The management of urinary infections: what have we learned in the past decade?

Regulation of renal aquaporin water channels in acute pyelonephritis

Acute pyelonephritis (APN) is most frequently caused by uropathogenic Escherichia coli (UPEC), which ascends from the bladder to the kidneys during a urinary tract infection. Patients with APN have been reported to have reduced renal concentration capacity under challenged conditions, polyuria, and increased aquaporin-2 (AQP2) excretion in the urine. We have recently shown increased AQP2 accumulation in the plasma membrane in cell cultures exposed to E. coli lysates and in the apical plasma membrane of inner medullary collecting ducts in a 5-day APN mouse model. This study aimed to investigate if AQP2 expression in host cells increases UPEC infection efficiency and to identify specific bacterial components that mediate AQP2 plasma membrane insertion. As the transepithelial water permeability in the collecting duct is codetermined by AQP3 and AQP4, we also investigated whether AQP3 and AQP4 localization is altered in the APN mouse model. We show that AQP2 expression does not increase UPEC infection efficiency and that AQP2 was targeted to the plasma membrane in AQP2-expressing cells in response to the two pathogen-associated molecular patterns (PAMPs), lipopolysaccharide and peptidoglycan. In contrast to AQP2, the subcellular localizations of AQP1, AQP3, and AQP4 were unaffected both in lysate-incubated cell cultures and in the APN mouse model. Our finding demonstrated that cellular exposure to lipopolysaccharide and peptidoglycan can trigger the insertion of AQP2 in the plasma membrane revealing a new regulatory pathway for AQP2 plasma membrane translocation, which may potentially be exploited in intervention strategies.NEW & NOTEWORTHY Acute pyelonephritis (APN) is associated with reduced renal concentration capacity and increased aquaporin-2 (AQP2) excretion. Uropathogenic Escherichia coli (UPEC) mediates changes in the subcellular localization of AQP2 and we show that in vitro, these changes could be elicited by two pathogen-associated molecular patterns (PAMPs), namely, lipopolysaccharide and peptidoglycan. UPEC infection was unaltered by AQP2 expression and the other renal AQPs (AQP1, AQP3, and AQP4) were unaltered in APN.

The biological function of the type II toxin-antitoxin system ccdAB in recurrent urinary tract infections

Urinary tract infections (UTIs) represent a significant challenge in clinical practice, with recurrent forms (rUTIs) posing a continual threat to patient health. Escherichia coli (E. coli) is the primary culprit in a vast majority of UTIs, both community-acquired and hospital-acquired, underscoring its clinical importance. Among different mediators of pathogenesis, toxin-antitoxin (TA) systems are emerging as the most prominent. The type II TA system, prevalent in prokaryotes, emerges as a critical player in stress response, biofilm formation, and cell dormancy. ccdAB, the first identified type II TA module, is renowned for maintaining plasmid stability. This paper aims to unravel the physiological role of the ccdAB in rUTIs caused by E. coli, delving into bacterial characteristics crucial for understanding and managing this disease. We investigated UPEC-induced rUTIs, examining changes in type II TA distribution and number, phylogenetic distribution, and Multi-Locus Sequence Typing (MLST) using polymerase chain reaction (PCR). Furthermore, our findings revealed that the induction of ccdB expression in E. coli BL21 (DE3) inhibited bacterial growth, observed that the expression of both ccdAB and ccdB in E. coli BL21 (DE3) led to an increase in biofilm formation, and confirmed that ccdAB plays a role in the development of persistent bacteria in urinary tract infections. Our findings could pave the way for novel therapeutic approaches targeting these systems, potentially reducing the prevalence of rUTIs. Through this investigation, we hope to contribute significantly to the global effort to combat the persistent challenge of rUTIs.

Recurrent infections drive persistent bladder dysfunction and pain via sensory nerve sprouting and mast cell activity

Urinary tract infections (UTIs) account for almost 25% of infections in women. Many are recurrent (rUTI), with patients frequently experiencing chronic pelvic pain and urinary frequency despite clearance of bacteriuria after antibiotics. To elucidate the basis for these bacteria-independent bladder symptoms, we examined the bladders of patients with rUTI. We noticed a notable increase in neuropeptide content in the lamina propria and indications of enhanced nociceptive activity. In mice subjected to rUTI, we observed sensory nerve sprouting that was associated with nerve growth factor (NGF) produced by recruited monocytes and tissue-resident mast cells. Treatment of rUTI mice with an NGF-neutralizing antibody prevented sprouting and alleviated pelvic sensitivity, whereas instillation of native NGF into naïve mice bladders mimicked nerve sprouting and pain behavior. Nerve activation, pain, and urinary frequency were each linked to the presence of proximal mast cells, because mast cell deficiency or treatment with antagonists against receptors of several direct or indirect mast cell products was each effective therapeutically. Thus, our findings suggest that NGF-driven sensory sprouting in the bladder coupled with chronic mast cell activation represents an underlying mechanism driving bacteria-independent pain and voiding defects experienced by patients with rUTI.

Engineered reporter phages for detection of Escherichia coli, Enterococcus, and Klebsiella in urine

The rapid detection and species-level differentiation of bacterial pathogens facilitates antibiotic stewardship and improves disease management. Here, we develop a rapid bacteriophage-based diagnostic assay to detect the most prevalent pathogens causing urinary tract infections: Escherichia coli, Enterococcus spp., and Klebsiella spp. For each uropathogen, two virulent phages were genetically engineered to express a nanoluciferase reporter gene upon host infection. Using 206 patient urine samples, reporter phage-induced bioluminescence was quantified to identify bacteriuria and the assay was benchmarked against conventional urinalysis. Overall, E. coli, Enterococcus spp., and Klebsiella spp. were each detected with high sensitivity (68%, 78%, 87%), specificity (99%, 99%, 99%), and accuracy (90%, 94%, 98%) at a resolution of ≥10³ CFU/ml within 5 h. We further demonstrate how bioluminescence in urine can be used to predict phage antibacterial activity, demonstrating the future potential of reporter phages as companion diagnostics that guide patient-phage matching prior to therapeutic phage application.

Glycomimetics for the inhibition and modulation of lectins

Carbohydrates are essential mediators of many processes in health and disease. They regulate self-/non-self- discrimination, are key elements of cellular communication, cancer, infection and inflammation, and determine protein folding, function and life-times. Moreover, they are integral to the cellular envelope for microorganisms and participate in biofilm formation. These diverse functions of carbohydrates are mediated by carbohydrate-binding proteins, lectins, and the more the knowledge about the biology of these proteins is advancing, the more interfering with carbohydrate recognition becomes a viable option for the development of novel therapeutics. In this respect, small molecules mimicking this recognition process become more and more available either as tools for fostering our basic understanding of glycobiology or as therapeutics. In this review, we outline the general design principles of glycomimetic inhibitors (Section 2). This section is then followed by highlighting three approaches to interfere with lectin function, i.e. with carbohydrate-derived glycomimetics (Section 3.1), novel glycomimetic scaffolds (Section 3.2) and allosteric modulators (Section 3.3). We summarize recent advances in design and application of glycomimetics for various classes of lectins of mammalian, viral and bacterial origin. Besides highlighting design principles in general, we showcase defined cases in which glycomimetics have been advanced to clinical trials or marketed. Additionally, emerging applications of glycomimetics for targeted protein degradation and targeted delivery purposes are reviewed in Section 4.

Innate Immune Program in Formation of Tumor-Initiating Cells from Cells-of-Origin of Breast, Prostate, and Ovarian Cancers

Tumor-initiating cells (TICs), also known as cancer stem cells (CSCs), are cancer cells that can initiate a tumor, possess self-renewal capacity, and can contribute to tumor heterogeneity. TICs/CSCs are developed from their cells-of-origin. In breast, prostate, and ovarian cancers, progenitor cells for mammary alveolar cells, prostate luminal (secretory) cells, and fallopian tube secretory cells are the preferred cellular origins for their corresponding cancer types. These luminal progenitors (LPs) express common innate immune program (e.g., Toll-like receptor (TLR) signaling)-related genes. Microbes such as bacteria are now found in breast, prostate, and fallopian tube tissues and their corresponding cancer types, raising the possibility that their LPs may sense the presence of microbes and trigger their innate immune/TLR pathways, leading to an inflammatory microenvironment. Crosstalk between immune cells (e.g., macrophages) and affected epithelial cells (e.g., LPs) may eventually contribute to formation of TICs/CSCs from their corresponding LPs, in part via STAT3 and/or NFκB pathways. As such, TICs/CSCs can inherit expression of innate-immunity/TLR-pathway-related genes from their cells-of-origin; the innate immune program may also represent their unique vulnerability, which can be explored therapeutically (e.g., by enhancing immunotherapy via augmenting TLR signaling).

