Treatment of Urinary Tract Infections and Antibiotic Stewardship

Characteristics and outcomes of urinary tract infections caused by Enterococci: A multicenter retrospective study from two tertiary hospitals in Saudi Arabia

Enterococci are Gram-positive coccus bacteria that are normally present in the gastrointestinal tract and ordinarily function commensally with humans. Very few studies have investigated the characteristics of enterococcal infections. We aimed to characterize patients with urinary tract infections (UTIs) due to Enterococci and their outcomes. This was a retrospective cohort study between June 2012-November 2022. Patients who had clinically and microbiologically confirmed Enterococcal UTI based on a urine culture positive for E. faecalis or E. faecium with a count of ≥105 CFU/mL and having urinary tract symptoms were included. A total of 396 patients were eligible and included. The patients had a median age of 61 years and were mostly females (56.8 %). The most common characteristics were hospitalization in a non-ICU ward, having a urinary catheter, and recent use of antibiotics within the last 3 months (66.4 %, 59.3 %, and 51.8 %, respectively). Infection with E. faecalis was more common than E. faecium (77.3 % vs. 22.7 %). However, the latter exhibited higher rates of antibiotic resistance (P < 0.001 to several antibiotics) and was associated with significantly higher median C-reactive protein level (26.7 vs. 13 mg/dL; P = 0.025), mortality (23 % vs. 10.1 %; P = 0.002), and median length of stay (25 vs. 11.5 days; P < 0.001). We found that most patients with enterococcal UTIs had a history of having a urinary catheter and recent antibiotic use and were mostly females and hospitalized in non-ICU wards. E. faecium-infected patients experienced more severe episodes and poorer outcomes compared to patients infected with E. faecalis; thus, would need more aggressive therapy.

Structural and functional diversity of Resistance-Nodulation-Division (RND) efflux pump transporters with implications for antimicrobial resistance

SUMMARYThe discovery of bacterial efflux pumps significantly advanced our understanding of how bacteria can resist cytotoxic compounds that they encounter. Within the structurally and functionally distinct families of efflux pumps, those of the Resistance-Nodulation-Division (RND) superfamily are noteworthy for their ability to reduce the intracellular concentration of structurally diverse antimicrobials. RND systems are possessed by many Gram-negative bacteria, including those causing serious human disease, and frequently contribute to resistance to multiple antibiotics. Herein, we review the current literature on the structure-function relationships of representative transporter proteins of tripartite RND efflux pumps of clinically important pathogens. We emphasize their contribution to bacterial resistance to clinically used antibiotics, host defense antimicrobials and other biocides, as well as highlighting structural similarities and differences among efflux transporters that help bacteria survive in the face of antimicrobials. Furthermore, we discuss technical advances that have facilitated and advanced efflux pump research and suggest future areas of investigation that will advance antimicrobial development efforts.

Distribution of chaperone-usher fimbriae and curli fimbriae among uropathogenic Escherichia coli

BACKGROUND

In the present study, we aimed to determine the frequency of the csgA, fimH, mrkD, foc, papaGI, papGII and papGIII genes, to provide and to design fimbrial adhesin gene (FAG) patterns and profiles for the isolated uropathogenic Escherichia coli (UPEC) strains.

METHODS

The enrollment of 108 positive urine samples was performed during seven months, between January 2022 and July 2022. The UPEC strains were confirmed through the standard microbiological and biochemical tests. The antimicrobial susceptibility test was performed through the Kirby-Bauer disc diffusion method. Molecular screening of FAGs was done through the polymerase chain reaction technology. The statistical analyses including chi square and Fisher's exact tests were performed to interpret the obtained results in the present study.

RESULTS

As the main results, the antimicrobial resistance (AMR) patterns, multi- (MDR) and extensively drug-resistance (XDR) patterns and FAG patterns were designed and provided. fimH (93.3%), csgA (90.4%) and papG (37.5%) (papGII (30.8%)) genes were recognized as the top three FAGs, respectively. Moreover, the frequency of csgA-fimH gene profile was identified as the top FAG pattern (46.2%) among the others. The isolates bearing csgA-fimH gene profile were armed with a versatile of phenotypic AMR patterns. In the current study, 27.8%, 69.4% and 1.9% of the UPEC isolates were detected as extended-spectrum ß-lactamases (ESBLs) producers, MDR and XDR strains, respectively.

