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NBHS are recognized as opportunistic pathogens particularly involved in infections of the elderly and immunocompromised patients. This study underlines their importance as common causes of severe and difficult-to-treat infections such as endocarditis.

SUMMARYStreptococcus agalactiaealso named Group BStreptococcus(GBS) is the most significant pathogen causing invasive infections, such as bacteremia and meningitis in neonates. Worldwide epidemiological studies have shown that a particular clonal complex (CC) of capsular serotype III, the CC17, is strongly associated with meningitis in neonates and is therefore designated as the hypervirulent clone. Macrophages are a permissive niche for intracellular bacteria of all GBS clones. In this study we deciphered the specific interaction of GBS CC17 strains with macrophages. Our study reveals that CC17 strains are phagocytosed at a higher rate than GBS non-CC17 strains by human monocytes and macrophages in cellular models and primary cells. CC17 hyper-phagocytosis is preceded by an initial hyper-attachment step to macrophages mediated by the PI-2b pilus (Spb1) and the CC17 specific HvgA surface protein. We showed that two different inhibitors of scavenger receptors (fucoidan and poly(I)) specifically inhibited CC17 phagocytosis while they did not affect non-CC17 phagocytosis. Once phagocytosed, both CC17 and non-CC17 strains remain in a LAMP-1 positive vacuole that ultimately fuses with lysosomes, and their survival within macrophages is similar. Bothe strains display a basal egress which occurs independently from actin and microtubules networks. Our findings provide new insights into the interplay between the hypervirulent GBS CC17 and major players of host innate immune response. This enhanced phagocytosis could reflect a peculiar capacity of CC17 lineage to subvert the host immune defense and establish a niche for intracellular persistence.

EE cases were retrospectively studied between January 2014 and January 2021. KP EE cases were analyzed to assess clinical, microbiological features, and outcome.Among the 33 EE cases identified, the first causative agent (24%,KP is an emerging cause of EE in a French center, consistently associated with liver abscesses, frequent cerebral involvement, and predominance of hvKP strains.

To identify factors associated with vaginal colonization and persistence by group B Streptococcus (GBS) and by the hypervirulent neonatal CC-17 clone in late pregnancy and after delivery, a multicentre prospective observational cohort with 3-month follow-up was established in two university hospitals, Paris area, France. Pregnant women were recruited when antenatal screening for GBS vaginal colonization at 34–38 weeks of gestational age was positive. Vaginal samples were analysed by conventional culture methods at antenatal screening, delivery, and 21 and 60 days following delivery. Identification of the hypervirulent neonatal GBS CC-17 was performed. Colonization was defined as persistent when all vaginal samples were positive for GBS. A total of 754 women were included. GBS vaginal colonization was persistent in 63% of the cases (95% CI 59%–67%). Persistent colonization was more likely in women born in Sub-Saharan Africa compared with women born in France (OR = 1.88, 95% CI 1.05–3.52), and GBS CC-17 was overrepresented in women born in Sub-Saharan Africa (OR = 2.09, 95% CI 1.20–3.57). Women born in Sub-Saharan Africa are at higher risk for GBS vaginal persistence than women born in France. This observation correlates with an increased prevalence of the hypervirulent GBS CC-17 in the former group, which likely reflect variations linked to ethnicity and vaginal community-state types and might account for the increased susceptibility of black neonates to GBS infections.

Group B Streptococcus (GBS) is the leading cause of neonatal infections and an important pathogen in pregnancy. However, the features of pregnancy-associated infections are poorly reported. We analyzed 336 cases of GBS invasive infections in women aged 18–50 years, including 242 (72.0%) pregnancy-associated infections. In pregnancy, most cases were intra-amniotic infections (55.8%), occurred preterm (61.3%), and were associated with obstetrical and neonatal complications (81.7%). The GBS clone CC-17 (18.8% of the cases) was overrepresented intrapartum (35.2%; odds ratio, 5.1 [95% confidence interval, 1.6–19.3]). This work highlights the burden of GBS and of the CC-17 clone infections during pregnancy.

