High rates of perinatal group B Streptococcus clindamycin and erythromycin resistance in an upstate New York hospital

Current research update on group B streptococcal infection related to obstetrics and gynecology

Group B streptococcal (GBS) is a Gram-positive bacterium that is commonly found in the gastrointestinal tract and urogenital tract. GBS infestation during pregnancy is a significant contributor to maternal and neonatal morbidity and mortality globally. This article aims to discuss the infectious diseases caused by GBS in the field of obstetrics and gynecology, as well as the challenges associated with the detection, treatment, and prevention of GBS.

Prelabour rupture of the membranes at term: antibiotic overuse in Italy

BACKGROUND

The proper management of women with premature rupture of membrane (PROM) and not spontaneously entering in labour remains controversial. The aim of this study was to identify the current management for women with PROM at term according to the Group B Streptococcus (GBS) status across different Italian hospitals.

METHODS

Anonymous online survey evaluating: the current practice of women with PROM in terms of management (expectant management vs. induction of labour) and antibiotic prophylaxis according to GBS status.

RESULTS

In case of negative GBS status, the 82.4% of respondents wait until 24 hours before labour induction. Antibiotics are administered for prophylaxis in 35.3%, 27.5% and 2% at 18, 12 and 24 hours respectively. The remaining 35.3% of respondents are divided between those using antibiotics only with signs of infections or according to different risk factors (i.e. meconium-stained amniotic fluid or suspected infection). Neonates born from a mother with negative GBS status almost never (90.2%) receive prophylactic antibiotics. In case of positive GBS status, induction is started as soon as possible by 49.1% of respondents; the remnants choose to wait 6 (15.7%), 12 (17.6%), 18 (3.9%) and 24 (13.7%) hours. Antibiotics are administered as soon as possible by 78.4% of clinicians. In the neonates, 51% of neonatologist administer antibiotics upon clinical indications (suspected sepsis); 15.7% use antibiotics routinely or with a short interval between maternal antibiotics and delivery (17.6%).

CONCLUSIONS

The management after PROM is highly heterogeneous with an inappropriate extension of antibiotic prophylaxis in cases with negative GBS status.

Establishing obstetrics-specific metrics and interventions for antimicrobial stewardship

Background

To describe baseline antimicrobial stewardship (AMS) metrics and apply AMS interventions in an inpatient obstetrical population.

Methods

From October 2018 to October 2019, our tertiary-care obstetrical center reviewed components of our AMS program, which included: (1) antimicrobial consumption data, (2) point prevalence surveys (PPS), and (3) prospective audit and feedback. We reviewed institutional data for antimicrobial consumption from the pharmacy database. Detailed point prevalence surveys were conducted for all antimicrobial prescriptions on two predefined dates each month. Daily audits and feedback assessed the appropriateness of all non-protocolized antimicrobials.

Results

Our average antimicrobial length of therapy (LOT) was 12 days per 100 patient-days, where erythromycin (2.33), amoxicillin (2.28), and ampicillin (1.81) were the greatest contributors. Point prevalence surveys revealed that 28.8% of obstetrical inpatients were on antimicrobials, of which 11.2% were inappropriate. Protocolized antimicrobials were 62% less likely (p = 0.027) to be inappropriate. From 565 audited prescriptions, 110 (19.5%) resulted in feedback, where 90% of recommendations were accepted and implemented. The most common reasons for interventions include incorrect dosage, recommending a diagnostic test before continuing antimicrobials, and changing antimicrobials based on specific culture and sensitivity.

Conclusions

Antimicrobial use in obstetrics is unique compared to general inpatients. We provide a baseline set of metrics for AMS at our obstetrical center intending to lay the groundwork for AMS programming in our discipline. Antimicrobial protocolization, as well as audit and feedback, are feasible interventions to improve antimicrobial prescribing patterns.

Prevalence of Group B Streptococcus maternal colonization, serotype distribution, and antimicrobial resistance in Sub-Saharan Africa: A systematic review and meta-analysis

OBJECTIVE

Group B Streptococcus (GBS)-associated maternal, perinatal, and neonatal mortality and morbidity disproportionately affects Sub-Saharan Africa (SSA). This systematic review and meta-analysis aimed to address the estimated prevalence, antimicrobial susceptibility, and serotype distribution of GBS isolates in SSA.

METHODS

This study was done according to PRISMA guidelines. MEDLINE/PubMed, CINAHL (EBSCO), Embase, SCOPUS, Web of Sciences databases, and Google Scholar were used to retrieve both published and unpublished articles. STATA software version 17 was used for data analysis. Forest plots using the random-effect model were used to present the findings. Heterogeneity was assessed using Cochrane chi-square (I²) statistics, while the Egger intercept was used to assess publication bias.

RESULTS

Fifty-eight studies that fulfilled the eligibility criteria were included for meta-analysis. The pooled prevalence of maternal rectovaginal colonization and vertical transmission of GBS were 16.06, 95% CI [13.94, 18.30] and 43.31%, 95% CI [30.75, 56.32], respectively. The highest pooled proportion of antibiotic resistance to GBS was observed in gentamicin (45.58%, 95% CI [4.12%, 91.23]), followed by erythromycin, (25.11%, 95% CI [16.70, 34.49]). The lowest antibiotic resistance was observed in vancomycin (3.84%, 95% CI [0.48, 9.22]). Our findings indicate that serotypes Ia/Ib/II/ III/and V cover almost 88.6% of serotypes in SSA.

CONCLUSIONS

The estimated high prevalence and resistance to different antibiotic classes observed in GBS isolates from SSA suggests the need for implementation of effective intervention efforts.

Characterization of Group B Streptococcus Recovered from Pregnant Women and Newborns Attending in a Hospital in Beijing, China

Purpose

We investigate the drug resistance, serotype and multilocus sequence typing (MLST) of Group B streptococcus (GBS) strains obtained from pregnant women and neonates in a hospital in Beijing.

Patients and Methods

In this cross-sectional study, 1470 eligible pregnant women at a gestational age of 35-37 weeks presented to our department between May 2015 and May 2016 were included. Vaginal and rectal samples from pregnant women together with sampling from neonatal samples were collected to screen GBS. GBS strains were subject to drug resistance and serotype analysis and MLST.

Results

GBS strains were isolated from 111 pregnant women (7.6%) and 6 neonates (0.99%) from 606 matched neonates. 102 strains from pregnant women and 3 strains from neonates were included in the drug sensitivity test, serotyping and MLST typing. All these strains were susceptible to ampicillin, penicillin, ceftriaxone, vancomycin, linezolid, and meropenem. Sixty strains (58.8%) showed multi-drug resistance. Serious cross-resistance was seen between erythromycin and clindamycin. There were eight serotypes, and 37 strains (36.3%) showed a serotype of type III serving as the major type. All 102 GBS strains isolated from pregnant samples could be divided into 18 STs types. They belonged to five clonal complexes and five single clones, with the predominant type of ST19/III, ST10/Ib, and ST23/Ia, with CC19 as the most common type. Three GBS strains isolated from neonates covered two serotypes (ie type III and Ia) that were consistent with those of the mothers.

