Current concepts of molecular defence mechanisms operative during urinary tract infection

Increased water intake dilutes protective uromodulin levels in urine and results in increased rates of pyelonephritis in a murine model

AIM

Urinary tract infections (UTIs) rank among the most prevalent infections in humans, carrying substantial implications for public health. Women experiencing recurrent UTIs are often advised to boost their fluid intake to help eliminate bacteria. In this study, we explored the impact of elevated fluid consumption during UTIs using a mouse model of pyelonephritis.

METHODS

UTI was induced in 8-10 w female BALB/cJ-mice by surgically injecting Escherichia coli (O6:K13:H1) into the bladder whereafter mice were randomized to gel food (GF) or regular chow. Immune response and infection severity were determined 24-h post-infection. In vitro bacterial growth (OD600) was determined in urine from mice or from human volunteers.

RESULTS

Gel feeding increased urine output (1.40 ± 0.77 μL min-1, p < 0.01) and diluted the urine (668.7 ± 177 mOsmol kg-1, p < 0.0001) compared to controls on regular chow (urine output: 0.34 ± 0.27 μL min-1, osmolality: 1439 ± 473.5 mOsmol kg-1). Mice on GF had a higher risk of pyelonephritis (87.5%) and more severe infections (26.22 ± 9.88 CFU mg-1 tissue) compared to controls (43.75%; 3.87 ± 3.56 CFU mg-1, p < 0.01). Correspondingly, the growth of E. coli was markedly reduced at osmolalities above 1200 mOsmol kg-1 compared to 600 mOsmol kg-1 and GF mice had lower urine levels of uromodulin (13.70 ± 1.89 μg mL-1, p < 0.01) compared to controls (24.65 ± 2.70 μg mL-1).

CONCLUSION

Increased water intake and urine flow in mice will markedly increase the risk of pyelonephritis. The increased risk may reflect reduced urine uromodulin combined with optimized growth conditions for E. coli. The study does not immediately support the notion that established UTIs can be eliminated by increased water intake.

An Atypical F-Actin Capping Protein Modulates Cytoskeleton Behaviors Crucial for Trichomonas vaginalis Colonization

Cytoadherence and migration are crucial for pathogens to establish colonization in the host. In contrast to a nonadherent isolate of Trichomonas vaginalis, an adherent one expresses more actin-related machinery proteins with more active flagellate-amoeboid morphogenesis, amoeba migration, and cytoadherence, activities that were abrogated by an actin assembly blocker. By immunoprecipitation coupled with label-free quantitative proteomics, an F-actin capping protein (T. vaginalis F-actin capping protein subunit α [TvFACPα]) was identified from the actin-centric interactome. His-TvFACPα was detected at the barbed end of a growing F-actin filament, which inhibited elongation and possessed atypical activity in binding G-actin in in vitro assays. TvFACPα partially colocalized with F-actin at the parasite pseudopod protrusion and formed a protein complex with α-actin through its C-terminal domain. Meanwhile, TvFACPα overexpression suppressed F-actin polymerization, amoeboid morphogenesis, and cytoadherence in this parasite. Ser2 phosphorylation of TvFACPα enriched in the amoeboid stage of adhered trophozoites was reduced by a casein kinase II (CKII) inhibitor. Site-directed mutagenesis and CKII inhibitor treatment revealed that Ser2 phosphorylation acts as a switching signal to alter TvFACPα actin-binding activity and the consequent actin cytoskeleton behaviors. Through CKII signaling, TvFACPα also controls the conversion of adherent trophozoites from amoeboid migration to the flagellate form with axonemal motility. Together, CKII-dependent Ser2 phosphorylation regulates TvFACPα binding to actin to fine-tune cytoskeleton dynamics and drive crucial behaviors underlying host colonization by T. vaginalis. IMPORTANCE Trichomoniasis is one of the most prevalent nonviral sexually transmitted diseases. T. vaginalis cytoadherence to urogenital epithelium cells is the first step in the colonization of the host. However, studies on the mechanisms of cytoadherence have focused mainly on the role of adhesion molecules, and their effects are limited when analyzed by loss- or gain-of-function assays. This study proposes an extra pathway in which the actin cytoskeleton mediated by a capping protein α-subunit may play roles in parasite morphogenesis, cytoadherence, and motility, which are crucial for colonization. Once the origin of the cytoskeleton dynamics could be manipulated, the consequent activities would be controlled as well. This mechanism may provide new potential therapeutic targets to impair this parasite infection and relieve the increasing impact of drug resistance on clinical and public health.

Design and computational analysis of an effective multi-epitope vaccine candidate using subunit B of cholera toxin as a build-in adjuvant against urinary tract infections

Introduction

Urinary tract infection (UTI) is one of the most common infections, usually caused by uropathogenic Escherichia coli (UPEC). However, antibiotics are a usual treatment for UTIs; because of increasing antibiotic-resistant strains, vaccination can be beneficial in controlling UTIs. Using immunoinformatics techniques is an effective and rapid way for vaccine development.

Methods

Three conserved protective antigens (FdeC, Hma, and UpaB) were selected to develop a novel multi-epitope vaccine consisting of subunit B of cholera toxin (CTB) as a mucosal build-in adjuvant to enhance the immune responses. Epitopes-predicted B and T cells and suitable linkers were used to separate them and effectively increase the vaccine's immunogenicity. The vaccine protein's primary, secondary, and tertiary structures were evaluated, and the best 3D model was selected. Since CTB is the TLR2 ligand, molecular docking was made between the vaccine protein and TLR2. Molecular dynamic (MD) simulation was employed to evaluate the stability of the vaccine protein-TLR2 complex. The vaccine construct was subjected to in silico cloning.

Results

The designed vaccine protein has multiple properties in the analysis. The HADDOCK outcomes show an excellent interaction between vaccine protein and TLR2. The MD results confirm the stability of the vaccine protein- TLR2 complex during the simulation. In silico cloning verified the expression efficiency of our vaccine protein.

Conclusion

The results of this study suggest that our designed vaccine protein could be a promising vaccine candidate against UTI, but further in vitro and in vivo studies are needed.

In silico design and in vivo evaluation of two multi-epitope vaccines containing build-in adjuvant with chitosan nanoparticles against uropathogenic Escherichia coli

BACKGROUND

Urinary pathogenic Escherichia coli (UPEC) is one of the most important bacterial causes of urinary tract infections (UTIs). Rising antimicrobial resistance and serious clinical challenges such as persistent and recurrent UTIs make it a serious public health concern. Therefore, preventative approaches such as vaccinations are required.

METHODS

In this study, we selected three conserve and protective antigens (FdeC, Hma and UpaB) and also subunit B of cholera toxin (as build-in adjuvant) to design two multi-epitope vaccines (construct B containing B cell epitopes and construct T containing T epitopes) using different bioinformatics methods. The expression of the recombinant protein was performed using the BL21(DE3)/pET28 expression system and purified through a Ni-NTA column. Vaccine proteins were encapsulated in chitosan nanoparticles (CNP) based on ionic gelation via a microfluidic system. Mice were immunized intranasally with different vaccine formulations. Antibody responses and also cytokine expression (IFN-γ and IL-4) were measured by ELISA and real-time PCR respectively. The effectiveness of immune responses was assessed by bladder challenge.

RESULTS

Based on the in silico study, construct B and construct T have high confidence value and stable structure in vivo. High yield expression of both constructs was confirmed by SDS-PAGE and western blot assay. Immunization of mice with construct B induced strong Th2 (IgG1 and IL4) responses and construct T shift immune responses to Th1 (IFNγ and IgG2a). Vaccine protein-encapsulated CNP elicited higher levels of antibodies and cell-mediated responses than the vaccine proteins alone.

CONCLUSIONS

The results of this study suggest that intranasal administration of the construct B has the potential to enhance humoral immunity and construct T has the potential to stimulate cellular immunity. In addition, the combination of CTB as a build-in adjuvant and CNP can be proposed as a potent adjuvant for the development of a novel vaccine against UTI.

Vesicoureteral Reflux and Innate Immune System: Physiology, Physiopathology, and Clinical Aspects

Vesicoureteral reflux represents one of the most concerning topics in pediatric nephrology due to its frequency, clinical expression with the potential to evolve into chronic kidney disease, and last but not least, its socio-economic implications. The presence of vesicoureteral reflux, the occurrence of urinary tract infections, and the development of reflux nephropathy, hypertension, chronic kidney disease, and finally, end-stage renal disease represent a progressive spectrum of a single physiopathological condition. For the proper management of these patients with the best clinical outcomes, and in an attempt to prevent the spread of uropathogens' resistance to antibacterial therapy, we must better understand the physiopathology of urinary tract infections in patients with vesicoureteral reflux, and at the same time, we should acknowledge the implication and response of the innate immune system in this progressive pathological condition. The present paper focuses on theoretical aspects regarding the physiopathology of vesicoureteral reflux and the interconditionality between urinary tract infections and the innate immune system. In addition, we detailed aspects regarding cytokines, interleukins, antimicrobial peptides, and proteins involved in the innate immune response as well as their implications in the physiopathology of reflux nephropathy. New directions of study should focus on using these innate immune system effectors as diagnostic and therapeutic tools in renal pathology.