International audience; Streptococcus agalactiae (group B Streptococcus, GBS) remains the leading cause of invasive diseases in neonates and an important cause of infections in the elderly. The aim of this study was to access the prevalence of GBS genito-rectal colonisation of pregnant women and to evaluate the genetic characteristics of invasive and non-invasive GBS isolates recovered throughout Serbia. A total of 432 GBS isolates were tested for antimicrobial susceptibility, capsular polysaccharide (CPS) types and the presence of the hvgA gene. One hundred one randomly selected isolates were further characterized by clustered regularly interspaced short palindromic repeats (CRISPRs) analysis and/or multilocus sequence typing (MLST). The prevalence of GBS colonization in pregnant women was 15%. Overall, six capsular types (Ia, Ib, II to V) were identified, the most common being III (32.2%) and V (25.2%). The hiper-virulent clone type III/ST17 was present in 43.1% and 6.3% (p

We analyzed group B Streptococcus (GBS) neonatal invasive infections reported during 2007–2019 in France. The hypervirulent clonal complex (CC) 17 GBS was responsible for 66% (827/1,262) of cases. The role of CC17 GBS increased over time (p for trend = 0.0001), together with the emergence of a multidrug-resistant CC17 GBS sublineage.

To identify factors associated with vaginal colonization and persistence by group B Streptococcus (GBS) and by the hypervirulent neonatal CC-17 clone in late pregnancy and after delivery, a multicentre prospective observational cohort with 3-month follow-up was established in two university hospitals, Paris area, France. Pregnant women were recruited when antenatal screening for GBS vaginal colonization at 34-38 weeks of gestational age was positive. Vaginal samples were analysed by conventional culture methods at antenatal screening, delivery, and 21 and 60 days following delivery. Identification of the hypervirulent neonatal GBS CC-17 was performed. Colonization was defined as persistent when all vaginal samples were positive for GBS. A total of 754 women were included. GBS vaginal colonization was persistent in 63% of the cases (95% CI 59%-67%). Persistent colonization was more likely in women born in Sub-Saharan Africa compared with women born in France (OR = 1.88, 95% CI 1.05-3.52), and GBS CC-17 was overrepresented in women born in Sub-Saharan Africa (OR = 2.09, 95% CI 1.20-3.57). Women born in Sub-Saharan Africa are at higher risk for GBS vaginal persistence than women born in France. This observation correlates with an increased prevalence of the hypervirulent GBS CC-17 in the former group, which likely reflect variations linked to ethnicity and vaginal community-state types and might account for the increased susceptibility of black neonates to GBS infections.

Group B Streptococcus (GBS) (Streptococcus agalactiae) is a pathogen of growing importance in adults. The objective of this study was to describe the features of invasive infections by GBS in non-pregnant adults.GBS infections were reported to the national reference centre for streptococci. Clinical information was abstracted from questionnaires. Capsular typing, identification of the hypervirulent CC-17 clone, and antibiotic susceptibility testing were performed for all GBS isolates. Multi-locus sequence typing and assignment to clonal complexes (CCs) was performed on a representative sample of 324 isolates.In total, 1960 GBS invasive infections were analysed from 2007 to 2019. The median age at onset was 71 years old (range 18-103). The main manifestation was bacteraemia without focus (54.5%). Meningitis was more frequent in patients under 40 (26/180, 14.4% versus 78/1780, 4.4%, p 0.0001). Capsular types Ia, Ib, II, III and V accounted for 91.0% of the cases (1786/1960). CC-1, -10, -17, -19 and -23 accounted for 96.3% (312/324) of the cases. Capsular type III and CC-17 were overrepresented in meningitis (38/104, 36.5%, p 0.001 and 22/104, 21.2%, p 0.01, respectively). All isolates were susceptible to β-lactam antibiotics. Resistance to erythromycin (32.7%) and clindamycin (26.3%) remained stable, whereas decreased susceptibility to fluoroquinolones increased, reaching 2.7% in 2019 (p for trend 0.002).This work highlights the susceptibility of the elderly to GBS infections and differences in the clinical manifestations according to the patients' age and GBS type. In agreement with worldwide reports on emerging multidrug-resistant GBS, it reinforces the need for a continued surveillance of GBS epidemiology.

