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While GBS is primarily recognized for its impact on neonatal health and pregnancy outcomes, emerging research suggests that it could play a role in the exacerbation or even potential onset of IBD.
Streptococcus agalactiae (GBS)
Researched by:
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Karen Pendergrass
ID
Karen Pendergrass
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.
Streptococcus agalactiae, also known as Group B Streptococcus (BS), is a Gram-positive, facultative anaerobe commonly found as a commensal organism in the gastrointestinal and urogenital tracts of humans. While asymptomatic colonization is frequent, BS is also a major pathogen, particularly in neonates, pregnant women, and immunocompromised individuals.
-
Karen Pendergrass
Researched by:
-
Karen Pendergrass
ID
Karen Pendergrass
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Karen Pendergrass
Overview Overview
Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is a Gram-positive, facultative anaerobe commonly found as a commensal organism in the gastrointestinal and urogenital tracts of humans. While asymptomatic colonization is frequent, GBS is also a major pathogen, particularly in neonates, pregnant women, and immunocompromised individuals. It is associated with conditions such as neonatal sepsis, meningitis, urinary tract infections, and soft tissue infections.
Associated Conditions
GBS is implicated in a wide range of conditions, from neonatal infections to associations with chronic diseases. Its ability to colonize multiple niches and influence immune responses has expanded our understanding of its clinical significance. Below is a table summarizing conditions directly or indirectly linked to Streptococcus agalactiae.
| Condition | Description |
|---|---|
| Meningitis | GBS can cross the blood-brain barrier in newborns, leading to inflammation of the protective membranes covering the brain and spinal cord. |
| Sepsis | A life-threatening response to infection where GBS bacteria enter the bloodstream, causing widespread inflammation, which can rapidly progress to tissue damage and organ failure. |
| Pneumonia | GBS can infect the lungs, especially in newborns, leading to pneumonia characterized by inflammation and fluid accumulation in the lungs. |
| Urinary Tract Infections (UTIs) | In adults, especially older women and those with other health issues, GBS can cause infections of the bladder or kidneys. |
| Endometriosis | Emerging research suggests that GBS is a major microbial association (MMA) in the microbiome signature of endometriosis. |
| Cervical cancer | Studies exploring the interaction between HPV, vaginal microbiota, pH, and immune mediators in cervical cancer progression, find ethnicity, increased GBS, and inflammation as significant factors alongside HPV. [x] Another study using 16S rRNA sequencing to analyze cervical microbiota changes in HPV-related cervical cancer progression identified GBS as the main pathogen associated with persistent HPV infection higher-grade squamous intraepithelial lesion (HSIL). [x] |
| Cervical glandular intraepithelial neoplasia | Studies find a direct and indirect association of GBS in the cervical microbiota with the risk of cervical intraepithelial neoplasia [x, x] |
| Inflammatory bowel disease | Crohn’s disease (CD), ulcerative colitis (UC), and pouchitis are distinct but related forms of chronic inflammatory bowel diseases (IBD) that are complex and multifactorial in nature. Recent findings have shown that patients with these IBD conditions have an increased presence of GBS in their intestinal microbiota. [x] |
Virulence Factors
Streptococcus agalactiae, commonly known as Group B Streptococcus (GBS), possesses several virulence factors contributing to its ability to cause disease, particularly in newborns and individuals with compromised immune systems.
| Virulence Factor | Function |
|---|---|
| Capsular Polysaccharide (CPS) | Serves as the primary virulence factor by inhibiting phagocytosis by immune cells, thus protecting the bacteria from the host’s immune system. Different serotypes vary in virulence. |
| Pili | Hair-like appendages that aid in the adherence to host cells, facilitating colonization and invasion, especially in the urogenital and gastrointestinal tracts. |
| Beta-hemolysin/cytolysin | A toxin that lyses red blood cells and other host cells, contributing to tissue damage and spreading the infection. |
| Sialic acid-rich oligosaccharides | Structures that mimic human cell surface molecules to evade immune detection. |
| DNases, RNases, and proteases | Enzymes that degrade DNA, RNA, and proteins, aiding in the spread of the infection by breaking down host tissues and evading host defenses. |
| Hyaluronidase | An enzyme that facilitates bacterial spread through tissues by breaking down hyaluronic acid, a component of the extracellular matrix. |
Metal and Mineral Requirements of Streptococcus agalactiae
The metal and mineral requirements of Streptococcus agalactiae (Group B Streptococcus, GBS) are essential for its growth, virulence, and survival, particularly within host environments. Recent advances in genomics and molecular biology have shed light on how GBS acquires and utilizes these essential elements to support critical functions such as enzymatic activity, immune evasion, and resistance to oxidative stress. These mechanisms are integral to its pathogenicity, allowing GBS to thrive and evade host defenses. Below is a summary table outlining key metals, their associated genetic mechanisms, and their roles in pathogenesis.
