Alarming regional differences in prevalence and antimicrobial susceptibility of group B streptococci in pregnant women: A systematic review and meta-analysis

Evaluation of a novel liquid-solid biphasic differential medium for screening of group B streptococcus in perinatal women

This study explored the capabilities of the commonly used blood agar plate in Chinese clinical microbiology laboratories and a novel liquid-solid biphasic differential medium (L-S StrepB) for detecting group B streptococcus (GBS) in peripartum women in China. A total of 11.2% (65/582) of pregnant women at 35-37 weeks of gestation were found to carry GBS. The sensitivity and specificity of L-S StrepB were 96.9% and 100%, respectively. Additionally, 87.3% (55/63) of GBS cases were detected within 15-24 h using L-S StrepB, demonstrating rapid processing time. This method is user-friendly, cost-effective, and requires no specialized equipment, making it suitable for use in primary healthcare settings.IMPORTANCEThe clinical application methods for group B streptococcus (GBS) detection among peripartum women in medical institutions in China are influenced by various factors, such as cost and personnel availability, leading to a lack of standardization. In this study, we evaluated a novel liquid-solid biphasic differential medium (L-S StrepB) that integrates liquid enrichment with solid agar for the detection of GBS. This is the first reported study in China to utilize biphasic medium for GBS detection. L-S StrepB demonstrates good sensitivity and specificity, with simple operations and low costs, while adhering to guidelines recommending initial enrichment followed by culturing.

Streptococcus agalactiae colonization is common among pregnant women with HIV infection and is neither predicted by hospital tier nor trimester in Mwanza, Tanzania

BACKGROUND

Streptococcus agalactiae, also known as Group B Streptococcus (GBS) is a member of the gastrointestinal tract and vaginal microbiota, and one of the commonest pathogens affecting pregnant women, neonates and infants. Its observed rate of colonization varies globally due to laboratory methods used, socio-cultural, epidemiological and clinical factors. This study therefore, aimed at determining the prevalence of GBS colonization and associated risk factors among HIV-infected and uninfected pregnant women in various health care facility tiers in Tanzania to guide priority screening and management.

METHODS

A cross-sectional analytical study was conducted from February to June 2021 from the antenatal clinics in the primary, secondary and tertiary health care levels in the northwestern part of Tanzania involving 872 pregnant women. Demographic, obstetric and other clinical data were collected using a pre-tested structured questionnaire. Two swabs (vaginal and rectal) were collected and cultured-on blood agar and CHROMagarTMStrepB agar, followed by antimicrobial susceptibility testing. A two-sample test of proportions was used to compare the GBS prevalence in various sub-groups, and logistic regression analysis was deployed to ascertain the association between predictor variables and GBS colonization.

RESULTS

The overall proportion of S. agalactiae colonization was 24.5% (214/872) [95% CI: 21.7 - 27.5%], and was significantly higher in the HIV infected group [63.1% (70/111)] than in the HIV-negative group [18.9% (144/761)]; OR (95% CI) = 7.33 (4.77-11.29, p-value < 0.001)]. Colonization was more prevalent in the rectal samples compared to vaginal samples [21.1% versus 8.83%, respectively; p-value < 0.001)] and S. agalactiae recovery was higher using CHROMagarTMStrepB agar compared to blood agar [24.4% versus 18.8%, respectively, p-value = 0.004]. There was no association between GBS colonization and health care facility levels or pregnancy trimesters. The S. agalactiae isolates were sensitive to ampicillin (100%), erythromycin (76.3%), clindamycin (84.4%) and vancomycin (98.1%).

CONCLUSIONS

Approximately a quarter of pregnant women are colonized by GBS in Mwanza, Tanzania; and colonization is remarkably higher among HIV-infected women. Ampicillin is recommended for prophylaxis and treatment of GBS. Introduction of routine GBS screening among all HIV-infected pregnant women using ultrasensitive CHROMagar™ Strep B agar is recommended, and molecular characterization of GBS isolates would be of interest to guide future vaccination strategies.