CONCLUSIONS

In conclusion, detection, providing and designing of patterns and profiles in association with FAGs, AMR feature in UPEC strains give us an effective option to have a successful and influential prevention for both of UTIs initiation and AMR feature.

Beyond urinalysis: evaluation of various clinical and laboratory reflex criteria to warrant urine culture collection in the emergency department

BACKGROUND

Clinical criteria are essential for diagnosing urinary tract infections (UTIs) followed by urine testing, including urinalysis (UA). No study has evaluated the potential related factors that may guide the appropriate collection of urine cultures. Therefore, we aimed to assess the factors that may guide the appropriate collection of urine cultures.

METHODS

This was a case-control study of patients for whom a urine culture and a UA were ordered in the emergency department (ED) between February 2018 and December 2022. The cases included patients with positive cultures, whereas the controls included patients without growth. Patients were excluded if they were pregnant, underwent any urological procedure, received antibiotics within 3 days before ED presentation, or before culture collection.

RESULTS

Of the 263 patients, 123 had growth and 140 did not have growth in urine cultures. In the univariate analysis, female gender, urinary symptoms, urinary white blood cell (WBC) count > 5 cells/hpf, and nitrite in urine were significantly associated with growth (P < 0.05). However, only female gender (aOR, 1.86; 95% CI, 1.06-3.24), urinary WBC count > 5 cells/hpf (aOR, 4.60; 95% CI, 2.21-9.59), and positive nitrite in urine (aOR, 21.90; 95% CI, 2.80-171.00) remained significant in the multivariable analysis. These factors also remained significant in the subgroup of patients with urinary symptoms, except for the female gender.

CONCLUSION

A high urinary WBC count and positive nitrite in UA should be utilized as a guide to collect urine culture, particularly in female patients, to limit the unnecessary ordering of urine culture in the ED. These factors can be used as evidence-based UA reflex criteria as an antimicrobial stewardship intervention.

The Impact of Polymerase Chain Reaction Urine Testing on Clinical Decision-Making in the Management of Complex Urinary Tract Infections

While urinary polymerase chain reaction (PCR) testing is effective in organism identification in patients with complex urinary tract infections (cUTI), limited data exists on the clinical usefulness of this test. We serially surveyed physicians treating symptomatic patients with cUTI both at presentation and after PCR, and urine culture (UC) results were available to ascertain how the test results modified the therapy. A total of 96 unique surveys completed by 21 providers were included in the data analysis. The mean age for female and male patients was 69.4 ± 15.5 and 71.6 ± 12.7 years, respectively. The test positivity and line-item concordance for UC and PCR were consistent with prior reports. The PCR results modified or confirmed treatment in 59/96 (61.5%) and 25/96 (26.0%) of the cases, respectively, with 12/29 (41.4%) and 47/67 (70.1%) having negative and positive PCR results, respectively, resulting in treatment change (difference 28.7%, p < 0.01). Of these, 55/59 (57.3%) were alterations in the antibiotic regimen. PCR use to modify treatment was similar across providers and not statistically different when stratified by patient age, gender, or prior empiric therapy. In 31/59 (52.5%) of the cases, the PCR results modified the treatment where UC would not; conversely, UC would have modified the treatment in 3/37 (8.1%) of the cases where PCR did not (difference 44.4%, p < 0.01). We find that PCR test results are used by clinicians in managing cUTI, and use of this test provides an opportunity to improve antibiotic stewardship in this difficult-to-treat subset of patients.

Unraveling the complex relationship: Multiple sclerosis, urinary tract infections, and infertility

BACKGROUND

Multiple sclerosis (MS) is an immune system disorder that affects the central nervous system (CNS) and progressively damages nerve fibers and protective myelin. People with MS often experience a wide range of complications, including lower urinary tract dysfunction, urinary tract infections (UTIs) and sexual dysfunction. MS is common in young people and can lead to sexual dysfunction (SD) and infertility, which becomes more pronounced as the disease progresses.

RESULTS

Over the past two decades, significant advances have been made in the management of MS, which may slow the progression of the disease and alter its course. However, UTI and SD remain significant challenges for these patients. Awareness of the underlying complications of MS, such as UTIs and infertility, is crucial for prevention, early detection and appropriate treatment, as there is a causal relationship between UTIs and the use of corticosteroids during an attack.

CONCLUSION

This article provides an overview of potential microbial pathogens that contribute to the development of MS, as well as an assessment of people with MS who report UTIs and infertility.