Group B Streptococcus (GBS) is the leading cause of neonatal infections in industrialized countries. Intrapartum antibiotic prophylaxis (IAP) given to colonized parturients is a key step for the prevention of neonatal early-onset infection. We compared the performances of Xpert® GBS polymerase chain reaction (PCR) (Cepheid, Sunnyvale, CA, USA) as a point-of-care system in labor wards to standard culture for intrapartum GBS detection. Pregnant women with a GBS-positive antenatal screening were prospectively included. A vaginal double swab was collected at the time of delivery for point-of-care Xpert® GBS PCR and GBS culture. A total of 565 pregnant women were included. Valid Xpert® GBS results were obtained for 488 (86.4%) women on the first attempt. Repeat testing improved the PCR success to 516 (91.3%) women. Among the 305 women positive for GBS by culture at delivery, only 238 (78.0%) were positive by Xpert® GBS PCR, cycle thresholds being correlated to culture quantification. Among 260 women negative for GBS culture, 56 (21.5%) were positive by Xpert® GBS PCR, including 50 where IAP was initiated before vaginal sampling. Overall, among the 565 women with GBS antenatal positive culture, only 335 (59.3%) were still positive at delivery whatever the technique used, resulting in unnecessary IAP for 40% of them. This large cohort study comparing intrapartum to antepartum GBS detection provides evidence that (i) Xpert® GBS PCR might be a valuable solution for intrapartum GBS detection compared to culture-based strategies and (ii) laboratory training of non-specialized staff is mandatory to reach the performances required for point-of-care tests.

International audience; Streptococcus agalactiae (group B streptococcus (GBS)) is the leading cause of invasive infections among newborns in industrialized countries, with two described syndromes: early-onset disease (EOD) and late-onset disease (LOD). Since the introduction in many countries of intrapartum antibioprophylaxis (IAP), the incidence of EOD has dramatically decreased, whereas that of LOD remains unchanged. We describe the clinical and bacteriological characteristics of 438 GBS neonatal invasive infections notified to the French National Reference Centre for Streptococci in France from 2007 to 2012. Clinical data were retrieved from hospitalization reports or questionnaires. Capsular type, assignment to the hypervirulent clonal complex (CC)17 and antibiotic susceptibility profiles were determined. One hundred and seventy-four (39.7%) and 264 (60.3%) isolates were responsible for EOD, including death in utero, and LOD, respectively. EOD was associated with bacteraemia (n = 103, 61%) and LOD with meningitis (n = 145, 55%). EOD was mainly due to capsular polysaccharide (CPS) III isolates (n = 99, 57%) and CPS Ia isolates (n = 40, 23%), and CPS III isolates were responsible for 80% (n = 211) of LOD cases. CC17 accounted for 80% (n = 121) of CPS III isolates responsible for meningitis (n = 151; total cases of meningitis, 188). Bad outcome risk factors were low gestational age and low birthweight. LOD represents almost 60% of cases of neonatal GBS disease in France and other countries in which IAP has been implemented. This observation reinforces the need to develop new prevention strategies targeting CC17, which is predominant in GBS neonatal infections.