Diagnostic and prognostic role of pancreatic secretory granule membrane major glycoprotein 2 (GP2) immunohistochemistry: A TMA study on 27,681 tumors

Pancreatic secretory granule membrane major glycoprotein 2 (GP2) is a membrane component of zymogen granules which is abundantly secreted by pancreatic acinar cells. Because RNA based analyses suggest a strict limitation of GP2 expression to the pancreas in normal tissues, and a strong preference to pancreatic cancer among tumors, GP2 expression analysis might have diagnostic utility. To better understand the role of GP2 protein expression, GP2 was successfully analyzed in 27,965 tumor samples from 132 different tumor types and subtypes as well as 8 samples each of 76 different normal tissue types by immunohistochemistry in a tissue microarray format (TMA). GP2 immunostaining was seen in 14 of 16 (87.5 %) acinar cell carcinomas, 6 of 507 (1.2 %) ductal adenocarcinomas, and 3 of 99 neuroendocrine neoplasms of the pancreas (3.0 %). GP2 was also found in 23 extra-pancreatic tumor entities including several types of neuroendocrine neoplasms (14.3-58.8 %), prostatic adenocarcinomas (8.2-18.8 %), various other adenocarcinomas (0.1-7.7 %), and several categories of benign and malignant salivary gland tumors (2.3-3.1 %). A strong GP2 positivity was only seen in 6 tumor categories including 50 % of 16 pancreatic acinus cell carcinomas, 11.8 % of 17 neuroendocrine tumors of the lung, 1.3 % of 80 primary Gleason 4 + 4 % and 0.6 % of 181 recurrent prostate cancers, as well as 0.8 % of 133 adenocarcinomas of the lung. In a cohort of 14,747 prostate cancers with follow up data, GP2 immunostaining was strongly linked to advanced pT stage, high Gleason grade, lymph node metastasis, and recurrence free survival (p < 0.0001 each). The prognostic impact of GP2 positivity was independent of established parameters in TMPRSS2:ERG fusion-negative cancers (p < 0.0001). In summary, our data show that GP2 is preferentially expressed in acinar cell carcinomas of the pancreas but the glycoprotein can - rarely - also be expressed in a variety of other tumor entities.

RNase 7 Inhibits Uropathogenic Escherichia coli-Induced Inflammation in Bladder Cells under a High-Glucose Environment by Regulating the JAK/STAT Signaling Pathway

Antimicrobial peptides (AMPs), which are natural antibiotics, protect against pathogens invading the urinary tract. RNase 7 with antimicrobial properties has rapid and powerful suppressive effects against Gram-positive and Gram-negative bacterial infections. However, its detailed antibacterial mechanisms have not been fully determined. Here, we investigate whether RNase 7 had an impact on bladder cells under uropathogenic Escherichia coli (UPEC) infection in a high-glucose environment using in vitro GFP-UPEC-infected bladder cell and PE-labeled TLR4, STAT1, and STAT3 models. We provide evidence of the suppressive effects of RNase 7 on UPEC infection and UPEC-induced inflammatory responses by regulating the JAK/STAT signaling pathway using JAK inhibitor and STAT inhibitor blocking experiments. Pretreatment with different concentrations of RNase 7 for 24 h concentration-dependently suppressed UPEC invasion in bladder cells (5 μg/mL reducing 45%; 25 μg/mL reducing 60%). The expressions of TLR4, STAT1, and STAT3 were also downregulated in a concentration-dependent manner after RNase 7 pretreatment (5 μg/mL reducing 35%, 54% and 35%; 25 μg/mL reducing 60%, 75% and 64%, respectively). RNase 7-induced decrease in UPEC infection in a high-glucose environment not only downregulated the expression of TLR4 protein and the JAK/STAT signaling pathway but also decreased UPEC-induced secretion of exogenous inflammatory IL-6 and IL-8 cytokines, although IL-8 levels increased in the 25 μg/mL RNase 7-treated group. Thus, inhibition of STAT affected pSTAT1, pSTAT3, and TLR4 expression, as well as proinflammatory IL-6 and IFN-γ expression. Notably, blocking JAK resulted in the rebound expression of related proteins, especially pSTAT1, TLR4, and IL-6. The present study showed the suppressive effects of RNase 7 on UPEC infection and induced inflammation in bladder epithelial cells in a high-glucose environment. RNase 7 may be an anti-inflammatory and anti-infective mediator in bladder cells by downregulating the JAK/STAT signaling pathway and may be beneficial in treating cystitis in DM patients. These results will help clarify the correlation between AMP production and UTI, identify the relationship between urinary tract infection and diabetes in UTI patients, and develop novel diagnostics or possible treatments targeting RNase 7.

Isolation, Identification, Characterization, and Plasmid Profile of Urinary Tract Infectious Escherichia coli from Clinical Samples

Objective

In recent times, urinary tract infection (UTI) is one of the most widely recognized bacterial diseases all over the planet. UTI influences individuals of any age and gender. The target of this study is to concentrate on the recurrence of uropathogens, the antimicrobial susceptibility pattern of the isolates, and the plasmid profile of people from the government clinics of Karaikudi.

Methods

From July 2017 to December 2017, 100 urine tests were gathered and handled for the isolation of pathogenic microbes. In total, 89 isolates were found from the samples collected.

Results

Escherichia coli was discovered as the most common bacterial isolate screened from the UTI-infected people, accounting for 28.09 percent of all isolates. E. coli was seen to be the highest prevalent bacterium for UTI in all age groups and demonstrated resistance to routinely used medications, especially cefpodoxime and novobiocin, which have been 100 percent resistant. The E. coli isolates screened were positive for beta-lactamase and film generation, and they have strong antimicrobial resistance. As a result, the E. coli strains with the highest prevalence of virulence determinants have become more resistant to many medications because they support the microorganism in overcoming the host's defense and colonizing or entering the urinary system. The amplified 16S rRNA product was analyzed, and phylogenetic relationships were determined. The presence of TEM (56 percent), CTX-M (64 percent), SHV (40 percent), and OXA (60 percent) was discovered. Among E. coli isolates, CTX-M was the most common extended spectrum-beta lactamase (ESBL). Multiplex PCR was also used to identify the existence of CTX-M subgroups in E. coli isolates.

Conclusion

Finally, we urge that antibiotic selection should be predicated on the awareness of the specific prevalence and that novel antimicrobial medicines for urinary infections be developed to combat the overuse of antibiotics.

Prevalence of antibodies in Iraqi Urinary Tract Infection patients using radial immunodiffusion (RID) assay

Urinary Tract Infection (UTI) is an infection every place in the urinary tract that may be in the urethra, bladder, or kidneys by microbes. Greatest UTIs are affected by bacteria, but some are affected by fungi and, in rare cases, by viruses. UTI is the most significant common infection in humans. This study deals with the prevalence of antibodies in UTI patients; this study aims to determine the level of antibodies in UTI patients and compare with healthy controls by using the radial immunodiffusion (RID) test. The study was done during the period November 2019 to April 2020 on UTI Iraqi patients. The study included 40 patients and 20 healthy controls. Results show UTI infection occurs in females more than males also; the mean age is 40 years. All the patients with UTI showed decreased IgM serum levels and increased IgG compared with the control group. IgG, IgG, and IgM showed high significance between two UTI patients and the control group groups, while IgM doesn’t show significant differences between study groups.

Urethral Catheter Biofilms Reveal Plasticity in Bacterial Composition and Metabolism and Withstand Host Immune Defenses in Hypoxic Environment

Biofilms composed of multiple microorganisms colonize the surfaces of indwelling urethral catheters that are used serially by neurogenic bladder patients and cause chronic infections. Well-adapted pathogens in this niche are Escherichia coli, Proteus, and Enterococcus spp., species that cycle through adhesion and multilayered cell growth, trigger host immune responses, are starved off nutrients, and then disperse. Viable microbial foci retained in the urinary tract recolonize catheter surfaces. The molecular adaptations of bacteria in catheter biofilms (CBs) are not well-understood, promising new insights into this pathology based on host and microbial meta-omics analyses from clinical specimens. We examined catheters from nine neurogenic bladder patients longitudinally over up to 6 months. Taxonomic analyses from 16S rRNA gene sequencing and liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics revealed that 95% of all catheter and corresponding urinary pellet (UP) samples contained bacteria. CB biomasses were dominated by Enterobacteriaceae spp. and often accompanied by lactic acid and anaerobic bacteria. Systemic antibiotic drug treatments of patients resulted in either transient or lasting microbial community perturbations. Neutrophil effector proteins were abundant not only in UP but also CB samples, indicating their penetration of biofilm surfaces. In the context of one patient who advanced to a kidney infection, Proteus mirabilis proteomic data suggested a combination of factors associated with this disease complication: CB biomasses were high; the bacteria produced urease alkalinizing the pH and triggering urinary salt deposition on luminal catheter surfaces; P. mirabilis utilized energy-producing respiratory systems more than in CBs from other patients. The NADH:quinone oxidoreductase II (Nqr), a Na+ translocating enzyme not operating as a proton pump, and the nitrate reductase A (Nar) equipped the pathogen with electron transport chains promoting growth under hypoxic conditions. Both P. mirabilis and E. coli featured repertoires of transition metal ion acquisition systems in response to human host-mediated iron and zinc sequestration. We discovered a new drug target, the Nqr respiratory system, whose deactivation may compromise P. mirabilis growth in a basic pH milieu. Animal models would not allow such molecular-level insights into polymicrobial biofilm metabolism and interactions because the complexity cannot be replicated.

