Near-term pregnant women in the Dominican Republic experience high rates of Group B Streptococcus rectovaginal colonization with virulent strains.

Maternal colonization with Group B Streptococcus (GBS) is an important cause of stillbirth, prematurity, and serious infection and death in infants worldwide. Resource constraints limit prevention strategies in many regions. Maternal GBS vaccines in development could be a more accessible prevention strategy, but data on geographic variations in GBS clones are needed to guide development of a broadly effective vaccine. In the Dominican Republic (DR), limited data suggest that pregnant women experience GBS colonization at rates among the highest globally. We aimed to determine the prevalence of maternal rectovaginal GBS colonization and describe clonal characteristics of colonizing strains in the DR. A cross-sectional study assessed rectovaginal GBS colonization in 350 near-term pregnant women presenting for routine prenatal care at an urban tertiary center in the DR. Rectovaginal samples were tested with chromogenic Strep B Carrot Broth and cultured for confirmatory whole-genome sequencing. In a secondary analysis, participants' demographics and histories were assessed for association with GBS colonization. Rectovaginal GBS colonization occurred in 26.6% of women. Serotypes Ia, Ib, II, III, IV, and V were detected, with no one serotype predominating; serotype III was identified most frequently (21.5%). Virulent and emerging strains were common, including CC17 (15.1%) and ST1010 (17.2%). In this first characterization of maternal GBS serotypes in the DR, we found high rates of rectovaginal colonization including with virulent and emerging GBS strains. The serotypes observed here are all targeted by candidate hexavalent GBS vaccines, suggesting effective protection in the DR.

Maternity care provider acceptance of a future Group B Streptococcus vaccine - A qualitative study in three countries.

INTRODUCTION: There are vaccines in clinical trials that target the bacterium Group B Streptococcus (GBS). When approved, GBS vaccines will be intended for administration to pregnant women to prevent infection in their infants. The success of any vaccine will depend on its' uptake in the population. Experience with prior maternal vaccines, e.g. influenza, Tdap and COVID-19 vaccines, teaches us that acceptance of vaccines, especially if novel, is challenging for pregnant women, and that provider recommendation is a key driver of vaccine uptake. METHODS: This study investigated attitudes of maternity care providers towards the introduction of a GBS vaccine in three countries (the United States (US), Ireland, and the Dominican Republic (DR)) with different GBS prevalence and prevention practices. Semi-structured interviews with maternity care providers were transcribed and coded for themes. The constant comparative method, and inductive theory building were used to develop conclusions. RESULTS: Thirty-eight obstetricians, 18 general practitioners and 14 midwives participated. There was variability in provider attitudes towards a hypothetical GBS vaccine. Responses ranged from enthusiasm to doubts over the need for a vaccine. Attitudes were influenced by perceived additional benefits of a vaccine over current strategy and confidence in the safety of vaccines during pregnancy. Knowledge, experience and approaches to GBS prevention differed geographically and according to provider type, and influenced how participants assessed the risks and benefits of a GBS vaccine. CONCLUSION: Maternity care providers are engaged in the topic of GBS management and there is opportunity to leverage attitudes and beliefs that will support a strong recommendation for a GBS vaccine. However, knowledge of GBS, and of the limitations of current prevention strategies vary among providers in different regions, and between different provider types. Targeted educational efforts with antenatal providers should focus on highlighting safety data the potential benefits of vaccination over current strategies.

Do we need to do fluorescence in situ hybridization analysis in myelodysplastic syndromes as often as we do?

Although conventional cytogenetics is considered the gold standard to detect chromosomal abnormalities in myelodysplastic syndromes (MDS), fluorescence in situ hybridization (FISH) is being increasingly used additionally. However, the real contribution of FISH analysis in the cytogenetic diagnosis of MDS has not been well defined. The aim of this study was to evaluate whether FISH studies are able to reveal chromosomal abnormalities in MDS patients undetected by conventional cytogenetics. One hundred seventy-four FISH studies were performed on bone marrow samples of 60 patients with MDS. The number of FISH studies in each patient was variable (1-5). FISH studies confirmed the G-banding cytogenetic findings in 99.4% (153/154) of samples and detected cytogenetic abnormalities in 25% (5/20) of cases in which the conventional cytognetic study failed. These results indicate that FISH studies provide relevant information in MSD in which the conventional cytogenetic analysis was unsuccessful but add little value to a normal katyotype in conventional cytogenetic analysis.

Hematopoiesis-related microRNA expression in myelodysplastic syndromes.

MicroRNAs (miRNAs) are negative regulators of expression of genes involved in hematopoiesis. The present study sought to link hematopoiesis-relevant miRNAs with myelodysplastic syndromes (MDS) and MDS progression to acute myeloid leukemia (AML). We assessed 25 mature miRNAs in total RNA from bone marrow (BM) and peripheral blood (PB) of 25 newly diagnosed patients with MDS and 12 controls. Twelve miRNAs in BM and six in PB were differentially expressed between patients with MDS and controls. Three of these miRNAs, belonging to the cluster 17-92, were overexpressed in both BM and PB. miR-15a in BM ( p = 0.034) and miR-16 in PB ( p = 0.005) were differentially expressed between low-risk and high-risk groups. miR-222 ( p = 0.0023) and miR-181a ( p = 0.014) expression was higher in AML than in MDS in both BM and PB. This study adds further evidence to the role of miRNAs in the pathogenesis of MDS and their transformation into AML.