Human Fecal Carriage of Streptococcus agalactiae Sequence Type 283, Thailand

Streptococcus agalactiae (group B Streptococcus) sequence type 283 bacteremia, found almost exclusively in Southeast Asia, is associated with consuming raw freshwater fish, but some patients deny consumption. We detected fecal carriage in 5/184 (2.7%) persons in northeast Thailand. Human carriers might contribute to transmission or be the original source of this sequence type.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

Group B Streptococcus (GBS) is a leading cause of invasive neonatal disease. Epidemiological surveillance of GBS is important to determine cumulative incidence, antimicrobial resistance rates, and maternal and neonatal disease prevention. In this study, we present an update on GBS epidemiology in Alberta, Canada, from 2014 to 2020. Over the 7-year period, 1,556 GBS isolates were submitted to the Alberta Public Health Laboratory for capsular polysaccharide (CPS) typing and antimicrobial susceptibility testing. We analyzed the distribution of CPS types in Alberta and found CPS types III (23.6%), Ia (16.0%), Ib (14.8%), II (13.3%), V (12.7%), IV (12.5%), and VI (2.38%) to be the most prevalent. Less than 1% each of CPS types VII, VIII, and IX were identified. In agreement with historical data, the presence of CPS type IV continued to rise across Alberta, particularly in cases of adult infection, where a 2-fold increase was observed. Cumulative incidences of GBS cases per 100,000 population and late-onset disease per 1,000 live births increased from 4.43 to 5.36 and 0.38 to 0.41, respectively, from 2014 to 2020. However, the incidence of early-onset disease decreased during the 7-year period from 0.2 to 0.07, suggestive of successful intrapartum chemoprophylaxis treatment programs. All GBS isolates were susceptible to penicillin and vancomycin. However, nonsusceptibility to erythromycin increased significantly, from 36.85% to 50.8%, from 2014 to 2020. Similarly, nonsusceptibility to clindamycin also increased significantly, from 21.0% to 45.8%. In comparison to historical data, the overall rates of GBS infection and antimicrobial resistance have increased and the predominant CPS types have changed. IMPORTANCE 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.

Streptococcus gallolyticus - A potentially neglected pathogen causing neonatal sepsis not covered by routine group B streptococcus screening

We report 4 cases of neonatal sepsis caused by Streptococcus gallolyticus. The clinical course was quite similar to early-and late-onset group B streptococcus disease. None of the mothers had group B streptococcus (GBS) colonization on prenatal screening nor received intrapartum antibiotics. We proposed the sporadic distribution of S. gallolyticus sepsis among neonates was partly due to relatively low colonization rate in adults compared with GBS. Species determination of S. gallolyticus may not be available using conventional microbiological methods and may contribute to underestimation or misclassification. In our series, we highlighted the importance of S. gallolyticus as an important pathogen in neonatal sepsis deserving further surveillance.

Use of Recombinant Endolysin to Improve Accuracy of Group B Streptococcus Tests

Group B Streptococcus (GBS) causes serious neonatal infection via vertical transmission. The prenatal GBS screening test is performed at the late stage of pregnancy to avoid risks of infection. In this test, enrichment culture is performed, followed by GBS identification. Selective medium is used for the enrichment; however, Enterococcus faecalis, which is a potential contaminant in swab samples, can interfere with the growth of GBS. Such bacterial contamination can lead to false-negative results. Endolysin, a bacteriophage-derived enzyme, degrades peptidoglycan in the bacterial cell wall; it is a promising antimicrobial agent for selectively eliminating specific bacterial genera/species. In this study, we used the recombinant endolysin EG-LYS, which is specific to E. faecalis; the endolysin potentially enriched GBS in the selective culture. First, in the false-negative model (coculture of GBS and E. faecalis, which disabled GBS detection in the subsequent GBS identification test), EG-LYS treatment at 0.1 mg/ml improved GBS detection. Next, we used 548 vaginal swabs to test the efficacy of EG-LYS treatment in improving GBS detection. EG-LYS treatment (0.1 mg/ml) increased the GBS-positive ratio to 17.9%, compared to 15.7% in the control (phosphate-buffered saline [PBS] treatment). In addition, there were an increased number of GBS colonies under EG-LYS treatment in some samples. The results were supported by the microbiota analysis of the enriched cultures. In conclusion, EG-LYS treatment of the enrichment culture potentially improves the accuracy of the prenatal GBS screening test. IMPORTANCE Endolysin is a bacteriophage-derived enzyme that degrades the peptidoglycan in the cell wall of host bacteria; it could be used as an antimicrobial agent for selectively eliminating specific bacterial genera/species. Group B Streptococcus (GBS) causes neonatal infection via vertical transmission; prenatal GBS screening test, in which enrichment culture is followed by bacterial identification, is used to detect the presence of GBS in pregnant women. However, the presence of commensal bacteria such as Enterococcus faecalis in clinical specimens can inhibit GBS growth in the selective enrichment culture, resulting in false-negative result. Here, we demonstrated that the application of originally isolated endolysin in the enrichment culture improved the test accuracy by inhibiting unwanted E. faecalis growth and therefore avoiding false-negative results, not only in experimental settings, but also in tests using vaginal swabs.

Group B streptococcal infections in infants in Iceland: clinical and microbiological factors

Introduction. Group B streptococcus (GBS) is a leading cause of invasive neonatal infections. These have been divided into early-onset disease (EOD; <7 days) and late-onset disease (LOD; 7-89 days), with different GBS clonal complexes (CCs) associated with different disease presentations.Hypothesis. Different GBS CCs are associated with timing of infection (EOD or LOD) and clinical presentation (sepsis, meningitis or pneumonia).Aim. To study infant GBS infections in Iceland from 1975 to 2019. Are specific GBS CCs related to disease presentation? Is CC17 overrepresented in infant GBS infections in Iceland?Methodology. All culture-confirmed invasive GBS infections in infants (<90 days) in Iceland from 1975 to 2019 were included. Clinical information was gathered from medical records.Results. A total of 127 invasive GBS infections in infants were diagnosed, but 105 infants were included in the study. Of these, 56 had EOD and 49 had LOD. The incidence of GBS infections declined from 2000 onwards but increased again at the end of the study period. Furthermore, there was a significant increase in LOD over the study period (P=0.0001). The most common presenting symptoms were respiratory difficulties and fever and the most common presentation was sepsis alone. Approximately one-third of the cases were caused by GBS CC17 of serotype III with surface protein RIB and pili PI-1+PI-2b or PI-2b. CC17 was significantly associated with LOD (P<0.001).Conclusion. CC17 is a major cause of GBS infection in infants in Iceland. This clone is associated with LOD, which has been increasing in incidence. Because intrapartum antibiotic prophylaxis only prevents EOD, it is important to continue the development of a GBS vaccine in order to prevent LOD infections.

Recurrent neonatal sepsis and progressive white matter injury in a premature newborn culture-positive for group B Streptococcus: A case report

RATIONALE

Group B Streptococcus (GBS) remains a principal pathogen causing neonatal sepsis and meningitis, particularly in premature infants with relatively insufficient immunity. Recurrence may occur uncommonly, largely associated with subclinical mucosal persistence or repetitive exposure to exogenous sources. White matter injury (WMI) including cystic periventricular leukomalacia (PVL) has been associated with intrauterine infection/inflammation, and neonatal infection as a more significant predictor including postnatal sepsis and recurrent infection, even without microbial neuroinvasion. Furthermore, clinical and experimental evidence of WMI by some bacteria other than GBS without central nervous system invasion has been reported. However, there is little evidence of WMI associated with neonatal GBS sepsis in the absence of meningitis in the literature.

PATIENT CONCERNS

A newborn at 30+4 weeks' gestation with low birthweight presented with 2 episodes (with a 13-day interval with no antibiotic therapy) of neonatal sepsis culture-proven for GBS with early-onset presentation after clinical chorioamnionitis via vertical GBS transmission and the associated conditions including prematurity-related neonatal immunodeficiency and persistent mucosal GBS carriage after the first antibiotic treatment. The perinatal GBS infection was complicated by progressive WMI presenting with ventriculomegaly and cystic PVL without a definite evidence of meningitis, intraventricular hemorrhage, and documented cerebral hypoxia or hypoperfusion conditions including septic shock.

DIAGNOSES

Recurrent group B streptococcal sepsis and cystic PVL with ventriculomegaly.

INTERVENTIONS

Two episodes of GBS sepsis were treated with 15-day parenteral antibiotic therapy, respectively.

