Treatment of non-obstructive, non-struvite urolithiasis is effective in treatment of recurrent urinary tract infections

Recurrent UTI in Women-Risk Factors and Management

Urinary tract infections (UTIs) are common in women; more than 50% of women will be diagnosed with a UTI in her lifetime. Many of these women will go on to develop recurrent UTI. Nevertheless, evidence-based prevention of recurrent UTI is under-utilized. Here, the authors provide detailed practical advice on UTI prevention with a thorough review of the evidence. Non-antibiotic prevention measures discussed include increased fluid intake, vaginal estrogen therapy, methenamine, and cranberry. Antibiotic prophyalxis for carefully selected patients is also discussed.

Assessment of Antibacterial Properties and Cytotoxic Effect of Ethanolic Extracts of Clitoria ternatea and Camellia sinensis Herbal Formulation Against Clinical Pathogens

Aim The study aims to evaluate the antibacterial properties of ethanolic extracts from Clitoria ternatea and Camellia sinensis against pathogens causing UTI, wound pathogens, and other clinical bacterial infections and their cytotoxic effects using the brine shrimp lethality assay (BSLA). Methods Ethanolic extracts of C. ternatea and C. sinensis were prepared, and their antibacterial activity was tested against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterococcus faecalis using the well diffusion method. The cytotoxicity was assessed through the BSLA, determining the LC50 values for each extract. Results The formulation of both plant extracts exhibited significant antibacterial activity against UTI pathogens, and wound pathogen bacteria showed higher efficacy compared to other studies. The BSLA revealed a dose-dependent increase in toxicity, with C. ternatea extracts demonstrating higher cytotoxicity than C. sinensis. Conclusion The ethanolic extracts of C. ternatea and C. sinensis possess antibacterial properties against UTI-causing bacteria and show cytotoxic effects in a brine shrimp model. These findings suggest the potential of these plants for developing alternative treatments for UTI. However, further research is necessary to fully understand their safety and efficacy in human subjects.

Role of Ureteroscopy (URS) and Stone Treatment in Patients with Recurrent UTIs: Outcomes over a 10-Year Period

Background. The study aimed to assess whether the eradication of kidney stones might result in a substantial reduction in the onset of recurrent UTIs. Methods. We selected all the patients who underwent ureteroscopy (URS) for stone disease between 2012 and 2021, with either a history of recurrent UTIs (rUTIs), urosepsis or pre-operative positive urine culture (UC). Data included patient demographics, microbiological data, stone parameters, stone-free and infection-free rates (SFR and IFR, respectively) at follow-up, defined as fragments <2 mm at imaging and the absence of symptoms and urine-culture-proven UTI. Results. Overall, 178 patients were selected. The median age was 62 years. The median cumulative stone size was 10 mm (7-17.25), and the commonest locations were the lower pole (18.9%) and proximal ureter (14.9%). The overall stone-free rate at follow-up was 89.3%. The IFR at 3 months was 88.3%. As follow-up duration increased, the IFR reduced to 85.4%, 74.2%, 68% and 65% at 6, 12, 18 and 24 months, respectively. Patients who had infection recurrence were more likely to present stone persistence or recurrence compared to those who were infection-free at follow-up (20% vs. 4.4%, p = 0.005). Conclusions. SFR after URS is a significant predicting variable for the likelihood of infection-free status at follow-up in patients with an rUTI or positive UC at the time of URS.

Phytochemical Analysis, Antibacterial and Antibiofilm Activities of Aloe vera Aqueous Extract against Selected Resistant Gram-Negative Bacteria Involved in Urinary Tract Infections

