Therapies in early development for the treatment of urinary tract inflammation

pH responsive fabrication of PVA-stabilized selenium nano formulation encapsulated with luteolin to reduce diabetic ureteral injury by decreasing NLRP3 inflammasome via Nrf2/ARE signaling

Diabetic ureteral injury (DUI) is a condition characterized by damage to the ureter, causing functional and morphological changes in the urinary system, which have a significant impact on a quality of life and requires appropriate medical treatment. The present study describes to novel design of luteolin (LT), a type of natural flavonoid, encapsulated selenium nanoparticles (Se NPs) to attain therapeutic potential for DUI. The physico-chemical characterizations of prepared Se NPs have benefitted zeta potential (-18 mV) and particle size (10-50 nm). In vitro assays were demonstrated the potential of LT-SeNPs by HEK 293 cells stimulated by STZ for DUI. Cytotoxicity assays on HEK 293 and NIH-3T3 showed >90% cell viability, which demonstrates the suitability of the nanoformulation for DUI treatment. The LT-SeNPs significantly inhibits the NLRP3 inflammasome through Nrf2/ARE pathway, which benefits for DUI treatment. The developed LT-SeNPs could be an effective formulation for the DUI therapy.

Effect of Mannan Oligosaccharides Extracts in Uropathogenic Escherichia coli Adhesion in Human Bladder Cells

Urinary tract infections (UTIs) are a common public health problem, mainly caused by uropathogenic Escherichia coli (UPEC). Patients with chronic UTIs are usually treated with long-acting prophylactic antibiotics, which promotes the development of antibiotic-resistant UPEC strains and may complicate their long-term management. D-mannose and extracts rich in D-mannose such as mannan oligosaccharides (MOS; D-mannose oligomers) are promising alternatives to antibiotic prophylaxis due to their ability to inhibit bacterial adhesion to urothelial cells and, therefore, infection. This highlights the therapeutic potential and commercial value of using them as health supplements. Studies on the effect of MOS in UTIs are, however, scarce. Aiming to evaluate the potential benefits of using MOS extracts in UTIs prophylaxis, their ability to inhibit the adhesion of UPEC to urothelial cells and its mechanism of action were assessed. Additionally, the expression levels of the pro-inflammatory marker interleukin 6 (IL-6) were also evaluated. After characterizing their cytotoxic profiles, the preliminary results indicated that MOS extracts have potential to be used for the handling of UTIs and demonstrated that the mechanism through which they inhibit bacterial adhesion is through the competitive inhibition of FimH adhesins through the action of mannose, validated by a bacterial growth impact assessment.

Dendrobium officinale polysaccharides attenuate uropathogenic Escherichia coli (UPEC)-induced pyroptosis in macrophage cells

Urinary tract infections (UTI) are recognized as one of the most common infectious diseases worldwide, and uropathogenic Escherichia coli (UPEC) is the main causative agent of UTI. Dendrobium officinale polysaccharides (DOPs), the main effective ingredient in Dendrobium officinale, have been reported to possess an anti-inflammatory role. Whether DOPs can attenuate the inflammatory injury (pyroptosis) induced by UPEC remains unknown. The present study aimed to assess the protective effect and potential mechanism of DOPs in UPEC-induced pyroptosis. Cell viability of THP-1 differentiated macrophage cells with DOPs was determined using MTT assay. Pyroptosis by UPEC in macrophage cells with or not DOPs pre-treatment was evaluated with flow cytometry analysis, lactate dehydrogenase (LDH) assay, and proinflammatory cytokines secretion. Expression level of key proteins in the NLRP3/Caspase-1/GSDMD pyroptotic pathway was analyzed with western blot. Furthermore the effect of DOPs on ROS activation was investigated. Results indicated that DOPs attenuated UPEC-induced cell damage in macrophage cells, inhibited the activation of NLRP3 mediated inflammasome, subsequently decreased induction and activation of caspase-1/GSDMD, and reduced the secretion of pro-inflammatory cytokine (IL-1β et al.). Moreover, pretreatment with DOPs significantly reduces ROS production, an important/putative pyroptosis stimulus signal. These results suggested that DOPs successfully mitigate UPEC-promoted pyroptosis in macrophage cells. The protective effects of DOPs are associated with the inhibition of the NLRP3/Caspase-1/GSDMD pathway and ROS signal activation.