OUTCOMES

Resolution of the recurrent GBS sepsis without further relapses, however, complicated by WMI and subsequent about 6 months delay in motor development at 12 months' corrected age.

LESSONS

This case suggests WMI associated with GBS bacteremia without central nervous system entry by viable GBS and also shows that in premature infants, intrauterine GBS infection with no interventions may lead to extensive and persistent GBS colonization, early-onset and recurrent GBS disease, and WMI. Postnatal as well as intrauterine infection/inflammation controls with maternal prophylaxis may be pivotal for prevention and limiting the magnitude of neurologic injury.

Estimation of country-level incidence of early-onset invasive Group B Streptococcus disease in infants using Bayesian methods

Neonatal invasive disease caused by Group B Streptococcus (GBS) is responsible for much acute mortality and long-term morbidity. To guide development of better prevention strategies, including maternal vaccines that protect neonates against GBS, it is necessary to estimate the burden of this condition globally and in different regions. Here, we present a Bayesian model that estimates country-specific invasive GBS (iGBS) disease incidence in children aged 0 to 6 days. The model combines different types of epidemiological data, each of which has its own limitations: GBS colonization prevalence in pregnant women, risk of iGBS disease in children born to GBS-colonized mothers and direct estimates of iGBS disease incidence where available. In our analysis, we present country-specific maternal GBS colonization prevalence after adjustment for GBS detection assay used in epidemiological studies. We then integrate these results with other epidemiological data and estimate country-level incidence of iGBS disease including in countries with no studies that directly estimate incidence. We are able to simultaneously estimate two key epidemiological quantities: the country-specific incidence of early-onset iGBS disease, and the risk of iGBS disease in babies born to GBS-colonized women. Overall, we believe our method will contribute to a more comprehensive quantification of the global burden of this disease, inform cost-effectiveness assessments of potential maternal GBS vaccines and identify key areas where data are necessary.

Invasive disease caused by Group B Streptococcus (GBS) in young infants continues to be a major public health problem in both developed and developing countries. However, data on the incidence of this infection during the first week of life are only available for a small number of countries, which has complicated the quantification of the burden of this disease globally. In this paper, we develop a Bayesian framework to estimate the incidence of invasive GBS infection that combines data from multiple types of epidemiological studies, with adjustment for relevant factors such as diagnostic methods used in the studies. We present estimates from a series of models, and our results highlight the potential weaknesses of different types of studies and the importance to consider the entire evidence when estimating global burden of invasive neonatal infections. We believe this model is a step toward better quantification of the number of cases in different regions.

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.

Application of the FTA elute card coupled with visual colorimetric loop-mediated isothermal amplification for the rapid diagnosis of Streptococcus agalactiae in farmed tilapia (Oreochromis niloticus)

A method combining the FTA Elute card and visual colorimetric loop-mediated isothermal amplification (FTA-e/LAMP) was tested to diagnose Streptococcus agalactiae infections in vitro and in vivo. FTA-e/LAMP consists of two main steps: first, the FTA card is used to extract DNA and then a colorimetric loop-mediated isothermal amplification (LAMP) reaction is carried out on the extracted DNA. In vitro sensitivity was 1.9 x 10²  CFU/mL, and regarding specificity, all nine S. agalactiae strains tested positive. All Streptococcus spp. tested negative, except for S. dysgalactiae, thereby indicating the need for another set of primers to distinguish this species from S. agalactiae. To diagnose S. agalactiae infections using FTA-e/LAMP in vivo, two experimental trials on juvenile Oreochromis niloticus infected with bovine or piscine strains were carried out. Sensitivity in symptomatic fish was 100%, and 50.7% of fish without signs were positive. All negative control fish tested negative (n = 28). No bacteria were detected after 16 days post-infection (dpi). Accuracy during the first week (1-7 dpi) was 89% and decreased to 44% thereafter (10-22 dpi). FTA-e/LAMP results suggest that this method is a promising tool for early and fast diagnosis of S. agalactiae on tilapia farms.

Mortality, neurodevelopmental impairments, and economic outcomes after invasive group B streptococcal disease in early infancy in Denmark and the Netherlands: a national matched cohort study

Background

Group B Streptococcus (GBS) disease is a leading cause of neonatal death, but its long-term effects have not been studied after early childhood. The aim of this study was to assess long-term mortality, neurodevelopmental impairments (NDIs), and economic outcomes after infant invasive GBS (iGBS) disease up to adolescence in Denmark and the Netherlands.

Methods

For this cohort study, children with iGBS disease were identified in Denmark and the Netherlands using national medical and administrative databases and culture results that confirmed their diagnoses. Exposed children were defined as having a history of iGBS disease (sepsis, meningitis, or pneumonia) by the age of 89 days. For each exposed child, ten unexposed children were randomly selected and matched by sex, year and month of birth, and gestational age. Mortality data were analysed with the use of Cox proportional hazards models. NDI data up to adolescence were captured from discharge diagnoses in the National Patient Registry (Denmark) and special educational support records (the Netherlands). Health care use and household income were also compared between the exposed and unexposed cohorts.

Findings

2258 children—1561 in Denmark (born from Jan 1, 1997 to Dec 31, 2017) and 697 in the Netherlands (born from Jan 1, 2000 to Dec 31, 2017)—were identified to have iGBS disease and followed up for a median of 14 years (IQR 7–18) in Denmark and 9 years (6–11) in the Netherlands. 366 children had meningitis, 1763 had sepsis, and 129 had pneumonia (in Denmark only). These children were matched with 22 462 children with no history of iGBS disease. iGBS meningitis was associated with an increased mortality at age 5 years (adjusted hazard ratio 4·08 [95% CI 1·78–9·35] for Denmark and 6·73 [3·76–12·06] for the Netherlands). Any iGBS disease was associated with an increased risk of NDI at 10 years of age, both in Denmark (risk ratio 1·77 [95% CI 1·44–2·18]) and the Netherlands (2·28 [1·64–3·17]). A history of iGBS disease was associated with more frequent outpatient clinic visits (incidence rate ratio 1·93 [95% CI 1·79–2·09], p<0·0001) and hospital admissions (1·33 [1·27–1·38], p<0·0001) in children 5 years or younger. No differences in household income were observed between the exposed and unexposed cohorts.

Interpretation

iGBS disease, especially meningitis, was associated with increased mortality and a higher risk of NDIs in later childhood. This previously unquantified burden underlines the case for a maternal GBS vaccine, and the need to track and provide care for affected survivors of iGBS disease.

Funding

The Bill & Melinda Gates Foundation.

Translations

For the Dutch and Danish translations of the abstract see Supplementary Materials section.

Molecular diagnostic assays for the detection of common bacterial meningitis pathogens: A narrative review

Bacterial meningitis is a major global cause of morbidity and mortality. Rapid identification of the aetiological agent of meningitis is essential for clinical and public health management and disease prevention given the wide range of pathogens that cause the clinical syndrome and the availability of vaccines that protect against some, but not all, of these. Since microbiological culture is complex, slow, and often impacted by prior antimicrobial treatment of the patient, molecular diagnostic assays have been developed for bacterial detection. Distinguishing between meningitis caused by Neisseria meningitidis (meningococcus), Streptococcus pneumoniae (pneumococcus), Haemophilus influenzae, and Streptococcus agalactiae and identifying their polysaccharide capsules is especially important. Here, we review methods used in the identification of these bacteria, providing an up-to-date account of available assays, allowing clinicians and diagnostic laboratories to make informed decisions about which assays to use.

A study of group B streptococcus in pregnant women in Lebanon: prevalence, risk factors, vaginal flora and antimicrobial susceptibility

Guidelines recommend universal screening of all pregnant women at 35-37 weeks of gestation for group B streptococcus (GBS) colonization and reserve a risk-factor-based approach for women who have no prenatal cultures. This study determines the prevalence of GBS among pregnant women in Lebanon and assesses the association between risk factors and vaginal flora in this patient population and antibiotic resistance pattern of the GBS isolates. Vaginal samples from women between 35-37 weeks of gestation were obtained and cultured on 5% sheep blood agar (BA), colistin nalidixic acid agar, Strep B Select chromogenic agar and Lim enrichment broth. Also, vaginal flora was evaluated on Gram-stained smears. Colonies on BA suggestive of GBS were identified by Gram staining, catalase test and agglutination in group B antiserum. Antimicrobial susceptibility to different antibiotics was tested on BA. Risk factors were obtained. The prevalence of vaginal GBS colonization was 18.4% (31/168). Evaluation of Gram-stained vaginal smears revealed an inverse relationship between the presence of lactobacilli and GBS colonization (p=0.029). Resistance of GBS to erythromycin and clindamycin was found to be 25.8% and 12.9%, respectively. Demographic and obstetric data did not reveal statistically significant differences in GBS colonization rates between age groups (p=0.498) or level of education (p=0.696) among these women. Prevalence of GBS remains high in this region with no identifiable risk factors for its acquisition. Furthermore, increase in resistance to erythromycin and clindamycin should prompt susceptibility testing of all GBS isolates. The resistance profile of these strains represents an emerging public health concern that needs further surveillance.