Development and evaluation of a centrifugal disk system for the rapid detection of multiple pathogens and their antibiotic resistance genes in urinary tract infection

Background

Urinary tract infections (UTIs) are some of the most common bacterial infections in the world. Nevertheless, as uncomplicated UTIs are treated empirically without culturing the urine, adequate knowledge of the resistance pattern of uropathogens is essential. Conventional urine culture and identification take at least 2 days. Here, we developed a platform based on LAMP and centrifugal disk system (LCD) to simultaneously detect the main pathogens and antibiotic resistant genes (ARGs) of urgent concern multidrug-resistant among UTIs.

Methods

We designed specific primers to detect the target genes above and evaluated their sensitivity and specificity. We also assessed the result of our preload LCD platform on 645 urine specimens with a conventional culturing method and Sanger sequencing.

Results

The results obtained with the 645 clinical samples indicated that the platform has high specificity (0.988-1) and sensitivity (0.904-1) for the studied pathogens and ARGs. Moreover, the kappa value of all pathogens was more than 0.75, revealing an excellent agreement between the LCD and culture method. Compared to phenotypic tests, the LCD platform is a practical and fast detection approach for methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococci, carbapenem-resistant Enterobacteriaceae, carbapenem-resistant Acinetobacter, carbapenem-resistant Pseudomonas aeruginosa (kappa value of all >0.75), and non-extended-spectrum β-lactamase producers.

Conclusion

We developed a detection platform that has high accuracy and that meets the need for rapid diagnosis, which can be completed within 1.5 h from specimen collection. It may be a powerful tool for evidence-based UTIs diagnosis, which has essential support for the rational use of antibiotics. More high-quality clinical studies are required to prove the effectiveness of our platform.

C‐reactive protein, procalcitonin, and erythrocyte sedimentation rate for the diagnosis of lower urinary tract infection in older people

This is a protocol for a Cochrane Review (diagnostic). The objectives are as follows:

Effect of bovine lactoferrin on recurrent urinary tract infections: in vitro and in vivo evidences

Uropathogenic Escherichia coli (UPEC) strains are the primary cause of urinary tract infections (UTIs). UPEC strains are able to invade, multiply and persisting in host cells. Therefore, UPEC strains are associated to recurrent UTIs requiring long-term antibiotic therapy. However, this therapy is suboptimal due to the increase of multidrug-resistant UPEC. The use of non-antibiotic treatments for managing UTIs is required. Among these, bovine lactoferrin (bLf), a multifunctional cationic glycoprotein, could be a promising tool because inhibits the entry into the host cells of several intracellular bacteria. Here, we demonstrate that 100 μg/ml bLf hinders the invasion of 2.0 ± 0.5 × 10⁴ CFU/ml E. coli CFT073, prototype of UPEC, infecting 2.0 ± 0.5 × 10⁵ cells/ml urinary bladder T24 epithelial cells. The highest protection (100%) is due to the bLf binding with host surface components even if an additional binding to bacterial surface components cannot be excluded. Of note, in the absence of bLf, UPEC survives and multiplies, while bLf significantly decreases bacterial intracellular survival. After these encouraging results, an observational survey on thirty-three patients affected by recurrent cystitis was performed. The treatment consisted in the oral administration of bLf alone or in combination with antibiotics and/or probiotics. After the observation period, a marked reduction of cystitis episodes was observed (p < 0.001) in all patients compared to the episodes occurred during the 6 months preceding the bLf-treatment. Twenty-nine patients did not report cystitis episodes (87.9%) whereas the remaining four (12.1%) experienced only one episode, indicating that bLf could be a worthwhile and safe treatment in counteracting recurrent cystitis.

Original Article Phytotherapy in Adults With Recurrent Uncomplicated Cystitis

BACKGROUND

Uncomplicated urinary tract infections are among the commonest bacterial infections. Because antibiotic resistance is on the rise, there is growing interest in alternative, non-antimicrobial treatment options. This systematic review presents the current evidence on phytotherapy for the treatment and prevention of recurrent uncomplicated cystitis.

METHODS

A systematic search of the relevant literature from January 2011 to August 2021 was carried out in the MEDLINE, Embase, and Cochrane Library databases and in two clinical trial registries. The trials included in the present review are ran - domized controlled trials (RCTs) of phytotherapeutic agents as monotherapy or combination therapy, in comparison to placebo, no treatment, non-pharmacological treatment, or drug treatment without any phytotherapeutic component. Two of the authors independently selected the publications, extracted the data, and estimated the risk of bias using the Cochrane Risk of Bias Tool.

RESULTS

12 RCTs with a total of 1797 female patients were included. A trial of acute therapy with Chinese plant-based medicine revealed non-inferiority to antibiotic treatment. Six trials of prophylaxis with cranberry products yielded mixed results with regard to efficacy against recurrent urinary tract infections. A trial of Seidlitzia rosmarinus for the prevention of cystitis showed that its use was associated with a lower cystitis rate than placebo (at 6 months: 33 vs. 73%, p <0.001). In all trials but one, the risk of bias was unclear or high. No standardized assessment of adverse events was carried out.

CONCLUSION

Phytotherapeutic agents are an option for the treatment and prevention of recurrent cystitis in women. Given the heterogeneous state of the evidence on phytotherapy, no dependable recommendations can now be made for the clinical management of these patients with respect to phytotherapeutic agents.

Minimizing treatment-induced emergence of antibiotic resistance in bacterial infections

Currently, treatment of bacterial infections focuses on choosing an antibiotic which matches a pathogen’s susceptibility, with less attention to the risk that even susceptibility-matched treatments can fail due to resistance emerging in response to treatment. Here, combining whole-genome sequencing of 1,113 pre- and post- treatment bacterial isolates with machine-learning analysis of 140,349 urinary tract infections (UTIs) and 7,365 wound infections, we find that treatment-induced emergence of resistance could be predicted and minimized at the individual-patient level. Emergence of resistance was common, yet driven not by de novo resistance evolution, but rather by rapid reinfection with a different strain resistant to the prescribed antibiotic. As most infections are seeded from the patient’s own microbiota, these resistance-gaining recurrences can be predicted based on the patient’s past infection history, and their expected risk minimized by machine learning personalized antibiotic recommendations, offering a means to reduce the emergence and spread of resistant pathogens.

Acute pyelonephritis: Increased plasma membrane targeting of renal aquaporin-2

AIM

Aquaporin-2 (AQP2) shuttling between intracellular vesicles and the apical plasma membrane is pivotal in arginine vasopressin-mediated urine concentration and is dysregulated in multiple diseases associated with water balance disorders. Children and adults with acute pyelonephritis have a urinary concentration defect and studies in children revealed increased AQP2 excretion in the urine. This study aimed to analyse AQP2 trafficking in response to acute pyelonephritis.

METHODS

Immunofluorescence analysis was used to evaluate subcellular localization of AQP2 and AQP2-S256A (mimicking non-phosphorylated AQP2 on serine 256) in cells stimulated with bacterial lysates and of AQP2 and pS256-AQP2 in a mouse model at day 5 of acute pyelonephritis. Western blotting was used to evaluate AQP2 levels and AQP2 phosphorylation on S256 upon incubation with bacterial lysates. Time-lapse imaging was used to measure intracellular cAMP levels in response to incubation with bacterial lysates.

RESULTS

In cell cultures, lysates from both uropathogenic and nonpathogenic bacteria-mediated AQP2 plasma membrane targeting and increased AQP2 phosphorylation on serine 256 (pS256) without increasing cAMP levels. Both bacterial lysates induced plasma membrane targeting of AQP2-S256A. Immunofluorescence analysis of renal sections from mice after 5 days of acute pyelonephritis revealed apical plasma membrane targeting of AQP2 and pS256-AQP2 in inner medullary collecting ducts.

CONCLUSION

Uropathogenic bacteria induce AQP2 plasma membrane targeting in vitro and in vivo. cAMP levels were not elevated by the bacterial lysates and AQP2 plasma membrane targeting could occur without S256 phosphorylation. This may explain increased AQP2 excretion in the urine during acute pyelonephritis.