Conclusion

Serotype III was the predominant serotype of GBS in this study. The predominant MLST type was ST19, ST10, and ST23, with ST19/III, ST10/Ib, and ST23/Ia serving as the most prevalent and CC19 as the most common clonal complex. GBS strains from neonates were consistent in the clonal complex, serotype, and MLST with these isolated from the mothers.

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.

Frequency and Antibiotic Susceptibility Patterns of Streptococcus agalactiae Strains Isolated from Women in Yaounde, Cameroon

Group B Streptococcus (GBS), a commensal in the body, causes a wide range of infectious diseases. This bacterium is dangerous for pregnant women and their babies, in whom it is responsible for early neonatal bacterial sepsis (EOS). The colonisation levels of GBS and its resistance profile to antibiotics provide important information that is useful for orienting prevention strategies. There are few data available on the subject on the determination of resistance phenotypes in Cameroon. We therefore aimed to determine the prevalence of colonisation and antibiotic resistance, including patterns of inducible resistance to clindamycin, of GBS in the city of Yaounde. To achieve this goal, a prospective cross-sectional study with an analytical component was carried out from 28 June to 29 August 2020 at the BIOSANTE laboratory and the Yaounde Gynaeco-Obstetrics and Paediatrics hospital. Vaginal swabs and urine were collected from 163 women. This samples were analysed using 5% defibrinated sheep blood agar and chocolate plus polyvitex agar. The isolates were identified using the morphology of the colony, Gram staining, haemolysis, catalase tests and latex grouping tests. Antibiotic susceptibility testing was carried out by disk diffusion method following the recommendations of the ACFSM 2019. The double disk diffusion method was used to identify isolates with clindamycin-inducible resistance. Our data were analysed with SPSS version 2.1. The results obtained showed that the overall prevalence of colonisation by GBS was 37% (57/163), or 40.3% in non-pregnant women and 59.7% in pregnant women. Pregnancy (p-value = 0.019) and earlier (from the second semester of pregnancy) gestational age (p-value = 0.025) constituted the risk factors of maternal colonisation by GBS. In addition, the strains of GBS were resistant to all 16 antibiotics tested. A D test showed that 64.7% of GBS strains were constitutively resistant to clindamycin. We also note the presence of M phenotypes. As a whole, our results demonstrated that the rate of GBS colonisation in this study was similar to or higher than those in previous reports in Cameroon. All these results indicate that attention should be paid to this bacterium in the monitoring of antimicrobial resistance and in the care of pregnant women and newborns.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Antimicrobial resistance in colonizing group B Streptococcus among pregnant women from a hospital in Vietnam

Few studies have been conducted on group B Streptococcus (GBS) in Vietnam. We determined the GBS colonization and antimicrobial resistance vaginal-rectal profile of 3863 Vietnamese pregnant women over 5 years. Maternal GBS colonization was characterized by antibiotic susceptibility. Overall, the GBS colonization rate was 8.02% (95% CI: 7.20-8.94%). Compared to sampling ≥ 35 weeks of gestation, the GBS colonization rate was statistically higher (p = 0.004) with sampling < 35 weeks. Among 272 antimicrobial susceptibility testing isolates, all were susceptible to ampicillin, penicillin, ceftriaxone, cefotaxime, vancomycin, and quinupristin/dalfopristin. Resistance was highest for tetracycline (89.66%), followed by erythromycin (76.23%) and clindamycin (58.21%). Multidrug resistance and resistance to ≥ 6 different antibiotics were 60.66% and 8.82%, respectively. Resistance to clindamycin but not erythromycin (L phenotype) was 2.2%. The clindamycin resistance rate was significantly increased (p = 0.005) during the study period. These data demonstrate a low rate of maternal GBS colonization. The high rate of erythromycin, clindamycin, and multidrug resistance to GBS that can be transmitted to neonates is an important risk factor to consider. β-lactams continue to be appropriate for first-line treatment and prophylaxis in the study area. Ongoing monitoring should be considered in the future.

Disease burden due to Group B Streptococcus in the Indian population and the need for a vaccine - a narrative review

Streptococcus agalactiae, a Gram-positive bacterium, causes invasive infection known as Group B streptococcal disease (GBS). It is a leading cause of neonatal death and complications prior to delivery. The burden of GBS is unknown in India despite the high incidence of preterm and stillbirths. In this study, we performed a narrative review of the available literature (published in the last 10 years) on the epidemiology of GBS, using PubMed and Google Scholar, to understand its impact in India and evaluate potential strategies to prevent the disease in the high-risk population, that is, neonates. The review showed that the incidence of early- and late-onset GBS in neonates (per 1000 live births) was in the ranges of 0.090-0.68 and 0.0-0.07 respectively. The overall case fatality rate reported in only one study was 0.63. In pregnant women, the prevalence of GBS colonization was 2-62% and its transmission to their newborns varied from 6.7% to 11.1%. The serotype distribution of GBS is unclear, but some studies reported the distribution of types Ia, Ib, II, III, V, VII among pregnant women in India. The associated risk factors for GBS colonization in pregnant women are unclear but a few studies suggest the role of age and multigravida, while the risk factors in neonates include preterm birth, prolonged rupture of membrane (⩾18 h), maternal fever, obstetric complications, and prolonged labor >18 h. Screening of GBS is not a routine practice in India and intrapartum antibiotics prophylaxis is limited to only in risk conditions to prevent neonatal disease transmission. A few studies also suggest that high birth rate, poor detection methods, and financial constraints limit routine GBS screening in a developing country such as India. Hence, maternal vaccination is the most promising strategy to prevent neonatal GBS and Pfizer's hexavalent GBS conjugate vaccine (GBS6) is being developed for GBS neonatal disease.

Group B Streptococcus Recto-Vaginal Colonization in Near-Term Pregnant Women, Southwest Ethiopia

Background

Group B Streptococcus (GBS) is recognized as an important cause of maternal and neonatal morbidity and mortality. Maternal vaginal carriage of GBS (Streptococcus agalactiae) can lead to vertical transmission to the neonate at the time of delivery. However, little is known about its prevalence, predictors and antibiotic susceptibility pattern in Jimma, Ethiopia. This study assessed the prevalence, antimicrobial susceptibility pattern and determinants of GBS recto-vaginal colonization among near-term pregnant women.

Methods

A cross-sectional study was conducted from May to August 2015 at Jimma University Medical Centre in Southwest Ethiopia. Data through questionnaire and GBS isolates from vaginal and rectal swabs were collected. Antimicrobial susceptibility testing was performed.

Results

The overall prevalence of GBS colonization among near term pregnant women (35-37 weeks) was 16.3% (22/135). The majority of GBS isolates were sensitive to Ampicillin and Penicillin G with 95.5% and 90.1%, respectively. Erythromycin and clindamycin were resisted by 50% and 40.9% of the isolates, respectively, whereas gentamicin was resisted by all isolates. GBS colonization was significantly associated with a history of preterm delivery (PTD) (AOR: 6.3, 95% CI: 1.42, 28.3) and history of urinary tract infection (UTI) during current pregnancy (AOR: 6.4, 95% CI, 1.95, 21.1).

