Limited effectiveness of over-the-counter plant preparations used for the treatment of urinary tract infections as inhibitors of the urease activity from Staphylococcus saprophyticus

The immune responses to different Uropathogens call individual interventions for bladder infection

Urinary tract infection (UTI) caused by uropathogens is the most common infectious disease and significantly affects all aspects of the quality of life of the patients. However, uropathogens are increasingly becoming antibiotic-resistant, which threatens the only effective treatment option available-antibiotic, resulting in higher medical costs, prolonged hospital stays, and increased mortality. Currently, people are turning their attention to the immune responses, hoping to find effective immunotherapeutic interventions which can be alternatives to the overuse of antibiotic drugs. Bladder infections are caused by the main nine uropathogens and the bladder executes different immune responses depending on the type of uropathogens. It is essential to understand the immune responses to diverse uropathogens in bladder infection for guiding the design and development of immunotherapeutic interventions. This review firstly sorts out and comparatively analyzes the immune responses to the main nine uropathogens in bladder infection, and summarizes their similarities and differences. Based on these immune responses, we innovatively propose that different microbial bladder infections should adopt corresponding immunomodulatory interventions, and the same immunomodulatory intervention can also be applied to diverse microbial infections if they share the same effective therapeutic targets.

One-step coordination of metal-phenolic networks as antibacterial coatings with sustainable and controllable copper release for urinary catheter applications

Catheter-associated urinary tract infections (CAUTIs) draw great concern due to increased demand for urinary catheters in hospitalization. Encrustation caused by urinary pathogens, especially Proteus mirabilis, results in blocking of the catheter lumen and further infections. In this study, a facile and low-cost surface modification strategy of urinary catheters was developed using one-step coordination of tannic acid (TA) and copper ions. The copper content of the coating could be manipulated by the number of TA-Cu (TC) layers, and the coating released copper in a pH-responsive manner. The coating exhibited high antibacterial efficiency (killed >99% of planktonic bacteria, and reduced biofilm coverage to <1% after 24 h) due to the synergistic antimicrobial effect of TA and copper ions. In vivo study with a rabbit model indicated that with two TC layers, the coated catheter could effectively inhibit bacterial growth in urine and colonization on the surface, and reduce encrustation formation. In addition, the TC-coated catheter exhibited better tissue compatibility compared to the unmodified catheter, probably due to the antibacterial performance of the coating. Such a straightforward coating strategy with good in vitro and in vivo antibacterial properties and biocompatibility holds great promise for combating CAUTIs in clinical practice.

Towards Advances in Medicinal Plant Antimicrobial Activity: A Review Study on Challenges and Future Perspectives

The increasing incidence of drug- resistant pathogens raises an urgent need to identify and isolate new bioactive compounds from medicinal plants using standardized modern analytical procedures. Medicinal plant-derived compounds could provide novel straightforward approaches against pathogenic bacteria. This review explores the antimicrobial activity of plant-derived components, their possible mechanisms of action, as well as their chemical potential. The focus is put on the current challenges and future perspectives surrounding medicinal plants antimicrobial activity. There are some inherent challenges regarding medicinal plant extracts and their antimicrobial efficacy. Appropriate and optimized extraction methodology plant species dependent leads to upgraded and selective extracted compounds. Antimicrobial susceptibility tests for the determination of the antimicrobial activity of plant extracts may show variations in obtained results. Moreover, there are several difficulties and problems that need to be overcome for the development of new antimicrobials from plant extracts, while efforts have been made to enhance the antimicrobial activity of chemical compounds. Research on the mechanisms of action, interplay with other substances, and the pharmacokinetic and/or pharmacodynamic profile of the medicinal plant extracts should be given high priority to characterize them as potential antimicrobial agents.

Dietary Yucca schidigera Extract Supplementation During Late Gestating and Lactating Sows Improves Animal Performance, Nutrient Digestibility, and Manure Ammonia Emission

This study was conducted to investigate the effect of dietary Yucca schidigera extract (YSE) supplementation to sow performance, nutrients digestibility and ammonia emission of manure. Total 80 sows were randomly divided into 4 groups and fed with either control, control + 0.06% YSE, control + 0.12% YSE or control + 0.24% YSE diet from day 80 of gestation to day 21 of lactation. The results showed that dietary YSE supplementation resulted in trends toward a reduced number of stillbirth piglets (P = 0.08), weak piglets (P = 0.06), pre-weanling mortality (P = 0.04) and diarrhea (P = 0.03), and improved apparent digestibility of dry matter (P = 0.04). Besides, YSE supplementation significantly increased catalase activity (P = 0.02) while decreasing malonaldehyde levels (P = 0.04) in sow blood. Furthermore, the loss of total nitrogen, urea nitrogen and ammonia nitrogen in sow manure were significantly reduced with supplementation of YSE. In summary, supplementation of YSE in sow diet during late gestation and lactation could improve sow and litter performance, nutrient digestibility, and reduce nitrogen loss in sow manure during storage.

Inhibition of urease activity in the urinary tract pathogens Staphylococcus saprophyticus and Proteus mirabilis by dimethylsulfoxide (DMSO)

AIMS

Urease is a virulence factor for the urinary tract pathogens Staphylococcus saprophyticus and Proteus mirabilis. Dimethylsulfoxide (DMSO) is structurally similar to urea, used as a solvent for urease inhibitors, and an effective treatment for interstitial cystitis/bladder pain syndrome (IC/BPS). The aims of this study were to test DMSO as a urease inhibitor and determine its physiological effects on S. saprophyticus and P. mirabilis.

METHODS AND RESULTS

Urease activity in extracts and whole cells was measured by the formation of ammonium ions. Urease was highly sensitive to noncompetitive inhibition by DMSO (K_i about 6 mmol l^-1 ). DMSO inhibited urease activity in whole cells, limited bacterial growth in media containing urea, and slowed the increase in pH which occurred in artificial urine medium.

CONCLUSIONS

DMSO should be used with caution as a solvent when testing plant extracts or other potential urease inhibitors. Because it can inhibit bacterial growth and delay an increase in pH, it may be an effective treatment for urinary tract infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first detailed study of the inhibition of urease by DMSO. Dimethylsulfoxide may be used to treat urinary tract infections that are resistant to antibiotics or herbal remedies.