Analysis of virulence factors and antibiotic resistance genes in group B streptococcus from clinical samples

BACKGROUND

Streptococcus agalacticae (Group B Streptococcus, GBS) is one of the most important causative agents of serious infections among neonates. This study was carried out to identify antibiotic resistance and virulence genes associated with GBS isolated from pregnant women.

METHODS

A total of 43 GBS isolates were obtained from 420 vaginal samples collected from HIV positive and negative women who were 13-35 weeks pregnant attending Antenatal Care at Chitungwiza and Harare Central Hospitals in Zimbabwe. Identification tests of GBS isolates was done using standard bacteriological methods and molecular identification testing. Antibiotic susceptibility testing was done using the modified Kirby-Bauer method and E-test strips. The boiling method was used to extract DNA and Polymerase Chain Reaction (PCR) was used to screen for 13 genes. Data was fed into SPSS 24.0.

RESULTS

Nine distinct virulence gene profiles were identified and hly-scpB-bca-rib 37.2% (16/43) was common. The virulence genes identified were namely hly 97.8% (42/43), scpB 90.1% (39/43), bca 86.0% (37/43), rib 69.8% (30/43) and bac 11.6% (5/43). High resistance to tetracycline 97.7% (42/43) was reported followed by 72.1% (31/43) cefazolin, 69.8% (30/43) penicillin G, 58.1% (25/43) ampicillin, 55.8% (24/43) clindamycin, 46.5% (20/43) ceftriaxone, 34.9% (15/43) chloramphenicol, and 30.2% (13/43) for both erythromycin and vancomycin using disk diffusion. Antibiotic resistance genes among the resistant and intermediate-resistant isolates showed high frequencies for tetM 97.6% (41/42) and low frequencies for ermB 34.5% (10/29), ermTR 10.3% (3/29), mefA 3.4% (1/29), tetO 2.4% (1/42) and linB 0% (0/35). The atr housekeeping gene yielded 100% (43/43) positive results, whilst the mobile genetic element IS1548 yielded 9.3% (4/43).

CONCLUSION

The study showed high prevalence of hly, scpB, bca and rib virulence genes in S. agalactiae strains isolated from pregnant women. Tetracycline resistance was predominantly caused by the tetM gene, whilst macrolide resistance was predominantly due to the presence of erm methylase, with the ermB gene being more prevalent. Multi-drug resistance coupled with the recovery of resistant isolates to antimicrobial agents such as penicillins indicates the importance of GBS surveillance and susceptibility tests. It was also observed that in vitro phenotypic resistance is not always accurately predicted by resistance genotypes.

Comprehensive study of antimicrobial susceptibility pattern and extended spectrum beta-lactamase (ESBL) prevalence in bacteria isolated from urine samples

Nowadays, increasing extended-spectrum β-lactamase (ESBL)-producing bacteria have become a global concern because of inducing resistance toward most of the antimicrobial classes and making the treatment difficult. In order to achieve an appropriate treatment option, identification of the prevalent species which generate ESBL as well as their antibiotic susceptibility pattern is essential worldwide. Hence, this study aimed to investigate the prevalence of ESBL-producing bacteria and assess their drug susceptibility in Fardis Town, Iran. A total of 21,604 urine samples collected from patients suspected to have urinary tract infection (UTI) were processed in the current study. The antimicrobial susceptibility of the isolates was tested by the disk diffusion method. The ESBL producing bacteria were determined by Double Disc Synergy Test (DDST) procedure. Bacterial growth was detected in 1408 (6.52%) cases. The most common bacterial strains causing UTI were found E. coli (72.16%), followed by K. pneumoniae (10.3%) and S. agalactiae (5.7%). Overall, 398 (28.26%) were ESBL producer. The highest ESBL production was observed in E. coli, followed by Klebsiella species. ESBL producers revealed a higher level of antibiotic resistance compared with non-ESBLs. In conclusion, ESBL production in uropathogens was relatively high. Carbapenems and Aminoglycosides were confirmed as the most effective treatment options for these bacteria.

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.

Clinical Utility of Pourmedia ViGBS Agar Medium for Group B Streptococcus Screening

Group B Streptococcus (hereinafter GBS) is the main pathogen in neonatal sepsis and meningitis, accounting for approximately one quarter of the cases. 1) Prevention of infection is therefore crucial. The GBS carriage testing of pregnant women is necessary to prevent infections. In this study, we examined the clinical utility of Pourmedia ViGBS agar medium (Eiken Chemical Co., Ltd.) in GBS screening, using a total of 197 vaginal and urine samples. Of these samples, 32 (16.2%) tested GBS positive with Pourmedia ViGBS agar medium, and 29 (14.7%) tested GBS positive with Nissui separated plate sheep blood agar/Drigalski agar medium (Nissui Pharmaceutical Co., Ltd.). These results indicate the usefulness of Pourmedia ViGBS agar medium as a GBS screening selective agar medium.

Isolation and molecular characterization of streptococcal species recovered from clinical infections in farmed Nile tilapia (Oreochromis niloticus) in the Philippines

Streptococcosis cause severe losses for global tilapia farming, especially in developing countries. The aim of this study was to identify and characterize streptococci recovered from Nile tilapia farmed in the Philippines. Moribund and apparently healthy fish were sampled from grow-out cages, ponds and hatcheries. Clinical signs observed included exophthalmia, eye opacity, ascites, lethargy, erratic swimming and haemorrhages. Results showed that both Streptococcus iniae and Streptococcus agalactiae were associated with disease in these sites. Consistent with global reports, including those from South-East Asia, S. agalactiae was more widespread than S. iniae. Molecular serotyping of the S. agalactiae isolates identified the serotype Ia and serotype Ib. Histopathological findings were meningitis, meningoencephalitis and septicaemia. Identical virulence profiles were found for all strains of S. iniae, while S. agalactiae strains were separated into virulence profile I and profile II. All strains were susceptible to the tested antibiotics and resistant to oxolinic acid. Only S. agalactiae serotype Ib showed resistance to sulphamethoxazole-trimethoprim. This is the first study from the Philippines to characterize the streptococci involved in disease outbreaks in tilapia aquaculture. Outputs from this study will promote the development of efficacious disease control strategies in tilapia farming for the Philippines and South-East Asia.

Local guidelines for admission to UK midwifery units compared with national guidance: A national survey using the UK Midwifery Study System (UKMidSS)

OBJECTIVES

To describe the extent to which local guidelines for admission to UK midwifery units align with national guidance; to describe variation in individual admission criteria; and to describe the extent to which alongside midwifery units (AMUs) are the default option for eligible women.

DESIGN

National cross-sectional survey.

SETTING

All 122 UK maternity services with midwifery units, between October 2018 and February 2019.

OUTCOME MEASURES

Alignment of local admission guidelines with national guidance (NICE CG190); frequency and nature of variation in individual admission criteria; percentage of services with AMU as default birth setting for eligible women.

RESULTS

Admission guidelines were received from 87 maternity services (71%), representing 153 units, and we analysed 85 individual guideline documents. Overall, 92% of local admission guidelines varied from national guidance; 76% contained both some admission criteria that were 'more inclusive' and some that were 'more restrictive' than national guidance. The most common 'more inclusive' admission criteria, occurring in 40-80% of guidelines, were: explicit admission of women with parity ≥4; aged 35-40yrs; with a BMI 30-35kg/m2; selective admission of women with a BMI 35-40kg/m2; Group B Streptococcus carriers; and those undergoing induction of labour. The most common 'more restrictive' admission criteria, occurring in around 30% of guidelines, excluded women who: declined blood products; had experienced female genital cutting; were aged <16yrs; or had not attended for regular antenatal care. Over half of services (59%) reported the AMU as the default option for healthy women with straightforward pregnancies.