Conclusion

Our study indicated that one among six near-term pregnant women had recto-vaginal GBS colonization. In places where universal screening is not feasible, selective screening for factors particularly history of PTD and UTI during current pregnancy may be a reasonable option. Antibiotic susceptibility testing should be performed while using Erythromycin, Clindamycin or Gentamicin.

Diseases and complications of the puerperium

BACKGROUND

In terms of maternal morbidity and mortality, the puerperium is just as significant as pregnancy and childbirth. Nearly half of all maternal deaths occur in the time after delivery.

METHODS

This review is based on pertinent articles in English and German from the years 2000- 2020 that were retrieved by a selective search in MEDLINE and EMBASE, as well as on the available guidelines in English and German and on German-language textbooks of obstetrics.

RESULTS

The most common and severe complications are, in the post-placental phase, bleeding and disturbances of uterine involution; in the first seven days after delivery, infection (e.g., endomyometritis, which occurs after 1.6% [0.9; 2.5] of all births) and hypertension-related conditions. Thromboembolism, incontinence and disorders of the pelvic floor, mental disease, and endocrine disturbances can arise at any time during the puerperium. In an Australian study, the incidence of embolism was 0.45 per 1000 births, with 61.3% arising exclusively after delivery.

CONCLUSION

Basic familiarity with the most common and severe diseases in the puerperium is important for non-gynecologists as well, among other things because highly acute, lifethreatening complications can arise that demand urgent intervention.

Middle-East OBGYN Graduate Education (MOGGE) Foundation practice guidelines: prevention of group B Streptococcus infection in pregnancy and in newborn. Practice guideline no. 02-O-20

Rectovaginal colonization with group B streptococcus (GBS) is commonly encountered in pregnancy. GBS is the most common cause of early onset neonatal sepsis, which is associated with 12% case-fatality rate. Although screening protocols and prophylactic treatment are readily available worldwide, practice in low-resource countries is challenged by lack of awareness and limited implementation of these protocols. In addition, antibiotic susceptibility pattern may vary globally owing to different regulations of antibiotic prescription or prevalence of certain bacterial serotypes. This guideline appraises current evidence on screening and management of GBS colonization in pregnancy particularly in low-resource settings.

Trends in molecular characteristics and antimicrobial resistance of group B streptococci: a multicenter study in Serbia, 2015-2020

Group B Streptococcus (GBS) is a major cause of neonatal morbidity and mortality. Serbia has not fully implemented preventive measures against GBS neonatal diseases. Therefore, we aimed to assess the maternal GBS colonisation and invasive neonatal disease rate, to reveal the trends of antimicrobial resistance and serotype distribution of GBS from various patient groups. Randomly selected non-invasive (n = 991) and all invasive GBS (n = 80) collected throughout Serbia from 2015 to 2020 were tested for antimicrobial susceptibility, capsular typing, and hvgA detection. Overall, 877/5621 (15.6%) pregnant women were colonised with GBS. Invasive GBS infections incidence in infants (0.18/1000 live births) showed a decreasing trend (0.3 to 0.1/1000 live births). Type III was overrepresented in infants with invasive infections (n = 35, 58.3%), whereas type V predominated among colonised adults (n = 224, 25.5%) and those with noninvasive (n = 37, 32.5%) and invasive infections (n = 8, 40%). The hypervirulent clone III/ST17 was highly associated with invasive infections (n = 28, 35%), particularly late-onset disease (n = 9, 47.4%), showing an increase from 12.3 to 14.8%. The GBS resistance to erythromycin and clindamycin was 26.7% and 22.1%, respectively, with an upward trend. The emergence of the hypervirulent clone III/ST17 and the escalation in GBS resistance highlight an urgent need for continuous monitoring of GBS infections.

The Impact of Rapid Species Identification on Management of Bloodstream Infections: What's in a Name?

Bloodstream infections are a leading cause of morbidity and mortality. Molecular rapid diagnostic tests (mRDTs) are transforming care for patients with bloodstream infection by providing the opportunity to dramatically shorten times to effective therapy and speeding de-escalation of overly broad empiric therapy. However, because of the novelty of these tests which provide information regarding microbial identification and whether specific antibiotic-resistance mutations were detected, many front-line providers still delay final decisions until complete phenotypic susceptibility results are available several days later. Thus the benefits of mRDTs have been largely limited to circumstances where antimicrobial stewardship programs closely monitor these tests and intervene as soon as the results are available. We searched PubMed and Google Scholar for articles published from 1980 to 2019 using the terms antibiotic, antifungal, bacteremia, bloodstream infection, candidemia, candidiasis, children, coagulase negative staphylococcus, consultation, contamination, costs, echocardiogram, endocarditis, enterobacteriaceae, enterococcus, Gram-negative, guidelines, IDSA, immunocompromised, infectious disease or ID, lumbar puncture, meningitis, mortality, MRSA, MSSA, neonatal, outcomes, pediatric, pneumococcal, polymicrobial, Pseudomonas, rapid diagnostic testing, resistance, risk factors, sepsis, Staphylococcus aureus, stewardship, streptococcus, and treatment. With the data from this search, we aim to provide guidance to front-line providers regarding the interpretation and immediate actions to be taken in response to the identification of common bloodstream pathogens by mRDTs. In addition to antimicrobial therapy, additional diagnostic or therapeutic interventions are recommended for particular organisms and clinical settings to either determine the extent of infection or control its source. Pediatric perspectives are offered for those bloodstream pathogens for which management differs from that in adults.

Does Quinolone- or Macrolide-Resistant Streptococcus agalactiae Bacteremia Affect Patient Outcome? A Multicenter Cohort Study

The prevalence of quinolone- and macrolide-resistant Group B Streptococcus (GBS) is increasing worldwide, but the relationship between the resistance of GBS to these antibiotics and patient outcome remains unclear. Therefore, we evaluated whether blood stream infection caused by quinolone- or macrolide-resistant GBS is associated with high mortality. Our findings in 77 patients with GBS bacteremia demonstrate that quinolone and macrolide resistance may not be risk factors for 30-day mortality.