Evaluation of antibacterial, antifungal and antibiofilm activities of A. baumannii-derived tannase and gallic acid against uropathogenic microorganisms

One of the most prevalent infectious diseases and a key driver of antibiotic prescriptions in pediatrics is urinary tract infection (UTI). Due to the emergence of more resistant uropathogenic bacterial and fungal strains, current treatments are no longer effective, necessitating the urgent development of novel antibacterial and antifungal drugs. In this study, the antifungal, antibacterial, and anti-biofilm capabilities of compounds, such as tannase (TN) and gallic acid (GA), which were produced from a novel natural source, Acinetobacter baumannii (AB11) bacteria, were assessed for the inactivation of uropathogenic microorganisms (UMs). Ammonium sulphate precipitation, ion exchange, high-performance liquid chromatography, and gel filtration were used to purify TN and GA that were isolated from A. baumannii. A 43.08 % pure TN with 1221.2 U/mg specific activity and 10.51 mg/mL GA was obtained. The antibacterial, antifungal and anti-biofilm activities of TN and GA were evaluated against UMs and compared to those of commercially available antibiotics including sulfamethoxazole (SXT), levofloxacin (LEV), ciprofloxacin (CIP), amikacin (Ak), and nitrofurantoin (F). The results showed that TN and GA were superior to commercial antibiotics in their ability to inactivate UMs and considerably reduced biofilms formation. Additionally, the GA emerges as the top substitute for currently available medications, demonstrating superior antibacterial and antibiofilm properties against all UMs evaluated in this study. The results of this investigation showed that A. baumannii-derived TN and GA could be utilized as an alternative medication to treat UTIs.

Performance of an innovative culture-based digital dipstick for detection of bacteriuria

IMPORTANCE

In this study, we explore the transformative potential of UTI-lizer, an emerging technology not yet commercially available. Our manuscript shows that UTI-lizer is a promising alternative for detecting the five main pathogens that cause urinary tract infections (UTIs). The results also indicate that digital dipsticks have the potential to uniquely provide UTI diagnostic quality on par with that of gold-standard testing, with the added benefits of ease of testing, rapid test handling time, and simple test equipment. This technology can be helpful in quickly ruling out bacterial infections and reducing the unnecessary use of antibiotics, especially in primary care settings or at the point of care. Moreover, the UTI-lizer test can reduce the number of negative urine samples sent to central laboratories, thus easing the burden of UTI diagnostics on the healthcare system. We believe our study, as well as current and upcoming research based on this technology, is highly relevant for clinical microbiologists, microbiology scientists, general practitioners, and urologists.

Characterization of uropathogenic E. coli from various geographical locations in India

Objectives

Uropathogenic Escherichia coli (UPEC) is the most common causative agent of urinary tract infection, accounting for more than 80% of cases worldwide. This study presents data on prevalent serotypes, resistance profiles, and colonization-aiding virulence characteristics of UPEC from different geographical regions in India.

Methods

UPEC were serotyped through microtiter plate agglutination. Standard techniques were used to detect various virulence characteristics, i.e., biofilm formation (tissue culture plate method), siderophore production (screened on Chrome Azurol S agar and categorized with Csaky's and Arnow's methods), colicin release (agar overlay technique), gelatin hydrolysis (on gelatinase agar), and cell surface hydrophobicity (salt aggregation method). Antibiotic resistance profiles (against 20 antimicrobial agents) and extended-spectrum beta-lactamase (ESBL) were evaluated according to Clinical and Laboratory Standards Institute guidelines.

Results

UPEC strains exhibited very high drug resistance rates to most of the commonly used antimicrobial agents; the highest resistance rates were observed for ampicillin (63.4%), nalidixic acid (63.4%), and cefotaxime (62.1%). High rates of multi-drug resistance (63.36%), ESBL-production (34.1%), and carbapenem-resistance (25.0%) were detected in UPEC strains from all geographical regions of India. Hydrophobicity (61.2%), biofilm production (62.5%), and siderophore production (67.7%) were the most common virulence characteristics of UPEC isolates. Co-expression of virulence characteristics was common (69.8%) in UPEC strains.

Conclusion

UPEC strains with very high antimicrobial-resistance are in circulation in India, and have diverse serotypes and virulence characteristics.

