin, and tigecycline. The majority of isolates were resistant to erythromycin (70.0%), clindamycin (72.1%), and tetracycline (81.4%), and 28.6% of isolates were resistant to levofloxacin and moxifloxacin. Of the 98 erythromycin-resistant strains, mreA, ermB, mefA, mefE, ermA, and ermTR were detected in 100%, 70.4%, 49.0%, 22.4%, 13.3%, and 9.2%, respectively. No linB was detected among 101 clindamycin-resistant strains. Of the 114 tetracycline-resistant strains, tetM, tetK, tetL and tetO were detected in 52.6%, 61.4%, 7.9%, and 23.7%, respectively. Regarding virulence genes, all strains carried rib and hylB, followed by scpB (98.6%), and bca (80.7%), whereas only one strain carried bac.

Conclusion

ST19/III and ST862/III were the most prevalent GBS subtypes. Penicillin G remains a first-line antibiotic for intrapartum antibiotic prophylaxis and treatment of GBS infections. The prevalence of resistance to clindamycin, erythromycin, and tetracycline is high among GBS isolates in the Fuzhou region. ST862 and ST651 are emerging animal origin STs in human infections, and may become potential zoonotic threats.

Maternal colonization with group B Streptococcus and antibiotic resistance in China: systematic review and meta-analyses

BACKGROUND

Maternal rectovaginal colonization with group B Streptococcus (GBS) or Streptococcus agalactiae is the most common pathway for this disease during the perinatal period. This meta-analysis aimed to summarize existing data regarding maternal colonization, serotype profiles, and antibiotic resistance in China.

METHODS

Systematic literature reviews were conducted after searching 6 databases. Meta-analysis was applied to analyze colonization rate, serotype, and antimicrobial susceptibility of GBS clinical isolates in different regions of China. Summary estimates are presented using tables, funnel plots, forest plots, histograms, violin plots, and line plots.

RESULTS

The dataset regarding colonization included 52 articles and 195 303 pregnant women. Our estimate for maternal GBS colonization in China was 8.1% (95% confidence interval [CI] 7.2%-8.9%). Serotypes Ia, Ib, III, and V account for 95.9% of identified isolates. Serotype III, which is frequently associated with the hypervirulent clonal complex, accounts for 46.4%. Among the maternal GBS isolates using multilocus sequence typing (MLST), ST19 (25.7%, 289/1126) and ST10 (25.1%, 283/1126) were most common, followed by ST12 (12.4%, 140/1126), ST17 (4.8%, 54/1126), and ST651 (3.7%, 42/1126). GBS was highly resistant to tetracycline (75.1% [95% CI 74.0-76.3%]) and erythromycin (65.4% [95% CI 64.5-66.3%]) and generally susceptible to penicillin, ampicillin, vancomycin, ceftriaxone, and linezolid. Resistance rates of GBS to clindamycin and levofloxacin varied greatly (1.0-99.2% and 10.3-72.9%, respectively). A summary analysis of the bacterial drug resistance reports released by the China Antimicrobial Resistance Surveillance System (CARSS) in the past 5 years showed that the drug resistance rate of GBS to erythromycin, clindamycin, and levofloxacin decreased slowly from 2018 to 2020. However, the resistance rates of GBS to all 3 antibiotics increased slightly in 2021.

CONCLUSIONS

The overall colonization rate in China was much lower than the global colonization rate (17.4%). Consistent with many original and review reports in other parts of the world, GBS was highly resistant to tetracycline. However, the resistance of GBS isolates in China to erythromycin and clindamycin was greater than in other countries. This paper provides important epidemiological information, to assist with prevention and treatment of GBS colonization in these women.

Molecular characteristics and antibiotic resistance mechanisms of clindamycin-resistant Streptococcus agalactiae isolates in China

Streptococcus agalactiae (Group B Streptococcus, GBS) is a major cause of neonatal infections with high morbidity and mortality, and clindamycin is the main antibiotic used to treat GBS infections in patients allergic to penicillin. We aimed to analyse the antibiotic sensitivity, sequence types, serotypes, virulence factors, and antibiotic resistance mechanisms of clinically isolated clindamycin-resistant S. agalactiae and provide basic data for the treatment, prevention, and control of clinical infection of S. agalactiae. A total of 110 strains of clindamycin-resistant S. agalactiae were collected from two tertiary hospitals in Hebei, China. We performed antibiotic sensitivity tests for 11 antibiotics on these strains and whole-genome sequencing analysis. All the strains were susceptible to penicillin, ampicillin, linezolid, vancomycin, tigecycline, and quinupristin-dalfopristin. Resistance to erythromycin, levofloxacin, tetracycline, and chloramphenicol were also observed. Genome sequence analysis revealed that all strains belonged to 12 sequence types (STs) related to six cloning complexes (CCs), namely CC10, CC19, CC23, CC651, CC1, and CC17. Five serotypes were identified, including IA, IB, II, III, and V. The most prominent resistance genes were mreA (100%) and ermB (81.8%). Furthermore, cfb, cylE, pavA and the gene cluster related to the pili were 100% present in all strains, followed by lmb (95.5%) and srr1 (67.2%). This study found that clindamycin-resistant S. agalactiae showed polymorphisms in molecular types and serotypes. Furthermore, multiple virulence factor genes have been identified in their genomes.