Host range, morphological and genomic characterisation of bacteriophages with activity against clinical Streptococcus agalactiae isolates

Streptococcus agalactiae or Group B Streptococcus (GBS) is a leading cause of sepsis in neonates. As a preventative measure prophylactic antibiotic administration is common in pregnant women colonised with GBS, but antibiotic-resistance and adverse effects on neonatal microbiomes may result. Use of bacteriophages (phages) is one option for targeted therapy. To this end, four phages (LF1 –LF4) were isolated from wastewater. They displayed lytic activity in vitro against S. agalactiae isolates collected from pregnant women and neonates, with 190/246 isolates (77.2%) and 10/10 (100%) isolates susceptible to at least one phage, respectively. Phage genomes ranged from 32,205–44,768 bp and all phages were members of the Siphoviridae family. High nucleotide identity (99.9%) was observed between LF1 and LF4, which were closely related to a putative prophage of S. agalactiae. The genome organisation of LF2 differed, and it showed similarity to a different S. agalactiae prophage, while LF3 was more closely related to a Streptococcus pyogenes phage. Lysogenic gene presence (integrase, repressor and regulatory modules), was suggestive of temperate phages. In a therapeutic context, temperate phages are not ideal candidates, however, the broad host range activity of these phages observed on clinical isolates in vitro is promising for future therapeutic approaches including bioengineered phage or lysin applications.

Antibiotic Susceptibility Patterns and Prevalence of Streptococcus Agalactiae Rectovaginal Colonization Among Pregnant Women in Iran

OBJECTIVE

 Streptococcus agalactiae is an important pathogen in neonates and pregnant women. Neonatal invasive infections due to S. agalactiae are life-threatening and preventive strategies for this challenge of human have become a concern. The aim of the present study was to determine the prevalence of rectovaginal colonization, related risk factors and antibiotic resistance pattern of S. agalactiae among pregnant women in Iran.

METHODS

 The present study was performed on 240 pregnant women. Vaginal and rectal swabs were obtained from all of the women and then were transferred to the laboratory. The isolation and identification of S. agalactiae was performed by standard microbiological tests and polymerase chain reaction (PCR) assay. The antimicrobial susceptibility patterns of the isolates were determined by the Kirby-Bauer disk diffusion. Polymerase chain reaction was used to detect ermB and mefA genes in erythromycin-nonsusceptible isolates.

RESULTS

 Out of 240 pregnant women, 16 cases (6.7%) were colonized by S. agalactiae. There is no significant association between demographic-obstetric factors and maternal S. agalactiae colonization in the pregnant women. Linezolid, vancomycin and ampicillin were the most effective antibiotics against S. agalactiae. The ermB gene was present in 6 (35.29%) S. agalactiae isolates. However, the mefA gene was not detected in any of the isolates.

CONCLUSION

 Given the relatively significant prevalence of S. agalactiae colonization in the pregnant women in the present study and the risk of serious neonatal infections, the screening of pregnant mothers for the bacteria seems necessary. Our findings highlight the importance of appropriate antibiotic prophylaxis during pregnancy for the prevention of early onset S. agalactiae-neonatal infection and comorbidity.

Phenotypic and Genotypic Characterization of Resistance to Macrolides and Lincosamides in Streptococcus agalactiae Isolated from Pregnant Women in Misiones, Argentina

The aim of this work was to determine the susceptibility, molecular profile, and clonal relationship in Streptococcus agalactiae (group B Streptococcus [GBS]) isolated from vaginal-rectal swab samples. We worked with 200 isolates collected from pregnant women between 35 and 37 weeks of gestation. The macrolide-lincosamide-streptogramin B (MLS_B) resistance phenotypes were determined using the double-disc assay. Susceptibility to erythromycin (ERI) and clindamycin (CLI) was performed with the E-test. Resistance genes ermB and ermTR were detected by polymerase chain reaction. Clonal studies were performed using the random amplification of polymorphic DNA. Twelve (6%) of the isolates were resistant to ERI and 10 (5%) of them to CLI. Fifty percent of the resistant strains corresponded to serotype III, 25% to serotype V, and the remaining 25% to serotype Ia, II, and nontypeable strains. The cMLS_B phenotype was detected in eight strains (66.67%) and the iMLS_B phenotype in four (33.33%). The minimum inhibitory concentration values were between 1.5 and 16 μg/mL for ERI, and between 1 and 32 μg/mL for CLI. Out of the 25 strains susceptible to ERI and CLI, the presence of the ermB gene was detected in eight of them and the ermTR gene in one strain. The ermB gene was detected in the 12 strains that initially had some macrolide resistance phenotype. The ermTR gene was detected in three out of the four strains with the iMLS_B phenotype. The resistance to macrolides in the province of Misiones is due to multiclonal spread. The phenotypic and genotypic characterization of macrolide resistance in GBS strains are crucial to contribute to the correct intrapartum prophylactic antibiotic therapy of allergic pregnant women and the epidemiological surveillance of these strains.

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

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

Gold Immunochromatographic Assay for Rapid On-Site Detection of Lincosamide Residues in Milk, Egg, Beef, and Honey Samples

Lincosamides (LMs), include clindamycin (CLIN), lincomycin (LIN), and pirlimycin (PIR), that are widely used as veterinary drugs. LM residues in edible animal origin foods endanger human health and are in urgent need of establishing fast, simple, and highly sensitive detection methods. A gold immunochromatographic strip is prepared to detect CLIN, LIN, and PIR residues simultaneously with a single monoclonal antibody. This antibody is obtained with the design of a novel Hapten and can simultaneously recognize CLIN, LIN, and PIR. Under optimized conditions, the strip results can be semi-quantitatively evaluated with the naked eye within 15 min, with cut-off values in phosphate-buffered saline of 1 ng mL^-1 for CLIN, 10 ng mL^-1 for LIN, and 25 ng mL^-1 for PIR, respectively. Besides, the strip can also be quantified using a hand-held strip scanner, and the spiked samples are used for establishing matrix curves. The limits of detection for CLIN, LIN, and PIR in spiked milk, egg, beef, and honey samples can satisfy the detection requirement. The utility of this strip is also confirmed by positive honey sample. In short, this strip should be expected to be a useful tool for the rapid on-site screening of lincosamide residues in milk, egg, beef, and honey samples.

Drugs for the Prevention and Treatment of Sepsis in the Newborn

Antimicrobial medications are the most commonly used medications in the neonatal intensive care unit. Antibiotics are used for infection prophylaxis, empiric treatment, and definitive treatment of confirmed infection. The choice of medication should be informed by the epidemiology and microbiology of infection in specific clinical scenarios and by the clinical condition of the infant. Understanding evolving pathogen susceptibility to antimicrobials and key pharmacotherapy determinants in neonates can inform optimal antibiotic use.

The activity of commercial antimicrobials, and essential oils and ethanolic extracts of Olea europaea on Streptococcus agalactiae isolated from pregnant women

BACKGROUND

Streptococcus agalactiae also known as Group B Streptococcus (GBS) is a major cause of disease in pregnant women and new born babies where it causes early and late onset disease characterised by sepsis, pneumonia and meningitis. Ten to 37 % of pregnant women in the world are colonised with GBS while intrapartum antibiotic prophylaxis has led to significant reduction in early onset disease. The increase in drug resistant microorganisms has become a major threat. Development of vaccines is still in progress so there is need for new and safer alternatives to treatment.

METHODS

Benzyl penicillin, Ampicillin, Cefotaxime, Ceftriaxone, Levofloxacin, Erythromycin, Clindamycin, Linezolid, Vancomycin, Tetracycline and Cotrimoxazole, Olea europaea leaf extracts and essential oil were tested against GBS isolates from South Africa and Namibia.