Multidrug Resistant Group B Streptococcus Isolates from Pregnant Women in Delta State, Nigeria

<b>Background and Objective:</b> Group B <i>Streptococci</i> (GBS) are globally recognized as a major risk factor for neonatal infections and various obstetric complications. More so, biofilm formation has been suggested to be important for GBS pathogenesis. The aim of this study was to determine the prevalence and antibiotic susceptibility pattern of GBS among pregnant women and their capacity to form biofilm. <b>Materials and Methods:</b> A total of 87 pregnant women at 34 to 37 weeks' gestation aged 17-45 years were recruited from 3 healthcare centres in Delta State, Nigeria. Cultures for the isolation of GBS were carried out using recto-vaginal swabs, according to standard microbiological methods. All strains isolated were used for susceptibility tests to various antibiotics as recommended by CLSI using the disk-diffusion method. <b>Results:</b> The overall prevalence of GBS colonization among pregnant women was 43.6% (38/87). The <u><</u>30 age group had the highest rate of GBS colonization. Resistance to erythromycin and vancomycin was 48.2 and 66.4%, respectively. The fluoroquinolones had the lowest resistant rates with no isolate showing resistance to ofloxacin. Multidrug resistance (MDR) (<u>></u>3 drug classes) was detected in 73.7% (28/38) of the GBS isolates. All GBS isolated in this study were either strong, moderate or weak biofilm producers. However, most 28 (73.7%) were strong biofilm producers. Resistance of GBS isolates to erythromycin and vancomycin, drugs used for treating GBS infection was high. <b>Conclusion:</b> This suggested the importance of testing antimicrobial susceptibilities in GBS colonized pregnant women in order to guide antibiotic therapy and minimize newborn infection and co-morbidity.

Maternal and neonatal group B streptococcus colonisation: A systematic review and the meta-analysis of matched-pair studies

AIM

To determine the prevalence of group B Streptococcus (GBS) carriage among parturient women and neonates, and the relative risk of vertical transmission, the relative risk of early and late-onset GBS and the pooled incidence of early-late-onset GBS infection.

METHODS

A systematic search of relevant cohort studies from three electronic databases to identify all relevant studies published up to 7 November 2022. The review was conducted in accordance with PRISMA guidelines. Estimates were pooled using random-effects meta-analyses.

RESULTS

A total of 54 articles with 355 787 matched pairs of parturient women and neonates from 30 countries were included in the analysis. The pooled prevalence of GBS colonisation was 17.1% among the pregnant women and 1.0% among neonates. The pooled prevalence of vertical transmission of GBS was 4.5% and the pooled relative risk of GBS colonisation of neonates born to mothers with GBS was 9.9.

CONCLUSION

We support the implementation of targeted intrapartum antibiotic prophylaxis for all women who are positive for GBS as well as women with risks factors for early onset GBS in their infants regardless of their GBS colonisation status.

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

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

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

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

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.

Genomic Analysis of Group B Streptococcus from Neonatal Sepsis Reveals Clonal CC17 Expansion and Virulence- and Resistance-Associated Traits After Intrapartum Antibiotic Prophylaxis

BACKGROUND

Group B Streptococcus (GBS) is a leading cause of invasive neonatal infections. This study aimed to investigate the trend of GBS serotype and genotype change and their correlation with antimicrobial resistance before and after implementation of intrapartum antibiotic prophylaxis (IAP).

METHODS

We performed serotyping, whole-genome sequencing, antimicrobial susceptibility testing, and single-nucleotide polymorphism (SNP)-based phylogenetic analysis on 238 invasive GBS isolates collected from October 1998 to February 2020 in Taiwan.

RESULTS

There were 7 serotypes and 6 clonal complexes (CCs) among the 238 GBS isolates, and more than half of the isolates carried multiple antimicrobial resistance genes. The expansion of CC17 strains and the increase in late-onset disease occurred synchronously after the implementation of IAP. Analysis of the carriage isolates from pregnant women showed diverse serotype distribution in the IAP era. The antimicrobial susceptibility testing showed that all 238 strains were susceptible to ampicillin and penicillin, while the number of various resistance genes in GBS genomes was found increased with the expansion of CC17. Compared with reference genomes, 697 nonsynonymous SNPs in 443 protein-coding genes were CC17 specific.

CONCLUSIONS

The study revealed the expansion of GBS CC17 and the increase of late-onset disease that occurred simultaneously with the implementation of IAP. Although the susceptibility of CC17 to antimicrobial agents is not different from that of other sequence types at present, GBS with phenotypic resistance to antimicrobials may emerge in the future, given the environmental selection pressure and the continued accumulation of SNP mutations.

Ali G, Alzubaidi K, Ali B, Ismail A, Daghfal J, Almaslamani M, Hadi HA. Microbiological and clinical characteristics of invasive Group B Streptococcal blood stream infections in children and adults from Qatar

INTRODUCTION

Group B Streptococci (GBS) colonize almost one third of human gastrointestinal and genitourinary tracts, particularly in females. The aim of this study is to evaluate the epidemiology, microbiological characteristics, and clinical outcomes of invasive GBS disease in Qatar from all age groups.

