Exposure to Moderate Glycosuria Induces Virulence of Group B Streptococcus

Area of Science:

• Microbiology
• Infectious Diseases
• Urology

Background:

• Urinary tract infections (UTIs) are common bacterial infections.
• Glycosuria, characterized by glucose in the urine, is often associated with diabetes.
• The link between glycosuria and uropathogen virulence is not fully understood.

Purpose of the Study:

• To investigate if glycosuria promotes the virulence of uropathogens, thereby facilitating UTIs.
• To determine the effect of glycosuria on the growth and pathogenic characteristics of group B Streptococcus (GBS).

Main Methods:

• Group B Streptococcus (GBS) strain 10/84 was exposed to human urine with and without added glucose (300 mg/dL) to mimic moderate glycosuria.
• Bacterial growth, kidney bacterial burden in a mouse model of ascending UTI, and virulence factors were assessed.
• Gene expression related to adherence, antimicrobial peptide resistance, and hemolytic activity was analyzed.

Main Results:

• Exposure to glycosuria significantly increased GBS growth and kidney bacterial burden in a mouse UTI model.
• Glycosuria enhanced GBS adherence to bladder epithelial cells, mediated by PI2a fimbrial gene expression.
• Increased resistance to antimicrobial peptide LL-37 and enhanced hemolytic activity were observed, linked to dltA and pore-forming toxin gene expression.

Conclusions:

• Moderate glycosuria significantly augments GBS virulence.
• Glycosuria promotes key pathogenic traits in GBS, including enhanced growth, adherence, antimicrobial resistance, and cytotoxicity.
• These findings suggest glycosuria may play a crucial role in facilitating UTIs caused by GBS.