RESULTS

The isolates showed 100% sensitivity to benzyl penicillin, ampicillin, ceftriaxone, levofloxacin, linezolid, vancomycin, O. europaea leaf extracts and essential oils. Only one isolate (0.6%) was resistant to cefotaxime and 23.4 and 10.4% were resistant to clindamycin and erythromycin respectively.

CONCLUSION

GBS isolates showed sensitivity to O. europaea extracts at low minimum inhibitory concentrations. Β lactams are still the drugs of choice for treatment of GBS disease but O. europaea extracts potent as an alternative source of antimicrobials.

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.

Microbiological and clinical characteristics of Group B Streptococcus isolates causing materno-neonatal infections: high prevalence of CC17/PI-1 and PI-2b sublineage in neonatal infections

PURPOSE

Group B Streptococcus (GBS) is one of the major pathogens in severe materno-neonatal infections. We aimed to describe the clinical and molecular characteristics of GBS isolates causing infections in 45 maternal and 50 neonatal subjects, collected from eight healthcare centres in mainland China over the period 2010- 2017.

METHODOLOGY

The phenotypic and genotypic features of the GBS isolates, including capsular polysaccharide (cps) serotypes, pilus island (PI) genes and antibiotic resistance profiles and genes, were characterized by both conventional and molecular methods. The clonal relationship between these strains was investigated using multilocus sequence typing (MLST).

RESULTS

Of the 95 isolates, the predominant serotypes were III (51, 53.7 %), V (13, 13.7 %) and Ib (13, 13.7 %). All GBS strains carried at least one pilus island, with 32.6 % carrying PI-2b and 67.4 % PI-2a, singly or in combination. The most frequently-detected pilus island pattern was the combination of PI-1 and PI-2a, accounting for 56.8 % (54 isolates), followed by PI-1 combined with PI-2b (28, 29.5 %), PI-2a (10, 10.5 %) and PI-2b (3, 3.2 %). The strains were classified into 17 individual sequence types, and further clustered into six clonal complexes (CCs). A high prevalence of CC17/PI-1 and PI-2b (17, 34.0 %) was detected in 50 GBS isolates causing neonatal infections. No strain was resistant to penicillin, ampicillin, ceftriaxone or vancomycin, whereas 78.9, 76.8 and 81.5 % were resistant to erythromycin, clindamycin and tetracycline, respectively.

CONCLUSION

Our study highlights the high genotypic diversity of GBS strains causing materno-neonatal infections, and the CC17/PI-1 and PI-2b sublineages should be noted in neonatal infections.

Multiclonal emergence of levofloxacin-resistant group B Streptococcus, Taiwan

Objectives

This study investigated the trend in antimicrobial resistance among group B Streptococcus (GBS) from a national surveillance programme in Taiwan and delineated characteristics of and factors associated with levofloxacin-resistant isolates.

Methods

Clinical isolates of all sample types and patient groups were collected from multiple hospitals biennially between 2002 and 2012. Susceptibilities to different antibiotics were determined by broth microdilution. Molecular studies of levofloxacin-resistant isolates included serotyping, PFGE, mutations in the QRDRs and MLST.

Results

A total of 1559 isolates were tested and all remained susceptible to penicillin, cephalosporins, meropenem and vancomycin. However, levofloxacin resistance increased from 2.2% (range 0%-3.3%) in 2002-06 to 6.2% (5.9%-7.5%) in 2008-12 (P = 0.016). Among the 88 levofloxacin-resistant isolates, the majority (79.5%) had the GyrA(S81L)+ParC(S79F/Y) double mutations and most (54.5%) were also resistant to clindamycin, erythromycin and tetracycline. The predominant genotype of the levofloxacin-resistant isolates was ST19/serotype III (43.2%). Four previously unreported genotypes, ST1 and its single-locus variants (ST920 and ST922)/serotype VI (28.4%) and ST1/serotype II (18.2%), were found to have circulated locally. Serotype III isolates were predominately from urine and female genital tract specimens and <65-year-old adult outpatients, while serotype II and VI isolates were mostly from respiratory and urine samples and >65-year-old inpatients. Multivariate analysis revealed that elderly age and respiratory samples were independent factors associated with levofloxacin resistance.

Conclusions

Multiclonal emergence and dissemination of levofloxacin-resistant GBS isolates occurred in healthcare and community settings in Taiwan. Continuous molecular-level surveillance is important to detect new epidemic trends.

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.

Genotyping and Phylogenetic Analysis of Group B Streptococcus by Multiple Locus Variable Number Tandem Repeat Analysis in Iran

Background:

Group B streptococcus (GBS), also known as Streptococcus agalactiae, is well known as a causative agent for neonatal invasive diseases; it is also a major pathogen in adults. Analytic epidemiology is required to monitor the clinical isolates of GBS. However, there is insufficient information on the genetic background of GBS in Iran, and this information is needed to guide and develop a GBS vaccine.

Materials and Methods:

In total, 90 well-char - acterized GBS isolates were collected from April 2014 to August 2015. In this study, molecular typing was used to disclose a relationship between the multiple-locus variable number tandem repeat analysis (MLVA) types, serotyping, and pilus islands. The isolates were characterized by the types of capsular polysaccharides and pilus islands and were examined by MLVA to study the epidemiological relationship of isolates.

Results:

The results indicate that there is a significant relationship between the distribution of serotypes and pilus island genes; GBS isolates were differentiated into 12 types by capsular polysaccharides and pilus islands analysis. The discriminatory power of an MLVA analysis was high based on the five most variable numbers of tandem repeat loci and 44 MLVA types that were identified.

Conclusion:

This study has provided useful insights into the genetic heterogeneity of GBS isolates in Tehran and Alborz, Iran. The extensive distribution of pilus islands in various serotypes and MLVA types throughout the GBS population refers to the advancement of the pilus-based GBS vaccines.

Phenotypic and molecular characterization of Streptococcus agalactiae colonized in Chinese pregnant women: predominance of ST19/III and ST17/III

Streptococcus agalactiae (GBS) remains a major cause of invasive infections in neonates and pregnant women. Our aim was to evaluate the phenotypic and molecular characteristics of GBS isolates in order to reveal potential relationships among molecular characteristics and differences in genotype-phenotype characteristics between ST17 and ST19. A total of 104 GBS isolates were collected from pregnant women. All isolates were tested for antibiotic susceptibility by disk diffusion method and molecular characteristics, including antibiotic-resistant genes, virulence genes, serotypes and STs. The prevalence of GBS colonization in pregnant women was 4.9%. All isolates were susceptible to penicillin, but a high prevalence of resistance was observed for tetracycline (76.9%) and erythromycin (72.1%), with the predominant resistant genes being tet(M), tet(O), erm(B) and mef (A/E). The most frequent serotypes were III, Ia and V, and the predominant STs were ST19, ST17, ST12, ST10 and ST651. A potential correlation existed between STs, serotypes and alp genes, with ST19/III/rib and ST17/III/rib as the most prevalent clones. Notably, we observed significant differences in phenotypic and genotypic characteristics between ST17 [levofloxacin-susceptible and tet(O)-positive] and ST19 [levofloxacin-resistant and tet(O)-negative]. Our findings reveal a high prevalence of ST19/III and ST17/III and significant characteristic differences between them.