CONCLUSIONS

The variation in local midwifery unit admission criteria found in this study represents a potentially confusing and inequitable basis for women making choices about planned place of birth. A review of national guidance may be indicated and where a lack of relevant evidence underlies variation in admission criteria, further research by planned place of birth is required.

Clonal Distribution of Clindamycin-Resistant Erythromycin-Susceptible (CRES) Streptococcus agalactiae in Korea Based on Whole Genome Sequences

BACKGROUND

The clindamycin-resistant erythromycin-susceptible (CRES) phenotype is rare in Streptococcus agalactiae (group B streptococci). We aimed to determine the molecular characteristics of CRES S. agalactiae using whole genome sequencing (WGS).

METHODS

Sixty-six S. agalactiae isolates obtained from blood (N=26), cerebrospinal fluid (N=10), urine (N=17), and vaginal discharge (N=13) between 2010 and 2017 in Korea were subjected to WGS. Based on the WGS data, we analyzed antimicrobial resistance (AMR) determinants, sequence types (STs), capsular polysaccharide (CPS) genotypes, and virulence gene profiles, and constructed a phylogenetic tree. We included the clindamycin-susceptible erythromycin-resistant (CSER) phenotype for comparison.

RESULTS

We identified seven CRES S. agalactiae isolates from urine (N=5) and vaginal discharge (N=2) collected between 2010 and 2011. All CRES isolates harbored AMR determinants of lnu(B), lsa(E), and aac(6')-aph(2″), revealed ST19 and CPS genotype III, and had a virulence gene profile of rib-lmb-cylE. Phylogenetic tree analysis revealed that all CRES isolates belonged to the same cluster, suggesting a clonal distribution. In contrast, seven CSER isolates showed a diverse distribution and clustered separately from the CRES isolates.

CONCLUSIONS

CRES isolates collected between 2010 and 2011 showed a unique cluster with ST19 and CPS genotype III in Korea. This is the first report on WGS-based characteristics of S. agalactiae in Korea.

Group B Streptococcus in Indian pregnant women: Its prevalence and risk factors

Purpose

To study the prevalence of group B streptococci (GBS) in Indian pregnant women and associated risk factors.

Methods

Four hundred and fifty pregnant women attending antenatal outpatient/inpatient department between 35-38 weeks of gestation were enrolled in the study. All enrolled subjects were assessed by a predefined proforma for their demographics, socio-economic characteristics, education, toilet habits, obstetric history and clinical outcome. Two cotton swabs each from lower vagina and rectum were collected and plated on selective solid media CHROM agar Strept B (CHROMagarTM) and selective Enrichment Broth LIM RambaQUICK StreptB broth (CHROMagarTM). Presumptive identification of GBS was growth of 1-3 mm grayish white β-hemolytic colonies on BAP or mauve coloured colonies on CHROM agar Strept B. All presumptively identified GBS were confirmed as group B streptococcus by automated identification system-Vitek MS (Bio Merieux).

Results

The recto vaginal colonization rate of GBS in this study was observed as 3.3% (n=15). GBS colonization was significantly associated with nulliparous women (p= 0.026) and use of western style toilet (p=0.017). GBS urinary tract infections was also seen more commonly in women with GBS rectovaginal colonization (p=0.002).

Conclusion

Due to the low GBS prevalence and no significant association with major risk factors, we recommend to institute universal screening of GBS in pregnant women, instead of risk based screening. Since this was a single centric study with low prevalence of GBS, its applicability may be limited, therefore further larger multi-centric prospective studies are required to understand the true GBS prevalence in Indian society.

Group B streptococcal transmission rates as determined by PCR

Background Group B Streptococcus (GBS) is a common cause of neonatal sepsis. GBS colonization of the newborn gastrointestinal tract (GIT) may be a critical precursor for late-onset infection. Assessment of the rate of neonatal GBS intestinal colonization has generally relied upon culture-based methods. We used polymerase chain reaction (PCR) and culture to determine the rate of GBS transmission to neonates. We hypothesized that PCR may enhance the detection of neonatal GBS colonization of the GIT, and that the rate will be higher when evaluated with PCR as compared to culture. Methods This was a cross-sectional study, in which mothers who were positive for GBS on routine screening and their healthy infants were eligible for recruitment. Newborn stool was collected after 24 h of life and before hospital discharge, and stored at -80°C for culture and PCR targeting the GBS-specific surface immunogenic protein (sip) gene. Results A total of 94 mother-infant pairs were enrolled; of these pairs, stool was collected from 83 infants. Based on PCR, the overall GBS transmission rate was 3.6% (3/83). The transmission rate was 2.4% (1/41) among vaginal deliveries and 4.8% (2/42) among cesarean deliveries. The results of culture-based transmission detection were identical. Conclusion These results indicate that the rate of GBS transmission is low and that detection may not be enhanced by PCR methods.

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.

Gangrenous mastitis in dromedary camels in UAE caused by Streptococcus agalactiae

BACKGROUND

Mastitis is a disease of economic concern that affects dairy industry worldwide. This study aimed to investigate and identify possible etiologies encountered in an episode of acute gangrenous mastitis in lactating she-camels in Al Dhafra region, Abu Dhabi Emirate, United Arab Emirates (UAE). Beside the routine clinical examination, conventional bacteriological methods were used to isolate and identify possible aerobic/anaerobic bacterial or fungal pathogens from cultured milk samples collected from the mastitic she-camels. Moreover, quantitative real-time polymerase chain reaction (qPCR) was used for the detection of Mycoplasma agalactiae and Mycoplasma bovis strains, and the 16S rRNA gene was sequenced to confirm the isolation. The isolates were also tested for their susceptibility to antimicrobials.

RESULTS

Acute gangrenous mastitis is reported in the dromedary camel herd with about 80% morbidity rate among lactating she-camels exhibited acute, painful hard swelling of affected teat, quarter or entire udder. About 41.7% of the infected animals were stamped out for culling due to complete or partial amputation of udder quarters. Streptococcus agalactiae was the sole isolated organism (6 isolates). The antimicrobial susceptibility testing revealed that, the Streptococcus agalactiae isolates were sensitive to both penicillin and ampicillin. Comparison of the 16S rRNA gene sequencing results by BLASTN confirmed the presence of Streptococcus agalactiae with high confidence (100% identity). Phylogenetic analysis indicated clustering of one isolate (CMAUAE accession number; MN267805.1) with Streptococcus agalactiae that infects multi-hosts including humans, while strains (CMBUAE to CMFUAE with accession numbers; MN267806.1 to MN267810.1 respectively) clustered with Streptococcus agalactiae that infects humans. No Mycoplasma spp was detected by qPCR analysis.

CONCLUSIONS

In the present study, the Streptococcus agalactiae was found to be the main cause of acute gangrenous mastitis in dromedary camels in UAE. More research should be done to investigate other possible causes of clinical or subclinical mastitis in dromedary camels in UAE.

Streptococcus agalactiae and Chlamydia trachomatis detection in women without symptoms of infection

BACKGROUND

Chlamydia trachomatis (C. trachomatis) and Streptococcus agalactiae (GBS) may be present in the female cervical canal without any symptoms of infection. Chronic chlamydial infections lead to many serious complications and perinatal infections, while the presence of GBS is a reservoir for infections of newborns or invasive streptococcal infection in adults.

OBJECTIVES

To examine healthy women for C. trachomatis without symptoms from the reproductive system, assess the frequency of asymptomatic infections, detect GBS in the cervical canal, demonstrate differences in drug susceptibility, and determine the serotype of S. agalactiae strains and correlations among the ones present in the cervical canal.

MATERIAL AND METHODS

A total of 315 cervical swabs were collected for genetic and microbiological analysis for the presence of C. trachomatis and S. agalactiae. Latex and diffusion-disk methods were used to determine the serotype and susceptibility of streptococci.

RESULTS

Ten out of 315 women (3.2%) were C. trachomatis-positive. Using traditional methods of microscopy, culture and serology, 42 strains (13.3% of the subjects) obtained from patients were identified as S. agalactiae and further analyzed. The most common serotypes identified were II (18/42, 42.9%), V (11/42, 26.2%) and III (10/42, 23.8%). The less common serotypes found were VII (2/10, 4.8%), and Ib (1/10, 2.4%); no Ia, IV or VII serotypes were found. All the strains were susceptible to penicillin, while 71.4% of them were susceptible to erythromycin and 81.0% were susceptible to clindamycin. Seven isolates (16.7%) were concomitantly resistant to erythromycin and clindamycin.