METHODS

A retrospective study was conducted on patients with confirmed GBS blood stream infections during the period between January 2015 and March 2019. Microbiological identification was performed using automated BD PhoenixTM system, while additional antimicrobial susceptibility tests were performed using E test and disc diffusion methods.

RESULT

During the four years period, the incidence steadily rose from 1.48 to 2.09 cases per 100.000 population. Out of 196 confirmed cases of invasive GBS infections, the majority were females (63.7%, 125/196) of which 44.8% were pregnant and 53.6% were colonized. Three distinct affected age groups were identified: children ≤ 4 years of age (35.7%), young adults 25-34 (20.9%) and the elderly ≥ 65 year (17.4%). Presenting symptoms were mild with fever in 53% of cases while 89% of cases had Pitt bacteraemia score of ≤ 2. Isolates were universally sensitive to penicillin, ceftriaxone, and vancomycin at 100% but with significant resistance to erythromycin (49%) and clindamycin (28.6%) while 16.8% had inducible clindamycin resistance. Clinical outcomes showed cure rate of 87.25% with complications in (8.76%) and 4% mortality.

CONCLUSION

There is a rising trend of Group B Streptococcal blood stream infections in Qatar with significantly high clindamycin and erythromycin resistance rates. Universal susceptibility rates were demonstrated for penicillin, ceftriaxone, and vancomycin.

Alterations in Genes rib, scpB and Pilus Island Decrease the Prevalence of Predominant Serotype V, Not III and VI, of Streptococcus agalactiae from 2008 to 2012

Streptococcus agalactiae (GBS) can infect newborns, pregnant women and immunocompromised or elderly people. This study aimed to investigate differences in three pilus genes and virulence genes pavA, cfb, rib and scpB and changes in predominant serotypes III, V and VI from 2008 to 2012. The susceptibilities to penicillin, ceftriaxone, azithromycin, erythromycin, clindamycin, levofloxacin and moxifloxacin of 145 GBS strains of serotype III, V and VI strains from 2008 and 2012 were determined using disc diffusion method. PCR identification of ST-17, the pilus genes and virulence genes; multilocus sequence typing (MLST); and conserved domain and phylogenetic analysis of scpB-1 and scpB-2 proteins were performed. A dramatic number reduction was observed in serotype V, not III and V, from 2008 to 2012. The rate of resistance to azithromycin, clindamycin and erythromycin was the highest in serotype V. ST-17 was only found in serotype III with pilus genes PI-1+PI-2b. The major pilus genotype was PI-1+PI-2a. Serotype V without the rib gene was reduced in number between two studied years. Compared to scpB-1, scpB-2 had a 128-bp deletion in a PA C5a-like peptidase domain and putative integrin-binding motif RGD. In conclusion, reduction in serotype V may be due to presence of scpB-2 or lack of genes scpB and rib.

Clinical Profile and Risk Factors of Group B Streptococcal Colonization in Mothers from the Eastern District of China

Objective

The main aim of this study was to determine the prevalence, capsular genotyping, antimicrobial susceptibility, and associated factors of colonizing Group B Streptococcus (GBS) in pregnant women admitted to a hospital in Jinan, East China.

Methods

Demographic data, clinical characteristics, and vaginal and rectal swabs were obtained from a group of expecting mothers subjected to GBS screening at the late stage of pregnancy who went into labor over the period from November 2019 to October 2020. Identification of GBS and determination of antimicrobial resistance patterns were performed using a BD Phoenix-100 system. Capsular genotypes were analyzed using polymerase chain reaction and the associated factors were evaluated via logistic regression.

Result

A total of 2761 pregnant women were recruited for this study. The GBS colonization rate was 6.70% (185/2761). Among the 172 GBS strains examined, all were susceptible to vancomycin and linezolid. Resistance was the highest for erythromycin (80.2%), followed by clindamycin (75.0%), levofloxacin (65.1%), and tetracycline (57.6%). The most common serotype identified was Ia (61.0%), followed by III (29.7%), VI (4.6%), II (3.5%), VII (0.6%), and a nontypeable strain. Risk factors for maternal GBS colonization included maternal age (older than 30 years) (OR = 1.913 (1.662, 2.478)), gestational age at birth (average gestational age) (OR = 1.992 (1.445, 2.746)), and prelabor rupture of membrane (OR = 3.838 (1.619, 9.099)).

Conclusion

The prevalence of GBS was relatively low. The maternal age was a factor associated with GBS colonization. Subjects showing GBS positivity during late pregnancy were prone to prolonged rupture of the membrane (PROM) and birth at lower a gestation age than the GBS-negative group. Penicillin could still be used as the first agent of choice for intrapartum antibiotic prophylaxis (IAP).

