Culture Of Urine Sediment Reveals Differences Between Patients With Overactive Bladder (OAB) And Controls: Are Changes In The Bladder Microbiome Responsible For Symptoms Of OAB?

Overactive bladder (OAB) is a common syndrome characterized by increased frequency, urinary urgency, urinary incontinence and nocturia. The cause of idiopathic OAB is unknown, however, a recent investigation has shown that antibiotics may reduce the symptoms of OAB in some patients (1). There is also an increasing body of evidence to suggest that the human bladder has a microbiome, missed by conventional urinalysis and culture (2). Consequently, infection may be a possible cause for the symptoms of OAB in some patients affected by this syndrome. We hypothesise that changes in the urinary tract microbiome are responsible for the symptoms of OAB. The aim of this investigation is to compare the species of bacteria in the urine of patients with OAB and age‐matched controls. Urine samples (5 ml), taken from females aged 35–87 via MSU sampling techniques, were centrifuged, re‐suspended and plated on chocolate agar plates in aerobic and anaerobic conditions for 7 days. Purity plating was performed and isolates identified by sequencing of the 16s rRNA gene. Sediment culture of MSU samples reveals a variety of species of bacteria in urine of both patients with OAB and controls. The average number of species, as identified by our methodology, is 5 per patient in both groups. In controls, the most notable species are Staphylococcus , Streptococcus and Lactobacillus . With increased age, these notable species decrease and other species such as Escherichia coli (E.coli), Campylobacter and Bifidobacterium increase in prevalence . Comparing the microbiome of age‐matched controls with that of patients with OAB, shows that the incidence of E.coli, Campylobacter, Enterococcus and Proteus are further increased. In an attempt to confirm that the bacteria observed was not a contamination artefact of using MSU samples, we performed similar analysis on CSU samples. Preliminary data indicates a trend for increases in the incidence of E.coli and Comamonadaceae and a decrease in Gardnerella and Staphylococcus in patients with OAB . Evidence presented here supports recent observation that the bladder has a microbiome and urine is not sterile. Furthermore, there appears to be differences in the bladder microbiome between patients with OAB and controls, and these differences become more apparent in the aged. A more thorough analysis of the microbiome, including antibiotic protection assays on each sample, is now under way. Support or Funding Information Kidney Research UK