Risk factor analyses for intraventricular hemorrhage in preterm infants: A retrospective cohort study

BACKGROUND

Very-low-birthweight (VLBW) infants can experience severe intraventricular hemorrhage (IVH) that can lead to life-long disability by impairing neurodevelopment. The aim of this study was to identify the risk and protective factors for severe IVH in VLBW infants.

METHODS

A retrospective, cross-sectional review of VLBW infants born at 22-28 weeks' gestation between January 2003 and December 2012 and listed in the Database of Neonatal Research Network in Japan was performed using a statistical model incorporating an odds ratio (OR) and medical center variation as a center variance ratio (CVR). A two-dimensional analysis using a combination of OR and the CVR described evolving measures of a clinical trial (for OR > 1) and standardization (for CVR > 1) concerning a factor of interest.

RESULTS

The noteworthy significant protective factors were antenatal steroids (ANS) with and without premature rupture of membrane (OR: 0.43, CVR: 1.08, and OR: 0.68, CVR: 1.14, respectively) and the number of neonatal beds (OR: 0.94, CVR: 0.99) and staff nurses per neonatal bed (OR: 0.89, CVR: 0.99).

CONCLUSIONS

Active promotion of ANS administration and consolidation of perinatal medical centers can mitigate the development of severe IVH in VLBW infants.

Survey of Obstetric Providers to Assess the Knowledge and Management of a Reported Penicillin Allergy in Pregnant Women

OBJECTIVE

Penicillin allergy is the most commonly reported drug allergy in the United States; however, less than 10% of individuals labeled with a penicillin allergy are truly allergic. A reported penicillin allergy in pregnancy is associated with adverse maternal and perinatal outcomes. Despite recommendations for penicillin allergy testing in pregnancy, limited literature regarding obstetric providers' comfort and knowledge in addressing penicillin allergy and referral patterns exists. The objective of this study is to survey obstetric providers to assess their clinical practice patterns and baseline penicillin allergy knowledge, identify potential knowledge gaps in the management of pregnant patients with reported penicillin allergy, and measure the impact of an educational intervention on provider knowledge and practice patterns.

STUDY DESIGN

An anonymous, electronic 23-question survey administered to all obstetric providers at a single academic medical center assessed obstetric provider characteristics, self-reported antibiotic practice patterns, and antibiotic allergy knowledge before (June 19, 2020) and after (September 16, 2020) a penicillin allergy educational intervention, which consisted of multiple small-group educational sessions and a culminating departmental educational session. Discrete knowledge comparison by provider type and experience level of pre- and postintervention was performed using chi-square tests.

RESULTS

Of 277 obstetric providers invited, 124 (45%) responded preintervention and 62 (22%) postintervention. In total, 27% correctly identified the percentage of patients labeled penicillin allergic who would tolerate penicillins, 45% identified cephalosporin cross-reactivity, 59% understood penicillin allergies can wane, and 54% identified penicillin skin testing (PST) as a valid allergy verification tool. Among 48 respondents who attended educational sessions and responded postintervention, their knowledge of penicillin allergy waning (79% preeducation vs. 98% posteducation, p < 0.01) and PST as a valid tool for penicillin allergy verification (50% preeducation vs. 83% posteducation, p < 0.01) improved.

CONCLUSION

Knowledge gaps related to penicillin allergy exist among obstetric providers. Educational initiatives may improve provider knowledge, help in the identification of patients requiring penicillin allergy evaluation, and reduce referral barriers.

KEY POINTS

· Obstetric providers lack adequate knowledge of penicillin allergy.. · Educational interventions can improve discrete knowledge.. · Limited knowledge is a barrier to allergy referral for penicillin allergy delabeling..

