Urinary bacteria in adult women with urgency urinary incontinence

Abstract

Introduction and hypothesis This study’s aims were to detect and quantify bacterial DNA in the urine of randomized trial participants about to undergo treatment for urinary urgency incontinence (UUI) without clinical evidence of urinary tract infection (UTI) and to determine if the presence of bacterial DNA in baseline urine relates to either baseline urinary symptoms or UTI risk after urinary tract instrumentation. Methods Women without clinical evidence of baseline UTI were randomized to cystoscopic onabotulinum toxin A injection and oral placebo medication versus cystoscopic placebo injection and active oral medication. Bacterial DNA in participants’ catheterized urine was measured by quantitative polymerase chain reaction (qPCR). Results Bacterial DNA was detected in the urine of 38.7 % of participants (60 out of 155). In these 60 qPCR-positive participants, baseline daily UUI episodes were greater than in the 95 qPCR-negative participants (5.71 [±2.60] vs 4.72 [±2.86], p=0.004). Neither symptom severity by questionnaire nor treatment outcome was associated with qPCR status or with qPCR level in qPCR-positive subjects. In contrast, the presence of urinary bacterial DNA was associated with UTI risk: only 10 % of the qPCR-positive women developed a UTI post-treatment, while 24 % of the qPCR-negative women did so. The median qPCR level for qPCR-positive samples did not differ significantly by UTI status (UTI 2.58×105 vs no UTI 1.35×105 copies/mL, p=0.6). Conclusions These results may indicate a urinary bacterial contribution to both baseline UUI and the risk of post-treatment UTI.

The female urinary microbiome in urgency urinary incontinence

“…Thus, we conservatively considered samples that amplified weakly to be sequence-negative to avoid over-interpretation of microbiota components. Even so, it is notable that the improved methods used in the current study reproducibly detected bacterial DNA in the urine of 56% of women in this population, compared to 39% in our previous analysis 3 .…”

“…Although the ABC study was designed prior to knowledge of the female urinary microbiota and our analysis was not based on an a priori hypothesis, the current findings add to the growing evidence that document the existence and define the characteristics of the female urinary microbiota 3, 4, 6, 7, 13–15 . Further study of the differences in biomass (sequence positive vs. sequence negative) and the microbial diversity by specific and dominant organisms is likely to advance our knowledge of UUI.…”

“…As the female urinary microbiota has only recently been detected 3, 4, 6, 7, 13–15 , an expanded perspective is warranted. The current study demonstrates that the status of the female urinary microbiota (sequence-positive or sequence-negative) can be used to sub-classify women with UUI and that sequence-positive women can be further sorted by composition into urotypes, based on the dominant bacterial genus or family or the lack thereof.…”

“…Our research team previously described the female urinary microbiota of women with UUI 3 using catheterized urine samples obtained at baseline from patientparticipants in a randomized clinical trial for the treatment of UUI who did not have clinical urinary tract infection (UTI) 1 . Previously, we also compared various techniques to verify that transurethral catheterization was an appropriate method to collect urine samples with minimal vulvo-vaginal contamination 4 .…”

The Clinical Urine Culture: Enhanced Techniques Improve Detection of Clinically Relevant Microorganisms

“…Given emerging evidence that documents the presence of urinary microbiota in many adult women (7)(8)(9)(10)(11)(12)(13)(14)(15), it is clear that the mere presence of an organism should not prompt antibiotic treatment. However, clinicians are likely to benefit from a more complete report of organisms present within a symptomatic patient's urine.…”