scholarly journals An empirical Bayes method for serotype case-carrier ratios, with an application to Group B streptococcus

2018 ◽  
Author(s):  
Joseph A. Lewnard ◽  
Lauren A. Cowley
Keyword(s):  
Empirical Bayes ◽  
Ad Hoc ◽  
Late Onset ◽  
Group B Streptococcus ◽  
Invasive Disease ◽  
Random Effects Model ◽  
Bayes Method ◽  
Disease States ◽  
Invasive Infections ◽  
Group B

ABSTRACTBackgroundCase-carrier ratios quantifying the relative pathogenicity of serotypes can inform vaccine formulations for antigenically-diverse pathogens. However, sparse serotype-specific counts in epidemiologic datasets may undermine such analyses, most notably for rare serotypes that pose emergence risks in vaccinated populations. This challenge is well-illustrated in Group B streptococcus (GBS), where serotype III dominates in both carriage and disease.MethodsWe develop an empirical Bayes random-effects model based on conjugate Dirichlet-multinomial distributions of serotype frequencies in carriage and disease states. We validate the model using simulated datasets, and apply it to data from 15 paired sets of GBS isolates from intrapartum rectovaginal colonization (n=3403) and neonatal invasive disease (NID; n=1088), 16 from blood (n=2352) and cerebrospinal fluid (n=780) neonatal specimens, and 3 from fatal (n=173) and non-fatal (n=1684) neonatal invasive infections.ResultsOur method accurately recovers parameters in simulated datasets. Using this approach, we confirm that GBS serotype III exhibits the greatest invasiveness, followed by serotype Ia with a 75.3% (95%CrI: 43.7-93.8%) lower estimate. Enhanced invasiveness of serotypes III and Ia is most evident in late-onset disease. Non–hexavalent-vaccine serotypes, which are rare in carriage and disease, generally show lower invasiveness; serotype IX/non-typeable GBS, the most prevalent cause of non–vaccine-preventable disease, is 98.7% (81.7-99.9%) and 94.2% (13.9-99.6%) less invasive than serotypes III and Ia, respectively.ConclusionsWe present a strategy for measuring associations of serotype with carrier and disease states in the presence of sparse counts, avoiding biases that exist in common ad-hoc approaches.

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

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dusan Kekic ◽  
Ina Gajic ◽  
Natasa Opavski ◽  
Milan Kojic ◽  
Goran Vukotic ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Late Onset ◽  
Group B Streptococcus ◽  
Neonatal Morbidity ◽  
Disease Rate ◽  
Molecular Characteristics ◽  
Group B Streptococci ◽  
Live Births ◽  
Invasive Infections ◽  
Group B

AbstractGroup 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.

Group B Streptococcus (Streptococcus agalactiae)

2018 ◽  
Author(s):  
Kirsty Le Doare ◽  
Christine E. Jones ◽  
Paul T. Heath
Keyword(s):  
Early Onset ◽  
Late Onset ◽  
Group B Streptococcus ◽  
Significant Risk ◽  
Neonatal Infection ◽  
Significant Risk Factor ◽  
Invasive Disease ◽  
Neurodevelopmental Outcomes ◽  
Intrapartum Antibiotic ◽  
Group B

Group B Streptococcus (GBS) is a leading cause of early neonatal infection and neonatal mortality, with long-term adverse neurodevelopmental outcomes in up to 50% of survivors of GBS meningitis. GBS has a likely underappreciated role in causing preterm birth and stillbirth. GBS colonizes the vagina and gastrointestinal tract of the pregnant woman, and transmission to the infant occurs during or just before delivery. Although the majority of these infants do not develop invasive disease, maternal colonization is a prerequisite for early onset disease (0–6 days of life, most commonly associated with sepsis and respiratory distress) and a significant risk factor for late onset disease (7–89 days of life, most commonly associated with sepsis and meningitis). The introduction of intrapartum antibiotic prophylaxis has resulted in significant declines in the incidence of early onset disease but provides no protection against late onset disease.

scholarly journals Epidemiological Characterization of Group B Streptococcus Infections in Alberta, Canada: An Update from 2014 to 2020