BACKGROUND In infants, the mode of acquisition of CC17 group B Streptococcus (GBS), the hypervirulent clone responsible for late-onset disease (LOD), remains elusive. METHODS In a prospective multicenter study in France, we evaluated GBS colonization in mother-baby pairs with 2 months of follow-up between 2012 and 2015. Criteria included positivity for GBS colonization at antenatal screening or at delivery. Maternal vaginal samples and infant oral cavity and stool samples were analyzed at delivery, 21 ± 7 days (D21), and 60 ± 7 days (D60) post-delivery. RESULTS A total of 890 mother-baby pairs were analyzed. GBS colonized 7%, 21%, and 23% of the infants at birth, D21, and D60, respectively, of which 10%, 11%, and 13% were identified as CC17 GBS. Concordance between maternal and infant GBS type was 96%. At D21, the main risk factors for infant colonization by GBS were simultaneous maternal colonization of the vagina (odds ratio [OR], 4.50; 95% confidence interval [CI], 1.69-15.61) and breast milk (OR, 7.93; 95% CI, 3.81-17.14). Importantly, 38% (95% CI, 23%-56%) of infants colonized by CC17 GBS appeared colonized for the first time at D60 vs 18% (95% CI, 14%-24%; P < .049) of infants colonized by non-CC17 GBS. Multivariate analysis showed a higher risk for de novo infant colonization by CC17 at D60 than by other GBS (OR, 2.45; 95% CI, 1.02-5.88). CONCLUSIONS The high incidence of CC17 GBS in LOD is likely due to an enhanced post-delivery mother-to-infant transmission.

The Group B Streptococcus (GBS) 'hypervirulent' ST-17 clone is strongly associated with invasive neonatal meningitis. Comparative genome analyses revealed that the serine-rich repeat (Srr) glycoprotein Srr2 is a cell wall-anchored protein specific for ST-17 strains, the non-ST-17 isolates expressing Srr1. Here, we unravel the binding capacity of GBS Srr proteins to relevant components of the host fibrinolysis pathway. We demonstrate that: (i) Srr2 binds plasminogen and plasmin whereas Srr1 does not; (ii) the ability of ST-17 strains to bind fibrinogen reflects a high level surface display of Srr2 combined with a higher affinity of Srr2 than Srr1 to bind this ligand; and (iii) Srr2 binding to host plasma proteins results in the formation of bacterial aggregates that are efficiently endocytosed by phagocytes. Importantly, we show that Srr2 increased bacterial survival to phagocytic killing and bacterial persistence in a murine model of meningitis. We conclude that Srr2 is a multifaceted adhesin used by the ST-17 clone to hijack ligands of the host coagulation system, thereby contributing to bacterial dissemination and invasiveness, and ultimately to meningitis.

This study describes the clinical and microbiological features associated with group B Streptococcus (GBS) bone and joint infections (BJIs). It was a retrospective analysis of adult cases of GBS BJIs reported to the French National Reference Center for Streptococci from January 2004 to December 2014. Clinical data and GBS molecular characteristics are reported. Strains were collected from 163 patients. The most frequent comorbidities were: solid organ cancer (n = 21, 21%) and diabetes mellitus (n = 20, 20%). The main infection sites were knee (47/155 = 30%) and hip (43/155 = 27%), and occurred on orthopedic devices in 71/148 cases (48%). CPS III (n = 47, 29%), Ia (n = 26, 16%) and V (n = 40, 25%) were predominant. Resistance to erythromycin, clindamycin and tetracycline was detected in 55/163 (34%), 35/163 (21%) and 132/163 (81%) strains, respectively. The most frequent sequence types were ST-1 (n = 21, 25%), ST-17 (n = 17, 20%) and ST-23 (n = 11, 13%). The rate of resistance to erythromycin was 0% for ST-17 strains, 52% (n = 11) for ST-1 and 44% (n = 7) for ST-23 (p 0.001). GBS bone and joint infections predominantly occur in patients aged50 years and/or with comorbidities such as cancer and diabetes mellitus. CPS type distribution and MLST are very similar to that of other adult GBS invasive infections.