Molecular Characterization of Italian Isolates of Fluoroquinolone-Resistant Streptococcus agalactiae and Relationships with Chloramphenicol Resistance

A total number of 368 clinical isolates of Streptococcus agalactiae (group B Streptococcus, GBS) were collected in 2010-2016 from three hospitals in a region of central Italy. Fluoroquinolone (FQ)-resistant isolates were selected using levofloxacin. Levofloxacin-resistant (LR) strains (11/368, 2.99%) were characterized for several features, and their FQ resistance was analyzed phenotypically and genotypically using seven additional FQs. Their gyrA and parC quinolone resistance-determining regions were sequenced. Of the 11 LR isolates, 10 showed high-level and 1 low-level resistance. The former isolates exhibited higher minimal inhibitory concentrations also of the other FQs and all shared one amino acid substitution in ParC (Ser79Phe) and one in GyrA (Ser81Leu); only Ser79Phe in ParC was detected in the low-level LR isolate. The 11 LR strains exhibited distinctive relationships between their susceptibilities to non-FQ antibiotics and typing data. Remarkably, despite the very rare occurrence of chloramphenicol resistance in S. agalactiae, no <4 of the 11 LR isolates were chloramphenicol-resistant. Studies of GBS resistance to FQs in Europe remain scarce, notwithstanding the emergence of multidrug-resistant isolates. The incidence of LR GBS isolates is still limited in Italy, consistent with the moderate (though growing) rates reported in Europe, and much lower than the very high rates reported in East Asia. The intriguing relationships between FQ and chloramphenicol resistance deserve further investigation.

Survey of strain distribution and antibiotic resistance pattern of group B streptococci (Streptococcus agalactiae) isolated from clinical specimens

AIM

The aims of the present study were to determine the antibiotic susceptibility profils with particular emphasis on susceptible or resistant strains to macrolides and lincosamids antibiotics and to determine possible antibiotic resistance mechanisms occurring in group B streptococci (GBS) strains using PCR assay and disk diffusion method.

METHODS

A total of 62 clinical GBS strains were investigated. Antibacterial susceptibility testing was performed using the disk diffusion method and inducible resistance test for clindamycin by standard double disk diffusion or D-zone test for all isolates to differentiate macrolide resistance phenotype (M), constitutive macrolide-lincosamide-streptogramin B phenotype (cMLSB) and induced macrolide-lincosamide-streptogramin B phenotype (iMLSB). In addition, minimum inhibitory concentrations (MIC) of penicillin were determined for all isolates. Finally, possible existence of antibiotic resistance genes for erythromycin (ermTR, ermB and mefA/E) and for clindamycin (linB) were examined among isolates using PCR assay.

RESULTS

All 62 isolates were susceptible to penicillin, ampicillin, linezolid, cefazoline and vancomycin. However, 93.5% (n=58) of isolates showed an increased MIC to penicillin. The overall rate of erythromycin resistance was 35.5% (n=22). All erythromycin-resistant isolates displayed the M phenotype (100%, n=22). All three erythromycin resistance genes (i.e. ermTR, ermB and mefA/E) were found in erythromycin-resistant isolates.

CONCLUSION

It was concluded that prescribing antibiotic without antibacterial susceptibility tests should be prevented because of the high prevalence of erythromycin-resistant GBS strains and the fact that erythromycin-resistant GBS strains has shown an increased MIC to penicillin, as the drug of choice for treating GBS infections.

Group B streptococcus antimicrobial resistance in neonates born to group B streptococcus-colonized mothers: Single-center survey

AIM

In this study, we collected group B streptococcus (GBS) screening data and analyzed screening rate, antimicrobial resistance rate, and neonatal observation room (NOR) admission rate due to inadequate chemoprophylaxis.

METHODS

The GBS screening data for January 2006-December 2013 were retrospectively collected and analyzed. We also collected data for neonates admitted to NOR due to inadequate chemoprophylaxis during the period 1 April 2010-31 December 2013.

RESULTS

A total of 12 200 pregnant women received rectovaginal culture during the 8-year study period. The overall screening rate was 53.8% and maternal colonization rate was 20.7%. The GBS screening rate increased remarkably, from 23.2% in 2006 to 70% in 2013. Antimicrobial resistance was common. The resistance rates for each antimicrobial used in pregnancy were as follows: clindamycin, 49.51%; erythromycin, 49.51%. A total of 297 neonates were admitted to NOR due to inadequate antibiotic prophylaxis during 1 April 2010-31 December 2013. The overall NOR admission rate due to inadequate chemoprophylaxis was 2.67%, and the inadequate chemoprophylaxis rate for those GBS colonized mothers was 19.6%. None of these 297 infants had positive blood culture for GBS sepsis.

CONCLUSION

The GBS screening rate increased remarkably, reaching 70% in 2013. The NOR admission rate due to inadequate chemoprophylaxis was 2.67% and there was no early onset GBS disease in a total of 11 123 deliveries in this 4-year cohort study.

Group B Streptococci serotype distribution in pregnant women in Ghana: assessment of potential coverage through future vaccines

OBJECTIVE

Group B streptococcal (GBS) colonization of pregnant women can lead to subsequent infection of the new-born and potentially fatal invasive disease. Data on GBS colonization prevalence and serotype distribution from Africa are scarce, although GBS-related infections are estimated to contribute substantially to infant mortality. In recent years, GBS vaccine candidates provided promising results in phase I and II clinical trials. We aimed to assess the prevalence and serotype distribution of GBS in Ghana since this knowledge is a prerequisite for future evaluation of vaccine trials.

METHODS

This double-centre study was conducted in one rural and one urban hospital in central Ghana, West Africa. Women in late pregnancy (≥35 weeks of gestation) attending the antenatal care clinic (ANC) provided recto-vaginal swabs for GBS testing. GBS isolates were analysed for serotype and antibiotic susceptibility. GBS-positive women were treated with intrapartum antibiotic prophylaxis (IAP) according to current guidelines of the Center for Disease Control and Prevention (CDC).

RESULTS

In total, 519 women were recruited at both study sites, recto-vaginal swabs were taken from 509. The overall prevalence of GBS was 19.1% (18.1% in rural Pramso and 23.1% in urban Kumasi, restrospectively). Capsular polysaccharide serotype (CPS) Ia accounted for the most frequent serotype beyond all isolates (28.1%), followed by serotype V (27.1%) and III (21.9%). No resistance to Penicillin was found, resistances to second line antibiotics clindamycin and erythromycin were 3.1% and 1%, respectively.