Expression and function of human ribonuclease 4 in the kidney and urinary tract

Antimicrobial peptides are essential host defense mechanisms that prevent urinary tract infections. Recent studies have demonstrated that peptides in the ribonuclease A superfamily have antimicrobial activity against uropathogens and protect the urinary tract from uropathogenic Escherichia coli (UPEC). Little is known about the antibacterial function or expression of ribonuclease 4 (RNase 4) in the human urinary tract. Here, we show that full-length recombinant RNase 4 peptide and synthetic amino-terminal RNase 4 peptide fragment have antibacterial activity against UPEC and multidrug-resistant (MDR)-UPEC. RNASE4 transcript expression was detected in human kidney and bladder tissue using quantitative real-time PCR. Immunostaining or in situ hybridization localized RNase 4 expression to proximal tubules, principal and intercalated cells in the kidney's collecting duct, and the bladder urothelium. Urinary RNase 4 concentrations were quantified in healthy controls and females with a history of urinary tract infection. Compared with controls, urinary RNase 4 concentrations were significantly lower in females with a history of urinary tract infection. When RNase 4 was neutralized in human urine or silenced in vitro using siRNA, urinary UPEC replication or attachment to and invasion of urothelial and kidney medullary cells increased. These data show that RNase 4 has antibacterial activity against UPEC, is expressed in the human urinary tract, and can contribute to host defense against urinary tract infections.NEW & NOTEWORTHY Ribonuclease 4 (RNase 4) is a newly identified host defense peptide in the human kidney and bladder. RNase 4 kills uropathogenic Escherichia coli (UPEC) and multidrug-resistant UPEC. RNase 4 prevents invasive UPEC infection and suppressed RNase 4 expression may be a risk factor for more severe or recurrent urinary tract infection.

Polysaccharides extract from Vaccaria segetalis seeds inhibits kidney infection by regulating cathelicidin expression

ETHNOPHARMACOLOGICAL RELEVANCE

According to the Chinese Pharmacopoeia, the seeds of Vaccaria segetalis, a traditional medicinal herb, can be used for treating urinary diseases. The polysaccharides extract from V. segetalis seeds (VSP) has been shown to prevent urinary tract infections (UTIs).

AIM OF THE STUDY

Investigate the effects of VSP on treating kidney infection induced by uropathogenic Escherichia coli (UPEC) and the underlying mechanisms.

MATERIALS AND METHODS

Both in vivo and in vitro infection models were established with the UPEC strain CFT073. After oral administration of VSP, the levels of bacterial load, cathelicidin (CRAMP), Toll-like receptors (TLRs) in the kidney were evaluated. The expression of cathelicidin (LL-37) in human renal cell carcinoma cell line (A498) was tested after the treatment of VSP.

RESULTS

In the kidneys of infection models, high-titer bacteria was detected. In the kidney of rat model, the expression of CRAMP was down-regulated, no significant change was observed in the levels of TLRs. After oral administration of VSP, the bacterial load was significantly decreased in rat and mouse models, and the levels of CRAMP and TLRs were significantly up-regulated in rat model. In vitro, the expression of LL-37 was significantly inhibited by CFT073. VSP up-regulated the expression of LL-37 in A498 cells.

CONCLUSIONS

The up-regulation of cathelicidin expression may contribute to the therapeutic effects of VSP on kidney infection.

Crude polysaccharides from the seeds of Vaccaria segetalis prevent the urinary tract infection through the stimulation of kidney innate immunity

ETHNOPHARMACOLOGICAL RELEVANCE

The seeds of Vaccaria segetalis (Neck.) Garcke is used for the treatment of urinary diseases in Traditional Chinese Medicine according to the Chinese Pharmacopoeia. Crude polysaccharides and the aqueous extract from the seeds of V. segetalis (SVCP) were proved to be effective on treating benign prostatic hyperplasia.

AIM OF THE STUDY

The aim of this study was to test the effects of SVCP on urinary tract infection (UTI) induced by uropathogenic Escherichia coli (UPEC) strain CFT073 in the rat model and to investigate the underlying mechanisms.

MATERIALS AND METHODS

A rat UTI model was established with the infection of UPEC strain CFT073. After oral administration of SVCP, the urinalysis and histological examination were evaluated. The levels of pro-inflammatory cytokines, procalcitonin (PCT) and polymeric Ig receptor (PIGR) were used to test the effects of SVCP on host immunity. The mRNA level of PapG in CFT073 was used to test the influence of SVCP on virulence factor. The effects of SVCP on the inhibition of bacterial adhesion were evaluated with mice UTI model.

RESULTS

In the rat UTI model, the levels of bacterial load, white blood cells (WBC) and red blood cells (RBC) in urine and the pathological injury in the bladder were significantly up-regulated, the expression of PIGR in kidney was down-regulated, no significant change was observed on the pro-inflammatory cytokines in urine. After oral administration of SVCP for 3 days, the levels of bacterial load, WBC and RBC in urine were significantly decreased, the pathological injury in the bladder were remarkably inhibited. The expression of IL-6, IL-8 in urine and PIGR in kidney were significantly up-regulated by SVCP (200 mg/kg). SVCP showed no effect on the concentration of PCT in serum. SVCP failed to down-regulate the mRNA level of PapG in CFT073. In the mice UTI model, pre-treatment of SVCP failed to inhibit the intracellular bacterial load in the bladder.

CONCLUSIONS

The therapeutic effects of SVCP on treating UTIs might result from the up-regulation of innate immunity in the kidney. SVCP can be used as an alternative therapeutic agent for UTIs.

Innate immunity and urinary tract infection

Urinary tract infections are a severe public health problem. The emergence and spread of antimicrobial resistance among uropathogens threaten to further compromise the quality of life and health of people who develop acute and recurrent upper and lower urinary tract infections. The host defense mechanisms that prevent invasive bacterial infection are not entirely delineated. However, recent evidence suggests that versatile innate immune defenses play a key role in shielding the urinary tract from invading uropathogens. Over the last decade, considerable advances have been made in defining the innate mechanisms that maintain immune homeostasis in the kidney and urinary tract. When these innate defenses are compromised or dysregulated, pathogen susceptibility increases. The objective of this review is to provide an overview of how basic science discoveries are elucidating essential innate host defenses in the kidney and urinary tract. In doing so, we highlight how these findings may ultimately translate into the clinic as new biomarkers or therapies for urinary tract infection.

TRPV4 Mediates Acute Bladder Responses to Bacterial Lipopolysaccharides

Urinary tract infections (UTI) affect a large proportion of the population, causing among other symptoms, more frequent and urgent micturition. Previous studies reported that the gram-negative bacterial wall component lipopolysaccharides (LPS) trigger acute epithelial and bladder voiding responses, but the underlying mechanisms remain unknown. The cation channel TRPV4 is implicated in the regulation of the bladder voiding. Since TRPV4 is activated by LPS in airway epithelial cells, we sought to determine whether this channel plays a role in LPS-induced responses in urothelial cells (UCs). We found that human-derived UCs display a fast increase in intracellular Ca²⁺ concentration upon acute application of Escherichia coli LPS. Such responses were detected also in freshly isolated mouse UCs, and found to be dependent on TRPV4, but not to require the canonical TLR4 signaling pathway of LPS detection. Confocal microscopy experiments revealed that TRPV4 is dispensable for LPS-induced nuclear translocation of NF-κB in mouse UCs. On the other hand, quantitative RT PCR determinations showed an enhanced LPS-induced production of proinflammatory cytokines in TRPV4-deficient UCs. Cystometry experiments in anesthetized wild type mice revealed that acute intravesical instillation of LPS rapidly increases voiding frequency. This effect was not observed in TRPV4-deficient animals, but was largely preserved in Tlr4 KO and Trpa1 KO mice. Our results suggest that activation of TRPV4 by LPS in UCs regulates the proinflammatory response and contributes to LPS-induced increase in voiding frequency. These findings further support the concept that TRP channels are sensors of LPS, mediating fast innate immunity mechanisms against gram-negative bacteria.