CONCLUSIONS

Chlamydia trachomatis was confirmed in 3.2% of the respondents, and GBS was found in 13.3%, despite a lack of symptoms of infection. The incidence of C. trachomatis infections and GBS colonization in Poland is similar to those in other European countries.

Universal screening versus risk-based protocols for antibiotic prophylaxis during childbirth to prevent early-onset group B streptococcal disease: a systematic review and meta-analysis

BACKGROUND

Early-onset group B streptococcal (EOGBS) disease (including sepsis, meningitis, and pneumonia) causes significant morbidity and mortality in newborn infants worldwide. Antibiotic prophylaxis can prevent vertical streptococcal transmission, yet no uniform criteria exist to identify eligible women for prophylaxis. Some guidelines recommend universal GBS screening to pregnant women in their third trimester (screening-based protocol), whereas others employ risk-based protocols.

OBJECTIVES

To compare the effectiveness of screening-based versus risk-based protocols in preventing EOGBS disease.

SEARCH STRATEGY

Key words for the database searches included GBS, Streptococcus agalactiae, pregnancy, screening, culture-based, risk-based.

SELECTION CRITERIA

Studies were included if they investigated EOGBS disease incidence in newborn infants and compared screening or risk-based protocols with each other or with controls.

DATA COLLECTION AND ANALYSIS

Risk ratios (RR) and 95% confidence intervals (CI) were determined using Mantel-Haenszel analyses with random effects.

MAIN RESULTS

Seventeen eligible studies were included. In this meta-analysis, screening was associated with a reduced risk for EOGBS disease compared either with risk-based protocols (ten studies, RR 0.43, 95% CI 0.32-0.56) or with no policy (four studies, RR 0.31, 95% CI 0.11-0.84). Meta-analysis could not demonstrate a significant effect of risk-based protocols versus no policy (seven studies, RR 0.86, 95% CI 0.61-1.20). In studies reporting on the use of antibiotics, screening was not associated with higher antibiotic administration rates (31 versus 29%).

CONCLUSIONS

Screening-based protocols were associated with lower incidences of EOGBS disease compared with risk-based protocols, while not clearly overexposing women to antibiotics. This information is of relevance for future policymaking.

TWEETABLE ABSTRACT

Meta-analysis: general screening is associated with lower rates of early-onset group B strep. neonatal sepsis compared with risk-based protocols.

Routine uterine culture swab during cesarean section and its clinical correlations: A retrospective comparative study

OBJECTIVES

Cesarean sections, particularly non-elective cesareans, are an important risk factor for the development of postpartum endometritis, a leading cause of postpartum febrile morbidity. We evaluated the yield of obtaining routine intrauterine culture during elective and non-elective cesarean sections, in the prevention and management of postpartum endometritis.

STUDY DESIGN

A retrospective comparative study investigating the distribution of uterine cultures obtained immediately after fetus and placenta delivery during cesarean sections performed in a single tertiary hospital during 2017. True pathogenic bacteria were included in the study analysis and considered as positive results, while other contaminant bacteria were excluded.

RESULTS

Positive uterine cultures were identified in 10.7 % (88/821) of cesarean sections, with no significant difference in prevalence between elective and non-elective cesareans. Escherichia coli (E.coli), isolated in 40.9 % of the positive cultures of all women, was the most common organism in non-elective cesareans vs. Group B Streptococcus (GBS) in elective cesareans. Higher rate of positive cultures was found in term vs. preterm cesareans (17.5 % vs 10.5 %, respectively, p-value = 0.04). E.coli was the most frequent pathogen reported in both women with intact membranes or premature rupture of membranes (46.3 % and 47.3 % respectively). Eight women (9.1 %) with positive cultures presented with postpartum fever; all had undergone non-elective cesarean section. In one-third of these cases the empirical antibiotic treatment was adjusted according to the uterine culture results and susceptibility testing results.

CONCLUSIONS

Obtaining routine intrauterine cultures during non-elective cesarean sections might be useful for detecting significant pathogens and tailoring the antibiotic treatment in postpartum endometritis.

Prevalence, antimicrobial susceptibility patterns, serotypes and risk factors for group B streptococcus rectovaginal isolates among pregnant women at Kenyatta National Hospital, Kenya; a cross-sectional study

BACKGROUND

Estimates of Group B Streptococcus (GBS) disease burden, antimicrobial susceptibility, and serotypes in pregnant women are limited for many resource-limited countries including Kenya. These data are required to inform recommendations for prophylaxis and treatment of infections due to GBS.

METHODS

We evaluated the prevalence, antimicrobial susceptibility patterns, serotypes, and risk factors associated with rectovaginal GBS colonization among pregnant women receiving antenatal care at Kenyatta National Hospital (KNH) between August and November 2017. Consenting pregnant women between 12 and 40 weeks of gestation were enrolled. Interview-administered questionnaires were used to assess risk factors associated with GBS colonization. An anorectal swab and a lower vaginal swab were collected and cultured on Granada agar for GBS isolation. Positive colonies were tested for antimicrobial susceptibility to penicillin G, ampicillin, vancomycin, and clindamycin using the disk diffusion method. Serotyping was performed by latex agglutination. Logistic regression was used to identify factors associated with GBS colonization.

RESULTS

A total of 292 women were enrolled. Median age was 30 years (Interquartile range {IQR} 26-35) and a median gestational age of 35 weeks (IQR 30-37). Overall GBS was identified in 60/292 (20.5%) of participants. Among the positive isolates, resistance was detected for penicillin G in 42/58 (72.4%) isolates, ampicillin in 32/58 (55.2%) isolates, clindamycin in 14/46 (30.4%) isolates, and vancomycin in 14/58 (24.1%) isolates. All ten GBS serotypes were isolated, and 37/53 (69.8%) of GBS positive participants were colonized by more than one serotype. None of the risk factors was associated with GBS colonization.

CONCLUSION

The prevalence of GBS colonization was high among antenatal women at KNH. In addition, a high proportion of GBS isolates were resistant to commonly prescribed intrapartum antibiotics. Hence, other measures like GBS vaccination is a potentially useful approaches to GBS prevention and control in this population. Screening of pregnant mothers for GBS colonization should be introduced and antimicrobial susceptibility test performed on GBS positive samples to guide antibiotic prophylaxis.

Phenotypic and genotypic characterization of Streptococcus spp. isolated from tilapia (Oreochromis spp.) cultured in river-based cage and earthen ponds in Northern Thailand

Streptococcus spp. are major pathogenic bacteria associated with massive mortality in tilapia. This study investigated the phenotypic and genotypic characterization of Streptococcus agalactiae (GBS) and Streptococcus iniae (S. iniae) isolated from tilapia in river-based floating cage and earthen pond farms in northern Thailand. Isolates were identified by biochemical and molecular analyses. Capsular typing, enterobacterial repetitive intergenic consensus polymerase chain reaction and multilocus sequence typing were performed to investigate the genetic relatedness. Six and one isolates were confirmed as GBS and S. iniae, respectively. All Streptococcus spp. isolates were obtained from 4 river-based cage farms (4/33), while samples collected from earthen pond farms (N = 28) were negative for streptococcosis. All GBS with serotype Ⅲ and sequence type (ST) 283 was observed. The β-haemolytic GBS isolates were resistant to five antimicrobials, while the S. iniae was susceptible to all antimicrobials. This study indicates both GBS and S. iniae are the major bacterial pathogens responsible for streptococcosis infection in farmed tilapia of northern Thailand with GBS as dominant species. This survey highlights that the river-based cage farms seriously impact on the healthy development of the tilapia industry.

Urine dipstick for predicting intrapartum recto-vaginal colonisation by group B streptococci

INTRODUCTION

In pregnant women, bacteriuria with group B streptococci (GBS) may be associated with a high degree of recto-vaginal GBS colonisation and therefore an increased risk of early-onset GBS disease. The aim of this study was to assess the performance of routine use of dipstick urine analysis during pregnancy for prediction of recto-vaginal GBS colonisation at the time of labour.

METHODS

Among 902 unselected Danish pregnant women, we obtained results from 1) dipstick urine analysis, 2) urine culture carried out during pregnancy, if indicated, and 3) recto-vaginal culture at labour. The inclusion criteria were age > 18 years and gestational age ≥ 37 weeks.

RESULTS

Intrapartum recto-vaginal GBS colonisation was predicted by a positive urine dipstick with 5% sensitivity only.