DISCUSSION

Group B Streptococcus serotype distribution in Ghana is similar to that worldwide, but variations in prevalence of certain serotypes between the urban and rural study site were high. Antibiotic resistance of GBS strains was surprisingly low in this study.

Antibiotic resistance of Streptococcus agalactiae isolated from pregnant women in Garankuwa, South Africa

Background

This study was undertaken to determine the susceptibility profile and the mechanism of antibiotic resistance in Group B streptococcus (GBS) isolates detected in vaginal and rectal swabs from pregnant women attending Dr George Mukhari Academic Hospital, a University Teaching Hospital in Pretoria, South Africa.

Methods

The samples were collected over an 11-month period, cultured on selective media (colistin and nalidixic acid agar and Todd-Hewitt broth), and GBS positively identified by using different morphological and biochemical tests. The susceptibility testing was done using the Kirby–Bauer and E test methods according to CLSI guidelines 2012. The D test method was used for the detection of inducible clindamycin resistance. Multiplex PCR with specific primers was used to detect different genes coding for resistance.

Results

Out of 413 samples collected, 128 (30.9 %) were positive with GBS. The susceptibility testing revealed that 100 % of isolates were sensitive to penicillin, ampicillin, vancomycin and high level gentamicin. Erythromycin and clindamycin resistance was 21.1 and 17.2 %, respectively, in which 69 % had harboured constitutive macrolide, lincosamide and streptogramin B (MLS_B), 17.4 % had inducible MLS_B. The M and L phenotypes were present in 6.8 % each. The methylation of target encoded by ermB genes was the commonest mechanism of resistance observed in 55 % of isolates, 38 % of isolates had both ermB and linB genes and efflux pump mediated by mefA genes was also distributed among the isolates.

Conclusions

The study reaffirmed the appropriateness of penicillin as the antibiotic of choice for treating GBS infection. However it identified the challenges of resistance to macrolides and lincosamides used as alternative drugs for individuals allergic to penicillin. More GBS treatment options for penicillin allergic patients need to be researched on.

Invasive group B streptococcal infection in infants in Shenzhen, China

OBJECTIVE

In this study, we aim to investigate the distribution and antibiotic susceptibility of Group B Streptococcus (GBS) in infants younger than 90 days in Shenzhen, China.

METHODS

A retrospective study was conducted to evaluate GBS infection over an 4-year period. Starting from January 2010, we evaluated the laboratory data, clinical manifestations, treatment and outcomes of patients admitted to our hospital with invasive GBS infection. Furthermore, we analyzed distribution of isolates from infants < 90 days with GBS or non-GBS invasive infection.

RESULTS

The registered cases of invasive GBS infection (n = 40, male: 23, female: 17) were classified as sepsis (n = 24), meningitis (n = 2), or both (n = 14). Patients with sepsis recovered completely. Among patients with meningitis, 1 (6.3%) died from ventricular hemorrhage, and 4 (25%) showed sequelae during the follow up of 3 months. Among the 377 isolates (45 from the 40 infants with invasive GBS infection, 332 from infants with non-GBS invasive infections), the detection rate of GBS was 11.9% (45/377), accounted for 11.2% of sepsis and 18.4% of meningitis cases. All 45 isolates were susceptible to penicillin, vancomycin, linezolid, tigecycline, and quinolones. Resistance to erythromycin, clindamycin, and tetracycline was found in 19 (42%), 29 (64%), and 42 (93%) isolates, respectively.

CONCLUSION

GBS is an important pathogen in infants < 90 days in Shenzhen, China, which results in high mortality and neurological sequelae. GBS strains show strong resistance to clindamycin and erythromycin.

[Group B streptococcal early-onset neonatal sepsis in the area of Barcelona (2004-2010). Analysis of missed opportunities for prevention]

OBJECTIVES

To study the evolution of the incidence of early-onset neonatal sepsis (EOS) by Streptococcus agalactiae in the area of Barcelona and to analyze failure of compliance with the prevention protocol.

METHODS

A retrospective review was carried out on EOS cases in 8 Health-Care Centers in the Barcelona area between 2004 and 2010.

RESULTS

Forty-nine newborns from 48 mothers were diagnosed with EOS. The incidence was 0.29‰ living newborns (0.18-0.47‰), with no significant differences in the fluctuations along the 7 years. The mortality rate was 8.16%. In 68.5% cases the maternal colonization studies were negative, and in 21% these studies were not performed. No risk factors were detected in 58.3% of pregnant women, and 22.9% of births were premature. In 58% of cases intra-partum antibiotic prophylaxis was not administered because it was not indicated, and in 42% due to failure to follow the protocol (3 strains were resistant to erythromycin). Resistance to clindamycin was 33.3%. The Streptococcus agalactiae serotypes more frequently isolated were iii, v, and ia.

CONCLUSIONS

No significant changes were detected in the incidence of Streptococcus agalactiae EOS in the 7 years of the study. The increased sensitivity of screening methods with the use of molecular techniques, the performance of susceptibility testing of strains isolated from pregnant women, and the improvement of communication between Health-Care Centers, can contribute to a better implementation of the protocol, as well as to reduce the incidence of EOS.

Multicenter clinical evaluation of the Xpert GBS LB assay for detection of group B Streptococcus in prenatal screening specimens

Neonatal infection with Streptococcus agalactiae (group B Streptococcus [GBS]) is a leading cause of sepsis and meningitis in newborns. Recent guidelines have recommended universal screening of all pregnant women to identify those colonized with GBS and administration of peripartum prophylaxis to those identified as carriers to reduce the risk of early-onset GBS disease in neonates. Enriched culture methods are the current standard for prenatal GBS screening; however, the implementation of more sensitive molecular diagnostic tests may be able to further reduce the risk of early-onset GBS infection. We report a clinical evaluation of the Xpert GBS LB assay, a molecular diagnostic test for the identification of GBS from broth-enriched vaginal/rectal specimens obtained during routine prenatal screening. A total of 826 specimens were collected from women undergoing prenatal screening (35 to 37 weeks' gestation) and tested at one of three clinical centers. Each swab specimen was tested directly prior to enrichment using the Xpert GBS assay. Following 18 to 24 h of broth enrichment, each specimen was tested using the Xpert GBS LB assay and the FDA-cleared Smart GBS assay as a molecular diagnostic comparator. Results obtained using all three molecular tests were compared to those for broth-enriched culture as the gold standard. The sensitivity and specificity of the Xpert GBS LB assay were 99.0% and 92.4%, respectively, compared to those for the gold standard culture. The Smart GBS molecular test demonstrated sensitivity and specificity of 96.8% and 95.5%, respectively. The sensitivities of the two broth-enriched molecular methods were superior to those for direct testing of specimens using the Xpert GBS assay, which demonstrated sensitivity and specificity of 85.7% and 96.2%, respectively.