Urinary tract infections: microbial pathogenesis, host-pathogen interactions and new treatment strategies

Urinary tract infections (UTIs) are common, recurrent infections that can be mild to life-threatening. The continued emergence of antibiotic resistance, together with our increasing understanding of the detrimental effects conferred by broad-spectrum antibiotic use on the health of the beneficial microbiota of the host, has underscored the weaknesses in our current treatment paradigm for UTIs. In this Review, we discuss how recent microbiological, structural, genetic and immunological studies have expanded our understanding of host-pathogen interactions during UTI pathogenesis. These basic scientific findings have the potential to shift the strategy for UTI treatment away from broad-spectrum antibiotics targeting conserved aspects of bacterial replication towards pathogen-specific antibiotic-sparing therapeutics that target core determinants of bacterial virulence at the host-pathogen interface.

The Responses of the Ribonuclease A Superfamily to Urinary Tract Infection

The lower urinary tract is routinely exposed to microbes residing in the gastrointestinal tract, yet the urothelium resists invasive infections by gut microorganisms. This infection resistance is attributed to innate defenses in the bladder urothelium, kidney epithelium, and resident or circulating immune cells. In recent years, surmounting evidence suggests that these cell types produce and secrete soluble host defense peptides, including members of the Ribonuclease (RNase) A Superfamily, to combat invasive bacterial challenge. While some of these peptides, including RNase 4 and RNase 7, are abundantly produced by epithelial cells, the expression of others, like RNase 3 and RNase 6, increase at infection sites with immune cell recruitment. The objective of this mini-review is to highlight recent evidence showing the biological importance and responses of RNase A Superfamily members to infection in the kidney and bladder.

Bacterial Profile And Antibiotic Susceptibility Pattern Of Urinary Tract Infection Among Children Attending Felege Hiwot Referral Hospital, Bahir Dar, Northwest Ethiopia

Background

Urinary tract infection (UTI) is a common and important clinical problem in pediatrics. Recurrent UTIs may lead to renal scarring, hypertension, and end-stage renal dysfunction later in life. The objective of the study was to determine bacterial profile and antimicrobial susceptibility pattern of urinary tract infections (UTIs) among children attending Felege Hiwot Referral Hospital (FHRH).

Methods

A cross-sectional study was conducted from February 2013 to May 2013 among children 5–15 years of age with symptoms of UTI. Samples were processed for culture and identification. Antimicrobial susceptibility was done for positive urine cultures by the Kirby-Bauer’s disk diffusion method based on standards of the Clinical Laboratory Standard Institute (CLSI). Data were entered into Epi-data version 3.2.1 and exported to the Statistical Package for the Social Science (SPSS) version 20 statistical software. Fisher’s exact test and binary logistic regression test results were used.

Results

A total of 259 urine samples were collected from children with UTI. The result revealed 41 (15.8%) samples had significant bacteriuria, among which the most prevalent pathogen was E. coli 14 (34.1%) followed by Pseudomonas species. Gram-negative bacteria showed high level of sensitivity to ciprofloxacin (70), norfloxacin (63.4%) and ceftriaxone (60%), whereas the level of resistance was high to ampicillin (80%) and nitrofurantoin (70%). Gram-positive isolates showed high sensitivity to ciprofloxacin (77.8%), penicillin (72.8%) and erythromycin (72.7%). Multiple drug resistance (MDR) for Gram-positive and Gram-negative bacteria was 100% and 83.1%, respectively.

Conclusion

E. coli is the predominant bacteria isolated in the present study. The results showed that the prevalence of resistance to at least one antibiotic to commonly prescribed antimicrobials was high. Hence, the guidelines for empiric treatment of UTI should be re-evaluated periodically based on local studies.

A Systematic Review and Meta-Analysis Examining the Impact of Sleep Disturbance on Postoperative Delirium

OBJECTIVES

Basic science and clinical studies suggest that sleep disturbance may be a modifiable risk factor for postoperative delirium. We aimed to assess the association between preoperative sleep disturbance and postoperative delirium.

DATA SOURCES

We searched PubMed, Embase, CINAHL, Web of Science, and Cochrane from inception until May 31, 2017.

STUDY SELECTION

We performed a systematic search of the literature for all studies that reported on sleep disruption and postoperative delirium excluding cross-sectional studies, case reports, and studies not reported in English language.

DATA EXTRACTION

Two authors independently performed study selection and data extraction. We calculated pooled effects estimates with a random-effects model constructed in Stata and evaluated the risk of bias by formal testing (Stata Corp V.14, College Station, TX), DATA SYNTHESIS:: We included 12 studies, from 1,238 citations that met our inclusion criteria. The pooled odds ratio for the association between sleep disturbance and postoperative delirium was 5.24 (95% CI, 3.61-7.60; p < 0.001 and I = 0.0%; p = 0.76). The pooled risk ratio for the association between sleep disturbance and postoperative delirium in prospective studies (n = 6) was 2.90 (95% CI, 2.28-3.69; p < 0.001 and I = 0.0%; p = 0.89). The odds ratio associated with obstructive sleep apnea and unspecified types of sleep disorder were 4.75 (95% CI, 2.65-8.54; p < 0.001 and I = 0.0%; p = 0.85) and 5.60 (95% CI, 3.46-9.07; p < 0.001 and I = 0.0%; p = 0.41), respectively. We performed Begg's and Egger's tests for publication bias and confirmed a null result for publication bias (p = 0.371 and 0.103, respectively).

CONCLUSIONS

Preexisting sleep disturbances are likely associated with postoperative delirium. Whether system-level initiatives targeting patients with preoperative sleep disturbance may help reduce the prevalence, morbidity, and healthcare costs associated with postoperative delirium remains to be determined.

Identification and characterization of OmpT-like proteases in uropathogenic Escherichia coli clinical isolates

Bacterial colonization of the urogenital tract is limited by innate defenses, including the production of antimicrobial peptides (AMPs). Uropathogenic Escherichia coli (UPEC) resist AMP‐killing to cause a range of urinary tract infections (UTIs) including asymptomatic bacteriuria, cystitis, pyelonephritis, and sepsis. UPEC strains have high genomic diversity and encode numerous virulence factors that differentiate them from non‐UTI‐causing strains, including ompT. As OmpT homologs cleave and inactivate AMPs, we hypothesized that UPEC strains from patients with symptomatic UTIs have high OmpT protease activity. Therefore, we measured OmpT activity in 58 clinical E. coli isolates. While heterogeneous OmpT activities were observed, OmpT activity was significantly greater in UPEC strains isolated from patients with symptomatic infections. Unexpectedly, UPEC strains exhibiting the greatest protease activities harbored an additional ompT‐like gene called arlC (ompTp). The presence of two OmpT‐like proteases in some UPEC isolates led us to compare the substrate specificities of OmpT‐like proteases found in E. coli. While all three cleaved AMPs, cleavage efficiency varied on the basis of AMP size and secondary structure. Our findings suggest the presence of ArlC and OmpT in the same UPEC isolate may confer a fitness advantage by expanding the range of target substrates.

Augmentation of Urinary Lactoferrin Enhances Host Innate Immune Clearance of Uropathogenic Escherichia coli

Urinary tract infection (UTI) is a prominent global health care burden. Although UTI is readily treated with antibiotics in healthy adults, complicated cases in immune-compromised individuals and the emerging antibiotic resistance of several uropathogens have accelerated the need for new treatment strategies. Here, we surveyed the composition of urinary exosomes in a mouse model of uropathgenic Escherichia coli (UPEC) UTI to identify specific urinary tract defense constituents for therapeutic development. We found an enrichment of the iron-binding glycoprotein lactoferrin in the urinary exosomes of infected mice. In subsequent in vitro studies, we identified human bladder epithelial cells as a source of lactoferrin during UPEC infection. We further established that exogenous treatment with human lactoferrin (hLf) reduces UPEC epithelial adherence and enhances neutrophil antimicrobial functions including bacterial killing and extracellular trap production. Notably, a single intravesicular dose of hLf drastically reduced bladder bacterial burden and neutrophil infiltration in our murine UTI model. We propose that lactoferrin is an important modulator of innate immune responses in the urinary tract and has potential application in novel therapeutic design for UTI.