CONCLUSION

Dipstick urine analysis had a low sensitivity for predicting intrapartum recto-vaginal colonisation with GBS.

FUNDING

none.

TRIAL REGISTRATION

not relevant.

Detection of Group B Streptococcus in pregnancy by vaginal volatile organic compound analysis: a prospective exploratory study

Our objective was to assess whether volatile organic compound (VOC) analysis of vaginal swabs can detect maternal Group B Streptococcus (GBS) during pregnancy in a prospective exploratory study. Around 243 women attending a high-risk antenatal clinic at one university teaching hospital in the UK consented to take part and provide vaginal swabs throughout pregnancy. VOC analysis of vaginal swabs was undertaken and compared with the reference standard of GBS detected using enrichment culture method. The chemical components that emanated from the vaginal swabs were measured by gas chromatograph ion mobility spectrometry. This platform has both high sensitivity and good specificity to a range of chemical compounds. Our main outcome was to determine the sensitivity and specificity of VOC analysis for the detection of maternal GBS in vaginal swabs during pregnancy. Our study has demonstrated that the sensitivity and specificity of the VOC analysis by GC-IMS for the detection of GBS from vaginal swabs was 0.81 (95% confidence interval [CI], 0.71-0.89) and 0.97 (95% CI, 0.91-1) respectively. We conclude that the use of VOCs as biomarkers for the detection of maternal GBS in the vagina is a novel tool. As this test produces results within minutes and is of low unit test cost, it has the potential to be used in clinical settings, where fast diagnosis is important, for example, a patient in early labour.

Streptococcus agalactiae Sequence Type 283 in Farmed Fish, Brazil

In 2016 and 2017, we characterized outbreaks caused by Streptococcus agalactiae serotype III sequence type (ST) 283 in Nile tilapia farms in Brazil. Whole-genome multilocus sequence typing clustered the fish isolates together with the zoonotic ST283 and other STs related to cases in humans, frogs, dogs, cattle, and dolphins.

Risk Factors and Mortality Rates Associated With Invasive Group B Streptococcus Infections Among Patients in the US Veterans Health Administration

IMPORTANCE

The incidence of invasive infections caused by group B Streptococcus (GBS) continues to increase in the United States. Although diabetes is a key risk factor for invasive GBS, the influence of long-term glycemic control is not well characterized; other risk factors and mortality rates associated with specific types of invasive GBS infections are unknown.

OBJECTIVE

To investigate risk factors and mortality rates associated with specific invasive GBS infectious syndromes.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used US Veterans Health Administration data to assess active users of the Veterans Affairs health care system between January 1, 2008, and December 31, 2017. Data analysis was conducted from April 2018 to August 2019.

EXPOSURES

Invasive GBS infections.

MAIN OUTCOMES AND MEASURES

The specific types of infectious syndromes and comorbid conditions among patients with an invasive GBS infection were evaluated.

RESULTS

Between 2008 and 2017, 5175 patients in the Veterans Affairs health care system experienced 5497 invasive GBS infections (5027 [97.1%] men, 3737 [72.2%] white, and 4545 [87.8%] non-Latino); all-cause 30-day mortality was 8.7% (451 of 5175). The most frequently observed infections were osteomyelitis (1171 [21.3%]), bacteremia without focus (1009 [18.4%]), skin or soft-tissue infections (919 [16.7%]), and pneumonia or empyema (694 [12.6%]). All-cause 30-day mortality following the index infection for each patient was highest among patients with peritonitis (38 of 138 [27.5%]) and pneumonia or empyema (116 of 664 [17.5%]) and lowest among those with osteomyelitis (15 of 1075 [1.4%]) or joint infection (17 of 501 [3.4%]). The most common comorbid conditions among patients with invasive GBS infections were diabetes (3364 [65.0%]), obesity (2669 [51.6%]), and chronic heart conditions (1633 [31.6%]). From 2008 to 2017, the incidence of invasive GBS infections increased from 9.23 to 11.67 cases per 100 000 person-years (P = .049). Stratification by body mass index showed the highest incidence of infections among patients at the extremes of body mass index (body mass index <18.5, 25.1 cases per 100 000 person-years; body mass index ≥40, 31.0 cases per 100 000 person-years). The incidence among patients with diabetes and poor long-term glycemic control (ie, hemoglobin A1c ≥9.5%) was 4-fold greater than among patients with diabetes and good glycemic control (ie, hemoglobin A1c <7.5%) (78.3 cases vs 19.0 cases per 100 000 person-years; unadjusted incident rate ratio, 4.1; 95% CI, 3.7-4.4; P < .001).

CONCLUSIONS AND RELEVANCE

In this cohort study, comorbid conditions and 30-day mortality varied among types of invasive GBS infections. Obesity and poor long-term glycemic control were associated with invasive GBS infections. Efforts to reverse the trend of an increased incidence of invasive GBS infections should continue to support reducing obesity and focus on improving glycemic control.

Developing a serocorrelate of protection against invasive group B streptococcus disease in pregnant women: a feasibility study

BACKGROUND

Group B streptococcus is the leading cause of infection in infants. Currently, intrapartum antibiotic prophylaxis is the major strategy to prevent invasive group B streptococcus disease. However, intrapartum antibiotic prophylaxis does not prevent maternal sepsis, premature births, stillbirths or late-onset disease. Maternal vaccination may offer an alternative strategy. Multivalent polysaccharide protein conjugate vaccine development is under way and a serocorrelate of protection is needed to expedite vaccine licensure.

OBJECTIVES

The ultimate aim of this work is to determine the correlate of protection against the major group B streptococcus disease-causing serotypes in infants in the UK. The aim of this feasibility study is to test key operational aspects of the study design.

DESIGN

Prospective cohort study of pregnant women and their infants in a 6-month period (1 July to 31 December 2018).

SETTING

Five secondary and tertiary hospitals from London and South England. National iGBS disease surveillance was conducted in all trusts in England and Wales.

PARTICIPANTS

Pregnant women aged ≥ 18 years who were delivering at one of the selected hospitals and who provided consent during the study period. There were no exclusion criteria.

INTERVENTIONS

No interventions were performed.

MAIN OUTCOME MEASURES

(1) To test the feasibility of collecting serum at delivery from a large cohort of pregnant women. (2) To test the key operational aspects for a proposed large serocorrelates study. (3) To test the feasibility of collecting samples from those with invasive group B streptococcus.

RESULTS

A total of 1823 women were recruited during the study period. Overall, 85% of serum samples were collected at three sites collecting only cord blood. At the two sites collecting maternal, cord and infant blood samples, the collection rate was 60%. A total of 614 women were screened for group B streptococcus with a colonisation rate of 22% (serotype distribution: 30% III, 25% Ia, 16% II, 14% Ib, 14% V and 1% IV). A blood sample was collected from 34 infants who were born to colonised women. Maternal and infant blood and the bacterial isolates for 15 newborns who developed invasive group B streptococcal disease during the study period were collected (serotype distribution: 29% III, 29% II, 21% Ia, 7% Ib, 7% IV and 7% V).

LIMITATIONS

Recruitment and sample collection were dependent on the presence of research midwives rather than the whole clinical team. In addition, individualised consent limited the number of women who could be approached each day, and site set-up for the national surveillance study and the limited time period of this feasibility study limited recruitment of all eligible participants.

CONCLUSIONS

We have verified the feasibility of collecting and processing rectovaginal swabs and blood samples in pregnant women, as well as samples from those with invasive group B streptococcal disease. We have made recommendations for the recruitment of cases within the proposed GBS3 study and for controls both within GBS3 and as an extension of this feasibility study.

FUTURE WORK

A large case-control study comparing specific immunoglobulin G levels in mothers whose infants develop invasive group B streptococcal disease with those in colonised mothers whose infants do not develop invasive group B streptococcal disease is recommended.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN49326091; IRAS project identification number 246149/REC reference number 18/WM/0147.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 67. See the NIHR Journals Library website for further project information.

[Colonization of group B streptococcus in the semen of chronic prostatitis patients of childbearing age and its influence on perinatal outcomes]

OBJECTIVE

To investigate the colonization of group B streptococcus (GBS) in the semen of chronic prostatitis patients of childbearing age and its influence on perinatal outcomes.

METHODS

This retrospective study included 592 cases of chronic prostatitis and another 472 non-prostatitis healthy males as controls. We collected semen samples from the subjects for bacterial and Ureaplasma urealyticum (UU) culture and quantitative fluorescence PCR analysis of chlamydia trachomatis (CT) and GBS. According to the results of culture, we divided the patients into a GBS-positive and a GBS-negative group and compared the perinatal outcomes among different groups of subjects.

