Substantial overlap between symptomatic and asymptomatic genitourinary microbiota states

Area of Science:

• Microbiology
• Genitourinary Health
• Metagenomics

Background:

• Urinary tract infection (UTI) diagnosis is complicated by the lack of a defined urinary microbiome health, especially with non-traditional pathogens or low bacterial counts.
• Standard urine tests often fail to capture the full microbial picture in symptomatic patients.

Purpose of the Study:

• To establish a baseline of asymptomatic genitourinary microbiota states using shotgun metagenomic sequencing.
• To contextualize the microbiota of patients with suspected UTIs against this baseline.
• To evaluate the efficiency of standard culture protocols in recovering the urinary microbiota.

Main Methods:

• Shotgun metagenomic sequencing of 30 longitudinal urine specimens from asymptomatic volunteers.
• Permutation tests to define asymptomatic microbiota states.
• Analysis of 122 urine specimens from patients with suspected UTIs.
• Comparison with standard-of-care culture protocols.

Main Results:

• A majority of genitourinary microbiota in individuals with suspected UTIs overlapped with asymptomatic microbiota states.
• Longitudinal analysis revealed temporal fluctuations in microbial functions and taxonomy in asymptomatic individuals.
• Urine specimens with "insignificant" or "no-growth" results often showed inflammation not linked to dysbiosis.
• Culture-based methods biased recovery towards common uropathogens like E. coli and K. pneumoniae.

Conclusions:

• Shotgun metagenomic sequencing established baseline asymptomatic genitourinary microbiota states.
• Substantial overlap exists between symptomatic and asymptomatic genitourinary microbiota.
• Bacterial presence alone does not fully explain the onset of clinical UTI symptoms.