Streptococcus agalactiae (Group B Streptococcus, GBS) is a Gram-positive encapsulated bacterium, found in the digestive and vaginal tracts of 20-30% healthy individuals. It is the leading cause of neonatal invasive infections (septicaemia and meningitis). Two GBS-associated syndromes have been recognized in neonates, the early-onset disease (EOD) and the late-onset disease (LOD), which occur in the first week of life (age 0-6 days) and after (age 7 days-3 months), respectively. Since the establishment of early antibiotic prophylaxis there has been a decrease in the incidence of EOD. However, LOD incidence remains stable. Epidemiological studies revealed a strong association between LOD and a single capsular serotype III ST-17 clone. This ST-17 clone, referred to as the "hypervirulent" clone, possesses specific virulence factors that could account for its increased virulence and neonatal tropism. Conjugate vaccines directed against several capsular serotypes are being developed to prevent invasive disease. However, hypervirulent strains having made a switch to a capsular serotype not covered by such vaccines are emerging, reinforcing the need to identify new candidate vaccines.

Background Streptococcus suis is a zoonotic pathogen which represents the leading cause of meningitis in Southeast Asia and an emerging pathogen in the Western world, the main risk factor for infection being contact with pigs. In Africa, the prevalence of S. suis infections in swine and humans is largely unrecognized, with only one recent report of a limited case series. Case presentation We describe a human case of meningitis due to S. suis in a 32-year-old man living in Togo. The patient had no particular medical history and no risk factors for immunodeficiency but reported regular contact with pork products. Using specific immunological and molecular methods, we characterized the isolate as S. suis serotype 2, ST1, one the most prevalent and virulent clone worldwide. The outcome was favorable after one week of adapted antibiotic therapy but the patient was left with severe hearing disorders. Conclusions This work highlights the emergence of this pathogen in Africa and reinforces the need for accurate epidemiological and surveillance studies of S. suis infections and for educating clinicians and exposed groups in non-endemic countries.

Linezolid has emerged as an important therapeutic option for the treatment of Staphylococcus aureus in patients with cystic fibrosis. We report the rapid emergence, upon treatment with linezolid, of linezolid-resistant S. aureus clinical isolates through the accumulation of resistance-associated 23S rRNA mutations, together with acquisition of an altered mutator phenotype.

International audience; Group B streptococcus (GBS) is a leading cause of neonatal morbidity and mortality. Multilocus sequence typing (MLST) revealed that the sequence type ST-17 defines a "highly virulent" serotype III clone strongly associated with neonatal invasive infections. Our aim was to identify a target sequence enabling rapid, simple, and specific detection of this clone by a real-time PCR assay. Conventional methods for DNA manipulation and gene analyses were used to characterize the gbs2018 gene variant specific for ST-17 clone and to design ST-17- and GBS-specific primers. Conventional and real-time PCR assays were developed to detect GBS and ST-17 clones in bacterial cultures and directly on clinical samples. One hundred and fifty-six French GBS strains from various geographical areas in France isolated between 1990 and 2005 were screened by PCR with ST-17-specific primers. Forty strains were positive, and all were validated by MLST as ST-17. A representative sampling of 49 ST-17-PCR-negative strains was confirmed by MLST as non-ST-17. Real-time PCR was further used to directly test 85 vaginal samples. Among these, 13 were GBS-positive, and one was identified as ST-17. The association between strain invasiveness and ST-17 lineage in neonates with late onset disease was highly significant: 78% (P

Le streptocoque du groupe B (SGB, Streptococcus agalactiae ) est une bacterie capsulee a Gram positif commensale des voies digestives et vaginales retrouvee chez 20 a 30 % des adultes sains. Son interet en medecine humaine reside principalement dans le fait que cette bacterie est la premiere cause d’infections neonatales invasives (septicemies, meningites) et un pathogene d’importance croissante chez l’adulte, en particulier chez le sujet âge et les individus porteurs de pathologies sousjacentes [].

Two types of selective media, the chromogenic medium Strepto B ID® and two non-chromogenic media Strepto B agar® and the Granada® medium, were tested and compared to blood agar plates (BAP) for screening of Group B streptococcus vaginal colonization in pregnant women. All tested media were comparable in terms of sensitivity however, their use in routine laboratories may markedly facilitate the rapid detection of GBS in vaginal samples.