Pathogenesis of Proteus mirabilis Infection

Proteus mirabilis, a Gram-negative rod-shaped bacterium most noted for its swarming motility and urease activity, frequently causes catheter-associated urinary tract infections (CAUTIs) that are often polymicrobial. These infections may be accompanied by urolithiasis, the development of bladder or kidney stones due to alkalinization of urine from urease-catalyzed urea hydrolysis. Adherence of the bacterium to epithelial and catheter surfaces is mediated by 17 different fimbriae, most notably MR/P fimbriae. Repressors of motility are often encoded by these fimbrial operons. Motility is mediated by flagella encoded on a single contiguous 54-kb chromosomal sequence. On agar plates, P. mirabilis undergoes a morphological conversion to a filamentous swarmer cell expressing hundreds of flagella. When swarms from different strains meet, a line of demarcation, a "Dienes line," develops due to the killing action of each strain's type VI secretion system. During infection, histological damage is caused by cytotoxins including hemolysin and a variety of proteases, some autotransported. The pathogenesis of infection, including assessment of individual genes or global screens for virulence or fitness factors has been assessed in murine models of ascending urinary tract infections or CAUTIs using both single-species and polymicrobial models. Global gene expression studies performed in culture and in the murine model have revealed the unique metabolism of this bacterium. Vaccines, using MR/P fimbria and its adhesin, MrpH, have been shown to be efficacious in the murine model. A comprehensive review of factors associated with urinary tract infection is presented, encompassing both historical perspectives and current advances.

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.

Actinobaculum massiliense Proteome Profiled in Polymicrobial Urethral Catheter Biofilms

Actinobaculum massiliense, a Gram-positive anaerobic coccoid rod colonizing the human urinary tract, belongs to the taxonomic class of Actinobacteria. We identified A. massiliense as a cohabitant of urethral catheter biofilms (CB). The CBs also harbored more common uropathogens, such as Proteus mirabilis and Aerococcus urinae, supporting the notion that A. massiliense is adapted to a life style in polymicrobial biofilms. We isolated a clinical strain from a blood agar colony and used 16S rRNA gene sequencing and shotgun proteomics to confirm its identity as A. massiliense. We characterized this species by quantitatively comparing the bacterial proteome derived from in vitro growth with that of four clinical samples. The functional relevance of proteins with emphasis on nutrient import and the response to hostile host conditions, showing evidence of neutrophil infiltration, was analyzed. Two putative subtilisin-like proteases and a heme/oligopeptide transporter were abundant in vivo and are likely important for survival and fitness in the biofilm. Proteins facilitating uptake of xylose/glucuronate and oligopeptides, also highly expressed in vivo, may feed metabolites into mixed acid fermentation and peptidolysis pathways, respectively, to generate energy. A polyketide synthase predicted to generate a secondary metabolite that interacts with either the human host or co-colonizing microbes was also identified. The product of the PKS enzyme may contribute to A. massiliense fitness and persistence in the CBs.

Cell-specific qRT-PCR of renal epithelial cells reveals a novel innate immune signature in murine collecting duct

The urinary tract is usually culture negative despite its close proximity to microbial flora. The precise mechanism by which the kidneys and urinary tract defends against infection is not well understood. The initial kidney cells to encounter ascending pathogens are the collecting tubule cells that consist of principal cells (PCs) that express aquaporin 2 (AQP2) and intercalated cells (ICs) that express vacuolar H+-ATPase (V-ATPase, B1 subunit). We have previously shown that ICs are involved with the human renal innate immune defense. Here we generated two reporter mice, VATPase B1-cre+tdT+ mice to fluorescently label ICs and AQP2-cre+tdT+ mice to fluorescently label PCs, and then performed flow sorting to enrich PCs and ICs for analysis. Isolated ICs and PCs along with proximal tubular cells were used to measure antimicrobial peptide (AMP) mRNA expression. ICs and PCs were significantly enriched for AMPs. Isolated ICs responded to uropathogenic Escherichia coli (UPEC) challenge in vitro and had higher RNase4 gene expression than control while both ICs and PCs responded to UPEC challenge in vivo by upregulating Defb1 mRNA expression. To our knowledge, this is the first report of isolating murine collecting tubule cells and performing targeted analysis for multiple classes of AMPs.

Host-Derived Nitric Oxide and Its Antibacterial Effects in the Urinary Tract

Urinary tract infection (UTI) is one of the most common bacterial infections in humans, and the majority are caused by uropathogenic Escherichia coli (UPEC). The rising antibiotic resistance among UPEC and the frequent failure of antibiotics to effectively treat recurrent UTI and catheter-associated UTI motivate research on alternative ways of managing UTI. Abundant evidence indicates that the toxic radical nitric oxide (NO), formed by activation of the inducible nitric oxide synthase, plays an important role in host defence to bacterial infections, including UTI. The major source of NO production during UTI is from inflammatory cells, especially neutrophils, and from the uroepithelial cells that are known to orchestrate the innate immune response during UTI. NO and reactive nitrogen species have a wide range of antibacterial targets, including DNA, heme proteins, iron-sulfur clusters, and protein thiol groups. However, UPEC have acquired a variety of defence mechanisms for protection against NO, such as the NO-detoxifying enzyme flavohemoglobin and the NO-tolerant cytochrome bd-I respiratory oxidase. The cytotoxicity of NO-derived intermediates is nonspecific and may be detrimental to host cells, and a balanced NO production is crucial to maintain the tissue integrity of the urinary tract. In this review, we will give an overview of how NO production from host cells in the urinary tract is activated and regulated, the effect of NO on UPEC growth and colonization, and the ability of UPEC to protect themselves against NO. We also discuss the attempts that have been made to develop NO-based therapeutics for UTI treatment.

Minimizing ICU Neurological Dysfunction with Dexmedetomidine-induced Sleep (MINDDS): protocol for a randomised, double-blind, parallel-arm, placebo-controlled trial

INTRODUCTION

Delirium, which is prevalent in postcardiac surgical patients, is an acute brain dysfunction characterised by disturbances in attention, awareness and cognition not explained by a pre-existing neurocognitive disorder. The pathophysiology of delirium remains poorly understood. However, basic science and clinical studies suggest that sleep disturbance may be a modifiable risk factor for the development of delirium. Dexmedetomidine is a α-2A adrenergic receptor agonist medication that patterns the activity of various arousal nuclei similar to sleep. A single night-time loading dose of dexmedetomidine promotes non-rapid eye movement sleep stages N2 and N3 sleep. This trial hypothesises dexmedetomidine-induced sleep as pre-emptive therapy for postoperative delirium.

METHODS AND ANALYSIS

The MINDDS (Minimizing ICU Neurological Dysfunction with Dexmedetomidine-induced Sleep) trial is a 370-patient block-randomised, placebo-controlled, double-blinded, single-site, parallel-arm superiority trial. Patients over 60 years old, undergoing cardiac surgery with planned cardiopulmonary bypass, will be randomised to receive a sleep-inducing dose of dexmedetomidine or placebo. The primary outcome is the incidence of delirium on postoperative day 1, assessed with the Confusion Assessment Method by staff blinded to the treatment assignment. To ensure that the study is appropriately powered for the primary outcome measure, patients will be recruited and randomised into the study until 370 patients receive the study intervention on postoperative day 0. Secondary outcomes will be evaluated by in-person assessments and medical record review for in-hospital end points, and by telephone interview for 30-day, 90-day and 180-day end points. All trial outcomes will be evaluated using an intention-to-treat analysis plan. Hypothesis testing will be performed using a two-sided significance level (type I error) of α=0.05. Sensitivity analyses using the actual treatment received will be performed and compared with the intention-to-treat analysis results. Additional sensitivity analyses will assess the potential impact of missing data due to loss of follow-up.

ETHICS AND DISSEMINATION

The Partners Human Research Committee approved the MINDDS trial. Recruitment began in March 2017. Dissemination plans include presentations at scientific conferences, scientific publications and popular media.

TRIAL REGISTRATION NUMBER

NCT02856594.

Urinary Tract Infections in Infants and Children

Urinary tract infections (UTI) are one of the most common infections in children and symptoms may be nonspecific. The risk of renal scarring is highest in children under 1 year of age with febrile UTI and high-grade vesicoureteral reflux (VUR). Although treatment of UTI is usually straightforward, given increased rates of antimicrobial resistance worldwide, the choice of treatment for pediatric UTI should be guided by community resistance patterns whenever feasible. The benefit of antimicrobial prophylaxis after first UTI and/or in the presence of VUR remains controversial, but a recent meta-analysis supports continuous antimicrobial prophylaxis in children with VUR, indicating a need for more research in this area.