Biofilm Formation by Escherichia coli Isolated from Urinary Tract Infections from Aguascalientes, Mexico

Uropathogenic Escherichia coli (UPEC) strains are among the leading causes of urinary tract infections (UTIs) worldwide. They can colonize the urinary tract and form biofilms that allow bacteria to survive and persist, causing relapses of infections and life-threatening sequelae. Here, we analyzed biofilm production, antimicrobial susceptibility, virulence factors, and phylogenetic groups in 74 E. coli isolated from diagnosed patients with UTIs to describe their microbiological features and ascertain their relationship with biofilm capabilities. High levels of ceftazidime resistance are present in hospital-acquired UTIs. Isolates of multidrug resistance strains (p = 0.0017) and the yfcV gene (p = 0.0193) were higher in male patients. All the strains tested were able to form biofilms. Significant differences were found among higher optical densities (ODs) and antibiotic resistance to cefazolin (p = 0.0395), ceftazidime (p = 0.0302), and cefepime (p = 0.0420). Overall, the presence of fimH and papC coincided with strong biofilm formation by UPEC. Type 1 fimbriae (p = 0.0349), curli (p = 0.0477), and cellulose (p = 0.0253) production was significantly higher among strong biofilm formation. Our results indicated that high antibiotic resistance may be related to male infections as well as strong and moderate biofilm production. The ability of E. coli strains to produce biofilm is important for controlling urinary tract infections.

Repurposing carvacrol, cinnamaldehyde, and eugenol as potential anti-quorum sensing agents against uropathogenic Escherichia coli isolates in Alexandria, Egypt

BACKGROUND

Urinary tract infections represent one of the most frequent hospital and community-acquired infections with uropathogenic Escherichia coli (UPEC) being the main causative agent. The global increase in the emergence of multidrug-resistant (MDR) UPEC necessitates exploring novel approaches. Repurposing natural products as anti-quorum sensing (QS) agents to impede bacterial virulence is gaining momentum nowadays. Hence, this study investigates the anti-QS potentials of carvacrol, cinnamaldehyde, and eugenol against E. coli isolated from urine cultures of Egyptian patients.

RESULTS

Antibiotic susceptibility testing was performed for 67 E. coli isolates and 94% of the isolates showed MDR phenotype. The usp gene was detected using PCR and accordingly, 45% of the isolates were categorized as UPEC. Phytochemicals, at their sub-inhibitory concentrations, inhibited the swimming and twitching motilities of UPEC isolates, with eugenol showing the highest inhibitory effect. The agents hindered the biofilm-forming ability of the tested isolates, at two temperature sets, 37 and 30 °C, where eugenol succeeded in significantly inhibiting the biofilm formation by > 50% at both investigated temperatures, as compared with untreated controls. The phytochemicals were shown to downregulate the expression of the QS gene (luxS) and critical genes related to motility, asserting their anti-QS potential. Further, the combinatory activity of the phytoproducts with five antibiotics was assessed by checkerboard assay. The addition of the phytoproducts significantly reduced the minimum inhibitory concentrations of the antibiotics and generated several synergistic or partially synergistic combinations, some of which have not been previously explored.

CONCLUSIONS

Overall, carvacrol, cinnamaldehyde, and eugenol could be repurposed as potential anti-QS agents, which preferentially reduce the QS-based communication and attenuate the cascades of gene expression, thus decreasing the production of virulence factors in UPEC, and eventually, subsiding their pathogenicity. Furthermore, the synergistic combinations of these agents with antibiotics might provide a new perspective to circumvent the side effects brought about by high antibiotic doses, thereby paving the way for overcoming antibiotic resistance.

A novel coli myophage and antibiotics synergistically inhibit the growth of the uropathogenic E. coli strain CFT073 in stoichiometric niches