Enteroaggregative Escherichia coli is associated with antibiotic resistance and urinary tract infection symptomatology

Background

Uropathogenic Escherichia coli (UPEC) is the causative agent of uncomplicated urinary tract infections (UTIs) in ambulatory patients. However, enteroaggregative E. coli (EAEC), an emergent bacterial pathogen that causes persistent diarrhoea, has recently been associated with UTIs. The aim of this study was to determine the frequency of EAEC virulence genes, antibiotic resistance, as well as biofilm production of UPEC isolates obtained from ambulatory patients with non-complicated UTIs that attended to the ISSSTE clinic in Chilpancingo, Guerrero, Mexico, and correlate these with the patients' urinary tract infection symptomatology.

Methods

One hundred clinical isolates were obtained. The identification of clinical isolates, antimicrobial susceptibility testing, and extended spectrum beta-lactamases (ESBLs) production were performed using the Vitek automated system. Assignment of E. coli phylogenetic groups was performed using the quadruplex phylo-group assignment PCR assay. UPEC virulence genes (hlyA, fimH, papC, iutA, and cnf1) and EAEC virulence genes (aap, aggR, and aatA) were detected by multiple PCR.

Results

We found that 22% of the isolates carried the aggR gene and were classified as UPEC/EAEC. The main phylogenetic group was B2 (44.1% were UPEC and 77.27% UPEC/EAEC isolates, respectively). Over half of the UPEC/EAEC isolates (63.64%) were obtained from symptomatic patients, however the aatA gene was the only one found to be associated with the risk of developing pyelonephritis (OR = 5.15, p = 0.038). A total of 77.71% of the UPEC/EAEC isolates were ESBL producers and 90.91% multidrug-resistant (MDR). In conclusion, UPEC/EAEC isolates are more frequent in symptomatic patients and the aatA gene was associated with a higher risk of developing pyelonephritis, along with UPEC genes hlyA and cfn1. UPEC/EAEC isolates obtained from UTI showed ESBL production and MDR.

Effect of sub-minimal inhibitory concentration ceftazidime on the pathogenicity of uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) is the most prevalent causative agent of urinary tract infections (UTIs). The pathogenicity of UPEC relies on the expression of virulence factors which could be regulated by intercellular signal molecules. Our previous study found that sub-minimal inhibitory concentration ceftazidime (sub-MIC CAZ) could inhibit the biofilm formation of E. coli by luxS/AI-2 or indole. Therefore, we speculated that sub-MIC CAZ might affect the pathogenic capacity of UPEC. In this study, the results showed that sub-MIC CAZ could significantly inhibit the adhesion ability, biofilm formation and swimming and swarming motilities of UPEC isolated from recurrent UTI patient. Meanwhile, obvious decreased hemolytic activity and cytotoxicity were observed in CAZ-pretreated UPEC. Furthermore, qRT-PCR results confirmed the downregulating ability of CAZ on the expression of adhesion genes, motility genes, toxin gene and signal molecule synthesis genes, which are important for virulence and biofilm formation of UPEC. Pre-treatment of UPEC with sub-MIC CAZ resulted in the reduced adhesion to human bladder epithelial cell 5637 and the decreased numbers of intracellular bacterial communities in cells. Consistent with the results in vitro, the pretreatment of CAZ resulted in the reduction of UPEC load in the bladder and the less severity of UPEC-induced inflammation compared with control group. The present study results indicated that sub-MIC CAZ could decrease the pathogenicity of UPEC and might be served as an effective antimicrobial agent to combat recurrent UTI caused by UPEC.

d-Mannose Treatment neither Affects Uropathogenic Escherichia coli Properties nor Induces Stable FimH Modifications