| Metal/Mineral | Genetic Mechanisms and Role |
|---|---|
| Iron | Genes such as HtsA, HtsB, HtsC encode heme uptake systems, while the SiaABC transporter facilitates sialic acid-mediated iron acquisition. Fur regulates iron homeostasis, and iron is critical for virulence factor expression. |
| Zinc | AdcA and AdcAII transporters import zinc, while the Lmb protein aids in adherence. Zinc supports enzyme function and immune evasion. |
| Manganese | The MntH transporter and MntABC system regulate manganese uptake, essential for oxidative stress resistance via superoxide dismutase (SOD). |
| Magnesium | MgtE and ABC transporters maintain magnesium homeostasis, which is crucial for stabilizing ribosomes, nucleic acids, and membranes. |
| Nickel and Cobalt | Nickel-dependent enzymes (e.g., urease) and cobalt utilization pathways are likely conserved but understudied in GBS. |
| Copper | Copper-exporting ATPases and metallochaperones help GBS resist copper toxicity, which is used as an antimicrobial defense by the host. |
Interventions
Targeting S. agalactiae requires a combination of traditional antibiotics and emerging therapies. Below is a detailed table categorizing interventions based on whether they increase or decrease the microbe, with mechanisms and evidence where available.
| Intervention | Effect on GBS | Mechanism and Evidence |
|---|---|---|
| Penicillin, Ampicillin | Decreases | Beta-lactam antibiotics inhibit bacterial cell wall synthesis, effectively treating GBS infections. Proven first-line therapy. |
| Clindamycin, Vancomycin | Decreases | Targets protein synthesis (clindamycin) or cell wall synthesis (vancomycin); used for penicillin-allergic patients. |
| Polyphenols (e.g., Curcumin) | Decreases | Disrupts biofilm formation and inhibits quorum sensing. Evidence shows significant reduction in biofilm-associated infections. [1] |
| Terpenes (e.g., Carvacrol) | Decreases | Induces membrane damage and bacterial lysis. Effective against biofilm-forming strains of GBS. [2] |
| Probiotics (e.g., Lactobacillus) | Decreases | Competitive exclusion of GBS in the vaginal microbiome; produces antimicrobial metabolites. [3] |
| HBOT (Hyperbaric Oxygen Therapy) | Decreases | High oxygen concentrations inhibit GBS growth and enhance host immune responses. [4] |
| Iron Chelators | Decreases | Starves GBS by blocking iron acquisition, a critical virulence factor. [5] |
| FMT (Fecal Microbiota Transplantation) | Decreases | Restores microbiome diversity; reduces GBS colonization in dysbiotic microbiota. [6] |
| Vitamin D | Decreases | Enhances immune defenses, reducing colonization and infection rates. [7] |
| Decreasing Vaginal pH (via Probiotics) | Decreases | Acidic environment inhibits GBS colonization and growth. [9] |
Polyphenols
Research on the antimicrobial properties of polyphenols against Streptococcus agalactiae is an emerging field. Polyphenols, naturally occurring compounds found in plants, have shown potential to inhibit the growth of various pathogens, including GBS.