Urinary tract infections are widespread bacterial infections affecting millions of people annually, with Escherichia coli being the most prevalent. Although phage therapy has recently gained interest as a promising alternative therapy for antibiotic-resistant bacteria, several studies have raised concerns regarding the evolution of phage resistance, making the therapy ineffective. In this study, we discover a novel coli myophage designated as Killian that targets E. coli strains, including the uropathogenic E. coli (UPEC) strain CFT073. It requires at least 20 minutes for 90% of its particles to adsorb to the host cells, undergoes subcellular activities for replication for 30 minutes, and eventually lyses the cells with a burst size of about 139 particles per cell. Additionally, Killian can withstand a wide variety of temperatures (4-50°C) and pHs (4-10). Genome analysis reveals that Killian's genome consists of 169,905 base pairs with 35.5% GC content, encoding 276 open reading frames; of these, 209 are functionally annotated with no undesirable genes detected, highlighting its potential as an antibiotic alternative against UPEC. However, after an 8-hour phage treatment at high multiplicities of infection, bacterial density continuously increases, indicating an onset of bacterial growth revival. Thus, the combination study between the phage and three different antibiotics, including amikacin, ciprofloxacin, and piperacillin, was performed and showed that certain pairs of phage and antibiotics exhibited synergistic interactions in suppressing the bacterial growth revival. These findings suggest that Killian-antibiotic combinations are effective in inhibiting the growth of UPEC. IMPORTANCE Phage therapy has recently been in the spotlight as a viable alternative therapy for bacterial infections. However, several studies have raised concerns about the emergence of phage resistance that occurs during treatment, making the therapy not much effective. Here, we present the discovery of a novel E. coli myophage that, by itself, can effectively kill the uropathogenic E. coli, but the emergence of bacterial growth revival was detected during the treatment. Phage and antibiotics are then combined to improve the efficiency of the phage in suppressing the bacterial re-growth. This research would pave the way for the future development of phage-antibiotic cocktails for the sustainable use of phages for therapeutic purposes.

Do or Don't: Results of a Multinational Survey on Antibiotic Prophylaxis in Urodynamics

Antibiotic prophylaxis contributes substantially to the increase in antibiotic resistance rates worldwide. This investigation aims to assess the current standard of practice in using antibiotic prophylaxis for urodynamics (UDS) and identify barriers to guideline adherence. An online survey using a 22-item questionnaire designed according to the Checklist for Reporting Results of Internet E-Surveys (CHERRIES) was circulated among urologists and gynecologists in Austria, Germany, and Switzerland between September 2021 and March 2022. A total of 105 questionnaires were eligible for analysis. Out of 105 completed surveys, most responders (n = 99, 94%) regularly perform dipstick urine analysis prior to urodynamics, but do not perform a urine culture (n = 68, 65%). Ninety-eight (93%) participants refrain from using antibiotic prophylaxis, and sixty-eight (65%) use prophylaxis if complicating factors exist. If asymptomatic bacteriuria is present, approximately 54 (52%) participants omit UDS and reschedule the procedure until antimicrobial susceptibility testing is available. Seventy-eight (78%) participants do not have a standard procedure for antibiotic prophylaxis in their department. Part of the strategy against the development of bacterial resistance is the optimized use of antibiotics, including antibiotic prophylaxis in urodynamics. Establishing a standard procedure is necessary and purposeful to harmonize both aspects in the field of urological diagnostics.

Uropathogenic Escherichia coli endeavors: an insight into the characteristic features, resistance mechanism, and treatment choice

Uropathogenic Escherichia coli (UPEC) are the strains diverted from the intestinal status and account mainly for uropathogenicity. This pathotype has gained specifications in structure and virulence to turn into a competent uropathogenic organism. Biofilm formation and antibiotic resistance play an important role in the organism's persistence in the urinary tract. Increased consumption of carbapenem prescribed for multidrug-resistant (MDR) and Extended-spectrum-beta lactamase (ESBL)-producing UPECs, has added to the expansion of resistance. The World Health Organization (WHO) and Centre for Disease Control (CDC) placed the Carbapenem-resistant Enterobacteriaceae (CRE) on their treatment priority lists. Understanding both patterns of pathogenicity, and multiple drug resistance may provide guidance for the rational use of anti-bacterial agents in the clinic. Developing an effective vaccine, adherence-inhibiting compounds, cranberry juice, and probiotics are non-antibiotical approaches proposed for the treatment of drug-resistant UTIs. We aimed to review the distinguishing characteristics, current therapeutic options and promising non-antibiotical approaches against ESBL-producing and CRE UPECs.

Fluorothiazinon inhibits the virulence factors of uropathogenic Escherichia coli involved in the development of urinary tract infection

Uropathogenic Escherichia coli (UPEC) is the most common pathogenic bacterium associated with urinary tract infection. Due to the development of antibiotic resistance and MDR, UPEC infection has become a serious problem in the last decade. In order to combat resistance, it is necessary to develop innovative antimicrobial agents that act by different mechanisms than conventional antibiotics. Among the new therapeutic strategies, suppression of pathogen virulence has become a promising alternative, since it fundamentally reduces selective pressure and the development of resistance. In our study, we showed that the compound Fluorothiazinon suppressed UPEC's ability to form biofilms and to move using the flagellum, as well as to penetrate into cells. Prophylactic use with subsequent treatment of FT in rodent models led to an improvement in survival and significantly reduced the bacterial load in the organs of the urinary system, thereby inhibiting the development of ascending infection and preventing the development of pathological changes in prostate tissues. These results suggest that FT affects several UPEC virulence factors at once and if similar results can be found in clinical trials it can potentially be used as a new drug against UPEC.