2021 ◽  
Author(s):  
Angela Ma ◽  
L. Alexa Thompson ◽  
Thomas Corsiatto ◽  
Donna Hurteau ◽  
Gregory J. Tyrrell
Keyword(s):  
Early Onset ◽  
Late Onset ◽  
Group B Streptococcus ◽  
Content Type ◽  
Adult Disease ◽  
Invasive Infections ◽  
Group B ◽  
Epidemiological Characterization

This work describes the epidemiology of invasive infections caused by the bacterium group B Streptococcus (GBS) in Alberta, Canada. We show that rates of invasive GBS disease have increased from 2014 to 2020 for both adult disease and late-onset disease in neonates, whereas the rate of early onset disease in neonates has decreased. We also show that the rate of resistance to erythromycin (an antibiotic used to treat GBS) has also increased in this time.

Associations between capsular serotype, multilocus sequence type, and macrolide resistance inStreptococcus agalactiaeisolates from Japanese infants with invasive infections

2013 ◽  
Vol 142 (4) ◽  
pp. 812-819 ◽  
Author(s):  
M. MOROZUMI ◽  
T. WAJIMA ◽  
Y. KUWATA ◽  
N. CHIBA ◽  
K. SUNAOSHI ◽  
...  
Keyword(s):  
Clonal Complex ◽  
Vaccine Development ◽  
Late Onset ◽  
Group B Streptococcus ◽  
Sequence Type ◽  
Macrolide Resistance ◽  
Invasive Infections ◽  
Resistant Strains ◽  
Group B ◽  
Sequence Types

SUMMARYStreptococcus agalactiae(group B streptococcus; GBS) isolates (n = 150) from infants with invasive infections between 2006 and 2011 were analysed for capsular serotype, multilocus sequence type, and antibiotic susceptibility. In cases with late-onset disease (n = 115), primary meningitis was predominant (62·6%), but represented only 39·1% in cases with early-onset disease (n = 23). The most common serotype was III (58·7%), followed by Ia (21·3%) and Ib (12·7%). Sequence types (STs) of serotype III strains included ST17 (50·0%), ST19 (26·1%), ST335 (18·2%), ST27 (4·5%), and ST1 (1·1%). Predominant STs of serotypes Ia and Ib were ST23 (81·3%) and ST10 (84·2%), respectively. No penicillin-resistant strains were detected, but 22·0% of strains hadmef(A/E),erm(A), orerm(B) genes, which mediate macrolide resistance. A new ST335, possessing anmef(A/E) gene belonging to clonal complex 19 gradually increased in frequency. Improved prevention of invasive GBS infections in infants requires timely identification, and ultimately vaccine development.

scholarly journals Molecular characteristics of group B Streptococcus isolates from infants in southern mainland China

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Juan Li ◽  
Wenjing Ji ◽  
Kankan Gao ◽  
Haijian Zhou ◽  
Lihua Zhang ◽  
...  
Keyword(s):  
Late Onset ◽  
Group B Streptococcus ◽  
Mainland China ◽  
Invasive Disease ◽  
Molecular Characteristics ◽  
Antibiotic Resistant ◽  
Invasive Group ◽  
Group B ◽  
And Control ◽  
Sequence Types

