Prevalence of maternal group B streptococcal colonisation in European countries

Transferring an extremely premature infant to an extra-uterine life support system: a prospective view on the obstetric procedure

To improve care for extremely premature infants, the development of an extrauterine environment for newborn development is being researched, known as Artificial Placenta and Artificial Womb (APAW) technology. APAW facilitates extended development in a liquid-filled incubator with oxygen and nutrient supply through an oxygenator connected to the umbilical vessels. This setup is intended to provide the optimal environment for further development, allowing further lung maturation by delaying gas exposure to oxygen. This innovative treatment necessitates interventions in obstetric procedures to transfer an infant from the native to an artificial womb, while preventing fetal-to-neonatal transition. In this narrative review we analyze relevant fetal physiology literature, provide an overview of insights from APAW studies, and identify considerations for the obstetric procedure from the native uterus to an APAW system. Lastly, this review provides suggestions to improve sterility, fetal and maternal well-being, and the prevention of neonatal transition.

Investigating the Association between Serum and Hematological Biomarkers and Neonatal Sepsis in Newborns with Premature Rupture of Membranes: A Retrospective Study

(1) Background: Neonatal early-onset sepsis (EOS) is associated with important mortality and morbidity. The aims of this study were to evaluate the association between serum and hematological biomarkers with early onset neonatal sepsis in a cohort of patients with prolonged rupture of membranes (PROM) and to calculate their diagnostic accuracy. (2) Methods: A retrospective cohort study was conducted on 1355 newborns with PROM admitted between January 2017 and March 2020, who were divided into two groups: group A, with PROM ≥ 18 h, and group B, with ROM < 18 h. Both groups were further split into subgroups: proven sepsis, presumed sepsis, and no sepsis. Descriptive statistics, analysis of variance (ANOVA) and a Random Effects Generalized Least Squares (GLS) regression were used to evaluate the data. (3) Results: The statistically significant predictors of neonatal sepsis were the high white blood cell count from the first (p = 0.005) and third day (p = 0.028), and high C-reactive protein (CRP) values from the first day (p = 0.004). Procalcitonin (area under the curve-AUC = 0.78) and CRP (AUC = 0.76) measured on the first day had the best predictive performance for early-onset neonatal sepsis. (4) Conclusions: Our results outline the feasibility of using procalcitonin and CRP measured on the first day taken individually in order to increase the detection rate of early-onset neonatal sepsis, in the absence of positive blood culture.

Multicenter Performance Evaluation of the Revogene® GBS DS Real-Time PCR Assay for Group B Streptococcus Detection During Labor

PURPOSE

This study aimed to evaluate the performance and ease of use of the Revogene® GBS DS PCR assay for the intrapartum detection of Group B Streptococcus (GBS) colonization, as compared with intrapartum culture and antenatal culture-based screening.

METHODS

Between April and August 2019, 398 women who gave birth in one of the three maternities participating in this study agreed to the collection of a vaginal swab when they arrived in the labor ward. The samples were immediately sent to the adjacent laboratory where they were discharged into the buffer provided with the Revogene® GBS DS assay. Part of the buffer was used to perform the Revogene® GBS DS test, and part of the same buffer was used for GBS culture.

RESULTS

The Revogene® GBS DS assay provided a valid result in less than 70 min for 356 (89%) women. The sensitivity of the test was 85.7% (66.4-95.3%). The specificity of the test was 99.1% (97.3-99.8%). The positive predictive value was 88.9% (69.7-97.1%). The negative predictive value was 98.9% (96.9-99.6%).

CONCLUSION

The easy-to-use Revogene® GBS DS assay provides a valuable tool for the detection of GBS colonization at the beginning of labor. The sensitivity and turn-around time are adequate. The high number of invalid results needs to be addressed before the Revogene® GBS DS test can be expected to replace the current screening-based approach.

Evaluation of two rapid commercial assays for detection of Streptococcus agalactiae from vaginal samples

INTRODUCTION

Streptococcus agalactiae, also known as group B streptococci (GBS), is associated with invasive infections in neonates. Identification of GBS vaginal colonization in pregnant women before delivery is essential for treatment with antibiotics to prevent intrapartum vertical transmission to the newborn. This study was designed to evaluate applicability of two rapid real-time PCRs in comparison to standard culture identification.

MATERIAL AND METHODS

We compared the Xpert GBS assay, hereafter referred to as Xpert, and GenomEra GBS PCR, hereafter referred to as GenomEra. The standard culture identification consisted of two different agar plates as well as an enrichment broth.

RESULTS

We analyzed vaginal samples of 260 pregnant women; 42 samples were tested GBS-positive by using standard culture as a gold standard, 30 by Xpert, and 37 by GenomEra. Xpert and GenomEra assays performed with sensitivities of 71.4% and 88.1% as well as specificities of 98.6% and 99.1%, respectively. Twelve vaginal samples were false-negative by Xpert and five samples by GenomEra. Interestingly, three negative Xpert results of standard culture-positive samples exhibited high Ct-values indicating the presence of GBS. If higher Ct-values are taken into consideration, the sensitivity of Xpert increases up to 78.6%. Moreover, only three Xpert PCRs had to be repeated, whereas two Genomera were invalid even after repetition and further 15 GenomEra PCRs were repeated because of borderline results or inhibition of the PCR test.

CONCLUSIONS

In this study, GenomEra assay performed with a higher sensitivity than the Xpert PCR. On the other hand, the Xpert assay needs less hands-on-time for a sample preparation and requires approximately four-fold less repetitions as compared to the GenomEra assay. This robust performance of the Xpert assay make it applicable as a rapid intrapartum point-of-care test, although a higher sensitivity would be desirable. Therefore, culture in the 35-37 week of gestation remains the gold standard to detect vaginal colonization.

Supplementation of Probiotics in Pregnant Women Targeting Group B Streptococcus Colonization: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to determine if probiotic supplementation in pregnancy reduced maternal Group B streptococcus (GBS) recto-vaginal colonization in pregnant women at 35–37 weeks of gestation. Electronic databases (i.e., PubMed, MEDLINE, ClinicalTrials.gov, ScienceDirect, and the Cochrane Library) were searched from inception up to February 2022. We included RCTs assessing the effects of probiotic supplementation in pregnancy on GBS recto-vaginal colonization. The primary outcome was GBS-positive recto-vaginal cultures performed at 35–37 weeks of gestation. Secondarily, we evaluated obstetric and short-term neonatal outcomes. A total of 132 publications were identified; 9 full-length articles were reviewed to finally include 5 studies. Probiotic supplementation reduced vaginal GBS colonization: the GBS positive culture rate was estimated at 31.9% (96/301) in the intervention group compared to 38.6% (109/282) in the control group (OR = 0.62, 95% CI 0.40–0.94, I2 4.8%, p = 0.38). The treatment started after 30 weeks of gestation and was more effective in reducing GBS colonization (OR 0.41, 95% CI 0.21–0.78, I2 0%, p = 0.55). Probiotic administration during pregnancy, namely in the third trimester, was associated with a reduced GBS recto-vaginal colonization at 35–37 weeks and a safe perinatal profile. Whether this new strategy could reduce the exposition of pregnant women to significant doses of antibiotics in labor needs to be evaluated in other trials.

Sublingual immunisation with GBS serotype III capsular polysaccharide-tetanus toxoid conjugate vaccine induces systemic and mucosal antibody responses which are opsonophagocytic and inhibit GBS colonisation of vaginal epithelial cells

No vaccines are currently licensed against Group B streptococcus (GBS), an important cause of morbidity and mortality in babies and adults. Using a mouse model, and in vitro opsonophagocytosis and colonisation assays, we evaluated the potential of a sublingually-administered polysaccharide-conjugate vaccine against GBS serotype III. Sublingual immunisation of mice with 10 µg of GBS conjugate vaccine once a week for 5 weeks induced a substantial systemic IgG anti-polysaccharide response which was similar to the level induced by subcutaneous immunsation. In addition, sublingual immunisation also induced mucosal (IgA) antibody responses in the mouth, intestines and vagina. Immune sera and intestinal washes were functionally active at mediating killing of the homologous GBS serotype III in an opsonophagocytosis assay. In addition, intestinal and vaginal washes inhibited the colonisation of mouse vaginal epithelial cells by the vaccine homologous strain. These results suggest that, in addition to the induction of high levels of IgG antibodies that could be transduced from the immunised mother to the foetus to protect the newborn against GBS infection, sublingual immunisation can elicit a substantial mucosal antibody response which might play an important role in the prevention of GBS colonisation in immunised women, thereby eliminating the risk of GBS transmission from the mother to the baby during pregnancy or at birth.