Antimicrobial Resistance Profile and Associated Factors of Group B Streptococci Colonization among Pregnant Women Attending Antenatal Clinics in Jigjiga, Southeast Ethiopia

Background

Streptococcus agalactiae (group B Streptococcus, GBS) is one of the causes of maternal and neonatal morbidity and mortality in many parts of the world. It is associated with severe maternal and neonatal outcomes. The colonization rate, associated factors, and antimicrobial sensitivity (AST) profile of GBS among pregnant women in Eastern Ethiopia is less studied.

Methods

A cross-sectional study was conducted from 1^st  March to 30^th May, 2021 in Jigjiga. A total of 182 pregnant women with a gestational period of ≥36 weeks were included. A structured questionnaire was used to collect data on the participants' demographic and clinical history. Vaginal-rectal samples were collected by brushing the lower vagina and rectum with a sterile cotton swab for bacteriological culture. An antimicrobial sensitivity test (AST) was performed using the Kary-Bauer disk diffusion method. Data were entered and analyzed using SPSS version 25. The logistic regression model was used to find out factors associated with GBS colonization.

Results

GBS colonization among pregnant women attending antenatal care was at 15.9% (29/182). The AST result showed that the majority of the isolates were sensitive to vancomycin (96.6%), chloramphenicol (96.6%), ampicillin (93.1%) azithromycin (89.7%), and penicillin (86.2%). In contrast, the isolates were found to be resistant to ceftriaxone, erythromycin, ciprofloxacin, clindamycin, and tetracycline at 17.2%, 20.7%, 27.6%, 27.6%, and 34.5%, respectively. Multidrug resistance (MDR) was noted in 4 isolates (13.79%). GBS colonization was significantly associated a with history of preterm labor (<37 weeks of gestation) (AOR = 3.87, 95% CI = 1.36–10.9) and a history of prolonged ruptured membrane (>18 hr.) (AOR = 3.44, 95% CI = 1.34–8.83).

Conclusions

The colonization rate of GBS was considerably high among pregnant women attending antenatal care in the present study area. The observed antimicrobial resistance for the common drugs and the reported MDR level calls for routine screening of pregnant women for GBS and actions to minimize antimicrobial resistance (AMR) should be strengthened.

Prevalence and antimicrobial susceptibility of group B streptococci among pregnant women in Ethiopia: A systemic review and meta-analysis study

Objective:

Maternal colonization or infection with drug-resistant Group B streptococcus is a serious disease that affects mother, fetus, and infant. The knowledge of maternal colonization and antimicrobial susceptibility test is substantially needed for a nation to formulate a policy or change the already existing one to reduce maternal, fetus, and infant mortality. As a result, the goal of this review was to determine the pooled prevalence Group B streptococcus colonization and antimicrobial susceptibility among Ethiopian pregnant women.

Methods:

Literature searches were carried out in the electronic biomedical databases and indexing services such as PubMed/MEDLINE, Scopus, Science Direct, Web of Science, and Google Scholar. Original records of research articles, available online from 2014 to December 2020, addressing prevalence and antimicrobial-resistance pattern of Group B streptococcus in pregnant women were identified and screened. Endnote citation manager software version X9 for windows was utilized to collect and organize search outcomes and for removal of duplicate articles. The relevant data were extracted from included studies using a format prepared in Microsoft Excel and exported to STATA 14.0 software for the outcome measures analyses and subgrouping. The I2 index was used to measure heterogeneity between studies and median, and interquartile (25%, 75%) was used to assess antimicrobial susceptibility rate.

Results and conclusion:

Sixteen original articles were found in both qualitative and quantitative analyses. Group B streptococcus colonization was recorded in 979 of the 5743 pregnant women, resulting in a 16% overall frequency (95% confidence interval: 13%−20%). The estimated prevalence varied significantly between studies with significant heterogeneity (χ2 = 154.31, p = 0.001, I2 = 90.28). Ampicillin (97.8%; interquartile range = 89.5%−100%), penicillin G (95.5%; interquartile range = 89.5%−100%), and vancomycin (100%; interquartile range = 89.5%−100%) susceptibility were all high in Group B streptococcus, whereas tetracycline (29%; interquartile range = 89.5%−100%) susceptibility was low. Group B streptococcus colonization rates in Ethiopian women during pregnancy were virtually similar to those in many underdeveloped countries, and Group B streptococcus isolates were highly sensitive to ampicillin, penicillin G, and vancomycin.

Positive association between the use of macrolides in food-producing animals and pneumococcal macrolide resistance: a global ecological analysis

BACKGROUND

The reasons underpinning the large differences in the prevalence of resistance to macrolides in Streptococcus pneumoniae are imperfectly understood. We assessed if the volume of macrolides used in food-animals could play a role.