International audience; Streptococcus agalactiae (group B Streptococcus, GBS), a normal constituent of the intestinal microbiota is the major cause of human neonatal infections and a worldwide spread 'hypervirulent' clone, GBS ST-17, is strongly associated with neonatal meningitis. Adhesion to epithelial and endothelial cells constitutes a key step of the infectious process. Therefore GBS surface-anchored proteins are obvious potential adhesion mediators of barrier crossing and determinant of hypervirulence. This review addresses the most recent molecular insights gained from studies on GBS surface proteins proven to be involved in the crossing of the brain-blood barrier and emphasizes on the specificity of a hypervirulent clone that displays meningeal tropism.

Low-level methicillin-resistant Staphylococcus aureus may be difficult to detect with the VITEK® 2 system (VK2). Here, we suggest that S. aureus exhibiting VK2-oxacillin MIC of 1 or 2 mg/L and a negative cefoxitin screen should be tested for the presence of mecA or its gene product.

Streptococcus agalactiae (or group B streptococcus; GBS) is a leading cause of neonatal morbidity and mortality in the developed countries. Several epidemiological typing tools have been developed for GBS to investigate the association between genotype and disease and to assess genetic variations within genogroups. This study compared the semi-automated repetitive sequence-based PCR Diversilab® system (DL) with MLST and pulsed field gel electrophoresis (PFGE) for determining the relatedness of invasive GBS strains. We analysed 179 unrelated GBS strains isolated from adult (n=108) and neonatal (n=71) invasive infections. By MLST, strains were resolved into 6 clonal complexes (CCs) including 23 sequence-types (STs), and 4 unique STs, whereas DL differentiated these isolates into 12 rep-PCR clusters (rPCs) and 9 unique rep-PCR types. The discriminatory power of both methods was similar, with Simpson's diversity indexes of 71.9% and 70.6%, respectively. However, their clustering concordance was low with Wallace concordance coefficients inferior to 0.4. PFGE was performed on 31 isolates representative of the most relevant DLrPCs clustered within the 3 major MLST CCs (CC-17, CC-23 and CC-1). As already observed with MLST, the concordance of DL with PFGE was low for all three CCs (Wallace coefficient

We developed a simple, specific, and sensitive two-multiplex-PCR assay that enabled the detection of all known group B streptococcal (GBS) capsular polysaccharides. This test is well adapted for GBS capsular polysaccharide typing in large-scale epidemiological studies.

International audience; Clinical features and molecular characterization of 109 group B streptococci causing neonatal invasive infections were determined over an 18-month period in France. Sixty-four percent of the strains were from late-onset infections, and 75% were capsular type III. The hypervirulent clone ST-17 was recovered in 80% of meningitis cases.

International audience; Environmental enteric dysfunction (EED) is an inflammatory syndrome postulated to contribute to stunted child growth and to be associated with intestinal dysbiosis and nutrient malabsorption. However, the small intestinal contributions to EED remain poorly understood. This study aimed to assess changes in the proximal and distal intestinal microbiota in the context of stunting and EED and to test for a causal role of these bacterial isolates in the underlying pathophysiology. We performed a cross-sectional study in two African countries recruiting roughly 1,000 children aged 2 to 5 years and assessed the microbiota in the stomach, duodenum, and feces. Upper gastrointestinal samples were obtained from stunted children and stratified according to stunting severity. Fecal samples were collected. We then investigated the role of clinical isolates in EED pathophysiology using tissue culture and animal models. We find that small intestinal bacterial overgrowth (SIBO) is extremely common (>80%) in stunted children. SIBO is frequently characterized by an overgrowth of oral bacteria, leading to increased permeability and inflammation and to replacement of classical small intestinal strains. These duodenal bacterial isolates decrease lipid absorption in both cultured enterocytes and mice, providing a mechanism by which they may exacerbate EED and stunting. Further, we find a specific fecal signature associated with the EED markers fecal calprotectin and alpha-antitrypsin. Our study shows a causal implication of ectopic colonization of oral bacterial isolated from the small intestine in nutrient malabsorption and gut leakiness in vitro. These findings have important therapeutic implications for modulating the microbiota through microbiota-targeted interventions.