Group B Streptococcus Capsular Serotype Alters Vaginal Colonization Fitness.

Background: Group B Streptococcus (GBS) remains a leading cause of infant morbidity and mortality. A candidate vaccine targets 6 GBS serotypes, offering a potential alternative to intrapartum antibiotic prophylaxis to reduce disease burden. However, our understanding of the contributions of specific capsule types to GBS colonization and disease remains limited.

Genome-Wide fitness analysis of group B Streptococcus in human amniotic fluid reveals a transcription factor that controls multiple virulence traits.

Streptococcus agalactiae (group B Streptococcus; GBS) remains a dominant cause of serious neonatal infections. One aspect of GBS that renders it particularly virulent during the perinatal period is its ability to invade the chorioamniotic membranes and persist in amniotic fluid, which is nutritionally deplete and rich in fetal immunologic factors such as antimicrobial peptides. We used next-generation sequencing of transposon-genome junctions (Tn-seq) to identify five GBS genes that promote survival in the presence of human amniotic fluid.

The Impact of Circulating Antibody on Group B Intestinal Colonization and Invasive Disease.

Gastrointestinal (GI) colonization with group B (GBS) is an important precursor to late-onset (LO) disease in infants. The host-pathogen interactions that mediate progression to invasive disease remain unknown due, in part, to a paucity of robust model systems. Passively acquired maternal GBS-specific antibodies protect newborns from early-onset disease, yet their impact on GI colonization and LO disease is unexplored.

High prevalence of Group B Streptococcus colonization among pregnant women in Amman, Jordan.

Background: Little is known of the burden of Group B Streptococcus (GBS) colonization among pregnant women in Jordan. We conducted a pilot study to determine the prevalence of GBS among pregnant women in Amman, Jordan, where GBS testing is not routine. We also explored GBS serotypes and the performance of a rapid GBS antigen diagnostic test.

High Rate of Serotype V Carriage in Pregnant Women in Botswana.

Maternal rectovaginal colonization is the major risk factor for early-onset neonatal sepsis due to Group B (GBS), a major cause of early life morbidity and mortality. Transmission generally occurs perinatally from colonized mothers to infants. Vaccines targeting a subset of GBS serotypes are under development, but GBS epidemiology remains poorly understood in many African nations.

A Counterselectable Sucrose Sensitivity Marker Permits Efficient and Flexible Mutagenesis in .

(group B [GBS]) is a cause of severe infections, particularly during the newborn period. While methods exist for generating chromosomal mutations in GBS, they are cumbersome and inefficient and present significant challenges if the goal is to study subtle mutations, such as single-base-pair polymorphisms. To address this problem, we have developed an efficient and flexible GBS mutagenesis protocol based on sucrose counterselection against levansucrase (SacB) expressed from a temperature-selective shuttle vector.

Improving the Sensitivity of Real-time PCR Detection of Group B Streptococcus Using Consensus Sequence-Derived Oligonucleotides.

Group B (GBS) is a perinatal pathogen and an emerging cause of disease in adults. Culture-independent GBS detection relies on polymerase chain reaction (PCR) of conserved genes, including . We demonstrate suboptimal sensitivity of the existing PCR strategy and validate an improved method based on consensus sequences from >100 GBS genomes.