Global, regional, and national burden of urinary tract infections from 1990 to 2019: an analysis of the global burden of disease study 2019

PURPOSE

We aimed to estimate the burden of UTIs by age, sex, and socioeconomic status in 204 countries and territories from 1990 to 2019.

METHODS

We used data from Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to analyse the incidence, mortality, and disability-adjusted life-years (DALYs) due to UTIs at the global, regional, and national levels. Estimates are presented as numbers and age-standardised or age-specific rates per 100,000 population, with 95% uncertainty intervals (UIs). We further explored the associations between the incidence, mortality, DALYs, and socio-demographic index (SDI) as a proxy for the development status of regions and countries.

RESULTS

In 2019, more than 404.6 million (95% UI 359.4-446.5) individuals had UTIs globally and nearly 236,786 people (198,433-259,034) died of UTIs, contributing to 5.2 million (4.5-5.7) DALYs. The age-standardised incidence rate increased from 4715.0 (4174.2-5220.6) per 100,000 population in 1990 to 5229.3 (4645.3-5771.2) per 100,000 population in 2019. At the GBD regional level, the highest age-standardised incidence rate in 2019 occurred in Tropical Latin America (13,852.9 [12,135.6-15,480.3] per 100,000 population). At the national level, Ecuador had the highest age-standardised incidence rate (15,511.3 [13,685.0-17,375.6] per 100,000 population). The age-standardised death rates were highest in Barbados (19.5 [13.7-23.5] per 100,000 population). In addition, age-standardised incidence, death, and DALY rates generally increased across the SDI.

CONCLUSIONS

Our study results suggest a globally rising trend of UTI burden between 1990 and 2019.

Antibiotic-functionalized gold nanoparticles for the detection of active β-lactamases

Antimicrobial resistance (AMR) continues to threaten the effective treatment and prevention of bacterial infections. The spread of resistant infections is accelerated by the lack of fast and cost-effective tests for the detection of AMR at the point-of-care. We aimed to address this challenge by developing a diagnostic tool to detect one of the major forms of AMR, the β-lactamase enzymes. Antibiotic-functionalized gold nanoparticles (AuNPs) have been successfully developed for the detection of β-lactamases in challenging biological media, namely undiluted urine. Furthermore, these tools are compatible with samples containing a urine sample preservative (boric acid) or hematuria (blood). The functionalized AuNPs interact with the active β-lactamases, resulting in the hydrolysis of the surface-bound antibiotics, which then inhibits binding of the AuNPs to a capture protein (a penicillin-binding protein) to indicate the presence of active β-lactamases. We successfully integrated the antibiotic-functionalized AuNPs into a new lateral flow assay (LFA), which can be used to detect active β-lactamases down to the detection limit of 11 nM. While we demonstrate the use of antibiotic-functionalized AuNPs in an LFA format to provide a novel method of detecting active β-lactamases, these functionalized AuNPs are amenable to a range of alternative diagnostic technologies and could lead to vital point-of-care diagnostics for the early detection of multi-drug resistant infections.

Bacterial uropathogens and susceptibility testing among patients diagnosed with urinary tract infections at Hiwot Fana Specialized University Hospital, Eastern Ethiopia

Background:

Urinary tract infection is a common infection posing a significant healthcare burden globally. Currently, it is becoming hard to manage due to the drug resistance of uropathogens. This study aimed to evaluate the rate of culture positivity and the susceptibility pattern of isolates among clinically diagnosed patients with urinary tract infection.

Methods:

An institution-based cross-sectional study was conducted on patients clinically diagnosed with urinary tract infections and received a drug prescription at Hiwot Fana Specialized University Hospital from August 2018 to June 2019. A clean-catch mid-stream urine specimen was collected and bacterial identification and susceptibility test were performed using standard microbiological methods. Data were entered into EpiInfo 7 and exported to STATA 15 for analysis. Data were analyzed using descriptive analysis and bi-variate and multivariate regression analyses and presented with graphs, frequency, and tables.

Results:

A total of 687 urine samples were collected from patients with clinically diagnosed urinary tract infections. The mean age was 31 years and 56.62% were female. 28.38% of the participants had a culture-positive result, of which 86.15% had monomicrobial infections. Inpatients (AOR = 3.8, 95% CI = (1.8–7.9)) and hypertensive patients (AOR = 2.1, 95% CI = (1.1–4.4)) had higher odds of culture-positive results. Staphylococcus species (35.3%), E. coli (25.34%), Pseudomonas species (6.8%), and other Enterobacterales are isolated. Most isolates showed resistance to more than one drug, and amikacin, gentamicin, and nitrofurantoin showed relatively higher activity against isolates.

Conclusion:

About one-third of the clinically diagnosed patients with urinary tract infection were culture-positive with many types of bacterial uropathogens. Inpatients and hypertensive patients had a higher risk of developing bacterial infections. Bacterial isolates showed different percentages of susceptibility to the tested antibiotics.

Sex effects in pyelonephritis

Urinary tract infections (UTIs) are generally considered a disease of women. However, UTIs affect females throughout the lifespan, and certain male populations (including infants and elderly men) are also susceptible. Epidemiologically, pyelonephritis is more common in women but carries increased morbidity when it does occur in men. Among children, high-grade vesicoureteral reflux is a primary risk factor for upper-tract UTI in both sexes. However, among young infants with UTI, girls are outnumbered by boys; risk factors include posterior urethral valves and lack of circumcision. Recent advances in mouse models of UTI reveal sex differences in innate responses to UTI, which vary somewhat depending on the system used. Moreover, male mice and androgenized female mice suffer worse outcomes in experimental pyelonephritis; evidence suggests that androgen exposure may suppress innate control of infection in the urinary tract, but additional androgen effects, as well as non-hormonal sex effects, may yet be specified. Among other intriguing directions, recent experiments raise the hypothesis that the postnatal testosterone surge that occurs in male infants may represent an additional factor driving the higher incidence of UTI in males under 6 months of age. Ongoing work in contemporary models will further illuminate sex- and sex-hormone-specific effects on UTI pathogenesis and immune responses.

Capture and detection of urine bacteria using a microchannel silicon nanowire microfluidic chip coupled with MALDI-TOF MS

Fast bacterial identification in urine samples was achieved by capturing bacteria on a microchannel silicon nanowire microfluidic chip, followed by MALDI-TOF MS detection. Under the optimized conditions, bacteria with a concentration of 106 CFU mL-1 in urine samples could be identified without culture. If cultured for 4 hours, bacteria with a concentration as low as 103 CFU mL-1 were identified.

Escherichia coli: placing resistance to third-generation cephalosporins and fluoroquinolones in Australia and New Zealand into perspective

At least 300 million urinary tract infections (UTIs) occur annually worldwide. Uropathogenic Escherichia coli (UPEC) are the leading cause of UTIs. The discovery of antibiotics has revolutionised modern medicine. Yet, overusing antibiotics has accelerated the emergence of antimicrobial resistance (AMR), with UPEC driving the dissemination of AMR globally. Resistance to broad-spectrum antibiotics like third-generation cephalosporins (3GCs) and fluoroquinolones threatens public health. Extended-spectrum β-lactamase (ESBL)-producing E. coli precipitate resistance, particularly when these antibiotics are used as empirical therapies against UPEC. In response, the Centers for Disease Control and Prevention in the United States have listed ESBL-producing Enterobacterales, such as E. coli as a severe threat. Additionally, the World Health Organization have classified 3GCs and fluoroquinolones as the highest priority (critically important antimicrobials), where these therapies are only recommended following susceptibility testing. The present report demonstrates the distributions of E. coli cases with resistance to 3GC and fluoroquinolones in Australia and New Zealand and contextualises trends with European reports. This investigation emphasises the value of epidemiology and the justification of evidence-based interventions using data as an essential resource for reducing resistance to our ‘first-line’ antibiotics.

Etiological Agents of Urinary Tract Infection and 7 Years Trend of Antibiotic Resistance of Bacterial Uropathogens in Sudan

Introduction:

Bacterial infections of the urinary tract represent a major cause of outpatient visits as well as hospital-acquired infections. As the prevalence of multidrug-resistant uropathogens is increasing, updated knowledge of the commonest bacterial causes and their susceptibility patterns is crucial for the proper selection and use of antimicrobial drugs and the development of effective local prescribing guidelines.