Akt Inhibition Promotes Autophagy and Clearance of Group B Streptococcus from the Alveolar Epithelium

Group B Streptococcus (GBS) is a gram-positive bacterium that is harmless for healthy individuals but may provoke invasive disease in young infants and immunocompromised hosts. GBS invades the epithelial barriers to enter the bloodstream, and thus strategies that enhance epithelial cell responses may hamper GBS invasion. In the present study, we sought to investigate whether the inhibition of Akt, a kinase that regulates host inflammatory responses and autophagy via suppression of mTOR, can enhance the response of non-phagocytic alveolar epithelial cells against GBS. Treatment of the alveolar epithelial cell line A549 with the Akt inhibitor MK-2206 resulted in the enhanced production of reactive oxygen species and inflammatory mediators in response to GBS. Additionally, Akt inhibition via MK-2206 resulted in elevated LC3II/I ratios and increased autophagic flux in alveolar epithelial cells. Importantly, the inhibition of Akt promoted GBS clearance both in alveolar epithelial cells in vitro and in lung tissue in vivo in a murine model of GBS pneumonia. The induction of autophagy was essential for GBS clearance in MK-2206 treated cells, as knockdown of ATG5, a critical component of autophagy, abrogated the effect of Akt inhibition on GBS clearance. Our findings highlight the role of Akt kinase inhibition in promoting autophagy and GBS clearance in the alveolar epithelium. The inhibition of Akt may serve as a promising measure to strengthen epithelial barriers and prevent GBS invasion in susceptible hosts.

Molecular Epidemiology of Group B Streptococci in Lithuania Identifies Multi-Drug Resistant Clones and Sporadic ST1 Serotypes Ia and Ib

Streptococcus agalactiae (Group B Streptococcus, GBS) is a leading cause of neonatal infections. Yet, detailed assessment of the genotypic and phenotypic factors associated with GBS carriage, mother-to-baby transmission, and GBS infection in neonates and adults is lacking. Understanding the distribution of GBS genotypes, including the predominance of different serotypes, antimicrobial resistance (AMR) genes, and virulence factors, is likely to help to prevent GBS diseases, as well as inform estimates of the efficacy of future GBS vaccines. To this end, we set out to characterise GBS isolates collected from pregnant and non-pregnant women in Kaunas region in Lithuania. Whole genome sequences of 42 GBS isolates were analysed to determine multi-locus sequence typing (MLST), the presence of acquired AMR and surface protein genes, and the phylogenetic relatedness of isolates. We identified serotypes Ia (42.9%, 18/42), III (33.3%, 14/42), V (21.4%, 9/42), and a single isolate of serotype Ib. Genomic analyses revealed high diversity among the isolates, with 18 sequence types (STs) identified, including three novel STs. 85.7% (36/42) of isolates carried at least one AMR gene: tetM or tetO (35/42), ermB or lsaC (8/42) and ant6-Ia and aph3-III (2/42). This study represents the first genomic analysis of GBS isolated from women in Lithuania and contributes to an improved understanding of the global spread of GBS genotypes and phenotypes, laying the foundations for future GBS surveillance in Lithuania.

Retrospective Study for the Clinical Evaluation of a Real-Time PCR Assay with Lyophilized and Ready-to-Use Reagents for Streptococcus agalactiae Detection in Prenatal Screening Specimens

Streptococcus agalactiae is a leading cause of sepsis and meningitis in newborns and young infants. Screening programs and intrapartum antibiotic prophylaxis have reduced early neonatal onset of disease. The aim of this study was to evaluate a molecular assay with lyophilized and ready-to-use reagents: VIASURE® Streptococcus B Real Time PCR detection kit (CerTest Biotec) (Viasure qPCR assay) compared to both the GBS culture and a molecular assay with separated and frozen reagents: Strep B Real-TM Quant (Sacace Biotecnologies®) (Sacace qPCR assay). A total of 413 vaginal−rectal swabs from women between the 35th and 37th weeks of pregnancy were processed. GBS culture was firstly achieved through Granada medium and Columbia CNA agar at 35 °C in aerobic conditions. Then, nucleic acid extraction was performed for subsequent molecular analysis using both commercial assays. Discordant results were resolved via bidirectional Sanger sequencing. Viasure qPCR assay clinical sensitivity was 0.97 (0.92−0.99) and specificity 1 (0.98−1). This retrospective study demonstrated the good clinical parameters and the strong overall agreement (99.3%) between the Viasure qPCR assay and both reference assays. Finally, the added value observed of the assay under study was the stabilized and ready-to-use format, reducing the number of time-consuming steps, permitting the storage at room temperature, facilitating transport, being environmentally respectful, and reducing additional costs.

Autism Risk and Perinatal Antibiotic Use

OBJECTIVES

Antibiotics are commonly administered during labor and delivery, and research has suggested that fetal exposure to antibiotics can increase risk for autism spectrum disorder (ASD). We assessed whether antibiotic exposure during labor and delivery increased the risk of ASD in the offspring.

METHODS

This retrospective cohort study included everyone who delivered a live singleton-term infant in British Columbia, Canada, between April 1, 2000, and December 31, 2014. This cohort included 569 953 deliveries. To examine the association among pregnant individuals being treated for the same indication, we studied a subcohort of those who tested positive for group B Streptococcus. Cox proportional hazards models were used to estimate unadjusted and adjusted hazard ratios in both cohorts. A sensitivity analysis was conducted using length of first stage of labor as a proxy measure for dose to assess for a dose-response relationship.

RESULTS

In this population-based study, antibiotic use during labor and delivery was not associated with an increased risk of ASD in offspring. The unadjusted and adjusted hazard ratios were 1.29 (95% confidence interval, 1.24-1.35) and 0.99 (0.94-1.04), respectively; and 1.07 (0.90-1.27) and 0.88 (0.74-1.05), respectively, in the group B Streptococcus-positive cohort. We observed no substantial difference in the association between antibiotic exposure and ASD depending on length of the first stage of labor.

CONCLUSIONS

Our findings suggest that concern for ASD should not factor into the clinical decision on whether to administer antibiotics during labor and delivery. Future research is needed to examine longer durations of prenatal antibiotic exposure.

TIRAP/Mal Positively Regulates TLR8-Mediated Signaling via IRF5 in Human Cells

Toll-like receptor 8 (TLR8) recognizes single-stranded RNA of viral and bacterial origin as well as mediates the secretion of pro-inflammatory cytokines and type I interferons by human monocytes and macrophages. TLR8, as other endosomal TLRs, utilizes the MyD88 adaptor protein for initiation of signaling from endosomes. Here, we addressed the potential role of the Toll-interleukin 1 receptor domain-containing adaptor protein (TIRAP) in the regulation of TLR8 signaling in human primary monocyte-derived macrophages (MDMs). To accomplish this, we performed TIRAP gene silencing, followed by the stimulation of cells with synthetic ligands or live bacteria. Cytokine-gene expression and secretion were analyzed by quantitative PCR or Bioplex assays, respectively, while nuclear translocation of transcription factors was addressed by immunofluorescence and imaging, as well as by cell fractionation and immunoblotting. Immunoprecipitation and Akt inhibitors were also used to dissect the signaling mechanisms. Overall, we show that TIRAP is recruited to the TLR8 Myddosome signaling complex, where TIRAP contributes to Akt-kinase activation and the nuclear translocation of interferon regulatory factor 5 (IRF5). Recruitment of TIRAP to the TLR8 signaling complex promotes the expression and secretion of the IRF5-dependent cytokines IFNβ and IL-12p70 as well as, to a lesser degree, TNF. These findings reveal a new and unconventional role of TIRAP in innate immune defense.

Characterization of a novel type of glycogen-degrading amylopullulanase from Lactobacillus crispatus

Glycogen is one of the major carbohydrates utilized by the human vaginal microbiota, which is commonly dominated by Lactobacillus, especially L. crispatus. An in silico analysis predicted that a type I pullulanase was involved in glycogen degradation in L. crispatus. The biochemical and genetic properties of the pullulanase still need to be determined. Here, we de novo identified the glycogen (Glg)-utilization enzyme (named GlgU) from L. crispatus through a biochemical assay. GlgU was optimally active at acidic pH, approximately 4.0 ~ 4.5, and was able to hydrolyze glycogen into low-molecular-weight malto-oligosaccharides. Actually, GlgU was a type II pullulanase (amylopullulanase) with just one catalytic domain that possessed substrate specificity toward both α-1,4 and α-1,6-glucosidic bonds. Phylogenetically, GlgU was obviously divergent from the known amylases and pullulanases (including amylopullulanases) in lactobacilli. In addition, we confirmed the catalytic activity of glgU in a nonglycogen-utilizing lactobacilli strain, demonstrating the essential role of glgU in glycogen metabolism. Overall, this study characterized a novel type of amylopullulanases, contributing to the knowledge of the glycogen utilization mechanism of the dominant species of human vaginal microbiota. KEY POINTS: • GlgU was a type II pullulanase, not a type I pullulanase predicted before. • GlgU was able to completely hydrolyze glycogen into malto-oligosaccharides. • GlgU played a key role in the metabolism of extracellular glycogen.