METHODS

Logistic regression was used to assess if the country-level prevalence of pneumococcal macrolide resistance was associated with country-level macrolide consumption in food animals and humans.

RESULTS

In both univariate and multivariate models, macrolide use in food-producing animals was significantly associated with pneumococcal macrolide resistance (coeff. = 339, 95% CI 21 - 658; P = 0.037).

CONCLUSIONS

In vitro and individual-level studies are required to verify or refute the hypothesis that macrolides used in food animals can promote the spread of macrolide resistance in humans.

Incidence of invasive Group B Streptococcus (iGBS) infections and the factors associated with iGBS mortality in adults during 2013-2017: a retrospective study at Thailand's largest national tertiary referral center

OBJECTIVES

To determine the incidence of invasive Group B streptococcal (iGBS) diseases and the factors significantly associated with iGBS mortality in adult patients.

MATERIAL AND METHODS

This retrospective study included adults with a positive culture for GBS isolated from a sterile site at Siriraj Hospital - Thailand's largest tertiary care hospital - during January 2013 to December 2017.

RESULTS

Of the 224 included patients, 75.9% had bacteraemia. The median age of patients was 63 years (interquartile range [IQR]: 53-73) and 52.7% were female. Among the 80% of all patients with comorbid diseases, diabetes mellitus (38.8%), cancer (18.8%), and heart disease (12.5%) were the most common. Skin and soft tissue infection (30.8%), septic arthritis (21.4%), primary bacteraemia (21.0%), and meningitis (7.1%) were the most common manifestations of iGBS diseases. The overall 30-day mortality was 11%. Patients that died were older and had more chronic kidney disease, bacteraemia, urinary tract infection, pneumonia, and iGBS-related morbidities than survivors. Pneumonia was the only factor independently associated with 30-day mortality with an adjusted odds ratio of 24.96 (95% confidence interval [CI]: 5.95-104.75).

CONCLUSIONS

Invasive GBS is not uncommon in non-pregnant adults, particularly among older adults and those with diabetes. Concomitant bacteraemia was frequently observed in iGBS patients. The overall mortality was low, but significant morbidities were observed.KEY MESSAGESIn our study, iGBS was not uncommon among older adults and those with diabetes.Two-thirds of patients with iGBS had bacteraemia, and the overall 30-day mortality was 11%.

Systematic Review and Meta-Analyses of Incidence for Group B Streptococcus Disease in Infants and Antimicrobial Resistance, China

We performed a systematic review and meta-analysis of the incidence, case-fatality rate (CFR), isolate antimicrobial resistance patterns, and serotype and sequence type distributions for invasive group B Streptococcus (GBS) disease in infants <1–89 days of age in China. We searched the PubMed/Medline, Embase, Wanfang, and China National Knowledge Infrastructure databases for research published during January 1, 2000–March 16, 2018, and identified 64 studies. Quality of included studies was assessed by using Cochrane tools. Incidence and CFR were estimated by using random-effects meta-analyses. Overall incidence was 0.55 (95% CI 0.35–0.74) cases/1,000 live births, and the CFR was 5% (95% CI 3%–6%). Incidence of GBS in young infants in China was higher than the estimated global incidence (0.49 cases/1,000 live births) and higher than previous estimates for Asia (0.3 cases/1,000 live births). Our findings suggest that implementation of additional GBS prevention efforts in China, including maternal vaccination, could be beneficial.

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

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

Biomarkers for a histological chorioamnionitis diagnosis in pregnant women with or without group B streptococcus infection: a case-control study

Background

Chorioamnionitis may cause serious perinatal and neonatal adverse outcomes, and group B streptococcus (GBS) is one of the most common bacteria isolated from human chorioamnionitis. The present study analyzed the impact of GBS infection and histological chorioamnionitis (HCA) on pregnancy outcomes and the diagnostic value of various biomarkers.

Methods

Pregnant women were grouped according to GBS infection and HCA detection. Perinatal and neonatal adverse outcomes were recorded with a follow-up period of 6 weeks. The white blood cell count (WBC), neutrophil ratio, and C-reactive protein (CRP) level from peripheral blood and soluble intercellular adhesion molecule-1 (sICAM-1), interleukin 8 (IL-8), and tumor necrosis factor α (TNF-α) levels from cord blood were assessed.