Methods:

Handling of urine samples, identification of organisms and antimicrobial susceptibility testing were made according to guidelines in Monica Cheesbrough 2000, 2006. The prevalence of resistance of the pathogens against each antibiotic was calculated as the proportion of resistant isolates over the entire tested isolates. Data were analyzed using Epi info; the chi-square test and Fisher exact test were used to assess the statistical significance of results.

Results:

In this study, 774 samples were cultured from patients with suspected urinary tract infection (UTI), 705 (91%) urinary isolates showed significant growth (>105 CFU /L) while the other 69 samples showed no significant growth. 431 (61%) of the patients were female, while the other 274 (39%) were males. 13 types of pathogens were identified in 705 urinary isolates. E.Coli was the main bacterial uropathogen identified. Microbiological susceptibility of a total of 28 antibiotics was tested; for each urinary isolate, different sets of these antibiotics were used. 601(96%) of the bacteria were resistant to at least one antibiotic. 17 antibiotics were found to have a bacterial resistance rate of more than 50%, including all B lactams (except cefuroxime), Nalidixic acid, Ciprofloxacin, Norfloxacin, Clindamycin, Co-Trimoxazole and Tetracyclines(Tetracycline and Doxycycline). Other antibiotics were found to have resistance rates of less than 50%. Amikacin & Imipenem had the highest susceptibility rates. Throughout the 7 years, resistance to most of the antibiotics showed an incremental pattern.

Conclusion:

Current empirical antibiotic therapy for UTI should be modified, and new guidelines should be established based on local resistance rates. This study comes up with precious regional data for evidence-based empirical antibiotic treatment, but a national sentinel surveillance system and regional antibiograms should be established to track the bacterial susceptibility profiles in Sudan.

Novel antibiotic-loaded particles conferring eradication of deep tissue bacterial reservoirs for the treatment of chronic urinary tract infection

A significant proportion of urinary tract infection (UTI) patients experience recurrent episodes, due to deep tissue infection and treatment-resistant bacterial reservoirs. Direct bladder instillation of antibiotics has proved disappointing in treating UTI, likely due to the failure of infused antibiotics to penetrate the bladder epithelium and accumulate to high enough levels to kill intracellular bacteria. This work investigates the use of nitrofurantoin loaded poly(lactic-co-glycolic acid) (PLGA) particles to improve delivery to intracellular targets for the treatment of chronic UTI. Using electrohydrodynamic atomisation, we produced particles with an average diameter of 2.8 μm. In broth culture experiments, the biodegradable particles were effective against a number of UTI-relevant bacterial strains. Dye-loaded particles demonstrated that intracellular delivery was achieved in all cells in 2D cultures of a human bladder epithelial progenitor cell line in a dose-dependent manner, achieving far higher efficiency and concentration than equivalent quantities of free drug. Time-lapse video microscopy confirmed that delivery occurred within 30 min of administration, to 100% of cells. Moreover, the particles were able to deliver the drug to cells through multiple layers of a 3D human bladder organoid model causing minimal cell toxicity, displaying superior killing of bacterial reservoirs harboured within bladder cells compared with unencapsulated drug. The particles were also able to kill bacterial biofilms more effectively than the free drug. These results illustrate the potential for using antibiotic-loaded microparticles to effectively treat chronic UTIs. Such a delivery method could be extrapolated to other clinical indications where robust intracellular delivery is required, such as oncology and gene therapy.

Warmer Weather and the Risk of Urinary Tract Infections in Women

PURPOSE

The incidence of urinary tract infections is seasonal, peaking in summer months. One possible mechanism for the observed seasonality of urinary tract infections is warmer weather.

MATERIALS AND METHODS

We identified all urinary tract infection cases located in approximately 400 metropolitan statistical areas in the contiguous United States between 2001 and 2015 using the Truven Health MarketScan® databases. A total of 167,078,882 person-years were included in this data set and a total of 15,876,030 urinary tract infection events were identified by ICD-9 code 599.0. Weather data for each metropolitan statistical area and date were obtained from the National Centers for Environmental Information. We computed the mean temperature during the period 0 to 7 days prior to the urinary tract infection diagnosis. We used a quasi-Poisson generalized linear model. The primary outcome was the number of urinary tract infections each day in a metropolitan statistical area in each age group. Covariates considered included age group, day of week, year and the temperature during the previous 7 days.

RESULTS

Warmer weather increases the risk of urinary tract infections among women treated in outpatient settings in a dose-response fashion. On days when the prior week's average temperature was between 25 and 30C, the incidence of urinary tract infections was increased by 20% to 30% relative to when the prior week's temperature was 5 to 7.5C.

CONCLUSIONS

The incidence of urinary tract infections increases with the prior week's temperature. Our results indicate that warmer weather is a risk factor for urinary tract infections. Furthermore, as temperatures rise, the morbidity attributable to urinary tract infections may increase.

Genomic Sequences of Uropathogenic Escherichia coli Strains with Various Fluoroquinolone Resistance Profiles

The emergence of drug-resistant uropathogenic Escherichia coli (UPEC) has hampered antibiotic therapy for urinary tract infections. To elucidate the resistance mechanisms of UPEC, we performed whole-genome sequencing of eight UPEC strains with different fluoroquinolone resistance levels. Here, we report our sequencing data, providing a valuable resource for understanding such mechanisms.

The emergence of drug-resistant uropathogenic Escherichia coli (UPEC) has hampered antibiotic therapy for urinary tract infections. To elucidate the resistance mechanisms of UPEC, we performed whole-genome sequencing of eight UPEC strains with different fluoroquinolone resistance levels. Here, we report our sequencing data, providing a valuable resource for understanding such mechanisms.

A Dual Enzyme-Based Biochemical Test Rapidly Detects Third-Generation Cephalosporin-Resistant CTX-M-Producing Uropathogens in Clinical Urine Samples

Extended-spectrum β-lactamase (ESBL)-producing Gram-negative bacteria (GNB) are increasingly identified as the cause of both community and healthcare-associated urinary tract infections (UTIs), with CTX-Ms being the most common ESBLs identified. CTX-M-producing GNB are resistant to most β-lactam antibiotics and are frequently multidrug-resistant, which limits treatment options. Rapid diagnostic tests that can detect ESBL-producing GNB, particularly CTX-M producers, in the urine of patients with UTIs are needed. Results from such a test could direct the selection of appropriate antimicrobial therapy at the point-of-care (POC). In this study, we show that a chromogenic, dual enzyme-mediated amplification system (termed DETECT [dual-enzyme trigger-enabled cascade technology]) can identify CTX-M-producing GNB from unprocessed urine samples in 30 minutes. We first tested DETECT against a diverse set of recombinant β-lactamases and β-lactamase-producing clinical isolates to elucidate its selectivity. We then tested DETECT with 472 prospectively collected clinical urine samples submitted for urine culture to a hospital clinical microbiology laboratory. Of these, 118 (25%) were consistent with UTI, 13 (11%) of which contained ESBL-producing GNB. We compared DETECT results in urine against a standard phenotypic method to detect ESBLs, and polymerase chain reaction and sequencing for CTX-M genes. DETECT demonstrated 90.9% sensitivity and 97.6% specificity (AUC, 0.937; 95% confidence interval, 0.822-1.000), correctly identifying 10 of 11 urine samples containing a clinically significant concentration of CTX-M-producing GNB (including Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis). Our results demonstrate the clinical potential of DETECT to deliver diagnostic information at the POC, which could improve initial antibiotic selection.

Trimethoprim-Loaded Microspheres Prepared from Low-Molecular-Weight PLGA as a Potential Drug Delivery System for the Treatment of Urinary Tract Infections

Commonly, therapy of urinary tract infections suffers from increasing resistance to antibiotics and the ability of uropathogenic Escherichia coli (UPEC) to invade bladder cells and cause recurring infections. As an alternative strategy for instillation into the bladder, trimethoprim-loaded microparticles with poly(d,l-lactic-co-glycolic acid) (PLGA) as a matrix were prepared. To reduce particle loss by washout, their surface was grafted with bioadhesive wheat germ agglutinin, providing biomimicry akin to UPEC. Since PLGA 503H has shown a slow drug release profile, the low-molecular-weight PLGA 2300 was studied. Whereas the drug loading of PLGA 503H particles amounted to 2.8%, the drug content of PLGA 2300 particles was twice as high. Although the drug release pattern started with an initial burst of 30% after 24 h for both PLGA types, half of the trimethoprim content was released after 4 days from PLGA 503H microparticles as opposed to 2 days in the case of PLGA 2300. Higher drug loading and accelerated release render PLGA 2300 a viable alternative to PLGA 503H.