Characteristics of Streptococcus agalactiae Colonizing Nonpregnant Adults Support the Opportunistic Nature of Invasive Infections

The prevalence and lineages of Streptococcus agalactiae (group B streptococci [GBS]) colonizing pregnant women are well studied, but less is known about colonization of nonpregnant adults. We characterized GBS colonization in adults as a potential reservoir for infections and tested for the presence of clones with a potentially higher invasive disease potential. We evaluated GBS gastrointestinal, genitourinary, and oral colonization among 336 nonpregnant adults in the community. We characterized the isolates by serotyping, multilocus sequence typing, profiling of surface protein genes and pili, and antimicrobial susceptibility and compared them with contemporary invasive isolates. The colonization rate (n = 107, 32%) among nonpregnant adults was like that of pregnant women. Colonization increased with age (~25% in the 18 to 29 and 30 to 44 years old groups and >42% in the ≥60 years old group), potentially explaining the higher incidence of disease with older age. Participants who were colonized at multiple sites (73%) were frequently carrying indistinguishable strains (93%), consistent with the existence of a single reservoir of colonization and transfer of GBS between sites within the same individual. The most frequent lineages found were serotype Ib/CC1 (n = 27), serotype V/CC1 (n = 19), serotype Ia/CC23 (n = 13), serotype III/ST17 (n = 13), and serotype Ib/CC10 (n = 11). Comparison with contemporary isolates causing invasive infections in Portugal did not reveal any lineage associated with either asymptomatic carriage or invasive disease. Asymptomatic colonization of nonpregnant adults is significant and could act as a reservoir for invasive disease, but in contrast to infant disease, we found no GBS lineages with an enhanced potential for causing invasive disease in adults.

IMPORTANCE The increasing incidence of Streptococcus agalactiae (group B streptococci [GBS]) infections in adults and the inability of antimicrobial prophylaxis peripartum to control late-onset infections in infants motivate the study of the asymptomatic carrier state in nonpregnant adults. We found an overall carriage rate like that of pregnant women, increasing with age, potentially contributing to the higher incidence of GBS infections with age. Colonization of diabetic participants was not higher despite the higher number of infections in this group. Comparison between contemporary genetic lineages causing infections and found in asymptomatic carriers did not identify particularly virulent lineages. This means that any prophylactic approaches targeting colonization by particular lineages are expected to have a limited impact on GBS disease in adults.

Neonatal Nasopharyngeal Bacterial Colonization: Prevalence, Antimicrobial Resistance, and Concomitant Early-onset Sepsis

Background: Early-onset neonatal sepsis (ENOS) is one of the most common causes of mortality in neonates. The bacteria causing ENOS are generally transferred from the mother to the infant before or during labor. Objectives: This study aimed to determine the prevalence rate of nasopharyngeal colonization with common bacterial agents causing ENOS and their relationship with blood culture outcomes in neonates. Methods: All neonates transferred to the neonatal intensive care unit were included in the study. Posterior pharynx secretions were swabbed and cultured in blood agar and MacConkey agar. Also, a blood specimen from each neonate was inoculated into a blood culture bottle. The grown bacteria were identified by biochemical standard tests. The antibiotic sensitivity test was performed by the disk diffusion method using Mueller-Hinton agar, and the results were evaluated according to the CLSI guidelines. Results: The pharyngeal specimens collected from 114 newborns were positive in 83 (72.8%) cases. Staphylococcus epidermidis was the most common bacterium in all weight groups. However, the isolates of Klebsiella, Escherichia coli, S. aureus, and Streptococcus agalactiae were also high. Thirteen newborns died. Neonates’ pharyngeal specimens were positive among 11 (84.6%) cases who died and 101 (71.2%) neonates who survived. Twelve neonates had positive blood cultures. Simultaneous positive blood and pharyngeal cultures were reported in eight (7%) cases, in which the bacterial isolates from blood and pharyngeal samples were similar in three cases (37.5%). Among pharyngeal isolates, E. coli was resistant to ampicillin in 100% and gentamicin, cefotaxime, and ceftazidime in 50% of the cases. Also, S. epidermidis and Acinetobacter isolates from blood samples were resistant to ampicillin in 100% of the cases. Conclusions: Staphylococcus epidermidis accounted for 38.6% of bacteria cultured from pharyngeal swabs and 66.7% of bacteria cultured from blood samples, 37.5% of which were resistant to ampicillin and 100% were sensitive to vancomycin. One-hundred percent of E. coli cultures from neonatal pharynges were resistant to ampicillin and about 50% of them were resistant to gentamicin, cefotaxime, and ceftriaxone.

Granadaene Photobleaching Reduces the Virulence and Increases Antimicrobial Susceptibility of Streptococcus agalactiae

Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is increasingly recognized as a major cause of soft tissue and invasive diseases in the elderly and diabetic populations. Antibiotics like penicillin are used with great frequency to treat these infections, although antimicrobial resistance is increasing among GBS strains and underlines a need for alternative methods not reliant on traditional antibiotics. GBS granadaene pigment is related to the hemolysin/cytolysin of GBS, which is critical for the pathogenesis of GBS diseases. Here, we show that photobleaching granadaene dampens the hemolytic activity of GBS. Furthermore, photobleaching of this antioxidant was found to increase GBS susceptibility to killing by reactive oxygen species like hydrogen peroxide. Treatment with light was also shown to affect GBS membrane permeability and contribute to increased susceptibility to the cell membrane-targeting antibiotic daptomycin. Overall, our study demonstrates dual effects of photobleaching on the virulence and antimicrobial susceptibility of GBS and suggests a novel approach for the treatment of GBS infection.

Preventing early-onset group B streptococcal sepsis: clinical risk factor-based screening or culture-based screening?

INTRODUCTION

Two strategies are available for prevention of early-onset group B streptococcal (GBS) sepsis - clinical risk factor-based screening and routine culture-based screening of pregnant women for GBS colonisation. In our hospital, we switched from the former to the latter approach in 2014.

METHODS

We compared the incidence of early-onset GBS sepsis during 2001-2015 between infants born to pregnant women who were screened for GBS colonisation and those born to women who were not screened.

RESULTS

Among 41,143 live births, there were nine cases of early-onset GBS sepsis. All infants with GBS sepsis were born to pregnant women who were not screened for GBS colonisation. The incidence of early-onset GBS sepsis among infants of women who were not screened was 0.41 per 1,000 live births (95% confidence interval [CI] 0.19-0.77) when compared to infants of women who were screened, for whom the sepsis incidence was zero per 1,000 live births (95% CI 0-0.19; p = 0.005).

CONCLUSION

Our data suggests that routine culture-based screening of pregnant women for GBS colonisation is a better preventive strategy for early-onset GBS sepsis in neonates when compared to clinical risk factor-based screening.

Polymer Adhesin Domains in Gram-Positive Cell Surface Proteins

Surface proteins in Gram-positive bacteria are often involved in biofilm formation, host-cell interactions, and surface attachment. Here we review a protein module found in surface proteins that are often encoded on various mobile genetic elements like conjugative plasmids. This module binds to different types of polymers like DNA, lipoteichoic acid and glucans, and is here termed polymer adhesin domain. We analyze all proteins that contain a polymer adhesin domain and classify the proteins into distinct classes based on phylogenetic and protein domain analysis. Protein function and ligand binding show class specificity, information that will be useful in determining the function of the large number of so far uncharacterized proteins containing a polymer adhesin domain.

Genomic and phenotypic characterisation of invasive neonatal and colonising group B Streptococcus isolates from Slovenia, 2001-2018

Background

Group B Streptococcus (GBS) is the leading cause of invasive neonatal disease in the industrialized world. We aimed to genomically and phenotypically characterise invasive GBS isolates in Slovenia from 2001 to 2018 and contemporary colonising GBS isolates from screening cultures in 2018.