Abstract Background Invasive group B Streptococcus (GBS) disease in Chinese infants has gradually gained attention in recent years, but the molecular epidemiology of the pathogen is still not well known. Methods This multicenter study retrospectively investigated distribution of capsular serotypes, sequence types (STs), and hypervirulent GBS adhesin gene (hvgA) in clinical GBS isolates that caused invasive disease in infants aged < 3 months of age in southern mainland China between January 2013 and June 2016. Genes for antibiotic resistance to tetracycline, erythromycin, and clindamycin were also examined. Results From a total of 93 GBS isolates taken from 34 early-onset disease (EOD, 0–6 days after birth) and 59 late-onset disease (LOD, 7–89 days after birth) cases, four serotypes were identified: serotypes III (79.6%), Ib (12.9%), Ia (4.3%), and V (3.2%). Serotype III accounted for 73.5% of EOD and 83.1% of LOD and was responsible for 75.5% of cases involving meningitis. Fifteen STs were found, with the majority being ST17 (61.3%), ST12 (7.5%), ST19 (7.5%), and others (23.7%). 96.8% of STs belonged to only five clonal complexes (CCs): CC17 (64.5%), CC10 (12.9%), CC19 (9.7%), CC23 (6.5%), and CC1 (3.2%). The hvgA gene was detected in 66.7% of GBS isolates and 95% of CC17 isolates, all of which were serotype III except one serotype Ib/CC17 isolate. A large proportion of GBS isolates were found to be resistant to tetracycline (93.5%), clindamycin (65.5%), and erythromycin (60.2%). Genes of tetO (74.7%) and tetM (46.0%) were found in tetracycline resistant isolates, linB (24.6%) in clindamycin resistant isolates, and ermB (87.5%) and mefA (3.6%) in erythromycin resistant isolates. Conclusion Our results reveal higher prevalence of serotype III, ST17, CC17, hvgA expressing, and antibiotic resistant GBS isolates than previously reported in southern mainland China. This study provides guidance for appropriate measures of prevention and control to be taken in the future.

scholarly journals Emergence of Invasive Serotype Ib Sequence Type 10 Group B Streptococcus Disease in Chinese Infants Is Driven by a Tetracycline-Sensitive Clone

2021 ◽  
Vol 11 ◽  
Author(s):  
Li Zhang ◽  
Wen-Juan Kang ◽  
Lei Zhu ◽  
Li-Jun Xu ◽  
Chao Guo ◽  
...  
Keyword(s):  
Late Onset ◽  
Medical Center ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Sequence Type ◽  
Genetic Lineage ◽  
Clinical Complications ◽  
Invasive Infections ◽  
Severe Infections ◽  
Group B

BackgroundGroup B streptococcus (GBS) is a leading cause of serious infections in infants. The extensive use of tetracycline has led to the selection of specific resistant and infectious GBS clones. The sequence type (ST) 10 GBS strain, causing invasive infections in infants, is becoming prevalent in China. We aimed to understand the clinical and microbiological characteristics of this GBS strain.MethodsWe conducted a retrospective study on infants with invasive GBS disease from the largest women’s and children’s medical center in Shanxi and collected data between January 2017 and October 2020. GBS isolates were analyzed by capsule serotyping, genotyping, antibiotic resistance, and surface protein genes.ResultsAll ST10 isolates belonged to serotype Ib; type Ib/ST10 strains were responsible for 66.7% (14/21, P &lt; 0.05) of infant invasive GBS infections during the period and all resulted in late-onset (LOD) and late LOD disease (14/14). Infants with type Ib/ST10 GBS disease had significantly higher rates of meningitis (9/14, 64.3%, p &lt; 0.05) and clinical complications (5/14, 35.7%, p &lt; 0.05). The Ib/ST10 GBS isolates had limited genetic diversity, clustered in the CC10/bca/PI-1 + PI-2a genetic lineage, showed resistance to erythromycin, lincomycin, and fluoroquinolones and sensitivity to tetracycline, and possessed genes ermT, ermB, and amino acid changes in gyrA and parC.ConclusionsThe probable clonal expansion can result in severe infections in infants and ongoing emergence of multi-drug resistant isolates. Continued monitoring for type Ib/ST10 GBS infections is warranted.

Pyomyositis as a manifestation of late‐onset group B Streptococcus disease

2021 ◽  
Author(s):  
Akihiko Shimizu ◽  
Mariko Shimizu ◽  
Shigeru Nomura ◽  
Yoshiyuki Yamada
Keyword(s):  
Late Onset ◽  
Group B Streptococcus ◽  
Group B ◽  
Onset Group

scholarly journals Poor Adherence to the Screening-Based Strategy of Group B Streptococcus Despite Colonization of Pregnant Women in Greece

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 418
Author(s):  
Maria Maroudia Berikopoulou ◽  
Aikaterini Pana ◽  
Theodota Liakopoulou-Tsitsipi ◽  
Nikos F. Vlahos ◽  
Vasiliki Papaevangelou ◽  
...  
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
Pregnant Women ◽  
Late Onset ◽  
Group B Streptococcus ◽  
Culture Collection ◽  
Carrier Status ◽  
Cross Sectional ◽  
Screening Guidelines ◽  
Group B

