Pathogenesis, Virulence Factors, and Antibiotic Resistance of Group B Streptococcus

Abstract

Streptococcus is an important genus in the gram-positive coccus, belonging to family Streptococcaceae. The members of the genus Streptococcus are biomedically relevant owing to their widespread pathogenic profile causing severe healthcare issues such as pharyngitis, pneumoniae, neonatal meningitis, sepsis, endocarditis, bacteremia, and urinary tract infections (UTIs). The diversified species of genus Streptococcus are basically categorized based on the inherent hemolytic properties, i.e., either facilitating the oxidation of iron in hemoglobin within the red blood cells (Alpha-hemolytic) or complete rupturing of red blood cells (beta-hemolytic). The beta-hemolytic group of Streptococci are further classified into several serotypes using Lancefield grouping system which is based on the presence or absence of specific carbohydrate moieties on the bacterial cell wall. Among the different serotypes, Lancefield group A (Group A Streptococcus) and Lancefield group B (Group B Streptococcus) are critically important in the medical settings based on their ability to cause life-threatening diseases in the immunocompromised individuals. Among the different species of genus Streptococcus, the most clinically relevant species are Streptococcus pneumoniae and S. viridians (belonging to Alpha-hemolytic group of Streptococcus). Apart from Alpha-hemolytic Streptococcus, Lancefield groups A and B (also known as “group A strep” and “group B strep”) are also considered to be highly relevant in clinical and biomedical setup. Group B Streptococcus is an opportunistic pathogenic bacteria causing severe neonatal sepsis, meningitis, bacteremia, urinary tract infections, endometritis, maternal bacteremia, and other associated diseases. The disease severity and chronic infection profile of GBS could be attributed to the presence of specific virulence determinants such as pore-forming toxins and capsular polysaccharides. The epidemiological profile of GBS gained considerable attention owing to its ability to exhibit resistance against conventional antibiotic treatment by forming recalcitrant biofilms. In the fight against GBS infection, specific antibiotics like penicillin and vancomycin, high throughput therapeutic strategy like intrapartum antibiotic prophylaxis (IAP), and public awareness programmes are considered to be effective in controlling the bacterial infections. In addition, novel drug molecules from natural sources could also be utilized as prolific arsenal against GBS infections. Despite the development in the therapeutic strategies to control GBS infections, the mortality and morbidity caused by GBS infections remain an uphill challenge for the scientific community. In this context, it is imperative to quest for novel strategies in preventing the GBS infections and that could be implemented through public awareness programmes and prenatal screening workshops apart from conventional therapeutic approach.