Susceptibility to Urinary Tract Infection: Benefits and Hazards of the Antibacterial Host Response

A paradigm shift is needed to improve and personalize the diagnosis of infectious disease and to select appropriate therapies. For many years, only the most severe and complicated bacterial infections received more detailed diagnostic and therapeutic attention as the efficiency of antibiotic therapy has guaranteed efficient treatment of patients suffering from the most common infections. Indeed, treatability almost became a rationale not to analyze bacterial and host parameters in these larger patient groups. Due to the rapid spread of antibiotic resistance, common infections like respiratory tract- or urinary-tract infections (UTIs) now pose new and significant therapeutic challenges. It is fortunate and timely that infectious disease research can offer such a wealth of new molecular information that is ready to use for the identification of susceptible patients and design of new suitable therapies. Paradoxically, the threat of antibiotic resistance may become a window of opportunity, by encouraging the implementation of new diagnostic and therapeutic approaches. The frequency of antibiotic resistance is rising rapidly in uropathogenic organisms and the molecular and genetic understanding of UTI susceptibility is quite advanced. More bold translation of the new molecular diagnostic and therapeutic tools would not just be possible but of great potential benefit in this patient group. This chapter reviews the molecular basis for susceptibility to UTI, including recent advances in genetics, and discusses the consequences for diagnosis and therapy. By dissecting the increasingly well-defined molecular interactions between bacteria and host and the molecular features of excessive bacterial virulence or host-response malfunction, it is becoming possible to isolate the defensive from the damaging aspects of the host response. Distinguishing "good" from "bad" inflammation has been a long-term quest of biomedical science and in UTI, patients need the "good" aspects of the inflammatory response to resist infection while avoiding the "bad" aspects, causing chronicity and tissue damage.

Testosterone suppresses uropathogenic Escherichia coli invasion and colonization within prostate cells and inhibits inflammatory responses through JAK/STAT-1 signaling pathway

Prostatitis is a common condition in adult men of all ages. Uropathogenic Escherichia coli (UPEC) are most frequent pathogen involved in bacterial prostatitis by refluxing the infected urine into prostatic ducts and resulting in an ascending urethral infection. However, the study about the mechanisms of UPEC to invade, replicate and persist in normal prostate epithelial cell is only few. Given the fact that UPEC is pathogen most frequently involved in prostatitis and that testosterone has been demonstrated to attenuate prostate inflammation caused by other etiologies. In this study we investigated whether the testosterone reduces the prostatitis and related mechanism by regulating IFN-γ/STAT1 signaling pathway. In the current study aimed to clarify whether testosterone influences the process of UPEC-induced prostate inflammation and invasion into the prostate epithelial cells. In addition, we set up a normal prostate cell model for UPEC infection to evaluate the ability to invade the urothelial cells as well as the colonization of intercellular bacterial communities in vitro. By using the model, we examine the effects of testosterone to suppress effectively the invasion and survival of UPEC in the prostate cells, and inhibit LPS-induced inflammatory responses through the JAK/STAT1 pathway have also been indicated. Our results demonstrated testosterone not only suppressed the invasion and colonization of UPEC, but also inhibited the expression of pro-inflammatory IL-1β, IL-6 and IL-8 cytokines expression induced by UPEC in a dose-dependent manner. We found the effective dose of testosterone to suppress UPEC infect prostate cells may be appropriate under 40μg/ml. Our data also revealed 20μg/ml testosterone treated PZ-HPV-7 cells significantly suppressed the LPS-induced JAK/STAT1 pathway and inflammatory responses, and reached to maximal effects at 40μg/ml treatment. These results indicate that testosterone plays an anti-inflammatory role in LPS-induced prostate cell inflammation by down-regulating JAK/STAT1 signaling pathway. Interestingly, the JAK inhibitor and testosterone for 24hr pretreatment rather markedly induced the colonization of UPEC in the PZ-HPV-7 cells. Based on the above data, the suppression of UPEC colonization in the prostate cells by testosterone seems to be unrelated with JAK/STAT signaling pathway, whereas the JAK may involve into the UPEC infection. Summing up these data, our findings have demonstrated the suppressive effects of testosterone on the invasion and survival of UPEC and induced inflammation in prostate epithelial cells. These findings indicate the action mechanism of testosterone as an anti-inflammatory mediator in the prostate cells is regulated through JAK/STAT1 signaling pathway, may be beneficial in treating prostate inflammation. Altogether, this study has provided the possibility that using testosterone in the prevention and clinical treatment of prostatitis is a new direction.

Antibiotic Resistance Patterns of Common Gram-negative Uropathogens in St. Paul's Hospital Millennium Medical College

Background

The resistance of bacteria causing urinary tract infection (UTI) to commonly prescribed antibiotics is increasing both in developing and developed countries. Resistance has emerged even to more potent antimicrobial agents. This study was undertaken to determine the current antibiotic resistance pattern among common bacterial uropathogens in St.paul's Hospital Millennium Medical College.

Methods

Using cross sectional study design, a total of 217 female and 207 male participants were consecutively recruited. Mid-urine samples were collected from all patients using wide mouthed urine cup. Inoculation was performed onto blood agar and MacConkey agar symoultaniously, and isolated organisms were identified by conventional methods. Antibiotic susceptibility was done by Kirby Bauer disk diffusion method. Thirteen different antibiotics representing different families of antibiotics were tested on all isolated organisms.

Results

Of the total 424 samples, 95(22.4%) showed significant growth. Gram negative organisms totaled 85(20.05%), and 10(2.4%) isolates were gram positive. The most frequently isolated gram negative bacterium was E. coli followed by Protues and Klebsiella spp. 53(12.5%), 8(8.4%), and 7(7.4%) respectively. Resistance to Tetracyclin, Ampicilin, Amoxycilin and Nalidixic Acid was more than 70% of all isolates of E.coli strains. There was relatively low resistance rate to Nitrofurantoin, Gentamycin and Trimethoprim-Sulfamethoxazole. However, there was emerging resistance to Ciprofloxacilin and Ceftriaxone especially for common bacteruria.

Conclusion

In this study setting, resistant rates to Tetracyclin, Ampicilin, Amoxycilin and Nalidixic Acid were high. Since most isolates were sensitive for Nitrofurantoin, Gentamycin and Trimethoprim-Sulfamethoxazole, they are considered as appropriate antimicrobials for empirical treatment for urinary tract infections with the absence of culture and sensitivity setting. Increasing antibiotic resistance trends indicate that it is imperative to rationalize the use of antimicrobials in the community and use these conservatively.

Characterization of Early-Phase Neutrophil Extracellular Traps in Urinary Tract Infections

Neutrophils have an important role in the antimicrobial defense and resolution of urinary tract infections (UTIs). Our research suggests that a mechanism known as neutrophil extracellular trap (NET) formation is a defense strategy to combat pathogens that have invaded the urinary tract. A set of human urine specimens with very high neutrophil counts had microscopic evidence of cellular aggregation and lysis. Deoxyribonuclease I (DNase) treatment resulted in disaggregation of such structures, release of DNA fragments and a proteome enriched in histones and azurophilic granule effectors whose quantitative composition was similar to that of previously described in vitro-formed NETs. The effector proteins were further enriched in DNA-protein complexes isolated in native PAGE gels. Immunofluorescence microscopy revealed a flattened morphology of neutrophils associated with decondensed chromatin, remnants of granules in the cell periphery, and myeloperoxidase co-localized with extracellular DNA, features consistent with early-phase NETs. Nuclear staining revealed that a considerable fraction of bacterial cells in these structures were dead. The proteomes of two pathogens, Staphylococcus aureus and Escherichia coli, were indicative of adaptive responses to early-phase NETs, specifically the release of virulence factors and arrest of ribosomal protein synthesis. Finally, we discovered patterns of proteolysis consistent with widespread cleavage of proteins by neutrophil elastase, proteinase 3 and cathepsin G and evidence of citrullination in many nuclear proteins.

Urinary tract infections (UTIs) are one of the world’s most widespread infectious diseases, with an estimated number of 150 million cases per year. Neutrophils play an important role in the defense of human patients against microbes causing UTIs. Molecules produced by neutrophils that migrate into the urinary tract can kill the invading microbes and resolve an infection, often without a need to treat patients with an antibiotic. Our work shows strong support for a mechanism called the formation of neutrophil extracellular traps (NETs), previously described for other infections and autoimmune conditions, which are involved in killing pathogens that have invaded the urinary tract. We show evidence of extracellular chromatin-containing structures using immunofluorescence microscopy and identified proteins that bind to the chromatin DNA and have functions to damage and kill bacterial cells or stop their growth.

Antimicrobial Resistance and Molecular Characterization of Extended-Spectrum β-Lactamases and Other Escherichia coli Isolated from Food of Animal Origin and Human Intestinal Isolates

Antibiotics have always appeared miraculous, saving innumerable lives. However, the unwise use of antimicrobial drugs has led to the appearance of resistant bacteria. The purpose of this study was to evaluate antimicrobial resistance in Escherichia coli (n =160) isolated from food of animal origin. The focus was on E. coli -producing extended-spectrum β-lactamases. E. coli was chosen because it is a part of the normal microbiota in mammals and can enter the food chain during slaughtering and food manipulation. Subsequently, its resistance genes can be transferred to pathogenic bacteria and human microbiota. Phenotypic and genotypic analyses of selected antimicrobial resistances were carried out together with a molecular analysis of virulence genes. E. coli isolates from food of animal origin were compared with clinical E. coli strains isolated from the human intestinal tract. Extended-spectrum β-lactamase-producing E. coli isolates were found in 9.4% of food isolates and in 1.8% of intestinal isolates. Phylogenetically, the majority of food (86.3%) and intestinal E. coli (58.1%) isolates were found to belong to the commensal phylogenetic groups A and B1. The distribution of 4 of 14 analyzed virulence factors was similar in the food and intestinal isolates. Strains isolated from food in Slovenia harbored resistance genes and virulence factors, which can constitute a problem for food safety if not handled properly.