Results

A total of 371 pregnant women were included. Pregnant women with GBS infection or HCA had a higher risk of pathological jaundice and premature rupture of membranes and higher levels of sICAM-1, IL-8, and TNF-α in umbilical cord blood. Univariate and multivariate regression analysis revealed that sICMA-1, IL-8, TNF-α, WBC, and CRP were significantly related to an increased HCA risk. For all included pregnant women, TNF-α had the largest receiver operating characteristic (ROC) area (area: 0.841; 95% CI: 0.778–0.904) of the biomarkers analyzed. TNF-α still had the largest area under the ROC curve (area: 0.898; 95% CI: 0.814–0.982) for non-GBS-infected pregnant women, who also exhibited a higher neutrophil ratio (area: 0.815; 95% CI: 0.645–0.985) and WBC (area: 0.849; 95% CI: 0.72–0.978), but all biomarkers had lower value in the diagnosis of HCA in GBS-infected pregnant women.

Conclusion

GBS infection and HCA correlated with several perinatal and neonatal adverse outcomes. TNF-α in cord blood and WBCs in peripheral blood had diagnostic value for HCA in non-GBS-infected pregnant women but not GBS-infected pregnant women.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03731-7.

Term newborns at risk for early-onset neonatal sepsis: Clinical surveillance versus systematic paraclinical test

INTRODUCTION

Early-onset neonatal sepsis is a rare but potentially lethal infection that is very often suspected in daily practice. Previous national guidelines recommended the use of systematic paraclinical tests for healthy term newborns with suspected infection. These guidelines were updated in 2017 by the French Health Authority (Haute Autorité de santé), and promote initial clinical monitoring taking into account the infectious risk level for term and near-term born infants.

OBJECTIVES

To assess the impact of the new recommendations on antibiotic therapy prescription and invasive tests, and on the outcomes of infants born from 36weeks' gestation.

MATERIALS AND METHODS

This study compared the management and the outcome of neonates born from 36weeks' gestation at the level III University Hospital of Nancy, according to their infectious risk level during two periods, before and after the update of national recommendations: from July 1 to December 31, 2017, versus July 1 to December 31, 2018. Data were retrospectively collected from the infants' files. This study compared the number and length of antibiotic treatment and the number of invasive tests, the number of documented infections, the number and length of hospitalization, and mortality between the two periods.

RESULTS

During the first period, among 1248 eligible newborns, 643 presented an infectious risk factor, versus 1152 newborns with 343 having an infectious risk factor during the second period. Antibiotic treatment was initiated for 18 newborns during the first period (1.4%) and for nine during the second (0.8%) (P=0.13). The mean (SD) duration of the antibiotic treatment was longer in the first than in the second period: 6.3±2days vs. 3.1±2.3days (P=0.003). There was no death related to neonatal infection. A total of 1052 blood samples were collected during the first period versus 51 during the second (P<0.01). There was no documented infection. In the first period, there were 18 newborns (1.4%) hospitalized for suspected infection versus nine (0.8%) in the second period (P=0.13). The duration of hospitalization was 5.7±1.7days in the first period versus 5.2±3days in the second (P=0.33).

CONCLUSION

In this study, the application of the new guidelines enabled a reduction of antibiotic exposure and a reduction of invasive tests without additional risk.

Group B Streptococcus serotypes associated with different clinical syndromes: Asymptomatic carriage in pregnant women, intrauterine fetal death, and early onset disease in the newborn

OBJECTIVES

To study Group B Streptococcus (GBS) isolates associated with different clinical syndromes: asymptomatic carriage in pregnant women, intrauterine fetal death (IUFD), and early onset disease (EOD) in the newborn.

METHODS

GBS isolates were collected from asymptomatic pregnant women admitted for labor, IUFD cases, and neonates with EOD. Serotypes and antibiotic susceptibilities were determined. Multilocus sequence typing (MLST) was performed to assess genetic epidemiology.

RESULTS

GBS carriage rate was 26.1% (280/1074). The dominant serotype among asymptomatic pregnant women was VI [98/240 women (40.8%)], followed by serotypes III, V and IV in 42/240 (17.5%), 30/240 (12.5%) and 28/240 (11.7%) women, respectively. The dominant serotype in IUFD cases was serotype VI [10/13 (76.9%)]. In contrast the prevalent serotype among EOD cases was III [16/19 (84.2%)]. ST-1 was associated with IUFD [7/13 (53.8%)], ST-17 was associated with serotype III and EOD in the newborn 14/19 (73.7%)]. Erythromycin and clindamycin resistance reached 36.8%, 7.7% and 20.0%among EOD, vaginal carriage and IUFD, respectively.

CONCLUSIONS

Serotypes VI and ST-1 were dominant among asymptomatic pregnant women and in IUFD cases while EOD was associated with serotype III and ST-17. Invasive mechanisms thus may differ between IUFD and EOD in the newborn and virulence may be related to capsule serotype. Resistance rates to erythromycin and clindamycin were high in EOD cases.