Group B streptococcus (GBS) is a leading cause of serious neonatal infections. Maternal GBS colonization is associated with early- and late-onset neonatal disease (EOD/LOD). In Greece, a screening-based strategy is recommended, in which concurrent vaginal-rectal cultures should be obtained between 36 0/7 and 37 6/7 weeks’ gestation. We sought to examine the level of adherence to the GBS screening guidelines and estimate the prevalence of GBS colonization among pregnant women. Although in Greece the screening-based strategy is followed, we also examined known EOD risk factors and linked them to GBS colonization. A cross-sectional study of 604 women postpartum in three hospitals and maternity clinics was conducted. Following written informed consent, data were collected via a short self-completed questionnaire and review of patients’ records. In 34.6% of the enrolled pregnant women, no culture had been taken. Of the remaining, 12.8% had proper vaginal-rectal sample collections. The overall maternal colonization rate was 9.6%. At least one risk factor for EOD was identified in 12.6% of participants. The presence of risk factors was associated with positive cultures (p = 0.014). The rate of culture collection did not differ between women with or without an EOD risk factor. Adherence to a universal screening of pregnant women with vaginal-rectal cultures was poor. Despite probable underestimation of GBS carrier status, almost 1 in 10 participants were GBS positive during pregnancy. Screening of women with risk factors for EOD should, at least, be prioritized to achieve prevention and prompt intervention of EOD.

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

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Tina Perme ◽  
Daniel Golparian ◽  
Maja Bombek Ihan ◽  
Andrej Rojnik ◽  
Miha Lučovnik ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Virulence Factors ◽  
Late Onset ◽  
Group B Streptococcus ◽  
Genomic Diversity ◽  
Neonatal Disease ◽  
Phenotypic Characterisation ◽  
High Prevalence ◽  
Group B ◽  
The Impact

Abstract Background Group B Streptococcus (GBS) is the leading cause of invasive neonatal disease in the industrialized world. We aimed to genomically and phenotypically characterise invasive GBS isolates in Slovenia from 2001 to 2018 and contemporary colonising GBS isolates from screening cultures in 2018. Methods GBS isolates from 101 patients (invasive isolates) and 70 pregnant women (colonising isolates) were analysed. Basic clinical characteristics of the patients were collected from medical records. Antimicrobial susceptibility and phenotypic capsular serotype were determined. Whole-genome sequencing was performed to assign multilocus sequence types (STs), clonal complexes (CCs), pathogenicity/virulence factors, including capsular genotypes, and genome-based phylogeny. Results Among invasive neonatal disease patients, 42.6% (n = 43) were females, 41.5% (n = 39/94) were from preterm deliveries (< 37 weeks gestation), and 41.6% (n = 42) had early-onset disease (EOD). All isolates were susceptible to benzylpenicillin with low minimum inhibitory concentrations (MICs; ≤0.125 mg/L). Overall, 7 serotypes were identified (Ia, Ib, II-V and VIII); serotype III being the most prevalent (59.6%). Twenty-eight MLST STs were detected that clustered into 6 CCs. CC-17 was the most common CC overall (53.2%), as well as among invasive (67.3%) and non-invasive (32.9%) isolates (p < 0.001). CC-17 was more common among patients with late-onset disease (LOD) (81.4%) compared to EOD (47.6%) (p < 0.001). The prevalence of other CCs was 12.9% (CC-23), 11.1% (CC-12), 10.5% (CC-1), 8.2% (CC-19), and 1.8% (CC-498). Of all isolates, 2.3% were singletons. Conclusions A high prevalence of hypervirulent CC-17 isolates, with low genomic diversity and characteristic profile of pathogenicity/virulence factors, was detected among invasive neonatal and colonising GBS isolates from pregnant women in Slovenia. This is the first genomic characterisation of GBS isolates in Slovenia and provides valuable microbiological and genomic baseline data regarding the invasive and colonising GBS population nationally. Continuous genomic surveillance of GBS infections is crucial to analyse the impact of IND prevention strategies on the population structure of GBS locally, nationally, and internationally.

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