Urinary Tract Infections Caused by Uropathogenic Escherichia coli Strains—New Strategies for an Old Pathogen

Urinary tract infections (UTIs) are among the most common infections worldwide. Uropathogenic Escherichia coli (UPECs) are the main causative agent of UTIs. UPECs initially colonize the human host adhering to the bladder epithelium. Adhesion is followed by the bacterial invasion of urothelial epithelial cells where they can replicate to form compact aggregates of intracellular bacteria with biofilm-like properties. UPEC strains may persist within epithelial urothelial cells, thus acting as quiescent intracellular bacterial reservoirs (QIRs). It has been proposed that host cell invasion may facilitate both the establishment and persistence of UPECs within the human urinary tract. UPEC strains express a variety of virulence factors including fimbrial and afimbrial adhesins, invasins, iron-acquisition systems, and toxins, which cooperate to the establishment of long lasting infections. An increasing resistance rate relative to the antibiotics recommended by current guidelines for the treatment of UTIs and an increasing number of multidrug resistant UPEC isolates were observed. In order to ameliorate the cure rate and improve the outcomes of patients, appropriate therapy founded on new strategies, as alternative to antibiotics, needs to be explored. Here, we take a snapshot of the current knowledge of coordinated efforts to develop innovative anti-infective strategies to control the diffusion of UPECs.

Investigation of the effects of antimicrobial and anti-biofilm peptide IDR1018 and chitosan nanoparticles on ciprofloxacin-resistant Escherichia coli

Peptide IDR1018 and chitosan nanoparticles (CNs) showed antimicrobial and anti-biofilm activity against bacteria. In this study, the antimicrobial effects of peptide IDR1018 and CNs were evaluated on 50 clinical isolates of uropathogenic Escherichia coli (UPEC) resistant to ciprofloxacin. Ion gelation method was applied for CNs synthesis. Scanning electron microscope (SEM) and dynamic light scattering (DLS) were utilized to evaluate the nanoparticles. Antimicrobial and synergistic activity of peptide IDR1018 and CNs with ciprofloxacin were evaluated by microtiter broth dilution method. The checkerboard test was used to investigate the antimicrobial effects of IDR1018 and CNS in combination with ciprofloxacin. Anti-biofilm effect of ciprofloxacin, peptide IDR1018, and CNs was evaluated using crystal violet method. Fourteen (28%), 21 (42%), and 15 (30%) of clinical isolates produced strong, moderate, and weak biofilm, respectively. The CNs were spherical and uniform under electron microscopy with an average diameter of 246 nm. The minimum inhibitory concentration (MIC) values were 16-128, 20-40, and 375-750 (µg/ml) for ciprofloxacin, peptide IDR1018, and CNs, respectively. Fractional inhibitory concentration (FIC) analysis indicated a synergistic effect of ciprofloxacin in combination with peptide IDR1018, but in combination with CNs, this antibiotic showed an additive effect. Our results revealed that peptide IDR1018 and CNs have antimicrobial properties on UPEC isolates. Biofilm inhibition and biofilm eradication of clinical isolate were shown by peptide IDR1018 and CNs in a concentration-dependent manner. The antimicrobial agents alone and in combination decreased the number of viable bacteria in the biofilms. Therefore, these components seem to be a treating approach against biofilm-forming UPEC isolates.