Micro vs. nano: PLGA particles loaded with trimethoprim for instillative treatment of urinary tract infections

Recurring infections and increasing resistances continue to complicate treatment of urinary tract infections. To investigate alternative treatment options, trimethoprim loaded micro- (D[4;3] of 1-9 µm) and nanoparticles (Z-Avg of 200-400 nm) were prepared from two types of poly(d,l-lactic-co-glycolic acid) (PLGA) for instillative therapy. While PLGA 503H microparticles could not be loaded with more than 2.6% trimethoprim, PLGA 2300 entrapped 22%. When preparing nanoparticles, both types displayed an even higher drug load of up to 29% using PLGA 2300, while PLGA 503H drug load stagnated at 10%. After eight hours, drug release from microparticles amounted to 55% (503H) and 35% (2300) whereas total drug release occurred after 8 (503H) and 9 days (2300). In case of nanoparticles, trimethoprim was liberated much faster with 60% after 2 h and a complete release after 24 h from both polymers. PLGA 2300 seems to be the better choice for entrapment of trimethoprim in microparticles considering the drug load. Both polymers, however, seem to be viable options for nanoparticles. Due to the higher overall drug load, nanoparticles seem to be advantageous over microparticles for instillative therapy, especially when prepared with PLGA 2300.

Age-related Trends in Adults with Urinary Tract Infections Presenting to the Emergency Department: A 5-Year Experience

INTRODUCTION

Urinary tract infections (UTIs) are among the most common bacterial infections, affecting 150 million people worldwide each year. Importantly, the incidence of UTI increases markedly with age. The increasing resistance to empirically prescribed antimicrobial agents complicates the management of this disease. This makes UTI an important issue in increasingly aging population and updated epidemiological investigation is advisable. To understand the epidemiological variation in UTI resistance patterns among differently aged populations, we conducted a retrospective study among patients presenting to the emergency department (ED) of a large tertiary-care hospital in Italy during January 2013 and June 2017.

METHODS

1281 patients who presented with UTI symptoms to the ED, were stratified into four age categories: young adults (18-44 years old;), adults (45-64), the elderly (65-84), and the oldest old (≥ 85). Inclusion criteria were urine collected in ED patients with UTI symptoms and first positive culture from one given patient in a given year.

RESULTS

362 (28.2%) patients had a urine culture with positive result, leading to a total of 459 germs isolated, stratified into four categories: young adults (58 isolates, 12.6%), adults (98, 21.4%), the elderly (174, 37.9%), and the oldest old (129, 28.1%). Escherichia coli represents the 60% of all monomicrobial infections, followed in frequency by Klebsiella pneumoniae (15%), and Enterococcus faecalis (5%). The other 20% of the infections are caused by various germs. The most common association of germs in polymicrobial is E. coli + E. faecalis, accounting for the 28% of all infections. Overall, we found a peak of susceptibility to amoxicillin (AMX) in the oldest old ( 81%), significantly higher compared to young adults (54%), adults (47%) and elderly (35%) (p<0,001). For ciprofloxacin (CIP) there is a greater susceptibility in the young adult (55.5%), but not so marked compared to the other three groups; for fosfomicin (FOS) the susceptibility was greater in the group of adults (60%) compared to young adults, elderly and the oldest old. Also for trimethoprim/ sulfamethoxazole (TMP-SMX) we found greater susceptibility in the adult group (60%), followed by the oldest old (57,6%), young adults (49%) and elderly (47%).

CONCLUSION

Age-related differences in antimicrobial-resistant microorganisms were evident for adults with UTI, and could potentially contribute to the risk of inappropriate empirical therapy in elderly patients. Thus, different empirical antimicrobial regimens should be considered for distinct age groups.

Fast identification of Escherichia coli in urinary tract infections using a virulence gene based PCR approach in a novel thermal cycler

Uropathogenic Escherichia coli (UPEC) is the most common causal agent of urinary tract infections (UTIs) in humans. Currently, clinical detection methods take hours (dipsticks) to days (culturing methods), limiting rapid intervention. As an alternative, the use of molecular methods could improve speed and accuracy, but their applicability is complicated by high genomic variability within UPEC strains. Here, we describe a novel PCR-based method for the identification of E. coli in urine. Based on in silico screening of UPEC genomes, we selected three UPEC-specific genes predicted to be involved in pathogenesis (c3509, c3686 (yrbH) and chuA), and one E. coli-specific marker gene (uidA). We validated the method on 128 clinical (UTI) strains. Despite differential occurrences of these genes in uropathogenic E. coli, the method, when using multi-gene combinations, specifically detected the target organism across all samples. The lower detection limit, assessed with model UPEC strains, was approximately 10⁴ CFU/ml. Additionally, the use of this method in a novel ultrafast PCR thermal cycler (Nextgen PCR) allowed a detection time from urine sampling to identification of only 52 min. This is the first study that uses such defined sets of marker genes for the detection of E. coli in UTIs. In addition, we are the first to demonstrate the potential of the Nextgen thermal cycler. Our E. coli identification method has the potential to be a rapid, reliable and inexpensive alternative for traditional methods.

Intravesical sodium hyaluronate reduces severity, frequency and improves quality of life in recurrent UTI

Purpose

Urinary tract infections (UTI) occur in nearly half of all women at least once, with around 35% experiencing recurrences. Bladder mucosal glycosaminoglycan (GAG) layer damage is postulated to contribute. Sodium hyaluronate (SH) replenishes the GAG layer and is believed to be protective. However, there is limited literature on patient-reported outcomes and quality of life (QoL) after treatment. Our objective was to observe changes in UTI severity and QoL after treatment with intravesical SH.

Methods

In this retrospective, observational patient-reported outcome study, we examined outcomes in UTI patients treated with intravesical SH. SH was instilled weekly for 6 weeks. If symptoms persisted, patients received further instillations on demand. Patients were sent postal questionnaires to score symptoms before and after treatment. Patient-reported UTI occurrences before treatment were compared with recurrences after treatment collected from their primary care providers.

Results

There were 18 (58.1%) valid replies. The median age was 75. The median duration of illness before treatment was 4.5 (IQR 2.8–7) years. The median number of infections fell from ten per year (IQR 7–10) before treatment to two per year (IQR 0–5) after treatment. Pain improved by 34%, urgency 30%, nocturia 30%, frequency 32%, ‘inability to carry out daily activities due to UTI related ill-health’ 37% and ‘loss of sleep’ by 38%. Patients reported a 76% improvement in ‘UTI-related QoL.’ No adverse events were reported.

Conclusion

SH is safe and useful for managing patients with recurrent UTI, with improvements in symptoms, QoL, a decrease in the number of UTI episodes and in the best interests of antimicrobial stewardship.

Comparison of Gene Expression Profiles of Uropathogenic Escherichia Coli CFT073 after Prolonged Exposure to Subinhibitory Concentrations of Different Biocides

Biocides are chemical compounds widely used for sterilization and disinfection. The aim of this study was to examine whether exposure to subinhibitory biocide concentrations influenced transcriptional expression of genes that could improve a pathogen’s drug resistance or fitness. We used DNA microarrays to investigate the transcriptome of the uropathogenic Escherichia coli strain CFT073 in response to prolonged exposure to subinhibitory concentrations of four biocides: benzalkonium chloride, chlorhexidine, hydrogen peroxide and triclosan. Transcription of a gene involved in polymyxin resistance, arnT, was increased after treatment with benzalkonium chloride. However, pretreatment of the bacteria with this biocide did not result in cross-resistance to polymyxin in vitro. Genes encoding products related to transport formed the functional group that was most affected by biocides, as 110 out of 884 genes in this category displayed altered transcription. Transcripts of genes involved in cysteine uptake, sulfate assimilation, dipeptide transport, as well as cryptic phage genes were also more abundant in response to several biocides. Additionally, we identified groups of genes with transcription changes unique to single biocides that might include potential targets for the biocides. The biocides did not increase the resistance potential of the pathogen to other antimicrobials.

The Widely Used Antimicrobial Triclosan Induces High Levels of Antibiotic Tolerance In Vitro and Reduces Antibiotic Efficacy up to 100-Fold In Vivo

The antimicrobial triclosan is used in a wide range of consumer products ranging from toothpaste, cleansers, socks, and baby toys. A bacteriostatic inhibitor of fatty acid synthesis, triclosan is extremely stable and accumulates in the environment.