Methods

GBS isolates from 101 patients (invasive isolates) and 70 pregnant women (colonising isolates) were analysed. Basic clinical characteristics of the patients were collected from medical records. Antimicrobial susceptibility and phenotypic capsular serotype were determined. Whole-genome sequencing was performed to assign multilocus sequence types (STs), clonal complexes (CCs), pathogenicity/virulence factors, including capsular genotypes, and genome-based phylogeny.

Results

Among invasive neonatal disease patients, 42.6% (n = 43) were females, 41.5% (n = 39/94) were from preterm deliveries (< 37 weeks gestation), and 41.6% (n = 42) had early-onset disease (EOD). All isolates were susceptible to benzylpenicillin with low minimum inhibitory concentrations (MICs; ≤0.125 mg/L). Overall, 7 serotypes were identified (Ia, Ib, II-V and VIII); serotype III being the most prevalent (59.6%). Twenty-eight MLST STs were detected that clustered into 6 CCs. CC-17 was the most common CC overall (53.2%), as well as among invasive (67.3%) and non-invasive (32.9%) isolates (p < 0.001). CC-17 was more common among patients with late-onset disease (LOD) (81.4%) compared to EOD (47.6%) (p < 0.001). The prevalence of other CCs was 12.9% (CC-23), 11.1% (CC-12), 10.5% (CC-1), 8.2% (CC-19), and 1.8% (CC-498). Of all isolates, 2.3% were singletons.

Conclusions

A high prevalence of hypervirulent CC-17 isolates, with low genomic diversity and characteristic profile of pathogenicity/virulence factors, was detected among invasive neonatal and colonising GBS isolates from pregnant women in Slovenia. This is the first genomic characterisation of GBS isolates in Slovenia and provides valuable microbiological and genomic baseline data regarding the invasive and colonising GBS population nationally. Continuous genomic surveillance of GBS infections is crucial to analyse the impact of IND prevention strategies on the population structure of GBS locally, nationally, and internationally.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05599-y.

The correlation between prelabour rupture of the membranes and neonatal infectious diseases, and the evaluation of guideline implementation in China: a multi-centre prospective cohort study

BACKGROUND

The aim of this study was to describe the epidemiology of prelabour rupture of membranes (PROM) in China and to assess the association between clinical practice following the guidelines and early neonatal infections.

METHODS

We conducted a prospective cohort study of 15926 deliveries in ShenZhen Baoan Women's and Children's Hospital, Xibei Women's and Children's Hospital and Chengdu Women's and Children's Hospital between August 1, 2017, to March 31, 2018. Clinical data were collected for each participant. The epidemiology of PROM was described. The association between PROM with early neonatal infectious outcomes and the influence of the implementation of the guideline on early neonatal infectious outcomes were assessed.

FINDINGS

The incidence of PROM was 18•7%. PROM was showed to be a risk factor for neonatal infectious diseases (adjusted OR 1•92, 95%CI 1•49~2•49, p<0•0001), early-onset pneumonia (EOP) (adjusted OR 1•81, 95%CI 1•29~2•53, p=0•0006) and early-onset sepsis(EOS) (adjusted OR 14•56, 95%CI 1•90~111•67, p=0•01) for term neonates. For term neonates born from mother with PROM, induction of labor according to the guideline was a protective factor for neonatal diseases(adjusted OR 0•50, 95%CI 0•25~1•00, p=0•00498) and EOP(adjusted OR 0•32, 95%CI 0•11~0•91, p=0•03). For preterm neonates born from mother with PROM, using antibiotics according to the guideline showed to be protective for neonatal infectious diseases (adjusted OR 0•14, 95%CI 0•09~0•23, p<0•0001) and EOP (adjusted OR 0•08, 95%CI 0•04~0•14, p<0•0001).

INTERPRETATION

Our study showed the risk of PROM for infectious diseases (including EOP and EOS) and the benefit of the usage of antibiotics according to the guideline for infectious diseases and EOP for preterm neonates.

FUNDING

National Natural Science Foundation of China, Capital Medical Development Research Fund of Beijing.

The effect of group B streptococcus on maternal and infants' prognosis in Guizhou, China

Group B Streptococcus (GBS) is a kind of opportunistic pathogenic bacteria and mainly strikes the lower digestive tract and genitourinary tract. It is a major risk factor for neonatal babies, seriously threatening their lives. In the present study, we aimed to detect the GBS colonization in late pregnant women, and to study the effect of GBS on maternal and infants’ prognosis. Pregnant women with a gestational age of 35–37 weeks were enrolled in the study. Real-time polymerase chain-reaction (RT-PCR) was used to detect the colonization of GBS in the vaginal and rectal secretions for late pregnant women according to the screening guidelines. Chi-square test was applied to analyze the relationship between GBS colonization and clinical characteristics. A follow-up of 6 weeks was performed on the puerpera and infants after delivery. The positive rate of GBS was 12.6% in late pregnant women. GBS carrier state was positively related to several pregnancy outcomes, including intrauterine infection, premature rupture of membranes, postpartum hemorrhage, fetal distress and puerperal infection, as well as to part neonatal outcomes, containing neonatal infection, neonatal pneumonia and neonatal sepsis (all P < 0.05). GBS infection in late pregnant women results in adverse effects on maternal and neonatal outcomes.

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.

Streptococcus agalactiae in pregnant women: serotype and antimicrobial susceptibility patterns over five years in Eastern Sicily (Italy)

Streptococcus agalactiae (also known Group B Streptococcus or GBS) represents the main pathogen responsible for early- and late-onset infections in newborns. The present study aimed to determine the antimicrobial susceptibility pattern and the capsular serotypes of GBS isolated in Eastern Sicily over 5 years, from January 2015 to December 2019. A total of 3494 GBS were isolated from vaginal swabs of pregnant women (37–39 weeks), as recommended by the Centers for Disease Control and Prevention. Capsular polysaccharide’s typing of GBS was determined by a commercial latex agglutination test containing reagents to serotypes I–IX. The antimicrobial resistance pattern of GBS was determined through the disk diffusion method (Kirby-Bauer) and the double-disk diffusion test on Mueller-Hinton agar plates supplemented with 5% defibrinated sheep blood, according to the guidelines of the Clinical and Laboratory Standards Institute. Serotypes III (1218, 34.9%) and V (1069, 30.6%) were the prevalent colonizers, followed by not typable (570, 16.3%) and serotypes Ia (548, 15.7%), Ib (47, 1.3%), II (40, 1.1%), and IV (2, 0.1%). All 3494 clinical isolates were susceptible to cefditoren and vancomycin. Resistance to penicillin, ampicillin, levofloxacin, clindamycin, and erythromycin was observed in 6 (0.2%), 5 (0.1%), 161 (4.6%), 1090 (31.2%), and 1402 (40.1%) of the strains, respectively. Most of erythromycin-resistant GBS (1090/1402) showed the cMLS_B phenotype, 276 the M phenotype, and 36 the iMLS_B phenotype. Our findings revealed a higher prevalence of serotype III and a relevant resistance rate, among GBS strains, to the most frequently used antibiotics in antenatal screening.

Streptococcus agalactiae in childbearing age immigrant women in Comunitat Valenciana (Spain)

Streptococcus agalactiae (GBS) remains the leading cause of meningitis and neonatal sepsis in the world, and causes disease in pregnant and puerperal women. This is a retrospective study of GBS infections on women of childbearing age living in Comunitat Valenciana, Spain (years 2009-2014) and GBS colonization rate on pregnant women attending Hospital La Fe (years 2013-2015) according to their origin. An aggregated total of 6,641,960 women exposed during the study period had an average GBS isolation rate of 5.19‰ (5.14-5.25‰), geographical group rates being: Western Europe (2.2‰), North America (2.1‰), Australia (3.7‰), Spain (4.6‰), Latin America II (4.5‰), Eastern Europe (5.3‰), Asia (6.7‰), Latin America I (7.7‰), Middle East (7.9‰), Indian Subcontinent (17.2‰), North Africa (17.8‰), Sub-Saharan Africa (22.7‰). The 4532 pregnant women studied had an average GBS colonization rate of 12.47% (11.51-13.43) and geographical group rates varied similar to geographical isolation rates. Low GDP and high temperatures of the birth country were associated with higher colonization rates. Thus, differences in GBS colonization depend on the country of origin; Africa and the Indian subcontinent presented the highest, while Western Europe and North America had the lowest. This variability portrays a geographical pattern influenced by temperature and GDP.