Urinary tract infections (UTIs) are mainly caused by uropathogenic Escherichia coli (UPEC). Acute and recurrent UTIs are commonly treated with antibiotics, the efficacy of which is limited by the emergence of antibiotic resistant strains. The natural sugar d-mannose is considered as an alternative to antibiotics due to its ability to mask the bacterial adhesin FimH, thereby preventing its binding to urothelial cells. Despite its extensive use, the possibility that d-mannose exerts "antibiotic-like" activity by altering bacterial growth and metabolism or selecting FimH variants has not been investigated yet. To this aim, main bacterial features of the prototype UPEC strain CFT073 treated with d-mannose were analyzed by standard microbiological methods. FimH functionality was analyzed by yeast agglutination and human bladder cell adhesion assays. Our results indicate that high d-mannose concentrations have no effect on bacterial growth and do not interfere with the activity of different antibiotics. d-mannose ranked as the least preferred carbon source to support bacterial metabolism and growth, in comparison with d-glucose, d-fructose, and l-arabinose. Since small glucose amounts are physiologically detectable in urine, we can conclude that the presence of d-mannose is irrelevant for bacterial metabolism. Moreover, d-mannose removal after long-term exposure did not alter FimH's capacity to bind to mannosylated proteins. Overall, our data indicate that d-mannose is a good alternative in the prevention and treatment of UPEC-related UTIs.

Suppressing the phenotypic virulence factors of Uropathogenic Escherichia coli using marine polysaccharide

Uropathogenic Escherichia coli (UPEC) is one of the keystone pathogen that cause 80-90% of community acquired urinary tract infections (UTIs) and Catheter associated urinary tract infections (CAUTIs). Pathogenicity and ability of UPEC to colonize the bladder majorly relies on the expression of phenotypic virulence factors like flagella, pili, curli, and non pilus adhesion. Pathogens that colonize on the indwelling medical devices are able to communicate using quorum sensing (QS) signals. QS Plays a vital role in coordinating biofilm formation which results in the bacterial cells encased inside an extracellular polymeric substance (EPS). Chitosan is a marine polysaccharide which is known for its antibacterial activity. In the present study we investigated the ability of chitosan extracted from marine biowaste to mitigate the QS mediated biofilm formation in UPEC. Extracted chitosan (EC) and Commercial chitosan (CC) showed percentage inhibition of 80-85% and 60-75% respectively on young biofilm inhibition and preformed biofilm disruption. EC and CC were assessed for its ability to suppress QS mediated virulence in UPEC. Hemolysis assay showed a percentage inhibition of 79% against EC. Both chitosan showed profound activity to suppress the phenotypic virulence factors like swarming motility which is mediated by type I pili and colony morphology assay showed repression in cellulose production in UPEC. Furthermore, Real-Time PCR confirmed the ability of EC to down regulate the virulent genes which are responsible for invasion in UPEC. Accordingly, the current study foresees the quorum sensing inhibiting (QSI) potential of chitosan extracted from marine biowaste which offers an antibiotic free approach to combat UTI caused by UPEC.

Antibiotic Resistance Among Uropathogenic Escherichia coli

Urinary tract infections (UTIs) belong to the most common community-acquired and nosocomial infections. A main etiological factor of UTIs is uropathogenic Escherichia coli (UPEC). This review describes the current state of knowledge on the resistance of UPEC to antibiotics recommended for the treatment of UTIs based on the available literature data. Nitrofurantoin and fosfomycin are recommended as first-line therapy in the treatment of uncomplicated cystitis, and the resistance to these antimicrobial agents remains low between UPEC. Recently, in many countries, the increasing resistance is observed to trimethoprim-sulfamethoxazole, which is widely used as the first-line antimicrobial in the treatment of uncomplicated UTIs. In European countries, the resistance of UPEC to this antimicrobial agent ranges from 14.6% to 60%. The widespread use of fluoroquinolones (FQs), especially ciprofloxacin, in the outpatients is the cause of a continuous increase in resistance to these drugs. The resistance of UPEC to FQs is significantly higher in developing countries (55.5–85.5%) than in developed countries (5.1–32.0%). Amoxicillin-clavulanic acid is recommended as first line-therapy for pyelonephritis or complicated UTI. Resistance rates of UPEC to amoxicillin-clavulanic acid are regionally variable. In European countries the level of resistance to this antimicrobial ranges from 5.3% (Germany) to 37.6% (France). Increasing rates of UPEC resistance to antimicrobials indicate that careful monitoring of their use for UTI treatment is necessary.