The antimicrobial triclosan is used in a wide range of consumer products ranging from toothpaste, cleansers, socks, and baby toys. A bacteriostatic inhibitor of fatty acid synthesis, triclosan is extremely stable and accumulates in the environment. Approximately 75% of adults in the United States have detectable levels of the compound in their urine, with a sizeable fraction of individuals (>10%) having urine concentrations equal to or greater than the minimal inhibitory concentration for Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA). Previous work has identified connections between defects in fatty acid synthesis and accumulation of the alarmone guanosine tetraphosphate (ppGpp), which has been repeatedly associated with antibiotic tolerance and persistence. Based on these data, we hypothesized that triclosan exposure may inadvertently drive bacteria into a state in which they are able to tolerate normally lethal concentrations of antibiotics. Here we report that clinically relevant concentrations of triclosan increased E. coli and MRSA tolerance to bactericidal antibiotics as much as 10,000-fold in vitro and reduced antibiotic efficacy up to 100-fold in a mouse urinary tract infection model. Genetic analysis indicated that triclosan-mediated antibiotic tolerance requires ppGpp synthesis but is independent of growth. These data highlight an unexpected and certainly unintended consequence of adding high concentrations of antimicrobials in consumer products, supporting an urgent need to reevaluate the costs and benefits of the prophylactic use of triclosan and other bacteriostatic compounds.

Uropathogenic Escherichia coli employs both evasion and resistance to subvert innate immune-mediated zinc toxicity for dissemination

Uropathogenic Escherichia coli (UPEC) is responsible for most urinary tract infections and is also a frequent cause of sepsis, thus necessitating an understanding of UPEC-mediated subversion of innate immunity. The role of zinc in the innate immune response against UPEC infection, and whether this pathogen counters this response, has not been examined. Here we demonstrate, both in vitro and in vivo, that UPEC both evades and resists innate immune-mediated zinc toxicity to persist and disseminate within the host. Moreover, we have defined the set of UPEC genes conferring zinc resistance and have developed highly selective E. coli reporter systems to track zinc toxicity. These innovative approaches substantially enhance our understanding of immune-mediated metal ion toxicity and bacterial pathogenesis.

Toll-like receptor (TLR)-inducible zinc toxicity is a recently described macrophage antimicrobial response used against bacterial pathogens. Here we investigated deployment of this pathway against uropathogenic Escherichia coli (UPEC), the major cause of urinary tract infections. Primary human macrophages subjected EC958, a representative strain of the globally disseminated multidrug-resistant UPEC ST131 clone, to zinc stress. We therefore used transposon-directed insertion site sequencing to identify the complete set of UPEC genes conferring protection against zinc toxicity. Surprisingly, zinc-susceptible EC958 mutants were not compromised for intramacrophage survival, whereas corresponding mutants in the nonpathogenic E. coli K-12 strain MG1655 displayed significantly reduced intracellular bacterial loads within human macrophages. To investigate whether the intramacrophage zinc stress response of EC958 reflected the response of only a subpopulation of bacteria, we generated and validated reporter systems as highly specific sensors of zinc stress. Using these tools we show that, in contrast to MG1655, the majority of intramacrophage EC958 evades the zinc toxicity response, enabling survival within these cells. In addition, EC958 has a higher tolerance to zinc than MG1655, with this likely being important for survival of the minor subset of UPEC cells exposed to innate immune-mediated zinc stress. Indeed, analysis of zinc stress reporter strains and zinc-sensitive mutants in an intraperitoneal challenge model in mice revealed that EC958 employs both evasion and resistance against zinc toxicity, enabling its dissemination to the liver and spleen. We thus demonstrate that a pathogen of global significance uses multiple mechanisms to effectively subvert innate immune-mediated zinc poisoning for systemic spread.

Reassessment of Routine Midstream Culture in Diagnosis of Urinary Tract Infection

Midstream urine (MSU) culture remains the gold standard diagnostic test for confirming urinary tract infection (UTI). We previously showed that patients with chronic lower urinary tract symptoms (LUTS) below the diagnostic cutoff on MSU culture may still harbor bacterial infection and that their antibiotic treatment was associated with symptom resolution. Here, we evaluated the results of the United Kingdom's MSU culture in symptomatic patients and controls. Next, we compared the bacterial enrichment capabilities of the MSU culture with those of a 50-µl uncentrifuged culture, a 30-ml centrifuged sediment culture, and 16S rRNA gene sequencing. This study was conducted on urine specimens from 33 LUTS patients attending their first clinical appointment (mean age, 48.7 years; standard deviation [SD], 16.5 years), 30 LUTS patients on treatment (mean age, 47.8 years; SD, 16.5 years) whose symptoms had relapsed, and 29 asymptomatic controls (mean age, 40.7 years, SD, 15.7 years). We showed that the routine MSU culture, adopting the UK interpretation criteria tailored to acute UTI, failed to detect a variety of bacterial species, including recognized uropathogens. Moreover, the diagnostic MSU culture was unable to discriminate between patients and controls. In contrast, genomic analysis of urine enriched by centrifugation discriminated between the groups, generating a more accurate understanding of species richness. In conclusion, the United Kingdom's MSU protocol misses a significant proportion of bacteria, which include recognized uropathogens, and may be unsuitable for excluding UTI in patients with LUTS.

Factors associated with the duration of symptoms in adult women with suspected cystitis in primary care

Objective

The aim of this study was to identify factors associated to the duration of symptoms of cystitis.

Patients and methods

We conducted a nested survival study using Druti study data. Druti was a cross-sectional survey conducted in adult women visiting a general practitioner in France, for a suspected urinary tract infection between January 2012 and February 2013. For this study, urine cultures were systematically performed for all women. The evolution of symptoms were monitored daily for two weeks. This nested study considered only women with suspected cystitis from Druti; women with pyelonephritis were excluded. To identify independent predictors for duration of symptoms, a Cox proportional hazards regression model was performed.

Results

In Druti, 449 patients had a suspected cystitis. Among them, 440 had a follow up at two weeks. Out of the 440 patients, 424 had a prescription of antibiotic treatment (96.4%). The urine culture was positive for 326 patients (74.1%). The median duration of symptoms after consultation was two days (interquartile 1–3). The absence of urinary frequency (median two days versus three days, p = 0.008), age over 55 years (median two days versus three days, p<0.001) and patient’s bet about the presence of a urinary tract infection (median two days, p = 0.021) were associated to a longer duration of symptoms. Positive culture (p = 0.99) and presence of a multi-drug resistant organism (p = 0.38) did not influence the duration of symptoms.

Conclusion

In a real-life study, factors influencing the duration of symptoms are clinical factors. The delay before re-evaluation in case of persistent symptoms after treatment could be adapted according to the initial clinical examination.

High molecular weight hyaluronic acid: a two-pronged protectant against infection of the urogenital tract?

OBJECTIVES

Recurrent urinary tract infections are associated with uropathogenic Escherichia coli (UPEC) ascending and infecting the urinary tract. Antibiotics provide only symptomatic relief, not prevent recurrence. Clinical evidence suggests that intravesical glycosaminoglycan therapy, such as hyaluronic acid (HA), helps reduce UTI recurrence. This has been investigated here using in vitro systems modelling the urogenital tract tissues.

METHODS

RT4 bladder cells were preconditioned with high molecular weight HA (> 1500 kDa) at 2 mg mL-1 and challenged with UPEC to analyse barrier protection and bacterial adherence. Untreated and HA-preconditioned VK2 E6/E7 vaginal cells were challenged with E. coli flagellin (50 ng mL-1) to mimic bacterial challenge, and media analysed for lipocalin-2, human β-defensin 2 and interleukin-8 by ELISA. Experiments were repeated after siRNA knockdown of Toll-like receptors 2, 4 and 5, and CD44 to investigate signalling.

RESULTS

Microscopic analyses showed reduced bacterial adherence and urothelial disruption with HA, suggesting that HA functions as a barrier protecting the epithelium from bacterial infection. Cells treated with HA and flagellin simultaneously produced more of the host antimicrobial peptide LCN2 and pro-inflammatory IL-8 (P < 0.05) compared to the no HA/flagellin challenges. Increased gene expression of DEFB4 (P < 0.05), but not the hBD2 peptide, was observed in the HA/flagellin-challenged cells.