Comprehensive Metaproteomic Analyses of Urine in the Presence and Absence of Neutrophil-Associated Inflammation in the Urinary Tract

Inflammation in the urinary tract results in a urinary proteome characterized by a high dynamic range of protein concentrations and high variability in protein content. This proteome encompasses plasma proteins not resorbed by renal tubular uptake, renal secretion products, proteins of immune cells and erythrocytes derived from trans-urothelial migration and vascular leakage, respectively, and exfoliating urothelial and squamous epithelial cells. We examined how such proteins partition into soluble urine (SU) and urinary pellet (UP) fractions by analyzing 33 urine specimens 12 of which were associated with a urinary tract infection (UTI). Using mass spectrometry-based metaproteomic approaches, we identified 5,327 non-redundant human proteins, 2,638 and 4,379 of which were associated with SU and UP fractions, respectively, and 1,206 non-redundant protein orthology groups derived from pathogenic and commensal organisms of the urogenital tract. Differences between the SU and UP proteomes were influenced by local inflammation, supported by respective comparisons with 12 healthy control urine proteomes. Clustering analyses showed that SU and UP fractions had proteomic signatures discerning UTIs, vascular injury, and epithelial cell exfoliation from the control group to varying degrees. Cases of UTI revealed clusters of proteins produced by activated neutrophils. Network analysis supported the central role of neutrophil effector proteins in the defense against invading pathogens associated with subsequent coagulation and wound repair processes. Our study expands the existing knowledge of the urinary proteome under perturbed conditions, and should be useful as reference dataset in the search of biomarkers.

Siderophore vaccine conjugates protect against uropathogenic Escherichia coli urinary tract infection

Uropathogenic Escherichia coli (UPEC) is the primary cause of uncomplicated urinary tract infections (UTIs). Whereas most infections are isolated cases, 1 in 40 women experience recurrent UTIs. The rise in antibiotic resistance has complicated the management of chronic UTIs and necessitates new preventative strategies. Currently, no UTI vaccines are approved for use in the United States, and the development of a highly effective vaccine remains elusive. Here, we have pursued a strategy for eliciting protective immunity by vaccinating with small molecules required for pathogenesis, rather than proteins or peptides. Small iron-chelating molecules called siderophores were selected as antigens to vaccinate against UTI for this vaccine strategy. These pathogen-associated stealth siderophores evade host immune defenses and enhance bacterial virulence. Previous animal studies revealed that vaccination with siderophore receptor proteins protects against UTI. The poor solubility of these integral outer-membrane proteins in aqueous solutions limits their practical utility. Because their cognate siderophores are water soluble, we hypothesized that these bacterial-derived small molecules are prime vaccine candidates. To test this hypothesis, we immunized mice with siderophores conjugated to an immunogenic carrier protein. The siderophore-protein conjugates elicited an adaptive immune response that targeted bacterial stealth siderophores and protected against UTI. Our study has identified additional antigens suitable for a multicomponent UTI vaccine and highlights the potential use of bacterial-derived small molecules as antigens in vaccine therapies.

Spatiotemporal Dynamics of Dexmedetomidine-Induced Electroencephalogram Oscillations

An improved understanding of the neural correlates of altered arousal states is fundamental for precise brain state targeting in clinical settings. More specifically, electroencephalogram recordings are now increasingly being used to relate drug-specific oscillatory dynamics to clinically desired altered arousal states. Dexmedetomidine is an anesthetic adjunct typically administered in operating rooms and intensive care units to produce and maintain a sedative brain state. However, a high-density electroencephalogram characterization of the neural correlates of the dexmedetomidine-induced altered arousal state has not been previously accomplished. Therefore, we administered dexmedetomidine (1mcg/kg bolus over 10 minutes, followed by 0.7mcg/kg/hr over 50 minutes) and recorded high-density electroencephalogram signals in healthy volunteers, 18–36 years old (n = 8). We analyzed the data with multitaper spectral and global coherence methods. We found that dexmedetomidine was associated with increased slow-delta oscillations across the entire scalp, increased theta oscillations in occipital regions, increased spindle oscillations in frontal regions, and decreased beta oscillations across the entire scalp. The theta and spindle oscillations were globally coherent. During recovery from this state, these electroencephalogram signatures reverted towards baseline signatures. We report that dexmedetomidine-induced electroencephalogram signatures more closely approximate the human sleep onset process than previously appreciated. We suggest that these signatures may be targeted by real time visualization of the electroencephalogram or spectrogram in clinical settings. Additionally, these signatures may aid the development of control systems for principled neurophysiological based brain-state targeting.

Polymorphisms in α-Defensin-Encoding DEFA1A3 Associate with Urinary Tract Infection Risk in Children with Vesicoureteral Reflux

The contribution of genetic variation to urinary tract infection (UTI) risk in children with vesicoureteral reflux is largely unknown. The innate immune system, which includes antimicrobial peptides, such as the α-defensins, encoded by DEFA1A3, is important in preventing UTIs but has not been investigated in the vesicoureteral reflux population. We used quantitative real-time PCR to determine DEFA1A3 DNA copy numbers in 298 individuals with confirmed UTIs and vesicoureteral reflux from the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) Study and 295 controls, and we correlated copy numbers with outcomes. Outcomes studied included reflux grade, UTIs during the study on placebo or antibiotics, bowel and bladder dysfunction, and renal scarring. Overall, 29% of patients and 16% of controls had less than or equal to five copies of DEFA1A3 (odds ratio, 2.09; 95% confidence interval, 1.40 to 3.11; P<0.001). For each additional copy of DEFA1A3, the odds of recurrent UTI in patients receiving antibiotic prophylaxis decreased by 47% when adjusting for vesicoureteral reflux grade and bowel and bladder dysfunction. In patients receiving placebo, DEFA1A3 copy number did not associate with risk of recurrent UTI. Notably, we found that DEFA1A3 is expressed in renal epithelium and not restricted to myeloid-derived cells, such as neutrophils. In conclusion, low DEFA1A3 copy number associated with recurrent UTIs in subjects in the RIVUR Study randomized to prophylactic antibiotics, providing evidence that copy number polymorphisms in an antimicrobial peptide associate with UTI risk.

Urinary Tract Infection: Pathogenesis and Outlook

The clinical syndromes comprising urinary tract infection (UTI) continue to exert significant impact on millions of patients worldwide, most of whom are otherwise healthy women. Antibiotic therapy for acute cystitis does not prevent recurrences, which plague up to one fourth of women after an initial UTI. Rising antimicrobial resistance among uropathogenic bacteria further complicates therapeutic decisions, necessitating new approaches based on fundamental biological investigation. In this review, we highlight contemporary advances in the field of UTI pathogenesis and how these might inform both our clinical perspective and future scientific priorities.

The Association between Serum 25-Hydroxy Vitamin D Level and Urine Cathelicidin in Children with a Urinary Tract Infection

OBJECTIVE

Cathelicidin is an important antimicrobial peptide in the urinary tract. Cathelicidin expression is strongly stimulated by 1,25-dihydroxy vitamin D in epithelial cells, macrophages/monocytes, and neutrophils. Vitamin D and cathelicidin status in children with urinary tract infection (UTI) caused by Escherichia coli is unknown. To establish the relationship between serum vitamin D and urine cathelicidin levels in children with a UTI caused by Escherichia coli.

METHODS

Serum 25-hydroxy vitamin D and urine cathelicidin levels were measured in 36 patients with UTI (mean age 6.8±3.6 years, range: 0.25-12.6 years) and 38 controls (mean age 6.3±2.8 years, range: 0.42-13 years).

RESULTS

There were no significant differences in urine cathelicidin levels between the study and control groups (p>0.05). Eight (22.2%) patients in the study group and 21 (58.3%) children in the control group were found to have sufficient vitamin D (≥20 ng/mL). Patients with sufficient vitamin D had higher urine cathelicidin levels than the controls with sufficient vitamin D (respectively 262.5±41.1 vs. 168±31.6 ng/mL, p=0.001). There were no significant differences between the patients and controls with insufficient vitamin D (p>0.05).

CONCLUSION

The children with vitamin D insufficiency may not be able to increase their urine cathelicidin level during UTI caused by Escherichia coli. There is a need of prospective studies in order to prove a beneficial effect of vitamin D supplementation for the restoration of cathelicidin stimulation and consequently for prevention of UTI recurrence.

