CULTURE INDEPENDENT ANALYSIS OFRECURRENT BACTERIAL CYSTITIS IN PATIENTS WITH REFRACTORY DETRUSOROVERACTIVITY
Z. CHEN1, L. J. BATES1, M. PHAN 2, M. A. SCHEMBRI 3, K.H. MOORE 4;
1Department of Urogynaecology,St George Hosp., NSW, Australia, 2Univ. of Queensland,NSW, Australia, 3Univ. of Queensland, Brisbane, Australia,4UNSW, Short Street, Kogarah, Australia.
Introduction: Recent research inrefractory detrusor overactivity (rDO) have demonstrated evidence ofintracellular bacterial communities as potential reservoirs forbacterial cystitis . Furthermore, recurrent urinary tractinfections (UTI) is an increasing problem affecting up to 40% of rDOpatients. High rate of infections caused by antibiotic resistantbacteria, especially uropathogenic E.coli impacts our ability tosuccessfully treat UTIs and manage rDO symptoms in this cohort.
Objective: Our aim was to investigate women with rDO andco-existent recurrent UTI over an extended time period using cultureindependent analysis. This was carried out using routine microbialculture to determine the primary bacteria during episodes ofsymptomatic UTI, as well as periodic analysis of urine usingculture-independent methods based on 16S rRNA amplicon sequencing todetermine the composition of bacteria present in the urine during thesame time period.
Methods: Recurrent UTI was defined as ≥2infections in 6 months or ≥3 infections in 1 year. Multiple MSUwith careful labial toilet were collected from women who had a priorhistory of recurrent UTI. Those who also had rDO were chosen forfurther analysis and number of UTIs over the proceeding 24 monthswere noted and treated with appropriate antibiotics. Half of theurine sample was sent to the Microbiology Unit, cultured routinely ata threshold of >106 CFU/mL, to identify the majorcausative organism and antibiotic resistance. Remaining samples werestored in frozen aliquots (-20°C) for subsequent extraction ofbacterial DNA. Genus-level characterization of the bacteria presentin the urine samples was determined using 16S rRNA gene amplificationand amplicon sequencing.
Results: 39 women gave MSUsover a 2-year period, of these 9 women had proven recurrent UTI andrDO. Median age 75 years (range 57-81). In the previous 6-24 monthsthere were 3-18 confirmed UTI (average 8/woman). 6/9 women have ahistory either past or present voiding issues, treated by doubleemptying, not requiring CISC. Of the 42 urine samples collected from9 patients (median 5 samples/patient; range 2-10), microbiologyculture results showed only 4 samples had no growth. 18 samples werepositive: 13 E. coli, 2 Enterococcus faecalis, 2Klebsiella pneumonia, 1 Citrobacter freundii. 17samples were reported as mixed perineal or bowel flora. 3 patientshad documented changes in the bacterial flora on routine microbiologyculture over time. Of the 18 positive samples, all but 4 wereresistant to multiple antibiotics. Culture independent 16S rRNAsequencing revealed a diverse array of organisms present in MSUs fromindividual patients shown in figure 1 (average 26.7 genera perpatient SD11.2, Median 25, IQR 21,36).
Patient 5 had 9 E.Coli UTI's someof which were resistance to amoxicillin and trimethoprim onmicrobiology. This coincided with a pattern of FimH43 via ampliconsequencing on 3 separate UTI's, indicating persistence of the straindespite treatment.
Conclusions: Results to date show thatorganisms isolated from women with recurrent UTI and a history of rDOalter over time, as does antibiotic resistance. Most laboratories donot routinely report all organisms grown, preferring to report onlythe dominant organism, which may lead to proliferation of unreportedorganisms and increased resistance. In these patients, we weresurprised to discover that 16S rRNA sequencing and E.coli specificfimH amplicon sequencing may help to understand the etiology ofrecurrent infections. Our data demonstrates that culture independent16S rRNA sequencing can enable profiling of all organisms present inurine over time, and link changes in the bacterial population toepisodes of symptomatic UTI. Overall, these findings may enable us tounderstand why a proportion of women with rDO do not respond toanticholinergics. Such pharmacotherapy is unlikely to be effective inthe presence of constantly evolving UTI.
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