CONCLUSION

These data suggest that exogenous HA has potential to protect the urogenital epithelia from UPEC infection via a two-pronged approach that involves the physical enhancement of the epithelial barrier and augmentation of its innate immune response.

High Prevalence of CTX-M-1-Like Enzymes in Urinary Isolates of Escherichia coli in Guayaquil, Ecuador

Escherichia coli is one of the major causes of urinary tract infections in primary healthcare, and treatment is more complicated due to the increase in antibiotic resistance. Extended-spectrum β-lactamases are the most common mechanism of resistance against third-generation cephalosporin, and CTX-M-like are among the most prevalent. The aim of our work is to investigate the prevalence of bla_CTX-M in isolates of E. coli obtained from samples of patients without previous known contact with the hospital. Ninety-four E. coli isolates with resistance to third-generation cephalosporin were collected between 2008 and 2013 in Guayaquil, Ecuador. Polymerase chain reaction, followed by sequencing, was performed to identify the type of bla_CTX-M-Like. Enterobacterial repetitive intergenic consensus (ERIC)-PCR was carried out to determine the clonal relationship between isolates. These results show an increase in resistance to third-generation cephalosporin from 10.58% to 23.96%. CTX-M-15 was the most prevalent mechanism of resistance being that the isolates were not clonal. Overall, these results show an increase in antibiotic resistance in the community over time, suggesting that more precise antibiotic stewardship needs to be implemented to control the dissemination of antibiotic-resistant bacteria in this region.

Recurrent Urinary Tract Infection After Midurethral Sling: A Retrospective Study

OBJECTIVES

Our primary objective was to estimate the proportion of patients with culture-proven urinary tract infection (UTI) and recurrent UTI after midurethral sling (MUS), as well as to evaluate their risk factors. Our secondary objective was to characterize the difference in the proportion of patients with recurrent UTI before and after MUS.

METHODS

We conducted a retrospective study of patients who underwent MUS from 2009 to 2012 within a large health maintenance organization and subsequently had documentation of at least 1 positive urine culture (>100 K CFU/mL) within 1 year. Validated procedural and diagnostic codes were used to identify patients undergoing MUS and the diagnosis of UTI, respectively.

RESULTS

Of the 7461 MUS performed, 883 (12%) patients had at least 1 culture-proven UTI and 258 (3.5%) patients met the definition of recurrent UTI postoperatively. Of those 883 patients, 89 (10%) patients met the definition of recurrent UTI before, and 258 (29%) patients after, MUS. McNemar χ test revealed that patients were more likely to have recurrent UTI after MUS compared with before (P < 0.0001). In multivariate logistic regression, Caucasian (odds ratio [OR], 1.60, 95% confidence interval [95% CI], 1.12-2.29; P = 0.01) and African-American (OR, 3.42; 95% CI, 1.42-8.29; P = 0.01) ethnicity, older age (OR, 1.02; 95% CI, 1.00-1.04; P = 0.03), and a history of recurrent UTI (OR 3.79, 95% CI 1.88-7.93, P = 0.0003) were risk factors for postoperative recurrent UTI.

CONCLUSIONS

In this population, preoperative recurrent UTI was the only modifiable risk factor associated with an increased risk of postoperative recurrent UTI.

Mismatch between suspected pyelonephritis and microbiological diagnosis: a cohort study from a UK teaching hospital

Urinary tract infections are a common reason for prescribing empirical antibiotics in the emergency department. This study investigated the role of microbiological culture and urinalysis in the diagnosis of pyelonephritis by extracting data on 105 patients with a clinical diagnosis of pyelonephritis at a London teaching hospital. In total, 99 of 102 patients were treated empirically with intravenous antibiotics, but only 55 of 100 patients who were sampled had microbiological evidence of infection in urine and/or blood. Almost half (10/21) of the patients with a negative urine dipstick test had a positive urine culture. Diagnostic uncertainty in this context undoubtedly drives inappropriate antibiotic use.

Temporal upregulation of host surface receptors provides a window of opportunity for bacterial adhesion and disease

Host surface receptors provide bacteria with a foothold from which to attach, colonize and, in some cases, invade tissue and elicit human disease. In this review, we discuss several key host receptors and cognate adhesins that function in bacterial pathogenesis. In particular, we examine the elevated expression of host surface receptors such as CEACAM-1, CEACAM-6, ICAM-1 and PAFR in response to specific stimuli. We explore how upregulated receptors, in turn, expose the host to a range of bacterial infections in the respiratory tract. It is apparent that exploitation of receptor induction for bacterial adherence is not unique to one body system, but is also observed in the central nervous, gastrointestinal and urogenital systems. Prokaryotic pathogens which utilize this mechanism for their infectivity include Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis and Escherichia coli. A number of approaches have been used, in both in vitro and in vivo experimental models, to inhibit bacterial attachment to temporally expressed host receptors. Some of these novel strategies may advance future targeted interventions for the prevention and treatment of bacterial disease.

Prospective Evaluation of Light Scatter Technology Paired with Matrix-Assisted Laser Desorption IonizationTime of Flight Mass Spectrometry for Rapid Diagnosis of Urinary Tract Infections

Urinary tract infections are one of the most common reasons for health care visits. Diagnosis and optimal treatment often require a urine culture, which takes an average of 1.5 to 2 days from urine collection to results, delaying optimal therapy. Faster, but accurate, alternatives are needed. Light scatter technology has been proposed for several years as a rapid screening tool, whereby negative specimens are excluded from culture. A commercially available light scatter device, BacterioScan 216Dx (BacterioScan, Inc.), has recently been advertised for this application. Paired use of mass spectrometry (MS) for bacterial identification and automated-system-based susceptibility testing straight from the light scatter suspension might provide dramatic improvement in times to a result. The present study prospectively evaluated the BacterioScan device, with culture as the reference standard. Positive light scatter specimens were used for downstream rapid matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) MS organism identification and automated-system-based antimicrobial susceptibility testing. Prospective evaluation of 439 urine samples showed a sensitivity of 96.5%, a specificity of 71.4%, and positive and negative predictive values of 45.1% and 98.8%, respectively. MALDI-TOF MS analysis of the suspension after density-based selection yielded a sensitivity of 72.1% and a specificity of 96.9%. Antimicrobial susceptibility testing of the samples identified by MALDI-TOF MS produced an overall categorical agreement of 99.2%. Given the high sensitivity and negative predictive value of results obtained, BacterioScan 216Dx is a reasonable approach for urine screening and might produce negative results in as few as 3 h, with no downstream workup. Paired rapid identification and susceptibility testing might be useful when MALDI-TOF MS results in an organism identification, and it might decrease the time to a result by more than 24 h.

An update on emerging therapies for urinary tract infections

INTRODUCTION

Urinary tract infections (UTIs) are the most common healthcare-acquired infections, and are associated with high morbidity and mortality. Worldwide use of antibiotics has led to a significant rise in resistant uropathogens emanating from both hospitals and communities. The huge concern of multidrug resistance (MDR) has led the Food and Drug Administration (FDA) to encourage drug companies to invest in the development of new antibiotics. Area covered: In this review we summarized data on already approved antibiotics, and selected emerging therapies that are currently in phase II and III trials with emphasis on complicated urinary tract infections (cUTIs). We performed our search using PubMed, ClinicalTrials.gov, Google Scholar and Pharmaprojects. Expert opinion: Efficacious antimicrobials are needed to overcome MDR organisms. There are several dugs in initial and later stages of development, but most of them lack full spectrum of activity against some Gram-negative organisms, particularly against MDR Pseudomonas aeruginosa. Better understanding of the pathogenesis of UTI and genetic engineering of pathogens can provide new drugs to combat resistance in the future.

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.

Bacteriophages to reduce gut carriage of antibiotic resistant uropathogens with low impact on microbiota composition

Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections (UTIs) worldwide, causing over 150 million clinical cases annually. There is currently no specific treatment addressing the asymptomatic carriage in the gut of UPEC before they initiate UTIs. This study investigates the efficacy of virulent bacteriophages to decrease carriage of gut pathogens. Three virulent bacteriophages infecting an antibiotic-resistant UPEC strain were isolated and characterized both in vitro and in vivo. A new experimental murine model of gut carriage of E. coli was elaborated and the impact of virulent bacteriophages on colonization levels and microbiota diversity was assessed. A single dose of a cocktail of the three bacteriophages led to a sharp decrease in E. coli levels throughout the gut. We also observed that microbiota diversity was much less affected by bacteriophages than by antibiotics. Therefore, virulent bacteriophages can efficiently target UPEC strains residing in the gut, with potentially profound public health and economic impacts. These results open a new area with the possibility to manipulate specifically the microbiota using virulent bacteriophages, which could have broad applications in many gut-related disorders/diseases and beyond.