Early-Onset Sepsis in Newborns

Early-onset sepsis can cause significant morbidity and mortality in newborn infants. Risk factors for sepsis include birth to mothers with inadequately treated maternal group B Streptococcus colonization, intra-amniotic infection, maternal temperature greater than 100.4°F (>38°C), rupture of membranes greater than 18 hours, and preterm labor. The organisms that most commonly cause early-onset sepsis include group B Streptococcus, Escherichia coli, and viridans streptococci. Infants often present within the first 24 hours after birth with clinical signs of sepsis, with respiratory distress as the most common presenting symptom. However, infants can also have respiratory distress from noninfectious etiologies. Therefore, when physicians are faced with asymptomatic infants with risk factors or infants with respiratory distress without risk factors, there is a delicate balance between empirically treating with antibiotics and observing these infants without treating.

A randomized controlled trial of an oral probiotic to reduce antepartum group B Streptococcus colonization and gastrointestinal symptoms

BACKGROUND

Probiotics have been suggested as a strategy to reduce antenatal group B Streptococcus colonization. Although probiotics are known to improve gastrointestinal symptoms, this has not been studied during pregnancy.

OBJECTIVE

This study aimed to evaluate the efficacy of a probiotic to reduce: (1) standard-of-care antenatal group B Streptococcus colonization and colony counts and (2) gastrointestinal symptoms of pregnancy.

STUDY DESIGN

In a double-blind fashion, 109 healthy adult pregnant people were randomized to Florajen3 probiotic or placebo capsules once daily from 28 weeks' gestation until labor onset. Baseline vaginal and rectal study swabs for group B Streptococcus colony-forming units and microbiome analysis were collected at 28 and 36 weeks' gestation. Standard-of-care vaginal to rectal group B Streptococcus swabs were collected from all participants at 36 weeks' gestation and determined the need for intrapartum antibiotic prophylaxis. Data collection included solicitation of adverse events, demographic information, Antepartum Gastrointestinal Symptom Assessment score, yogurt ingestion, sexual activity, and vaginal cleaning practices.

RESULTS

A total of 83 participants completed the study to 36 weeks' gestation with no adverse events. Standard-of-care group B Streptococcus colonization was 20.4% in the control group and 15.4% in probiotic group participants (-5%; P=.73). The relative risk for positive standard-of-care vaginal-rectal group B Streptococcus colonization was 1.33 (95% confidence interval, 0.5-3.40) times higher in the control group than in the probiotic group (P=.55). There were no differences in median vaginal (P=.16) or rectal (P=.20) group B streptococcus colony-forming units at baseline or at 36 weeks (vaginal P>.999; rectal P=.56). Antepartum Gastrointestinal Symptom Assessment scores were similar at baseline (P=.19), but significantly decreased in probiotic group participants at 36 weeks (P=.02). No covariates significantly altered group B Streptococcus colonization. Significantly more Florajen3 bacteria components were recovered from the vaginal-rectal samples of probiotic group participants (32%; P=.04) compared with controls.

CONCLUSION

The findings of this study provided insufficient evidence for the clinical application of the Florajen3 probiotic intervention to reduce standard-of-care vaginal-rectal group B Streptococcus colonization. The prevalence of group B Streptococcus was lower than expected in the study population, and intervention adherence was poor. Probiotic bacteria colonization of the genitourinary tract occurred more in intervention group participants than in controls and significantly reduced gastrointestinal symptoms of pregnancy.

Sorting Out the Risks and Benefits of the #797 Recommended Intrapartum Vancomycin Dosing Approach

ACOG Committee Opinion #797 proposed intrapartum vancomycin dosing guidelines in the absence of thorough evaluation of its risk versus benefit profile on the maternal and neonatal systems. The previously published serum and cord-blood concentration-time data of vancomycin given to mothers in the intrapartum period was analyzed in this work with a two-compartment pharmacokinetic (PK) model. Monte Carlo simulation was used to establish exposure for the studied population for doses of 1000 mg to 2000 mg every 8 h for gestational ages (GA) of 33 to 40 weeks and for birth times up to 4-h intervals. Probabilities of target attainment (PTA) were calculated for efficacy and toxicity indices unique to the peripartum maternal and neonatal population. Neonatal evaluations indicate uniformly high PTAs for the evaluated dosing regimens when the efficacy target is considered. On the other hand, the PTAs for potentially nephrotoxic exposure is expected to reach undesirable levels when three or more doses were to be administered. The risk is profoundly high in GA below 36 weeks and birth times beyond 20 h after the initiation of intrapartum prophylaxis and with doses greater than 1250 mg. Maternal vancomycin exposures seem reasonable up to two intrapartum doses given at 8 h intervals when the dose is kept to 1250 mg or less. Most mothers (up to 83%) who receive three or more doses of the commonly administered regimens are subjected to nephrotoxic exposures. Thus, it appears that the current recommendations by #797 for dosing of vancomycin pose considerable risk to mother and newborn alike, especially in cases with lengthy duration of preterm labor. Capping of doses at 1250 mg may be considered to minimize the need for therapeutic drug monitoring (TDM) interventions. Alternatively, and irrespective of the baseline maternal renal function, TDM for all cases requiring more than two doses of 1500 mg or higher must be assured.