Microarray Analysis of Group B Streptococci Causing Invasive Neonatal Early- and Late-onset Infection

BACKGROUND

Group B Streptococcus is the leading cause of meningitis and sepsis in newborns. Until now, there is no data of fast and simple typing of group B Streptococcus virulence factors using a genetic microarray and comparing these data to clinical manifestations.

METHODS

A prospective active surveillance study was conducted via 2 independent and nationwide reporting systems, the German Pediatric Surveillance Unit (ESPED) and the Laboratory Sentinel Group at Robert Koch-Institute. Surveillance was performed between 2001 and 2003 and between 2008 and 2010. Typing of virulence factors, serotypes, pilus islands and alpha-like proteins was done by means of a newly developed microarray method.

RESULTS

We evaluated 475 isolates of invasive neonatal infections. Predominant virulence factors were serotype III (63%), pilus island 2b and pilus island 1 (50%) and alp rib (64%) (alp - alpha-like protein, rib -resistance to proteases, immunity, group B). There was no significant change over time or geographically within Germany. Serotype III, pilus island 2b + 1 and alp rib showed significant associations with late-onset disease and meningitis, whereas alp 5 had a significant association with early-onset disease. Based on serotypes, pilus islands and alpha-like proteins, it was possible to cluster 86% of all isolates into 5 genetic groups.

CONCLUSIONS

The molecular epidemiology of a large collection of invasive neonatal infections showed similar distributions, as shown in smaller cohorts before. The microarray used proved to be a fast and reliable technique. Using this new tool, we were able to cluster the isolates according to their virulence factors. The clusters showed a better association with clinical data than single virulence factors.

Integrated Microfluidic Sample-to-Answer System for Direct Nucleic Acid-Based Detection of Group B Streptococci in Clinical Vaginal/Anal Swab Samples

The group B Streptococcus (GBS) is a type of pathogen that seriously threatens the health of mothers and infants. Prompt and timely diagnosis is crucial for good patient outcomes. However, the traditional bacterial culture and polymerase chain reaction methods are limited by their speed and involve complex operating procedures. Herein, we successfully established an integrated microfluidic sample-to-answer system for nucleic acid-based detection of GBS directly in vaginal/anal swab samples. Meanwhile, we demonstrated a dynamical reaction mechanism of Bst/FEN1-based nucleic acid amplification, which differs from traditional Bst-based isothermal amplification strategies. The system integrates cell lysis and nucleic acid purification, separation, amplification, and detection, enabling rapid (about 45 min to the entire analysis) and highly accurate (98% accuracy) analysis in a clinical setting. Experimental results show that the system offers a good detection limit (500 CFU/mL), perfect specificity (no cross-reactivity with 25 other common pathogens), excellent stability (coefficient of variation less than 3%), and good anti-interference performance. This novel system holds great potential as a nucleic acid-based diagnostic tool in clinical applications for detecting not only GBS but also other types of pathogens.

Evaluation of the Results of Group B Streptococcus Screening by MALDI-TOF MS among Pregnant Women in a Hungarian Hospital

Pregnant women colonized by Streptococcus agalactiae, or group B streptococcus (GBS), are at an increased risk of premature delivery and stillbirth, and their neonates can be endangered by the development of an invasive GBS disease. In this study, the results of the GBS screening among pregnant women performed between 2012 and 2018 (n = 19267) are presented. For the GBS positive samples, the antibiotic susceptibility of the isolated strains was also tested (n = 3554). During the examined period, the colonization rate varied between 17.4% and 19.8%. The overall rate of erythromycin and clindamycin resistance in the GBS positive samples was 34.9% and 34.6%, respectively. The frequency of the erythromycin and clindamycin resistant strains showed an increasing tendency. An analysis of the MALDI-TOF MS spectra of 260 GBS isolates revealed that 46.5% of them belonged to either the ST-1 or the ST-17 sequence types, indicating a high prevalence of these potentially invasive GBS strains in our region. More than half of the strains identified as ST-1 (52.1%) proved to be resistant to erythromycin and clindamycin.

Nationwide epidemiology of early-onset sepsis in Israel 2010-2015, time to re-evaluate empiric treatment

AIM

Early-onset neonatal sepsis (EOS) may lead to significant morbidity and mortality, yet the recommended antimicrobials have not changed for many years. We aimed to optimise EOS treatment by examining EOS pathogens, resistance rates and resistance risk factors.

METHODS

A retrospective, nationwide cohort study analysing 2010-2015 EOS data in Israel.

RESULTS

The 21 participating centres constitute 92% of the total birth cohort (around 180 000 live births/year). Of 549 EOS neonates (0.57/1000 live births), 306 (56%) and 243 (44%) were full-term and preterm, respectively (0.35 vs. 2.94 per/1000 live births). Gram-negative pathogens predominated, especially in preterms. Escherichia coli and Streptococcus agalactiae were most common pathogens (0.2 and 0.19 per 1000 live births, respectively). In 277 Gram-negatives, 16%, 14%, 8% and 3% were gentamicin-resistant, extended-spectrum beta-lactamase (ESBL)-positive, gentamicin-resistant and ESBL-positive, and amikacin-resistant, respectively; preterms had higher resistance rates. No risk factors for antimicrobial resistance were identified. Mortality was reported in 21% of Gram-negative EOS versus 7% of Gram-positive EOS [OR 3.4 (95% CI 1.8-6.2), p < 0.01].

CONCLUSION

In this nationwide study, EOS was caused predominantly by Gram-negatives, with high gentamicin resistance and ESBL phenotype rates, without identifiable resistance risk factors. As EOS is life-threatening, modification of empiric therapy for amikacin-based regimens should be considered, mainly in preterms.

No. 276-Management of Group B Streptococcal Bacteriuria in Pregnancy

OBJECTIVE

To provide information regarding the management of group B streptococcal (GBS) bacteriuria to midwives, nurses, and physicians who are providing obstetrical care.

OUTCOMES

The outcomes considered were neonatal GBS disease, preterm birth, pyelonephritis, chorioamnionitis, and recurrence of GBS colonization.

EVIDENCE

Medline, PubMed, and the Cochrane database were searched for articles published in English to December 2010 on the topic of GBS bacteriuria in pregnancy. Bacteriuria is defined in this clinical practice guideline as the presence of bacteria in urine, regardless of the number of colony-forming units per mL (CFU/mL). Low colony counts refer to <100 000 CFU/mL, and high (significant) colony counts refer to ≥100 000 CFU/mL. Results were restricted to systematic reviews, randomized controlled trials, and relevant observational studies. Searches were updated on a regular basis and incorporated in the guideline to February 2011. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

Recommendations were quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on Preventive Health Care (Table).

BENEFITS, HARMS, AND COSTS

The recommendations in this guideline are designed to help clinicians identify pregnancies in which it is appropriate to treat GBS bacteriuria to optimize maternal and perinatal outcomes, to reduce the occurrences of antibiotic anaphylaxis, and to prevent increases in antibiotic resistance to GBS and non-GBS pathogens. No cost-benefit analysis is provided.

RECOMMENDATIONS

Rectovaginal Colonization With Pathogenic Escherichia coli During Pregnancy And Neonatal Outcomes

Purpose

The role of pathogenic Escherichia coli colonization in asymptomatic pregnant women is not well understood. The purpose of this work was to determine the prevalence, antimicrobial susceptibility, and neonatal outcomes of pathogenic E. coli colonization in pregnant women.

Patients and methods

A total of 137 women from southern Taiwan with singleton pregnancies were enrolled between March 2016 and June 2017. The women were prospectively screened for E. coli colonization in the rectovaginal region during prenatal examination. The exclusion criteria are twin pregnancy of the mother and major anomaly of the neonate. All E. coli isolates were identified as either pathogenic or commensal strains, and their susceptibility to various antimicrobials was investigated. Clinical data of the infants were retrieved from their medical records.

Results

Results showed that 35.8% of asymptomatic pregnant women had pathogenic E. coli colonization in the rectovaginal region. Neonates born to such mothers showed significant morbidities, including hospitalization (OR= 3.74, 95% CI= 1.18~11.87), hyperbilirubinemia (OR= 2.81, 95% CI= 1.24~6.38), and gastrointestinal symptoms (OR= 5.53, 95% CI= 1.39~21.94). Maternal colonization with pathogenic E. coli at rectoanal site was a risk factor for neonatal hyperbilirubinemia after Benjamini–Hochberg (BH) adjustment (52% vs 24%, adjusted P= 0.048).

Conclusion

The prevalence of pathogenic E. coli colonization in Taiwanese asymptomatic pregnant women was high, and the neonates born to colonized mothers exhibited potential neonatal morbidities. Larger studies are necessary to confirm these findings.