Intrapartum GBS screening and antibiotic prophylaxis: a European consensus conference

Group B streptococcus (GBS) remains worldwide a leading cause of severe neonatal disease. Since the end of the 1990s, various strategies for prevention of the early onset neonatal disease have been implemented and have evolved. When a universal antenatal GBS screening-based strategy is used to identify women who are given an intrapartum antimicrobial prophylaxis, a substantial reduction of incidence up to 80% has been reported in the USA as in other countries including European countries. However recommendations are still a matter of debate due to challenges and controversies on how best to identify candidates for prophylaxis and to drawbacks of intrapartum administration of antibiotics. In Europe, some countries recommend either antenatal GBS screening or risk-based strategies, or any combination, and others do not have national or any other kind of guidelines for prevention of GBS perinatal disease. Furthermore, accurate population-based data of incidence of GBS neonatal disease are not available in some countries and hamper good effectiveness evaluation of prevention strategies. To facilitate a consensus towards European guidelines for the management of pregnant women in labor and during pregnancy for the prevention of GBS perinatal disease, a conference was organized in 2013 with a group of experts in neonatology, gynecology-obstetrics and clinical microbiology coming from European representative countries. The group reviewed available data, identified areas where results were suboptimal, where revised procedures and new technologies could improve current practices for prevention of perinatal GBS disease. The key decision issued after the conference is to recommend intrapartum antimicrobial prophylaxis based on a universal intrapartum GBS screening strategy using a rapid real time testing.

Molecular-based screening for perinatal group B streptococcal infection: implications for prevention and therapy

Group B streptococci (GBS) are a leading cause of infectious neonatal morbidity and mortality. Timely and accurate identification of colonized pregnant women is imperative to implement intrapartum antibioprophylaxis (IAP) to reduce the risk of early neonatal sepsis. Current guidelines recommend screening for GBS carriage with vaginal-rectal cultures. However, cultures require 24-72 h, thus precluding their use for intrapartum screening and these are only performed at 35-37 weeks gestation. New rapid molecular-based tests can detect GBS within hours. They have the potential to be used intrapartum and to allow for selective IAP in women carrying GBS. An advantage is that they can sometimes be performed by non-laboratory staff in the labor suite, thus avoiding delays in sample transfers to the microbiology laboratory. Another possible use of molecular-based assays is for the diagnosis of neonatal sepsis, where tests with a short turnaround time and high sensitivity and specificity are crucial. In this situation, the detection of microorganisms once antibiotic therapy has already been started is important, as treatment is started immediately once sepsis is suspected without waiting for microbiological confirmation. In this article, we discuss the state-of-the-art molecular-based tests available for GBS screening during pregnancy, as well as their implications for IAP for the diagnosis and prevention of neonatal sepsis.

High prevalence of Streptococcus agalactiae from vaginas of women in Taiwan and its mechanisms of macrolide and quinolone resistance

BACKGROUND/PURPOSE

Streptococcus agalactiae (GBS), is the most common pathogen causing infections among perinatal women and neonatal babies. Nonetheless, there are few studies on the occurrence of GBS among the pregnant women and the mechanisms of GBS resistance to quinolones and macrolides in Taiwan.

METHODS

GBS were isolated from vaginas of the pregnant and non-pregnant symptomatic women in Taiwan. The prevalence, antimicrobial susceptibility, and mechanisms of resistance against erythromycin and quinolone of total 188 isolates were studied.

RESULTS

The isolation rate of GBS from pregnant women was significantly higher at 21.8% compare with the non-pregnant women of 13.2%. Antibiotic susceptibility test of the 188 GBS isolates revealed a high non-susceptible rate for erythromycin (50.0%) while the rate for levofloxacin was only 4.8%. Among 94 erythromycin non-susceptible GBS isolates, ermB gene was detected 83.1% (59/71) for those GBS that were non-susceptible to both clindamycin and tetracycline, which was significantly higher than GBS that are susceptible to clindamycin but resistant to tetracycline at 43.8% (7/16). No ermA or mef gene was detected in any isolate. Mutations were detected in the parC and gyrA genes in 14 out of 18 levofloxacin non-susceptible isolates. The predominant mutation type was the combination of Ser79Tyr in parC and Ser81Leu mutations in gyrA.

CONCLUSION

GBS is the most common isolated pathogens in vaginal infections in Taiwan, resistance to tetracycline and erythromycin is higher than the rate observed for other regions of the world, while the resistance rate for levofloxacin was relatively lower in Taiwan.

Group B streptococcal epidemiology and vaccine needs in developed countries

Development of a group B streptococcal vaccine (GBS) vaccine is the most promising approach for the prevention of GBS infections in babies, given the potential adverse effects of intrapartum antibiotic prophylaxis as well as the need for effective prevention of both adult and late perinatal disease. There are numerous prevention strategies at this time but none are 100% effective in the eradication of neonatal early onset GBS disease and there are no preventative strategies for late onset disease. The need for a GBS vaccine is therefore, of utmost importance. Efforts applying genomics to GBS vaccine development have led to the identification of novel vaccine candidates. The publication of GBS whole genomes coupled with new technologies including multigenome screening and bioinformatics has also allowed researchers to overcome the serotype limitation of earlier vaccine preparations in the search of a universal effective vaccine against GBS. This review brings together the key arguments concerning the potential need of a GBS vaccine in developed countries and describes the current status with GBS epidemiology and microbiology in these countries.

Penicillin susceptibility and macrolide-lincosamide-streptogramin B resistance in group B Streptococcus isolates from a Canadian hospital

BACKGROUND

Intrapartum antibiotic prophylaxis (IAP) is recommended for pregnant women who test positive for group B Streptococcus (GBS) in their genitourinary tract to prevent GBS-induced neonatal sepsis. Penicillin G is used as the primary antibiotic, and clindamycin or erythromycin as the secondary, if allergies exist. Decreased susceptibility to penicillin G has occasionally been reported; however, clindamycin and erythromycin resistance is on the rise and is causing concern over the use of clindamycin and erythromycin IAP.

METHODS

Antibiotic resistance was characterized phenotypically using a D-Test for erythromycin and clindamycin, while an E-Test (E-strip) was used for penicillin G. GBS was isolated from vaginal-rectal swabs and serologically confirmed using Prolex (Pro-Lab Diagnostics, Canada) streptococcal grouping reagents. Susceptibility testing of isolates was performed according to the Clinical Laboratory Standards Institute guidelines.

RESULTS

All 158 isolates were penicillin G sensitive. Inducible macrolide-lincosamide-streptogramin B (MLSB) resistance was observed in 13.9% of isolates. Constitutive MLSB resistance was observed in 12.7% of isolates. M phenotype resistance was observed in 6.3% of isolates. In total, erythromycin resistance was present in 32.9% of the GBS isolates, while clindamycin resistance was present in 26.6%.

DISCUSSION

The sampled GBS population showed no sign of reduced penicillin susceptibility, with all being well under susceptible minimum inhibitory concentration values. These data are congruent with the large body of evidence showing that penicillin G remains the most reliable clinical antibiotic for IAP. Clindamycin and erythromycin resistance was higher than expected, contributing to a growing body of evidence that suggests the re-evaluation of clindamycin and erythromycin IAP is warranted.