Multicenter Evaluation of the Cepheid Xpert GBS LB XC Test

Early-onset neonatal sepsis due to Streptococcus agalactiae (group B Streptococcus [GBS]) infection is one of the leading causes of newborn mortality and morbidity. The latest guidelines published in 2019 recommended universal screening of GBS colonization among all pregnant women and intrapartum antibiotic prophylaxis for positive GBS. The updated procedures allow rapid molecular-based GBS screening using nutrient broth-enriched rectovaginal samples. Commercially available molecular assays for GBS diagnosis target mainly the cfb gene, which encodes a hemolysin protein responsible for producing the Christie-Atkins-Munch-Petersen (CAMP) factor. cfb is considered a conserved gene in essentially all GBS isolates. However, false-negative GBS results on Cepheid Xpert GBS and GBS LB tests due to deletions in or near the region that encodes cfb were reported recently. Therefore, the new Xpert GBS LB XC test was developed. This study is a multicenter evaluation of the new test for GBS identification from nutrient broth-enriched rectal/vaginal samples from antepartum women. A total of 621 samples were prospectively enrolled. The samples were tested with the Xpert GBS LB XC test, the composite comparator method, which included the Hologic Panther Fusion GBS test combined with bacterial culture, followed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) identification, and bacterial culture alone, followed by MALDI-TOF MS identification. The respective sensitivity and specificity of the Xpert GBS LB XC test were 99.3% and 98.7% compared to the composite comparator method and 99.1% and 91.8% compared to bacterial culture alone with MALDI-TOF MS identification. Overall, the Xpert GBS LB XC test performed comparatively to the composite comparator method and is equivalent to traditional bacterial culture followed by MALDI-TOF MS.

Maternally transferred mAbs protect neonatal mice from HSV-induced mortality and morbidity

Neonatal herpes simplex virus (nHSV) infections often result in significant mortality and neurological morbidity despite antiviral drug therapy. Maternally transferred herpes simplex virus (HSV)-specific antibodies reduce the risk of clinically overt nHSV, but this observation has not been translationally applied. Using a neonatal mouse model, we tested the hypothesis that passive transfer of HSV-specific human mAbs can prevent mortality and morbidity associated with nHSV. The mAbs were expressed in vivo via vectored immunoprophylaxis or recombinantly. Through these maternally derived routes or through direct administration to pups, diverse mAbs to HSV glycoprotein D protected against neonatal HSV-1 and HSV-2 infection. Using in vivo bioluminescent imaging, both pre- and post-exposure mAb treatment significantly reduced viral load in mouse pups. Together these studies support the notion that HSV-specific mAb-based therapies could prevent or improve HSV infection outcomes in neonates.

Study on the relationship between intrapartum group B streptococcus prophylaxis and food allergy in children

Objective

To investigate the associations between intrapartum antibiotic prophylaxis of group B streptococcus (GBS) in pregnant women and the risk of food allergy in Chinese children.

Design

Retrospective cohort study of 2,909 mother-child pairs.

Setting

Taixing People's Hospital in Eastern China.

Participants

Term infants born 2018-2019, followed longitudinally from birth to 3 years.

Exposures

The GBS-IAP was defined as therapy with intravenous penicillin G or ampicillin or cefazolin ≥4 h prior to delivery to the mother. Reference infants were defined as born without or with other intrapartum antibiotic exposure.

Methods

To investigate the incidence information of food allergy in children aged 18 months and three years old. Kaplan-Meier survival analysis and log-rank tests were used to evaluate the cumulative incidence in the group with GBS-IAP and the group without GBS-IAP. Cox proportional hazards models were conducted to determine the univariate and multivariate association between maternal GBS-IAP and incident food allergy after various covariates were adjusted.