Clinical and Microbiological Characteristics of Group B Streptococcus from Pregnant Women and Diseased Infants in Intrapartum Antibiotic Prophylaxis Era in Taiwan

Group B Streptococcus (GBS) is one of the most important pathogens for neonates. This study included 69 invasive GBS diseases in neonates, including 7 early-onset disease (EOD), 55 late-onset disease, and 7 very-late-onset disease from 2013 to 2017. A significant reduction of EOD after the deployment of intrapartum antibiotic prophylaxis (IAP) in 2012 was observed. A previously-recognized hypervirulent clone GBS III ST17, accounting for 68% of the overall infections and 71% of the meningitis, was identified among the 69 cases. A novel GBS Ia ST890 emerged, becoming the fourth most common clone. Overall 96% of the invasive GBS infections were caused by serotypes Ia, Ib, and III. We collected 300 GBS isolates from vagina of the healthy pregnant women in 2014 and 2017. The serotype distribution of the maternal colonization isolates was VI (35%), III (21%), V (15%), Ib (13%) and Ia (11%) in 2014, and VI (32%), III (22%), V (16%), Ia (16%), and Ib (8%) in 2017. The most common sequence types were ST1 (32%), ST12 (22%), and ST23 (15%). Serotype diversity of maternal colonization strains did not change between 2014 and 2017. The study provides useful information in surveillance of GBS disease in the era of IAP.

Vaginal-perineal cultures for detecting group B streptococci and extended spectrum β-lactamase producing bacteria in pregnancy

OBJECTIVE

To compare the detection rates of vaginal-perineal cultures for group B streptococci (GBS) with the standard vaginal and rectal cultures and evaluate the diagnostic yield of vaginal-perineal vs. rectal swabs for extended spectrum β-lactamase producing Enterobacterales (ESBL-E) during the third trimester of pregnancy.

STUDY DESIGN

Vagino-perineal and rectal swabs were collected cross-sectionally from pregnant women between 35-37 weeks gestation and tested for the presence of GBS and ESBL-E. Accuracy of the vagino-perineal swab was compared to the combined vagino-perineal/rectal swab. Risk factors for ESBL carriage were examined. Degrees of pain, discomfort and stress related to the rectal swab were analyzed on visual analogue scales.

RESULTS

48 out of 250 participants (19.2%) were GBS positive. The vagino-perineal swab was positive in 44 of 48 women (91.7%) yielding a negative predictive value of 98.1%. Agreement (kappa) between the two methods was 0.95. Six out of 190 women with additional ESBL-E screening (3.2%) tested positive by rectal swab. Of these, only two had also a positive vagino-perineal swab. The rectal swab caused overall little subjective discomfort, pain or stress, as indicated by low scores indicated on the visual scales.

CONCLUSIONS

The GBS detection rate of the vagino-perineal swab was lower compared to the reference standard. However, agreement between the two screening methods was high and there were no cases of GBS neonatal sepsis in the recruited population, supporting this less invasive screening strategy. In contrast, the vaginal-perineal swab was inferior to the rectal swab for detecting ESBL-E, indicating that this less invasive method for detecting antibiotic resistant bacteria that may be potentially transferred to the neonate during labor and delivery would be inappropriate for ESBL-E screening in pregnant women. The low ESBL-E carriage rate among pregnant women likely reflects the prevalence in the general population.

Maternal obesity and the risk of group B streptococcal colonisation in pregnant women

The aim of the study was to test if maternal obesity and being overweight are independent risk factors for rectovaginal Group B Streptococcus (GBS) colonisation in pregnancy and for early onset GBS disease in the neonate. A case-control study of 9877 deliveries was conducted. The obese gravidas were significantly more likely to be colonised by GBS when compared with non-obese gravidas (22.7% versus 17.5%, P < .001). Obese gravidas were still 33% more likely than non-obese women to test positive for GBS after adjusting for the perinatal factors (adjusted OR 1.33 [95% CI 1.12-1.56]). The risk of early onset GBS disease was not calculated due to its very low incidence. The conclusion is that maternal obesity is a significant risk factor for GBS colonisation at term. Impact statement What is already known on this subject? Group B Streptococcus (GBS) is as an important cause of perinatal mortality and morbidity if prophylaxis is not performed. Intrapartum antibiotics are given if the carrier status is positive or unknown, provided that the risk factors are present. What do the results of this study add? Maternal obesity is a significant and independent risk factor for GBS colonisation at term. What are the implications of these findings for clinical practice and/or further research? Maternal obesity may be considered as a risk factor that should be taken into account in strategies for reducing GBS disease in neonates.

Streptococcus agalactiae maternal colonization, antibiotic resistance and serotype profiles in Africa: a meta-analysis

Background

Maternal rectovaginal colonization with Streptococcus agalactiae (Group B Streptococcus or GBS) is the most common route for the GBS disease in the perinatal period. The knowledge of maternal colonization, antibiotic resistance and serotype profiles is substantially needed to formulate the broad vaccine. However, it has not been estimated in Africa. This meta-analysis was aimed to determine the pooled prevalence of colonization, antibiotic resistance and serotype profiles of GBS reported in Africa.

Methods

Potentially relevant studies from 1989 to 31th January, 2019 were retrieved from the Medline/PubMed, EMBASE, HINARI online databases, periodicals and by requesting authors. Unpublished studies retrieved from grey literature through Google and Google Scholar. Pooled estimates were calculated using the random effect model. Subgroup analysis was done to investigate the burden of colonization across sub-regions, sampling site and countries. Summary estimates were presented using words, Forest plots and Tables. Heterogeneity was assessed using the I² statistic.

Results

Eighty-three articles were assessed, of which 57 studies conducted in five sub-regions with 21 countries (22,206 pregnant women) met pre-specified inclusion criteria. The overall estimate of recto-vaginal colonization was 19.3% (95% CI 16.9, 21.7). The highest estimate was observed in Southern Africa, 23.8% (95% CI 18.7, 28.9), followed by Northern Africa, 22.7% (95% CI 18.2, 27.2) while the lowest was driven from the Eastern Africa, 15.4% (95% CI 12.1, 18.7). Considerable heterogeneity across and within regions, sampling site, screening methods and countries (I² > 75%); and the publication bias were observed (p = 0.031). GBS showed the highest resistance to tetracycline. Resistance to penicillin, amoxicillin, chloramphenicol, ampicillin, ceftriaxone, ciprofloxacin, erythromycin, vancomycin and clindamycin also observed. The V, III, Ia, Ib, and II serotypes altogether were accounted 91.8% in the African studies.

Conclusions

The pooled estimate of the maternal colonization with GBS was 19.3% which is equivalent with other many primary and review reports worldwide. The most antibiotic resistance estimate was recorded in the tetracycline followed by penicillin. Five serotypes were the most prevalent in Africa and more data on the antibiotic résistance and serotype distribution patterns are needed from developing countries to devise the effective preventive measures. In addition, the antibiotic susceptibility test methods used in the Africa shall be assessed for its quality.

Trial registration Prospero Registration Number CRD42018094525

Prevalence and capsular type distribution of Streptococcus agalactiae isolated from pregnant women in Namibia and South Africa

Background

Streptococcus agalactiae or Group B Streptococcus (GBS) is the leading cause of neonatal morbidity and mortality resulting in septicaemia, bacteraemia and meningitis. Long term problems in children range from loss of hearing to mental retardation. While Intrapartum Antibiotic Prophylaxis (IAP) has reduced the incidence of S. agalactiae infection, it still remains the leading cause of disease in neonates. GBS has ten capsular types whose distribution varies across the world. Therefore, this study sought to determine the prevalence of GBS in Namibia and South Africa amongst pregnant women between 35 and 37 weeks gestation and elucidate the capsular types.

Methods

Lower vaginal and rectal swabs were collected from pregnant women between 35 and 37 weeks gestation. Five hundred and thirty pregnant women were recruited into the study in Windhoek, Namibia while one hundred pregnant women were recruited in the Eastern Cape, South Africa. The swabs were cultured on 5% sheep blood agar (Biomerieux, New Jersey, USA) for isolation of GBS. Presumptive isolates were confirmed using both the Vitek (2) and molecular techniques targeting the scpB gene. Capsular typing was performed in a multiplex PCR with capsular specific primer pairs.

Results

The prevalence of GBS in Namibia was 13.6 and 37% in South Africa respectively. In both countries most women were dually colonised with GBS. Capsular types II, III and V were the most prevalent.

Conclusions

The prevalence of GBS in Namibia was lower than in South Africa in this study. The prevalence in both countries was not different from those reported in other African countries and around the world. The predominant capsular types in this study are the ones commonly associated with adverse maternal outcomes.

