Introduction & Objectives
\nContaminated or mixed urine cultures create uncertainty before endourological stone surgery. Urology clinic data associate mixed cultures with female sex, while in catheterised stone patients polymicrobial findings may reflect device-related colonisation rather than simple pre-analytical contamination. We evaluated the prevalence and predictors of contaminated pre-operative urine cultures in patients undergoing endourological stone treatment.
\nMaterials & Methods
\nWe retrospectively analysed consecutive endourological stone procedures performed at a tertiary centre between September 2022 and August 2024, including ureteroscopy, retrograde intrarenal surgery, percutaneous nephrolithotomy, endoscopic combined intrarenal surgery and endoscopic bladder stone treatment. Urine cultures were classified as negative, positive, contaminated\/mixed or missing. The primary endpoint was contaminated\/mixed culture among procedures with available culture classification. Associations with sex, age, procedure type, pre-operative catheter status and culture-to-surgery interval were assessed using univariable analysis and multivariable logistic regression. Procedures without linkage to sex or catheter data were excluded from covariate-specific analyses. Ethics approval was waived due to the retrospective anonymised design. AI-assisted tools were used for language editing; all data and content were reviewed by the authors.
\nResults
\nA total of 460 procedures in 292 patients were analysed. Urine culture was classified as positive, negative or contaminated\/mixed in 420 procedures; 33\/420 were contaminated\/mixed, corresponding to a contamination rate of 7.9%. Overall, 73\/460 procedures, 15.9%, had either missing\/unclassified or contaminated\/mixed cultures, representing non-actionable microbiological assessment. Sex and catheter status were available in 418\/420 classified procedures. Contamination was more frequent in females than males: 25\/229, 10.9%, versus 8\/189, 4.2%, p=0.017. It was also more frequent in catheterised patients: 24\/222, 10.8%, versus 9\/196, 4.6%, p=0.028. On multivariable analysis, female sex and catheter status remained independently associated with contamination: adjusted OR 3.02, 95% CI 1.31-6.93, p=0.009; and adjusted OR 2.79, 95% CI 1.25-6.25, p=0.013, respectively. Age, RIRS versus non-RIRS procedure, and culture-to-surgery interval were not independently associated with contamination.
\nConclusions
\nContaminated\/mixed pre-operative urine cultures occurred in 7.9% of classified cultures and were independently associated with female sex and pre-operative catheter status. These findings support targeted improvement of urine sampling pathways before stone surgery, especially in catheterised patients, where interpretation may be affected by device-related colonisation. Reducing non-actionable cultures is a practical diagnostic-stewardship target for perioperative infection prevention.<\/p>","protected":false},"excerpt":{"rendered":"
Introduction & Objectives Contaminated or mixed urine cultures create uncertainty before endourological stone surgery. Urology clinic data associate mixed cultures with female sex, while in catheterised stone patients polymicrobial findings may reflect device-related colonisation rather than simple pre-analytical contamination. We … read more<\/a><\/p>","protected":false},"author":3,"featured_media":285,"menu_order":0,"template":"","meta":{"_acf_changed":false},"portfolio-type":[19],"portfolio-tag":[],"class_list":["post-284","portfolio","type-portfolio","status-publish","has-post-thumbnail","hentry","portfolio-type-unmoderated-posters"],"acf":[],"_links":{"self":[{"href":"https:\/\/ice26.eposter.civired.com\/en\/wp-json\/wp\/v2\/portfolio\/284","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ice26.eposter.civired.com\/en\/wp-json\/wp\/v2\/portfolio"}],"about":[{"href":"https:\/\/ice26.eposter.civired.com\/en\/wp-json\/wp\/v2\/types\/portfolio"}],"author":[{"embeddable":true,"href":"https:\/\/ice26.eposter.civired.com\/en\/wp-json\/wp\/v2\/users\/3"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ice26.eposter.civired.com\/en\/wp-json\/wp\/v2\/media\/285"}],"wp:attachment":[{"href":"https:\/\/ice26.eposter.civired.com\/en\/wp-json\/wp\/v2\/media?parent=284"}],"wp:term":[{"taxonomy":"portfolio-type","embeddable":true,"href":"https:\/\/ice26.eposter.civired.com\/en\/wp-json\/wp\/v2\/portfolio-type?post=284"},{"taxonomy":"portfolio-tag","embeddable":true,"href":"https:\/\/ice26.eposter.civired.com\/en\/wp-json\/wp\/v2\/portfolio-tag?post=284"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}