| Polyphenol | Research Findings |
|---|---|
| Resveratrol | EGCG, predominantly found in green tea, has shown the ability to inhibit the growth of GBS and reduce its virulence factors. |
| Epigallocatechin gallate (EGCG) | Predominantly found in green tea, EGCG has shown the ability to inhibit the growth of GBS and reduce its virulence factors. |
| Curcumin | Derived from turmeric, curcumin has been studied for its anti-inflammatory properties and its ability to inhibit GBS growth and biofilm formation. |
| Ellagic Acid | Found in fruits like raspberries and pomegranates, ellagic acid has shown promise in reducing the viability of GBS in vitro studies. |
Terpenes
Terpenes, which are aromatic compounds found in many plants, have demonstrated potential antimicrobial properties against various pathogens, including Streptococcus agalactiae.
| Terpene | Research Findings |
|---|---|
| Limonene | Menthol, derived from mint oils, has been researched for its ability to inhibit GBS growth and enhance the efficacy of other antimicrobial agents. |
| Menthol | Thymol, present in thyme oil, has potent antibacterial properties. It has strong activity against GBS, possibly through disruption of bacterial protein synthesis. |
| Eucalyptol | Found in eucalyptus oil, eucalyptol has exhibited antimicrobial activity against GBS by disrupting its cell membrane. |
| Thymol | Present in thyme oil, thymol has potent antibacterial properties that include strong activity against GBS, possibly through disruption of bacterial protein synthesis. |
Flavones and Flavonols
Flavones and flavonols, subclasses of flavonoids found abundantly in fruits, vegetables, and certain beverages, have been investigated for their antimicrobial properties.
| Flavone/Flavonol | Research Findings |
|---|---|
| Quercetin | A widely studied flavonol, quercetin has shown inhibitory effects against GBS by disrupting bacterial membranes and inhibiting biofilm formation. |
| Kaempferol | Found in a variety of plants and foods, kaempferol has demonstrated the ability to inhibit GBS growth and reduce its virulence. |
| Myricetin | This flavonol has exhibited antibacterial activity against GBS, potentially through interference with bacterial DNA and protein synthesis. |
| Apigenin | Apigenin, a common flavone in many fruits and vegetables, has been researched for its potential to inhibit the growth of GBS and disrupt bacterial cell processes. |
Phenolic Acids
Research into the antimicrobial properties of phenolic acids against Streptococcus agalactiae is part of an expanding area of interest due to the potential health benefits of these natural compounds.
| Phenolic Acid | Research Findings |
|---|---|
| Gallic Acid | Demonstrated antibacterial activity against GBS by disrupting bacterial cell walls and inhibiting biofilm formation. |
| Ellagic Acid | Studied for its ability to inhibit the growth of GBS, likely through interference with bacterial DNA synthesis. |
| Caffeic Acid | Shown to possess antimicrobial effects against GBS, possibly due to its antioxidant properties and membrane interaction. |
| Ferulic Acid | Explored for its antibacterial potential against GBS, contributing to oxidative stress within bacterial cells. |
Alkaloids
Alkaloids, known for their broad range of pharmacological activities, have also been investigated for their antimicrobial properties against GBS.
| Alkaloid | Research Findings |
|---|---|
| Berberine | Demonstrated significant antibacterial activity against GBS, affecting bacterial cell structure and metabolic processes. |
| Sanguinarine | Found to inhibit the growth of GBS, likely through interactions with bacterial membranes and DNA. |
| Piperine | Studied for its potential to enhance the effectiveness of traditional antibiotics against GBS infections. |
| Chelerythrine | Showed promise in reducing GBS viability, potentially through disruption of bacterial cell functions. |
Endometriosis
Endometriosis involves ectopic endometrial tissue causing pain and infertility. Validated and Promising Interventions include Hyperbaric Oxygen Therapy (HBOT), Low Nickel Diet, and Metronidazole therapy.
Zinc
Zinc is an essential trace element vital for cellular functions and microbiome health. It influences immune regulation, pathogen virulence, and disease progression in conditions like IBS and breast cancer. Pathogens exploit zinc for survival, while therapeutic zinc chelation can suppress virulence, rebalance the microbiome, and offer potential treatments for inflammatory and degenerative diseases.
Flavones and Flavonols
Flavones and flavonols are plant-derived compounds known for their antioxidant, anti-inflammatory, and antimicrobial properties.