Antibiotic Resistance and Molecular Epidemiological Characteristics of Streptococcus agalactiae Isolated from Pregnant Women in Guangzhou, South China

Streptococcus agalactiae colonization in pregnant women can cause postpartum intrauterine infections and life-threatening neonatal infections. To formulate strategies for the prevention and treatment of S. agalactiae infections, we performed a comprehensive analysis of antibiotic resistance and a molecular-based epidemiological investigation of S. agalactiae in this study. Seventy-two S. agalactiae strains, collected from pregnant women, were subjected to antibiotic susceptibility tests; then, the screened erythromycin and clindamycin nonsusceptible isolates were used for macrolides and clindamycin resistance genes detection, respectively. Detection of resistance genes, serotyping, and determination of virulence genes were performed by polymerase chain reaction. The clonal relationships among the colonized strains were evaluated by multilocus sequence typing. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) mass peak analysis was performed to discriminate the specific sequence types (STs). In our study, 69.4% and 47.2% of the strains were nonsusceptible to erythromycin and clindamycin, respectively; the multidrug resistance rate was 66.7%. All erythromycin nonsusceptible strains harbored resistance genes, whereas only 52.9% of the clindamycin nonsusceptible strains possessed the linB gene. Erythromycin resistance was mainly mediated by the ermB or mefA/E genes. Four serotypes were identified, and the most common serotype was serotype III (52.8%), followed by Ib (22.2%), Ia (18.0%), and II (4.2%). All the strains were divided into 18 STs that were assigned to nine clonal complexes. Most of the major STs were distributed into specific serotypes, including ST19/serotype III, ST17/serotype III, ST485/serotype Ia, ST862/serotype III, and ST651/serotype III. Analysis of virulence genes yielded seven clusters, of which bca-cfb-scpB-lmb (61.6%) was the predominant virulence gene cluster. Among all ST strains distributed in this region, only the ST17 strains had a mass peak at 7620 Da. The outcomes of this study are beneficial for the epidemiological comparison of colonized S. agalactiae in different regions and may be helpful for developing the strategies for the prevention of S. agalactiae infection in Guangzhou. Furthermore, our results show that MALDI-TOF MS can be used for the rapid identification of the ST17 strains.

Galleria mellonella as an infection model for the multi-host pathogen Streptococcus agalactiae reflects hypervirulence of strains associated with human invasive disease

Streptococcus agalactiae, or group B Streptococcus (GBS), infects diverse hosts including humans and economically important species such as cattle and fishes. In the context of human health, GBS is a major cause of neonatal infections and an emerging cause of invasive disease in adults and of foodborne disease in Southeast Asia. Here we show that GBS is able to establish a systemic infection in Galleria mellonella larvae that is associated with extensive bacterial replication and dose-dependent larval survival. This infection model is suitable for use with GBS isolates from both homeothermic and poikilothermic hosts. Hypervirulent sequence types (ST) associated with invasive human disease in neonates (ST17) or adults (ST283) show increased virulence in this model, indicating it may be useful in studying GBS virulence determinants, albeit with limitations for some host-specific virulence factors. In addition, we demonstrate that larval survival can be afforded by antibiotic treatment and so the model may also be useful in the development of novel anti-GBS strategies. The use of G. mellonella in GBS research has the potential to provide a low-cost infection model that could reduce the number of vertebrates used in the study of GBS infection.

Group B streptococcus colonisation and associated risk factors among pregnant women: A hospital-based study and implications for primary care

BACKGROUND

Group B streptococcus (GBS), which asymptomatically colonises the vaginal and rectal areas of women, is a leading cause of neonatal mortality and morbidity. This study aimed to determine the prevalence and factors associated with GBS colonisation among pregnant women in Shenzhen, China.

METHODS

A hospital-based cross-sectional survey was conducted, using a multistage sampling method. Pregnant women at ≥28 weeks' gestation completed a questionnaire and vaginal swabs were obtained for GBS analysis. Data were analysed by chi-squared tests and logistic regression models.

RESULTS

The colonisation rate of GBS among pregnant women was 4.9%. The influencing factors associated with GBS colonisation included body mass index before pregnancy (odds ratio [OR] = 3.79, 95% CI 1.28-11.26), gestational age (OR = 5.81, 95% CI 1.20-28.15), induced abortion (OR = 0.63, 95% CI 0.40-0.98) and lotion use before pregnancy (OR = 1.59, 95% CI 1.04-2.44).