RESULTS

The rate of GBS colonization in the semen of the chronic prostatitis patients was 11.8% (70/592). Bacteria were detected in the semen of 54.4% of the patients (322/592), mainly including GBS (21.7% ［70/322］) and E coli (19.9% ［64/322］), and in 7.8% of the healthy controls (37/472), Staphylococcus aureus comprising 83.8% (31/37), with statistically significant difference in the rate of bacteria detection between the two groups (P < 0.01). The incidence rate of adverse perinatal outcomes in the cases of successful pregnancy was significantly higher in the GBS-positive (32.8% ［19/58］) than in the GBS-negative (22.0% ［29/132］) and the healthy control group (2.2% ［6/271］) (P < 0.05).

CONCLUSIONS

The rate of GBS colonization is significantly increased in the semen of chronic prostatitis patients of childbearing age, and so is the incidence of adverse perinatal outcomes in the spouses of GBS-positive males. Importance should be attached to normalized screening of GBS in chronic prostatitis patients and to standardized prevention and intervention as well.

45-year-old woman • fever and chills • diffuse abdominal pain • shortness of breath • Dx?

Fever and chills. Diffuse abdominal pain. Shortness of breath.

Klebsiella pneumoniae and Streptococcus agalactiae: Passengers in the sperm travel

During their journey through the female reproductive tract to reach the oocyte in the ampulla of the fallopian tube, spermatozoa interact with substances and microorganisms that affect sperm quality, thus altering their fertilizing capacity.

OBJECTIVES

To determine in vitro the effect of Streptococcus agalactiae, Klebsiella pneumoniae and their soluble factors on sperm parameters, and to evaluate the ability of human sperm to interact with and transport these bacteria.

METHODS

The effects of S. agalactiae, K. pneumoniae and their soluble factors on the viability, sperm motility and functional sperm parameters were quantified. In addition, motile spermatozoa were incubated with decreasing concentrations of bacteria for one hour, washed and post-infection treatments were performed with trypsin and transport capacity was assessed by quantitative cultures.

RESULTS

Incubation of spermatozoa with K. pneumoniae decreased progressive motility. The soluble factors of K. pneumoniae increased the number of necrotic spermatozoa and the soluble factors of S. agalactiae increased lipid peroxidation of the sperm membrane (p<0.05). A strong interaction between sperm and bacteria was observed in the transport assays even in washed trypsin-treated samples.

CONCLUSION

Human spermatozoa act as vectors for infections, generating strong interactions with K. pneumoniae and S. agalactiae favoring their diffusion through the female reproductive tract. This interaction affects male fertility by altering progressive motility, increasing the number of necrotic cells and inducing apoptosis.

Genomic characterisation of perinatal Western Australian Streptococcus agalactiae isolates

As a leading cause of neonatal sepsis, Streptococcus agalactiae, commonly known as Group B Streptococcus, is a major neonatal pathogen. Current global screening practices employ risk- or culture-based protocols for detection of these organisms. In Western Australia (WA), universal culture-based screening is provided, with subsequent intrapartum antibiotic prophylaxis for all S. agalactiae-positive women during labour. Widespread antibiotic exposure is not ideal and this is one of the factors driving development of vaccines against S. agalactiae. Vaccine candidates have focused on the capsule, surface proteins and pilus types, however, capsule serotypes are known to vary geographically. The aim of this study was to use genome sequencing to gain an understanding of the circulating genotypes in WA, and to assess variations in the associated gene pools. We sequenced 141 antenatal carriage (vaginal/rectal) isolates and 10 neonatal invasive disease isolates from WA. Based on the global PubMLST database, the 151 strains were characterised into 30 sequence types, with clustering of these mainly into clonal complexes 1, 12, 17, 19 and 23. Of the genes encoding eleven surface proteins that were analysed, the most prevalent were fbp, lmb and scpB which were present in ≥ 98% of isolates. A cluster of non-haemolytic isolates, one of which was a neonatal invasive disease isolate, appeared to lack the entire cyl locus. Admixture analysis of population structure revealed evidence of genetic transfer among the WA isolates across structural groups. When compared against the PubMLST S. agalactiae data, WA isolates showed high levels of strain diversity with minimal apparent clustering. This is the first whole genome sequence study of WA S. agalactiae isolates and also represents the first addition of Australian isolate data to PubMLST. This report provides insight into the distribution and diversity of vaccine targets of S. agalactiae within Western Australia, indicating that the most appropriate capsular vaccine for this population would be the proposed pentavalent (Cps Ia, Ib, II, III and V) preparation, whilst vaccines targeting surface proteins should ideally utilise Fbp, Lmb and/or ScpB.

Antimicrobial resistance and molecular characterization of Streptococcus agalactiae from pregnant women in southern China

INTRODUCTION

This study aimed to characterize antimicrobial resistance (AMR), molecular determinants of AMR and virulence, as well as clonal relationship of Streptococcus agalactiae isolates from women at 35-37 weeks of gestation in the Chaoshan metropolitan area of southern China.

METHODOLOGY

Bacterial strains isolated from vaginal swabs were identified and antimicrobial susceptibility tests were performed by using a Vitek 2 Compact system (BioMérieux, France). Resistance and virulence genes were detected by polymerase chain reaction (PCR) and the clonal relationship was analysed by multiple locus variable number tandem repeat analysis (MLVA). Statistical analysis was carried out by using SPSS software, version 19.0.

RESULTS

All GBS were susceptible to benzylpenicillin, ampicillin, quinupristin/dalfopristin, tigecycline, linezolid and vancomycin, but a considerable proportion was resistant to clindamycin (29.67%), erythromycin (46.15%)， azithromycin (63.74%), tetracycline (84.62%) and quinolones (25.27%). The carrier rates of ermB (69.04%) and mefA/E (64.28%) were detected in these GBS strains resistant to erythromycin. In terms of MLVA detection, 91 GBS strains were categorized into 43 genotypes and 6 clusters. All GBS harboured hylB and cylE genes, most of which carried a combination of PI-1 and PI-2a genes as a common virulence gene profile.

CONCLUSIONS

The high level of resistance conferred by some corresponding resistance genes to macrolides, lincosamides and quinolones of GBS isolates from pregnant women in southern China, has reinforced the necessity for monitoring GBS strain resistance to the above agents. Comparative genetic studies of GBS isolates, especially efforts to understand the relationship between pilus islands and genotype, were essential for conducting infection control and epidemiological comparisons between countries.

Biofilm production and distribution of pilus variants among Streptococcus agalactiae isolated from human and animal sources

Streptococcus agalactiae (group B Streptococcus, GBS) is a major pathogen in humans and animals. Pili and biofilm may be important virulence factors in this bacterial species. Here, biofilm production and the distribution of pilus variants among 134 GBS isolates from human and animal sources were evaluated. Biofilm production was significantly enhanced in 1% glucose-supplemented medium (p < 0.05). Using this medium, most GBS strains were strong biofilm producers. Biomass was mainly composed of proteins, followed by extracellular DNA, while polysaccharides represented a minor portion. All GBS strains presented at least one pilus variant. PI-2a was the most common among human GBS while PI-2b was the most common among animal isolates. Human GBS harboring PI-2b and animal GBS harboring PI-2a presented significantly reduced biofilm production (p = 0.0033). In conclusion, strong biofilm production seems to be a common characteristic in GBS, and association of the clinical source with the pilus variant may be crucial for this.

Case for diagnosis. Suppurative nodule or something deeper?

The authors report the case of a 62-year-old man with a history of total left hip arthroplasty nine years previously presenting with a large infiltrated plaque on the posterior area of the left thigh with three months of evolution without systemic symptoms or elevated inflammatory markers. Computed tomography of the left lower limb revealed a 12-centimeter linear extension of the lesion to the posterior part of the left proximal femur. Prosthesis joint infection, although rare, is a surgical complication to be taken into account, even if the surgery was performed many years before.

One hypervirulent clone, sequence type 283, accounts for a large proportion of invasive Streptococcus agalactiae isolated from humans and diseased tilapia in Southeast Asia

Background

In 2015, Singapore had the first and only reported foodborne outbreak of invasive disease caused by the group B Streptococcus (GBS; Streptococcus agalactiae). Disease, predominantly septic arthritis and meningitis, was associated with sequence type (ST)283, acquired from eating raw farmed freshwater fish. Although GBS sepsis is well-described in neonates and older adults with co-morbidities, this outbreak affected non-pregnant and younger adults with fewer co-morbidities, suggesting greater virulence. Before 2015 ST283 had only been reported from twenty humans in Hong Kong and two in France, and from one fish in Thailand. We hypothesised that ST283 was causing region-wide infection in Southeast Asia.