Adhesive Pili in UTI Pathogenesis and Drug Development

Urinary tract infections (UTIs) are one of the most common bacterial infections, affecting 150 million people each year worldwide. High recurrence rates and increasing antimicrobial resistance among uropathogens are making it imperative to develop alternative strategies for the treatment and prevention of this common infection. In this Review, we discuss how understanding the: (i) molecular and biophysical basis of host-pathogen interactions; (ii) consequences of the molecular cross-talk at the host pathogen interface in terms of disease progression; and (iii) pathophysiology of UTIs is leading to efforts to translate this knowledge into novel therapeutics to treat and prevent these infections.

Microbiological Characteristics of Unresolved Acute Uncomplicated Cystitis

This study sought to compare the antimicrobial susceptibility rates between acute uncomplicated cystitis patients with failed initial antimicrobial treatment, who were considered unresolved cases, and newly presenting acute uncomplicated cystitis patients without recent antimicrobial use within 3 months and to determine whether different treatment strategies should be applied according to recent antimicrobial exposure (RAE). Female acute uncomplicated cystitis patients with Escherichia coli growth, who visited our hospital's urology department from 2010 to 2014, were divided according to RAE. The antimicrobial susceptibility of E. coli was compared between the group with RAE and the group with no antimicrobial exposure (NAE) within 3 months. The total number of acute uncomplicated cystitis patients with E. coli growth was 259: 40 patients comprised the RAE group and 219 patients formed the NAE group. The mean age was significantly older and previous recurrent cystitis history was higher in the RAE group (p < 0.05). Furthermore, the antimicrobial susceptibility of E. coli to amoxicillin-clavulanic acid, cefotaxime, cefoxitin, ciprofloxacin, and trimethoprim-sulfamethoxazole was significantly lower in the RAE group, with susceptibility results of 64.7%/88.0% (RAE/NAE), 77.5%/89.0%, 79.4%/95.3%, 31.3%/64.2%, and 42.5%/70.6%, respectively. RAE was an independent factor for antimicrobial resistance. This study showed that antimicrobial susceptibilities were significantly lower in acute uncomplicated cystitis patients with failed initial antimicrobial treatment, who are defined as unresolved cases. Our results suggest that first-line antimicrobials might show poor efficacy in cases of unresolved, acute uncomplicated cystitis and alternative or secondary antimicrobials should be considered in these cases.

Kidney function and the use of nitrofurantoin to treat urinary tract infections in older women

BACKGROUND

The antibiotic nitrofurantoin is commonly used to treat uncomplicated urinary tract infections. However, when this drug is used by patients with reduced kidney function, its urine concentration may be subtherapeutic.

METHODS

We conducted a population-based study of older women (mean age 79 years) in Ontario, Canada, whose estimated glomerular filtration rate was relatively low (median 38 mL/min per 1.73 m(2)) and for whom 1 of 4 antibiotics had been prescribed for urinary tract infection: nitrofurantoin, ciprofloxacin, norfloxacin or trimethoprim-sulfamethoxazole. We assessed 2 measures of treatment failure in the subsequent 14 days: receipt of a second antibiotic indicated for urinary tract infection and hospital encounter (emergency department visit or hospital admission) with a urinary tract infection. We repeated the analysis for older women with relatively high estimated glomerular filtration rate (median 69 mL/min per 1.73 m(2)).

RESULTS

The baseline characteristics of the 4 antibiotic groups were similar. Relative to nitrofurantoin, the other antibiotics (including ciprofloxacin) were associated with a lower rate of treatment failure among women with relatively low estimated glomerular filtration rate (for ciprofloxacin v. nitrofurantoin: second antibiotic prescription, 130/1989 [6.5%] v. 516/3739 [13.8%], odds ratio [OR] 0.44, 95% confidence interval [CI] 0.36-0.53; hospital encounter, 21/1989 [1.1%] v. 95/3739 [2.5%], OR 0.41, 95% CI 0.25-0.66). However, a similar risk of treatment failure with nitrofurantoin was also observed among women with relatively high estimated glomerular filtration rate. The results were consistent in multiple additional analyses.

INTERPRETATION

In this study, the presence of mild or moderate reductions in estimated glomerular filtration rate did not justify avoidance of nitrofurantoin.

Human urinary exosomes as innate immune effectors

Exosomes are small extracellular vesicles, approximately 50 nm in diameter, derived from the endocytic pathway and released by a variety of cell types. Recent data indicate a spectrum of exosomal functions, including RNA transfer, antigen presentation, modulation of apoptosis, and shedding of obsolete protein. Exosomes derived from all nephron segments are also present in human urine, where their function is unknown. Although one report suggested in vitro uptake of exosomes by renal cortical collecting duct cells, most studies of human urinary exosomes have focused on biomarker discovery rather than exosome function. Here, we report results from in-depth proteomic analyses and EM showing that normal human urinary exosomes are significantly enriched for innate immune proteins that include antimicrobial proteins and peptides and bacterial and viral receptors. Urinary exosomes, but not the prevalent soluble urinary protein uromodulin (Tamm-Horsfall protein), potently inhibited growth of pathogenic and commensal Escherichia coli and induced bacterial lysis. Bacterial killing depended on exosome structural integrity and occurred optimally at the acidic pH typical of urine from omnivorous humans. Thus, exosomes are innate immune effectors that contribute to host defense within the urinary tract.

Rethinking the composition of a rational antibiotic arsenal for the 21st century

The importance of the human microbiome in health may be the single most valuable development in our conception of the microbial world since Pasteur's germ theory of the 1860s. Its implications for our understanding of health and pathogenesis are profound. Coupled with the revolution in diagnostics that we are now witnessing - a revolution that changes medicine from a science of symptoms to a science of causes - we cannot continue to develop antibiotics as we have for the past 80 years. Instead, we need to usher in a new conception of the role of antibiotics in treatment: away from single molecules that target broad phylogenetic spectra and towards targeted molecules that cripple the pathogen while leaving the rest of the microbiome largely intact.

A FimH inhibitor prevents acute bladder infection and treats chronic cystitis caused by multidrug-resistant uropathogenic Escherichia coli ST131

BACKGROUND

Escherichia coli O25b:H4-ST131 represents a predominant clone of multidrug-resistant uropathogens currently circulating worldwide in hospitals and the community. Urinary tract infections (UTIs) caused by E. coli ST131 are typically associated with limited treatment options and are often recurrent.

METHODS

Using established mouse models of acute and chronic UTI, we mapped the pathogenic trajectory of the reference E. coli ST131 UTI isolate, strain EC958.

RESULTS

We demonstrated that E. coli EC958 can invade bladder epithelial cells and form intracellular bacterial communities early during acute UTI. Moreover, E. coli EC958 persisted in the bladder and established chronic UTI. Prophylactic antibiotic administration failed to prevent E. coli EC958-mediated UTI. However, 1 oral dose of a small-molecular-weight compound that inhibits FimH, the type 1 fimbriae adhesin, significantly reduced bacterial colonization of the bladder and prevented acute UTI. Treatment of chronically infected mice with the same FimH inhibitor lowered their bladder bacterial burden by >1000-fold.

CONCLUSIONS

In this study, we provide novel insight into the pathogenic mechanisms used by the globally disseminated E. coli ST131 clone during acute and chronic UTI and establish the potential of FimH inhibitors as an alternative treatment against multidrug-resistant E. coli.

Resistance is futile: the bacteriocin model for addressing the antibiotic resistance challenge

Pathogenic bacteria resistant to many or all antibiotics already exist. With the decline in microbiological research at pharmaceutical companies, the high rate at which resistance has evolved and spread has demanded a novel approach to addressing this critical human health issue. In the present paper, we propose a new paradigm in antibiotic discovery and development, one that applies ecological and evolutionary theory to design antimicrobial drugs that are more difficult and/or more costly to resist. In essence, we propose to simply adopt the strategies invented and applied by bacteria for hundreds of millions of years. Our research focuses on bacteriocins, powerful biological weapons, and their use as alternative therapeutics in human health.