CONCLUSIONS

Our findings suggest that obesity, gestational age, induced abortion and lotion use were significantly associated with GBS colonisation. Further longitudinal research is needed to establish the causal relationship and its biological mechanisms.

Risk factors for neonatal group B streptococcus vertical transmission: a prospective cohort study of 1815 mother-baby pairs

BACKGROUND

The potential factors associated with group B streptococcus (GBS) vertical transmission have not been studied in detail.

STUDY DESIGN

A prospective cohort study was conducted to recruit 1815 mother-neonate pairs for GBS analysis. Pearson's chi-squared tests and generalized linear models were used to explore the risk factors for neonatal GBS colonization.

RESULTS

The rate of GBS vertical transmission was 14.1%. GBS colonization in all neonates was significantly associated with maternal GBS colonization, mode of delivery, episiotomy, number of prenatal vaginal exams, parity, and hypertension. For neonates born to GBS-positive mothers, GBS vertical transmission was associated with the mode of delivery, episiotomy, and sexually transmitted diseases. For neonates born to GBS-negative mothers, neonatal GBS colonization was associated with the number of prenatal vaginal exams, parity, and hypertension.

CONCLUSION

These findings suggest the need for prenatal GBS screening for pregnant women and intrapartum antimicrobial prophylaxis for GBS-colonized women.

Molecular characteristics of Streptococcus agalactiae in a mother-baby prospective cohort study: Implication for vaccine development and insights into vertical transmission

BACKGROUND

Streptococcus agalactiae (GBS) is a leading cause of neonatal sepsis and meningitis in many countries. This study aimed to determine the molecular characteristics of GBS colonized in mothers and their infants so as to provide implication for vaccine strategies and confirm vertical transmission.

METHODS

A prospective cohort study was conducted to recruit 1815 mother-neonate pairs. All GBS isolates from pregnant women and her infants were tested for serotypes, multilocus sequence types and virulence genes. The relationship between multiple molecular characteristics of GBS isolates was tested by the correspondence analysis, and the agreement between mother-neonate paired data in molecular characteristics was analyzed using Kappa tests.

RESULTS

The predominant serotypes were III, Ia and V, and the most prevalent sequence types (STs) were ST19, ST17, ST10, and ST12. All isolates carried at least one pilus island (PI). The most common combination of PIs was PI-2b alone, followed by PI-1+PI-2a and PI-2a alone, and the most prevalent alpha-like protein (alp) genes were rib, epsilon and alphaC. Moreover, a strong relationship was noted between STs, serotypes, alp genes and PIs, including ST17 associated with serotype-III/rib/PI-2b, ST19 with serotype-III/rib/PI-1+PI-2a, and ST485 with serotype-Ia/epsilon/PI-2b. The rate of GBS vertical transmission was 14.1%, and the kappa test revealed good agreement in multiple molecular characteristics among GBS-positive mother-neonate pairs. Notably, the switching of molecular characteristics was found during vertical transmission.

CONCLUSIONS

Our findings underscore the value of monitoring multiple molecular characteristics so as to provide implication for multivalent strategies and gain insights into GBS vertical transmission and vertical characteristic switching.

Neonatal colonization of group B Streptococcus in China: Prevalence, antimicrobial resistance, serotypes, and molecular characterization

BACKGROUND

Group B Streptococcus (GBS) remains a leading cause of neonatal mortality and morbidity. This study aimed to determine the prevalence, antimicrobial susceptibility, serotypes, and molecular characterization of GBS colonized in neonates.

METHODS

A cross-sectional study was conducted using a multistage sampling method. Swabs for GBS identification were taken from infants' ear, oral cavity, and umbilicus immediately after birth. All GBS isolates were tested for antimicrobial susceptibility, resistance genes, serotyping, multilocus sequence typing, and virulence genes.

RESULTS

Of the 1,814 neonates, 1.3% tested positive for GBS, with 66.7% tested as multidrug resistant. All GBS isolates were susceptible to penicillin, but rates of resistance to tetracycline and erythromycin were high (70.8%), with the predominant resistance genes being tetM and ermB. The predominant serotype was III, followed by Ia and Ib, and the most common genotypes were sequence type (ST) 19, ST10, and ST485. Notably, we found that ST19 and ST17 isolates were associated with serotype III, resistant to tetracycline, erythromycin, and clindamycin, and carrying ermB, tetM, and rib; ST10 and ST12 isolates were associated with serotype Ib, resistant to erythromycin and clindamycin, and carrying ermB and alphaC; and ST485 isolates were associated with serotype Ia and carrying mefA/E, tetM, and epsilon.

CONCLUSIONS

These findings indicate a high prevalence of multidrug-resistant GBS and specific phenotype-genotype combinations for GBS clones.