Relationship between virulence factors, resistance to antibiotics and phylogenetic groups of uropathogenic Escherichia coli in two locations in Mexico

INTRODUCTION

Escherichia coli is the major causative agent of urinary tract infections (UTI), and virulence factors are responsible for the severity of these emerging infections. The aim of this study was to evaluate the relationship between virulence determinants and antibiotic susceptibility with phylogenetic groups of E.coli isolates of UTI in two locations in Mexico.

METHODS

An analysis was performed on 50 isolates of E.coli from the centre of the country and 57 from a town in the southwest. The isolates were characterized by phenotype (serotyping assays, in vitro adhesion, biofilm formation, production of haemolysin, and antibiotic susceptibility) and genotype (phylogenetic groups and virulence genes).

RESULTS

In the centre of the country location the phylogenetic group B2 (60%) and F (12%) were significantly more prevalent and had a higher frequency of genes, fimH (96%), iutA (66%), sat (36%), compared to the southwest location, where the group A (35%) and B1 (21%) were significantly predominant and had fewer virulence genes. About one-fifth (21.5%) of all isolates belonged to the O25-ST131 group. Haemolysin and biofilm producing strains were significantly higher in the southwest location. Resistance to ampicillin (92.5%), tetracycline (76.6%), and trimethoprim/sulfamethoxazole (70.1%) were the most common in both groups.

CONCLUSION

The phylogenetic group, virulence factors, and antibiotic susceptibility of the E.coli that causes UTI in the community, varies significantly among the Mexican populations studied. Phylogenetic groups A and B1 may be multidrug resistant and have the ability to produce UTI.

Strengths and Limitations of Model Systems for the Study of Urinary Tract Infections and Related Pathologies

Urinary tract infections (UTIs) are some of the most common bacterial infections worldwide and are a source of substantial morbidity among otherwise healthy women. UTIs can be caused by a variety of microbes, but the predominant etiologic agent of these infections is uropathogenic Escherichia coli (UPEC). An especially troubling feature of UPEC-associated UTIs is their high rate of recurrence. This problem is compounded by the drastic increase in the global incidence of antibiotic-resistant UPEC strains over the past 15 years. The need for more-effective treatments for UTIs is driving research aimed at bettering our understanding of the virulence mechanisms and host-pathogen interactions that occur during the course of these infections. Surrogate models of human infection, including cell culture systems and the use of murine, porcine, avian, teleost (zebrafish), and nematode hosts, are being employed to define host and bacterial factors that modulate the pathogenesis of UTIs. These model systems are revealing how UPEC strains can avoid or overcome host defenses and acquire scarce nutrients while also providing insight into the virulence mechanisms used by UPEC within compromised individuals, such as catheterized patients. Here, we summarize our current understanding of UTI pathogenesis while also giving an overview of the model systems used to study the initiation, persistence, and recurrence of UTIs and life-threatening sequelae like urosepsis. Although we focus on UPEC, the experimental systems described here can also provide valuable insight into the disease processes associated with other bacterial pathogens both within the urinary tract and elsewhere within the host.

Transurethral instillation with fusion protein MrpH.FimH induces protective innate immune responses against uropathogenic Escherichia coli and Proteus mirabilis

Urinary tract infections (UTIs) are among the most common infections in human. Innate immunity recognizes pathogen-associated molecular patterns (PAMPs) by Toll-like receptors (TLRs) to activate responses against pathogens. Recently, we demonstrated that MrpH.FimH fusion protein consisting of MrpH from Proteus mirabilis and FimH from Uropathogenic Escherichia coli (UPEC) results in the higher immunogenicity and protection, as compared with FimH and MrpH alone. In this study, we evaluated the innate immunity and adjuvant properties induced by fusion MrpH.FimH through in vitro and in vivo methods. FimH and MrpH.FimH were able to induce significantly higher IL-8 and IL-6 responses than untreated or MrpH alone in cell lines tested. The neutrophil count was significantly higher in the fusion group than other groups. After 6 h, IL-8 and IL-6 production reached a peak, with a significant decline at 24 h post-instillation in both bladder and kidney tissues. Mice instilled with the fusion and challenged with UPEC or P. mirabilis showed a significant decrease in the number of bacteria in bladder and kidney compared to control mice. The results of these studies demonstrate that the use of recombinant fusion protein encoding TLR-4 ligand represents an effective vaccination strategy that does not require the use of a commercial adjuvant. Furthermore, MrpH.FimH was presented as a promising vaccine candidate against UTIs caused by UPEC and P. mirabilis.

Genetic Variations in Vesicoureteral Reflux Sequelae

Urinary tract infections (UTI) are a common condition in children. Vesicoureteral reflux (VUR) represents a common associated condition with childhood UTI. UTI susceptibility appears to have a genetic component based on family and UTI cohort studies. Targeted analysis of innate immune system genetic variations indicate that these variations are important in UTI susceptibility. In this overview, we discuss how current cohorts and genetic strategies can be implemented to discover new susceptibility loci in patients with UTI.

Urinary pellet sample preparation for shotgun proteomic analysis of microbial infection and host-pathogen interactions

Urine is one of the most important biofluids in clinical proteomics, and in the past decades many potential disease biomarkers have been identified using mass spectrometry-based proteomics. Current studies mainly perform analyses of the urine supernatant devoid of cells and cell debris, and the pellet (or sediment) fraction is discarded. However, the pellet fraction is biologically of interest. It may contain whole human cells shed into the urine from anatomically proximal tissues and organs (e.g., kidney, prostate, bladder, urothelium, and genitals), disintegrated cells and cell aggregates derived from such tissues, viruses and microbial organisms which colonize or infect the urogenital tract. Knowledge of the function, abundance, and tissue of origin of such proteins can explain a pathological process, identify a microbe as the cause of urinary tract infection, and measure the human immune response to the infection-associated pathogen(s). Successful detection of microbial species in the urinary pellet via proteomics can serve as a clinical diagnostic alternative to traditional cell culture-based laboratory tests. Filter-aided sample preparation (FASP) has been widely used in shotgun proteomics. The methodology presented here implements an effective lysis of cells present in urinary pellets, solubilizes the majority of the proteins derived from microbial and human cells, and generates enzymatic digestion-compatible protein mixtures using FASP followed by optimized desalting procedures to provide a peptide fraction for sensitive and comprehensive LC-MS/MS analysis. A highly parallel sample preparation method in 96-well plates to allow scaling up such experiments is discussed as well. Separating peptides by nano-LC in one dimension followed by online MS/MS analysis on a Q-Exactive mass spectrometer, we have shown that more than 1,000 distinct microbial proteins and 1,000 distinct human proteins can be identified from a single experiment.

Integrated Pathophysiology of Pyelonephritis

Pyelonephritis represents a subset of urinary tract infections that occur from bacteria ascending from the lower to the upper reaches of the genitourinary system, such as the kidney. The renal system contains a range of hydrodynamically and immunologically challenging, interconnected microenvironments where the invading pathogen may populate during the course of the infection. The situation at the infection foci changes dynamically, vacillating between bacterial colonization and clearance, to which the outcome is a summation of all host-pathogen elements in play. A selection of important determinants includes factors of microbial origin, effects of eukaryotic cell signaling, physiological facets of the infected organ, and signals from distal organs. Improved understanding of the multifactorial aspects of molecular pathogenesis of infection requires intravital, cross-disciplinary approaches with high spatio-temporal resolution. The advancement of such approaches promises to eventually provide a comprehensive understanding of the integrated pathophysiology of pyelonephritis.

Amplifying renal immunity: the role of antimicrobial peptides in pyelonephritis

Urinary tract infections (UTIs), including pyelonephritis, are among the most common and serious infections encountered in nephrology practice. UTI risk is increased in selected patient populations with renal and urinary tract disorders. As the prevalence of antibiotic-resistant uropathogens increases, novel and alternative treatment options will be needed to reduce UTI-associated morbidity. Discoveries over the past decade demonstrate a fundamental role for the innate immune system in protecting the urothelium from bacterial challenge. Antimicrobial peptides, an integral component of this urothelial innate immune system, demonstrate potent bactericidal activity toward uropathogens and might represent a novel class of UTI therapeutics. The urothelium of the bladder and the renal epithelium secrete antimicrobial peptides into the urinary stream. In the kidney, intercalated cells--a cell-type involved in acid-base homeostasis--have been shown to be an important source of antimicrobial peptides. Intercalated cells have therefore become the focus of new investigations to explore their function during pyelonephritis and their role in maintaining urinary tract sterility. This Review provides an overview of UTI pathogenesis in the upper and lower urinary tract. We describe the role of intercalated cells and the innate immune response in preventing UTI, specifically highlighting the role of antimicrobial peptides in maintaining urinary tract sterility.