Results

The cumulative incidence of food allergy in the group with GBS-IAP was higher than that in the group without GBS-IAP in children under 18 months old (8.1% vs. 4.5%, P = 0.005, log-rank test), but no significant differences were observed in children under three years old (9.2% vs. 7.0%, P = 0.146, log-rank test). The univariate cox proportional hazards model in children under 18 months old revealed that children in the GBS-IAP group had faster food allergy development when compared with children in the group without GBS-IAP (HR.: 1.887,95% CI: 1.207-2.950, P = 0.005), so was the multivariate model (HR.: 1.906,95% CI: 1.158-3.137, P = 0.011). However, both univariate (HR: 1.343, 95% CI: 0.891∼2.026, P = 0.159) and multivariate (HR: 1.253, 95%CI: 0.796∼1.972, P = 0.329) cox proportional hazards model in children under three years old showed no significant differences between children in the group with GBS-IAP and group without GBS-IAP.

Conclusion

Intrapartum antibiotic prophylaxis of group B streptococcus may increase the cumulative incidence and risk of food allergy in children under 18 months old, but it had no significant effect on children under three years old.

Updates on Group B Streptococcus Infection in the Field of Obstetrics and Gynecology

Group B Streptococcus (GBS, Streptococcus agalactiae) is a Gram-positive bacterium that is commonly found in the gastrointestinal and urogenital tracts. However, its colonization during pregnancy is an important cause of maternal and neonatal morbidity and mortality worldwide. Herein, we specifically looked at GBS in relation to the field of Obstetrics (OB) along with the field of Gynecology (GY). In this review, based on the clinical significance of GBS in the field of OBGY, topics of how GBS is being detected, treated, and should be prevented are addressed.

Group B Streptococcus Screening and Treatment Adherence in Pregnancy: A Retrospective Cohort Study and Opportunities for Improvement

Introduction

Pregnancy is a time of increased healthcare screening, and past adherence to evolving guidelines informs best practices. Although studies of Group B Streptococcus guideline adherence have focused primarily on treatment of Group B Streptococcus carriers, this study broadly evaluated long-term adherence to both Group B Streptococcus screening and treatment guidelines. Adherence was evaluated across provider types (obstetrics and gynecology, certified nurse midwives, and family medicine).

Methods

We conducted a retrospective cohort study. Demographic and clinical information were extracted from all prenatal care and delivery patients at a single institution in a single year. Vancomycin prescriptions in pregnancy were tracked for 10 years to determine long-term adherence. Adherence was defined as no deviation from 2010 Group B Streptococcus screening and treatment guidelines.

Results

Adherence occurred in 89% (1,610/1,810) of patients. Reasons for deviations from guidelines could not always be determined. There was no significant difference in maternal age, race, prenatal provider type, provider type at delivery, gestational age at delivery, delivery mode, or whether antibiotic sensitivities were performed between compliant and noncompliant groups. Significant differences in adherence were found between obstetric clinics (high-risk obstetrics clinic, maternal‒fetal medicine fellows clinic, continuity of care clinic, and faculty private clinic) (p<0.0001) and between the faculty family medicine clinic and resident family medicine clinic (p=0.001). Vancomycin prescription practice did not change significantly over the10-year period.

Conclusions

High rates of adherence to Group B Streptococcus screening and treatment guidelines in pregnancy have positive implications for reducing antibiotic resistance. Given evolving guidelines, there is a need to periodically evaluate adherence and to re-educate providers about standard practices and best documentation practices.

Group B Streptococcus and Pregnancy: Critical Concepts and Management Nuances

Importance

Group B Streptococcus (GBS) is a common pathogen with an effective treatment. However, it remains a significant cause of neonatal sepsis, morbidity, and mortality. The screening and management of this infection are some of the first concepts learned during medical training in obstetrics. However, effective screening and evidence-based management of GBS are nuanced with many critical caveats.

Objective

The objectives of this review are to discuss the essential aspects of GBS screening and management and to highlight recent changes to recommendations and guidelines.

Evidence Acquisition

Original research articles, review articles, and guidelines on GBS were reviewed.

Results

The following recommendations are based on review of the evidence and professional society guidelines. Screening for GBS should occur between 36 weeks and the end of the 37th week. The culture swab should go 2 cm into the vagina and 1 cm into the anus. Patients can perform their own swabs as well. Penicillin allergy testing has been shown to be safe in pregnancy. Patients with GBS in the urine should be treated at term with antibiotic prophylaxis, independent of the colony count of the culture. Patients who are GBS-positive with preterm and prelabor rupture of membranes after 34 weeks are not candidates for expectant management, as this population has higher rates of neonatal infectious complications. Patients with a history of GBS colonization in prior pregnancy who are GBS-unknown in this current pregnancy and present with labor should receive intrapartum prophylaxis. Work on the GBS vaccine continues.

Conclusions

Although all of the efforts and focus on neonatal early-onset GBS infection have led to lower rates of disease, GBS still remains a major cause of neonatal morbidity and mortality requiring continued vigilance from obstetric providers.