Streptococcus agalactiae from Ethiopian pregnant women; prevalence, associated factors and antimicrobial resistance: alarming for prophylaxis

Background

Maternal Streptococcus agalactiae (Group B Streptococcus, GBS) colonization rates and its antibiotic resistance patterns provide important information useful in guiding prevention strategies. There is a paucity of evidence about GBS in the Amhara National Regional State, Ethiopia.

Objective

To determine colonization prevalence, associated risk factors, and antibiotics resistance including inducible clindamycin resistance patterns of GBS among Ethiopian pregnant women.

Methods

A prospective cross-sectional study was conducted from 1st December 2016 to 30th November 2017 at the University of Gondar Referral hospital delivery ward. Combined recto-vaginal swabs were collected from 385 pregnant women and analyzed at the University of Gondar Bacteriology Laboratory by using LIM broth and 5% defibrinated sheep blood agar culture methods. Isolates were identified by using colony morphology, gram reaction, hemolysis, and CAMP test. Antibiotic susceptibility test was done using the disc diffusion method. Double disc diffusion method was used to identify inducible clindamycin resistance isolates. Data were analyzed by SPSS version 20 software. p ≤ 0.05 was considered as statistically significant.

Results

The overall prevalence of maternal GBS colonization was 25.5% (95% CI 21–29.5%). Experiencing meconium stained amniotic fluid (AOR = 3.018, 95% CI 1.225, 7.437), and longer duration of premature rupture of membrane (AOR = 1.897, 95% CI 1.014, 3.417) were statistically significant to maternal colonization. Furthermore, GBS resistant to 0 (8.2%), 1 (25.5%) and 3 (39.8%) or more antibiotics were identified. A D-test showed 15.2% inducible clindamycin resistant GBS. Constitutive macrolide lincosamide–streptogramin_B, L-, and M-phenotypes were also detected.

Conclusions

Maternal GBS colonization rate in this study was higher compared to the previous reports in Ethiopia. This much prevalence and antibiotics resistance results are the clue to which attention shall be given to this bacterium during management of pregnant women and the newborns.

Harbouring group B streptococci in a neonatal intensive care unit led to an outbreak among preterm infants

We report a nosocomial outbreak with group B streptococci (GBS) in a level two neonatal intensive care unit (NICU) at Sachs' Children and Youth Hospital, Stockholm, Sweden, in 2014. There were five very preterm infants with severe late-onset septicaemia, and 10 further infants were colonised. Pulsed-field gel electrophoresis and multilocus sequence typing genetic characterisation showed that one GBS strain was the cause: serotype Ia, sequence type 23, clonal complex 23. The NICU environment cultures revealed GBS reservoirs on surfaces near sick and colonised patients. We identified workflows and guidelines that could increase the risks of nosocomial infections. Conclusion: This nosocomial GBS outbreak among preterm infants demonstrates that GBS can be harboured in the NICU environment.

Maternal Carriage of Group B Streptococcus and Escherichia coli in a District Hospital in Mozambique

BACKGROUND

In low-income countries, data on prevalence and effects of group B Streptococcus (GBS) and Escherichia coli (E. coli) colonization among pregnant women are scarce, but necessary to formulate prevention strategies. We assessed prevalence of GBS and E. coli colonization and factors associated among pregnant women, its effect in newborns and acceptability regarding the utilized sampling methods in a semirural Mozambican hospital.

METHODS

Pregnant women were recruited from June 2014 to January 2015, during routine antenatal clinics at gestational age ≥ 34 weeks (n = 200); or upon delivery (n = 120). Maternal risk factors were collected. Vaginal and vagino-rectal samples for GBS and E. coli determination were obtained and characterized in terms of antimicrobial resistance and serotype. Anti-GBS antibodies were also determined. Neonatal follow-up was performed in the first 3 months after birth. Semistructured interviews were performed to investigate acceptability of sample collection methods.

RESULTS

In total, 21.3% of women recruited were GBS carriers, while 16.3% were positive for E. coli. Prevalence of HIV was 36.6%. No association was found between being colonized by GBS and E. coli and maternal risk factors. GBS isolates were fully susceptible to penicillin and ampicillin. Serotypes V (32.4%), Ia (14.7%) and III (10.3%) were the most commonly found and 69.2% of the women tested had immunoglobuline G antibodies against GBS. E. coli isolates showed resistance to ampicillin in 28.9% and trimethoprim/sulfamethoxazole in 61.3% of the cases.

CONCLUSION

Prevalence of GBS and/or E. coli colonization among pregnant women is high in this semirural community and comparable with those reported in similar settings. Four serotypes accounted for nearly 70% of all isolates of GBS. Population-based data on infant GBS infections would enable the design of prevention strategies for GBS disease in Mozambique.

Operative vaginal delivery and post-partum infection

During the past decade, there has been an increase in the awareness of infections associated with pregnancy and delivery. The most significant cause of post-partum infection is caesarean section; 20-25% of operations are followed by wound infections, endometritis or urinary tract infections. Approximately 13% of women in the UK undergo operative vaginal delivery (OVD) with forceps or vacuum, which is also associated with an increased risk of infection, estimated at 0.7%-16% of these deliveries. Despite this, previous reviews have identified only one small trial of antibiotic prophylaxis in 393 women and concluded that there was insufficient evidence to support the routine use of prophylactic antibiotics after OVD. The ANODE trial, a multicentre, blinded, placebo-controlled trial from the UK, is due to report findings from more than 3400 women in 2019 and will be the largest study to date of antibiotic prophylaxis following OVD.

Streptococcus agalactiae carriage among pregnant women living in Rio de Janeiro, Brazil, over a period of eight years

Group B Streptococcus (GBS) carriage by pregnant women is the primary risk factor for early-onset GBS neonatal sepsis. Intrapartum antibiotic prophylaxis (IAP) can prevent this transmission route, and two main approaches are recommended to base the selection of pregnant women to be submitted to IAP: the risk-based and the culture-based strategies. In Brazil, compliance to such recommendations is poor, and not much is known about GBS carriage. In the present study, 3,647 pregnant women living in Rio de Janeiro State, Brazil, were screened for GBS anogenital colonization, over a period of 8 years (2008–2015). GBS was detected in 956 (26.2%) of them, and presence of vaginal discharge was the only trait associated with a higher risk for GBS colonization. Serotypes Ia (257; 37.3%) and II (137; 19.9%) were the most frequent among 689 (72.1% of the total) GBS isolates evaluated, followed by NT isolates (84; 12.1%), serotype Ib (77; 11.1%), V (63; 9.1%), III (47; 6.8%) and IV (24; 3.5%). Estimated coverage of major serotype-based GBS vaccines currently under clinical trials would vary from 65.2% to 84.3%. All 689 isolates tested were susceptible to ampicillin and vancomycin. Resistance to chloramphenicol, clindamycin, erythromycin, levofloxacin, and tetracycline was observed in 5% (35), 2% (14), 14% (97), 5% (35) and 86% (592) of the isolates, respectively. No significant fluctuations in colonization rates, serotype distribution and antimicrobial susceptibility profiles were observed throughout the period of time investigated. The culture-based approach for IAP recommendation showed to be the best choice for the population investigated when compared to the risk-based, since the first did not increase the number of pregnant women submitted to antibiotic therapy and covered a larger number of women who were actually colonized by GBS. The fact the not all isolates were available for additional characterization, and serotype IX antiserum was not available for testing represent limitations of this study. Nevertheless, to the best of our knowledge, this is the largest investigation on GBS carriage among pregnant women in Brazil up to date, and results are useful for improving GBS prevention and treatment strategies.

Perinatal microbial exposure may influence aortic intima-media thickness in early infancy

Background

The maternal and infant microbiome may influence infant cardiovascular risk through immune programming. The maternal vagino-enteric microbiome is often sampled for group B streptococcus (GBS) colonization during pregnancy. Our aim was to investigate the association between maternal GBS colonization, intrapartum antibiotics, antenatal pet exposure and infant aortic intima-media thickness (aIMT), an intermediate vascular phenotype, and whether this association varied by mode of delivery.

Methods

The Barwon Infant Study is a population-derived pre-birth cohort. Perinatal data were collected on participants. Women were tested for vagino-enteric group B streptococcus (GBS) colonization during third trimester. Six-week infant aIMT was measured by trans-abdominal ultrasound. Adjustment for confounders included maternal age, pre-pregnancy body mass index (BMI), smoking, socioeconomic status, gestational diabetes, length of gestation, infant sex, birthweight and aortic internal diameter.