Ultrasound-activated microbubbles as a novel intracellular drug delivery system for urinary tract infection

The development of new modalities for high-efficiency intracellular drug delivery is a priority for a number of disease areas. One such area is urinary tract infection (UTI), which is one of the most common infectious diseases globally and which imposes an immense economic and healthcare burden. Common uropathogenic bacteria have been shown to invade the urothelial wall during acute UTI, forming latent intracellular reservoirs that can evade antimicrobials and the immune response. This behaviour likely facilitates the high recurrence rates after oral antibiotic treatments, which are not able to penetrate the bladder wall and accumulate to an effective concentration. Meanwhile, oral antibiotics may also exacerbate antimicrobial resistance and cause systemic side effects. Using a human urothelial organoid model, we tested the ability of novel ultrasound-activated lipid microbubbles to deliver drugs into the cytoplasm of apical cells. The gas-filled lipid microbubbles were decorated with liposomes containing the non-cell-permeant antibiotic gentamicin and a fluorescent marker. The microbubble suspension was added to buffer at the apical surface of the bladder model before being exposed to ultrasound (1.1 MHz, 2.5 Mpa, 5500 cycles at 20 ms pulse duration) for 20 s. Our results show that ultrasound-activated intracellular delivery using microbubbles was over 16 times greater than the control group and twice that achieved by liposomes that were not associated with microbubbles. Moreover, no cell damage was detected. Together, our data show that ultrasound-activated microbubbles can safely deliver high concentrations of drugs into urothelial cells, and have the potential to be a more efficacious alternative to traditional oral antibiotic regimes for UTI. This modality of intracellular drug delivery may prove useful in other clinical indications, such as cancer and gene therapy, where such penetration would aid in treatment.

Urinary tract infection: Pathogenicity, antibiotic resistance and development of effective vaccines against Uropathogenic Escherichia coli

Urinary tract infections (UTIs) are recognized as one of the most common infectious diseases in the world that can be divided to different types. Uropathogenic Escherichia coli (UPEC) strains are the most prevalent causative agent of UTIs that applied different virulence factors such as fimbriae, capsule, iron scavenger receptors, flagella, toxins, and lipopolysaccharide for their pathogenicity in the urinary tract. Despite the high pathogenicity of UPEC strains, host utilizes different immune systems such as innate and adaptive immunity for eradication of them from the urinary tract. The routine therapy of UTIs is based on the use of antibiotics such as β-lactams, trimethoprim, nitrofurantoin and quinolones in many countries. Unfortunately, the widespread and misuse of these antibiotics resulted in the increasing rate of resistance to them in the societies. Increasing antibiotic resistance and their side effects on human body show the need to develop alternative strategies such as vaccine against UTIs. Developing a vaccine against UTI pathogens will have an important role in reduction the mortality rate as well as reducing economic costs. Different vaccines based on the whole cells (killed or live-attenuated vaccines) and antigens (subunits, toxins and conjugatedvaccines) have been evaluated against UTIs pathogens. Furthermore, other therapeutic strategies such as the use of probiotics and antimicrobial peptides are considered against UTIs. Despite the extensive efforts, limited success has been achieved and more studies are needed to reach an alternative of antibiotics for treatment of UTIs.

UroPathogenic Escherichia coli (UPEC) Infections: Virulence Factors, Bladder Responses, Antibiotic, and Non-antibiotic Antimicrobial Strategies

Urinary tract infections (UTIs) are one of the most common pathological conditions in both community and hospital settings. It has been estimated that about 150 million people worldwide develop UTI each year, with high social costs in terms of hospitalizations and medical expenses. Among the common uropathogens associated to UTIs development, UroPathogenic Escherichia coli (UPEC) is the primary cause. UPEC strains possess a plethora of both structural (as fimbriae, pili, curli, flagella) and secreted (toxins, iron-acquisition systems) virulence factors that contribute to their capacity to cause disease, although the ability to adhere to host epithelial cells in the urinary tract represents the most important determinant of pathogenicity. On the opposite side, the bladder epithelium shows a multifaceted array of host defenses including the urine flow and the secretion of antimicrobial substances, which represent useful tools to counteract bacterial infections. The fascinating and intricate dynamics between these players determine a complex interaction system that needs to be revealed. This review will focus on the most relevant components of UPEC arsenal of pathogenicity together with the major host responses to infection, the current approved treatment and the emergence of resistant UPEC strains, the vaccine strategies, the natural antimicrobial compounds along with innovative anti-adhesive and prophylactic approaches to prevent UTIs.