In bacterial infections, including urinary tract infections (UTIs), the gap between the development of new antimicrobials and antimicrobial resistance is dramatically increasing, especially in Gram-negative (Gram–) bacteria. All healthy products that can be used per se or that may be sources of antibacterial compounds should be considered in the fight against this major public health threat. In the present study, the phytochemical composition of Aloe vera extract was investigated by HPLC–MS/MS, and we further evaluated its antibacterial and antibiofilm formation activity against selected resistant Gram– bacteria involved in UTIs, namely, Achromobacter xylosoxidans 4892, Citrobacter freundii 426, Escherichia coli 1449, Klebsiella oxytoca 3003, Moraxella catarrhalis 4222, Morganella morganii 1543, Pseudomonas aeruginosa 3057, and a reference strain E. coli ATCC 25922. Inhibition zones (IZs) of the extract were determined using the well diffusion method, minimum inhibitory (MIC), and bactericidal (MBC) concentration by the two-fold serial microdilution assay, and antibiofilm formation activity by the crystal violet attachment assay. Aloe-emodin and its derivatives were the major constituent (75.74%) of A. vera extract, the most important of them being aloesin (30.22%), aloe-emodin-diglucoside (12.58%), and 2′-p-methoxycoumaroylaloeresin B (9.64%). The minerals found in the extract were sulfur (S), silicon (Si), chlorine (Cl), potassium (K), and bromine (Br). Except for the clinical strain E. coli 1449, which was totally non-susceptible, A. vera demonstrated noteworthy antibacterial activity with MIC and MBC values ranging from 0.625 to 5 mg/mL and 5 to 10 mg/mL, respectively. A. vera also demonstrated dose-dependent antibacterial effects, and the reference strain E. coli ATCC 25922 was the most susceptible with MIC = 0.625 and IZ = 19 mm at 20 mg/mL. The antibiofilm formation potential of A. vera extract was strong at 2MIC and MIC (93–100% of biofilm formation inhibition), moderate at MIC/2 (32–41%), weak at MIC/4 (14–21%), and nil at MIC/8.

Oxalate Alters Cellular Bioenergetics, Redox Homeostasis, Antibacterial Response, and Immune Response in Macrophages

Individuals with calcium oxalate (CaOx) kidney stones can have secondarily infected calculi which may play a role in the development of recurrent urinary tract infection (UTI). Uropathogenic Escherichia coli (UPEC) is the most common causative pathogen of UTIs. Macrophages play a critical role in host immune defense against bacterial infections. Our previous study demonstrated that oxalate, an important component of the most common type of kidney stone, impairs monocyte cellular bioenergetics and redox homeostasis. The objective of this study was to investigate whether oxalate compromises macrophage metabolism, redox status, anti-bacterial response, and immune response. Monocytes (THP-1, a human monocytic cell line) were exposed to sodium oxalate (soluble oxalate; 50 µM) for 48 hours prior to being differentiated into macrophages. Macrophages were subsequently exposed to calcium oxalate crystals (50 µM) for 48 hours followed by UPEC (MOI 1:2 or 1:5) for 2 hours. Peritoneal macrophages and bone marrow-derived macrophages (BMDM) from C57BL/6 mice were also exposed to oxalate. THP-1 macrophages treated with oxalate had decreased cellular bioenergetics, mitochondrial complex I and IV activity, and ATP levels compared to control cells. In addition, these cells had a significant increase in mitochondrial and total reactive oxygen species levels, mitochondrial gene expression, and pro-inflammatory cytokine (i.e. Interleukin-1β, IL-1β and Interleukin-6, IL-6) mRNA levels and secretion. In contrast, oxalate significantly decreased the mRNA levels and secretion of the anti-inflammatory cytokine, Interleukin-10 (IL-10). Further, oxalate increased the bacterial burden of primary macrophages. Our findings demonstrate that oxalate compromises macrophage metabolism, redox homeostasis, and cytokine signaling leading to a reduction in anti-bacterial response and increased infection. These data highlight a novel role of oxalate on macrophage function.

Management of Small, Non-obstructing Renal Stones in Adults With Recurrent Urinary Tract Infections

The management of small, non-obstructing renal stones in adults with recurrent lower urinary tract infections remains unclear. Whereas for larger or obstructing stones the decision to intervene becomes clearer, for stones smaller than 5 to 6 mm the decision to intervene requires consideration of multiple factors. This review describes these factors, including history, imaging, laboratory studies, as well as a comprehensive review of the literature. It remains of utmost importance that patients have additional possible etiologies appropriately evaluated and managed prior to intervention for their small renal stones.