Results

Data were available on 835 mother-infant pairs. Of these, 574 (69%) women delivered vaginally; of those, 129 (22%) were GBS-colonized; and of these women, 111 (86%) received prophylactic intrapartum antibiotics. An association between maternal GBS colonization and infant aIMT was observed among those delivered vaginally (β = 19.5 µm, 95% CI 9.5, 29.4; P  < 0.0001) but not by Caesarean section ( P for interaction = 0.02). A similar pattern was seen for intrapartum antibiotics. There was a negative association between antenatal pet exposure and aIMT observed in those delivered vaginally.

Conclusion

Maternal GBS colonization and intrapartum antibiotics were associated with increased infant aIMT in those delivered vaginally, whereas antenatal pet exposure was associated with decreased aIMT. These data suggest that differences in early life microbial experience may contribute to an increased cardiovascular risk.

Group B Streptococcal Colonization, Molecular Characteristics, and Epidemiology

Streptococcus agalactiae or group B streptococcus (GBS) is a leading cause of serious neonatal infections. GBS is an opportunistic commensal constituting a part of the intestinal and vaginal physiologic flora and maternal colonization is the principal route of GBS transmission. GBS is a pathobiont that converts from the asymptomatic mucosal carriage state to a major bacterial pathogen causing severe invasive infections. At present, as many as 10 serotypes (Ia, Ib, and II–IX) are recognized. The aim of the current review is to shed new light on the latest epidemiological data and clonal distribution of GBS in addition to discussing the most important colonization determinants at a molecular level. The distribution and predominance of certain serotypes is susceptible to variations and can change over time. With the availability of multilocus sequence typing scheme (MLST) data, it became clear that GBS strains of certain clonal complexes possess a higher potential to cause invasive disease, while other harbor mainly colonizing strains. Colonization and persistence in different host niches is dependent on the adherence capacity of GBS to host cells and tissues. Bacterial biofilms represent well-known virulence factors with a vital role in persistence and chronic infections. In addition, GBS colonization, persistence, translocation, and invasion of host barriers are largely dependent on their adherence abilities to host cells and extracellular matrix proteins (ECM). Major adhesins mediating GBS interaction with host cells include the fibrinogen-binding proteins (Fbs), the laminin-binding protein (Lmb), the group B streptococcal C5a peptidase (ScpB), the streptococcal fibronectin binding protein A (SfbA), the GBS immunogenic bacterial adhesin (BibA), and the hypervirulent adhesin (HvgA). These adhesins facilitate persistent and intimate contacts between the bacterial cell and the host, while global virulence regulators play a major role in the transition to invasive infections. This review combines for first time epidemiological data with data on adherence and colonization for GBS. Investigating the epidemiology along with understanding the determinants of mucosal colonization and the development of invasive disease at a molecular level is therefore important for the development of strategies to prevent invasive GBS disease worldwide.

Incidence and serotype characterisation of Streptococcus agalactiae in a Portuguese hospital

AIMS

Streptococcus agalactiae, commonly known as group B Streptococcus (GBS), has been recognised as a worldwide causative pathogenic agent of neonatal sepsis, meningitis and pneumonia. To better understand the behaviour of S. agalactiae in pregnant women from a hospital from the North of Portugal, retrospective analyses were performed to describe epidemiological, clinical and microbiological characteristics of the isolates obtained.

METHODS

Based on laboratorial records and the hospital's patient files, a 6-year retrospective study was performed to analyse S. agalactiae isolates from screened pregnant women between 35 and 37 weeks of gestation and hospitalised neonates from pregnant women between 24 and 41 weeks of gestation admitted in Hospital Pedro Hispano. Serotype characterisation was also performed in 67 GBS strains.

RESULTS

In 6692 pregnant women between 35 and 37 weeks of gestation screened between 2011 and 2016, a total of 1377 S. agalactiae isolates (21%) were found. A high percentage (40%) of unknown colonisation status among hospitalised neonates from pregnant women between 24 and 41 weeks of gestations was also found. The incidence of neonatal sepsis was 8.7 (95% CI 7.0 to 10.8) cases per 1000 live births. Regarding serotype characterisation, serotype III (22.4%) was the most frequent, followed by serotype Ia (19.4%) and serotypes Ib and V (both with 17.9%).

CONCLUSION

High epidemiological values of GBS colonisation and incidence were found in this study. In Portugal studies on the epidemiology and behaviour of S. agalactiae remain limited, reinforcing the importance and need for S. agalactiae screening across the country.

Maternal Colonization With Group B Streptococcus and Serotype Distribution Worldwide: Systematic Review and Meta-analyses

BACKGROUND

Maternal rectovaginal colonization with group B Streptococcus (GBS) is the most common pathway for GBS disease in mother, fetus, and newborn. This article, the second in a series estimating the burden of GBS, aims to determine the prevalence and serotype distribution of GBS colonizing pregnant women worldwide.

METHODS

We conducted systematic literature reviews (PubMed/Medline, Embase, Latin American and Caribbean Health Sciences Literature [LILACS], World Health Organization Library Information System [WHOLIS], and Scopus), organized Chinese language searches, and sought unpublished data from investigator groups. We applied broad inclusion criteria to maximize data inputs, particularly from low- and middle-income contexts, and then applied new meta-analyses to adjust for studies with less-sensitive sampling and laboratory techniques. We undertook meta-analyses to derive pooled estimates of maternal GBS colonization prevalence at national and regional levels.

RESULTS

The dataset regarding colonization included 390 articles, 85 countries, and a total of 299924 pregnant women. Our adjusted estimate for maternal GBS colonization worldwide was 18% (95% confidence interval [CI], 17%-19%), with regional variation (11%-35%), and lower prevalence in Southern Asia (12.5% [95% CI, 10%-15%]) and Eastern Asia (11% [95% CI, 10%-12%]). Bacterial serotypes I-V account for 98% of identified colonizing GBS isolates worldwide. Serotype III, associated with invasive disease, accounts for 25% (95% CI, 23%-28%), but is less frequent in some South American and Asian countries. Serotypes VI-IX are more common in Asia.

CONCLUSIONS

GBS colonizes pregnant women worldwide, but prevalence and serotype distribution vary, even after adjusting for laboratory methods. Lower GBS maternal colonization prevalence, with less serotype III, may help to explain lower GBS disease incidence in regions such as Asia. High prevalence worldwide, and more serotype data, are relevant to prevention efforts.

Toll-Like Receptor 8 Is a Major Sensor of Group B Streptococcus But Not Escherichia coli in Human Primary Monocytes and Macrophages

TLR8 is the major endosomal sensor of degraded RNA in human monocytes and macrophages. It has been implicated in the sensing of viruses and more recently also bacteria. We previously identified a TLR8-IFN regulatory factor 5 (IRF5) signaling pathway that mediates IFNβ and interleukin-12 (IL-12) induction by Staphylococcus aureus and is antagonized by TLR2. The relative importance of TLR8 for the sensing of various bacterial species is however still unclear. We here compared the role of TLR8 and IRF5 for the sensing of Group B Streptococcus (GBS), S. aureus, and Escherichia coli in human primary monocytes and monocyte-derived macrophages (MDM). GBS induced stronger IFNβ and TNF production as well as IRF5 nuclear translocation compared to S. aureus grown to the stationary phase, while S. aureus in exponential growth appeared similarly potent to GBS. Cytokine induction in primary human monocytes by GBS was not dependent on hemolysins, and induction of IFNβ and IL-12 as well as IRF5 activation were reduced with TLR2 ligand costimulation. Heat inactivation of GBS reduced IRF5 and NF-kB translocation, while only the viable E. coli activated IRF5. The attenuated stimulation correlated with loss of bacterial RNA integrity. The E. coli-induced IRF5 translocation was not inhibited by TLR2 costimulation, suggesting that IRF5 was activated via a TLR8-independent mechanism. Gene silencing of MDM using siRNA revealed that GBS-induced IFNβ, IL-12-p35, and TNF production was dependent on TLR8 and IRF5. In contrast, cytokine induction by E. coli was TLR8 independent but still partly dependent on IRF5. We conclude that TLR8-IRF5 signaling is more important for the sensing of GBS than for stationary grown S. aureus in human primary monocytes and MDM, likely due to reduced resistance of GBS to phagosomal degradation and to a lower production of TLR2 activating lipoproteins. TLR8 does not sense viable E. coli, while IRF5 still contributes to E. coli-induced cytokine production, possibly via a cytosolic nucleic acid sensing mechanism.