Methodology/Principal findings

We performed a literature review, whole genome sequencing on 145 GBS isolates collected from six Southeast Asian countries, and phylogenetic analysis on 7,468 GBS sequences including 227 variants of ST283 from humans and animals. Although almost absent outside Asia, ST283 was found in all invasive Asian collections analysed, from 1995 to 2017. It accounted for 29/38 (76%) human isolates in Lao PDR, 102/139 (73%) in Thailand, 4/13 (31%) in Vietnam, and 167/739 (23%) in Singapore. ST283 and its variants were found in 62/62 (100%) tilapia from 14 outbreak sites in Malaysia and Vietnam, in seven fish species in Singapore markets, and a diseased frog in China.

Conclusions

GBS ST283 is widespread in Southeast Asia, where it accounts for a large proportion of bacteraemic GBS, and causes disease and economic loss in aquaculture. If human ST283 is fishborne, as in the Singapore outbreak, then GBS sepsis in Thailand and Lao PDR is predominantly a foodborne disease. However, whether transmission is from aquaculture to humans, or vice versa, or involves an unidentified reservoir remains unknown. Creation of cross-border collaborations in human and animal health are needed to complete the epidemiological picture.

An outbreak due to a bacterium called Streptococccus agalactiae in Singapore in 2015 was caused by a clone called ST283, and was associated with consumption of raw freshwater-fish. It was considered unique as it was the only reported foodborne outbreak of this bacterium. Our new data show that invasive ST283 disease is far from unique. ST283 has been causing disease in humans and farmed fish in SE Asian countries for decades. Reports of ST283 are almost absent outside Asia. We suspect that human ST283 is fishborne in other Asian countries, as it was in Singapore, but we haven’t looked at this yet. We don’t know where ST283 originally came from; it may have been transmitted from humans to fish, or come from another animal. More studies are needed to determine ST283’s geographical extent and burden of disease, as well as its origin, how it is transmitted, and what enables it to be so aggressive. We may then be able to interrupt transmission, to the benefit of fish, farmers, and the general public.

Surveillance for incidence and etiology of early-onset neonatal sepsis in Soweto, South Africa

BACKGROUND

Globally, over 400,000 neonatal deaths in 2015 were attributed to sepsis, however, the incidence and etiologies of these infections are largely unknown in low-middle income countries. We aimed to determine incidence and etiology of community-acquired early-onset (<72 hours age) sepsis (EOS) using culture and molecular diagnostics.

METHODS

This was a prospective observational study, in which we conducted a surveillance for pathogens using a combination of blood culture and a polymerase chain reaction (PCR)-based test. Blood culture was performed on all neonates with suspected EOS. Among the subset fulfilling criteria for protocol-defined EOS, blood and nasopharyngeal (NP) respiratory swabs were tested by quantitative real-time reverse-transcriptase PCR using a Taqman Array Card (TAC) with 15 bacterial and 12 viral targets. Blood and NP samples from 312 healthy newborns were also tested by TAC to estimate background positivity rates. We used variant latent-class methods to attribute etiologies and calculate pathogen-specific proportions and incidence rates.

RESULTS

We enrolled 2,624 neonates with suspected EOS and from these 1,231 newborns met criteria for protocol-defined EOS (incidence- 39.3/1,000 live-births). Using the partially latent-class modelling, only 26.7% cases with protocol-defined EOS had attributable etiology, and the largest pathogen proportion were Ureaplasma spp. (5.4%; 95%CI: 3.6-8.0) and group B Streptococcus (GBS) (4.8%; 95%CI: 4.1-5.8), and no etiology was attributable for 73.3% of cases. Blood cultures were positive in 99/1,231 (8.0%) with protocol-defined EOS (incidence- 3.2/1,000 live-births). Leading pathogens on blood culture included GBS (35%) and viridans streptococci (24%). Ureaplasma spp. was the most common organism identified on TAC among cases with protocol-defined EOS.

CONCLUSION

Using a combination of blood culture and a PCR-based test the common pathogens isolated in neonates with sepsis were Ureaplasma spp. and GBS. Despite documenting higher rates of protocol-defined EOS and using a combination of tests, the etiology for EOS remains elusive.

Modelling the effect of the introduction of antenatal screening for group B Streptococcus (GBS) carriage in the UK

OBJECTIVES

To estimate the potential impact of the addition of culture-based screening for group B streptococcus (GBS) carriage in pregnancy to a risk-based prevention policy in the UK. We aimed to establish agreement within a multidisciplinary group of key stakeholders on the model input parameters.

DESIGN

Deterministic model using a consensus approach for the selection of input parameters.

SETTING AND PARTICIPANTS

A theoretical annual cohort of 711 999 live births in the UK (excluding births by elective caesarean section).

INTERVENTIONS

Culture-based screening for GBS at 35-37 weeks of pregnancy added to the recommended risk-based prevention policy in place on the date of modelling.

OUTCOME MEASURES

Outcomes assessed included use of intrapartum antibiotic prophylaxis (IAP), early onset GBS (EOGBS), EOGBS mortality, severe EOGBS-related morbidity and maternal penicillin anaphylaxis.

RESULTS

With no prophylaxis strategy, the model estimated that there would be 421 cases of culture positive EOGBS in a year (0.59/1000 live births). In the risk-based prophylaxis scenario, 30 666 women were estimated to receive IAP and 70 cases of EOGBS were prevented. Addition of screening resulted in a further 96 260 women receiving IAP and the prevention of an additional 52 to 57 cases of EOGBS. This resulted in the prevention of three EOGBS deaths and four cases of severe disability. With screening, an additional 1675 to 1854 women receive IAP to prevent one EOGBS case and 24 065 to 32 087 receive IAP to prevent one EOGBS death.

CONCLUSIONS

The evidence base available for a broad range of model input parameters was limited, leading to uncertainty in the estimates produced by the model. Where data was limited, the model input parameters were agreed with the multidisciplinary stakeholder group, the first time this has been done to our knowledge. The main impact of screening is likely to be on the large group of low-risk women where the clinical impact of EOGBS tends to be less severe. This model suggests that the reduction in mortality and severe disability due to EOGBS with antenatal GBS screening is likely to be very limited, with a high rate of overdetection and overuse of antibiotics.

Early Detection of Inflammation and Joint Destruction Revealed by Ultrasound in a Patient with Sternoclavicular Septic Arthritis

A 53-year-old Japanese man experienced fever/neck pain, and neck magnetic resonance imaging revealed a spinal epidural abscess. The following day, he developed a palpable mass with evident inflammatory signs in the right sternoclavicular joint (SCJ) with severe pain. Ultrasound revealed synovitis with remarkable power Doppler signals in the right SCJ. Blood cultures yielded Streptococcus agalactiae growth. After 12 days, ultrasound showed right distal clavicle bone erosion. His symptoms improved with long-term parenteral antibiotic treatment, but the right SCJ joint destruction progressed for several months. We diagnosed him with sternoclavicular septic arthritis complicated with a spinal epidural abscess and bacteremia.

Racial disparities in intrapartum group B Streptococcus colonization: a higher incidence of conversion in African American women

OBJECTIVE

To compare the incidence of group B Streptococcus (GBS) conversion from a negative antepartum to a positive intrapartum culture among women who self-identify as non-Hispanic black, Hispanic, or non-Hispanic white.

STUDY DESIGN

This was a prospective cohort study of women with a negative rectovaginal GBS culture obtained within 35 days of enrollment. An intrapartum rectovaginal swab was collected and cultured for GBS. Data were compared with chi-square, Fisher's exact, or Wilcoxon rank-sum test. Modified Poisson regression was used.

RESULTS

We enrolled 737 women; 75.4% were non-Hispanic white, 17.6% were non-Hispanic black, and 6.9% were Hispanic. Non-Hispanic black women were more likely to convert to GBS positive than non-Hispanic white women, 9.2% as compared to 5.3% (RR: 2.0; 95% CI: 1.02-3.8).

CONCLUSION

The increased incidence of positive intrapartum GBS cultures among non-Hispanic black women suggests that non-Hispanic black race is a risk factor for GBS conversion in the late third trimester.