Ratiometric PCR in a Portable Sample-to-Result Device for Broad-Based Pathogen Identification

Polymerase chain reaction (PCR)-based diagnostic testing is the gold standard method for pathogen identification (ID) with recent developments enabling automated PCR tests for point-of-care (POC) use. However, multiplexed identification of several pathogens in PCR assays typically requires optics for an equivalent number of fluorescence channels, increasing instrumentation's complexity and cost. In this study, we first developed ratiometric PCR that surpassed one target per color barrier to allow multiplexed identification while minimizing optical components for affordable POC use. We realized it by amplifying pathogenic targets with fluorescently labeled hydrolysis probes with a specific ratio of red-to-green fluorophores for each bacterial species. We then coupled ratiometric PCR and automated magnetic beads-based sample preparation within a thermoplastic cartridge and a portable droplet magnetofluidic platform. We named the integrated workflow POC-ratioPCR. We demonstrated that the POC-ratioPCR could detect one out of six bacterial targets related to urinary tract infections (UTIs) in a single reaction using only two-color channels. We further evaluated POC-ratioPCR using mock bacterial urine samples spiked with good agreement. The POC-ratioPCR presents a simple and effective method for enabling broad-based POC PCR identification of pathogens directly from crude biosamples with low optical instrumentation complexity.

A Three-Year Look at the Phylogenetic Profile, Antimicrobial Resistance, and Associated Virulence Genes of Uropathogenic Escherichia coli

Uropathogenic Escherichia coli is the most common cause of urinary tract infections, resulting in about 150 million reported annual cases. With multidrug resistance on the rise and the need for global and region surveillance, this investigation looks at the UPEC isolates collected for a 3-year period, with a view of ascertaining their antimicrobial susceptibility patterns and associated virulence determinants. The identification of bacteria isolates, antimicrobial susceptibility, and extended-spectrum beta-lactamases (ESBLs) production was determined with a Vitek 2 Compact Automated System (BioMerieux, Marcy L’Etoile, France). ESBLs were confirmed by the combined disc test (CDT) and basic biochemical test. The isolates were distributed into A (11%), B1 (6%), B2 (62.4%), and D (20.6%). Resistance to the penicillin group was high, between 88% and 100%. Additionally, resistance was high to cephalosporins (100%) in 2017 and 2018. The isolates were all sensitive to tigecycline, while resistance against imipenem and meropenem was low, at 4–12% in 2017 and 2018 and 0% in 2019. The results also showed that ESBL isolates were seen in 2017 and 2018. They were confirmed positive to CTX/CLA (88.5%) and CAZ/CLA (85%). By 2019, the number of resistant isolates reduced, showing only 4% ESBL isolates. Two virulence genes, fimH (46%) and papE/F (15%), were detected among the isolates by PCR. In conclusion, this study found that phylogroups B2 and D carried the most virulence genes as well as MDR and ESBL characteristics, suggesting the UPEC strains to be extraintestinal pathogens responsible for UTIs.

Study of Antibacterial Chemical Substances and Molecular Investigation among Sulfamethoxazole-trimethoprim (SXT)-Resistant Escherichia coli Isolates

Background

Escherichia coli (E. coli) remains one of the leading agents of urinary tract infection (UTIs), it has become resistant to many drugs. Current work aimed to evaluate some chemical substances as antibacterial agents and molecular study of virulence factors associated with UTIs.

Methods

This work involved 133 urine specimens obtained from females' patients suffering from UTIs, Methods of well diffusion and disk diffusion were achieved to assay the effect of some chemical substances and antibiogram profiles toward Sulfamethoxazole-trimethoprim (SXT)-resistant E. coli respectively. Virulence genes were done based on the technique of Polymerase Chain Reaction (PCR).

Results

The results recorded 49/133 (36.84%) E. coli among women suffering UTIs, 28/49 (57.14%) were resistant to SXT drug. imipenem, meropenem, and nitrofurantoin were recorded more effectively. Chemicals substances at the concentration 0.3 (g/ml) recorded percentages of inhibition, reaching 9.143±1.442, 15.36±0.5914, and 21.82±0.8699 for NaHCO3, Ch4c, and Viroxide Super™ respectively. PCR demonstrated that 28/28 (100%) of SXT-resistant E. coli isolates were harbored Sul-2, FeoB and PapC genes, while 14/28 (50%), 15/28 (53.57%), 19/28 (67.85%) and 26/28 (92.85%) in U250 (pet), FumC, Sul-1 and IutA genes, respectively. Sul-3 gene was not observed.

Conclusion

Observed a high percentage of E. coli that were resistant to SXT drug, and having several virulence genes, poses a real threat, it requires a real pause to create substitutions to limit the spreading of this threat.

Combination of bactericidal antibiotics and inhibitors of Universal stress protein A (UspA): a potential therapeutic alternative against multidrug resistant Escherichia coli in urinary tract infections

The increasing incidence of multidrug resistant uropathogenic E. coli (MDR-UPEC), the most common opportunistic pathogen in urinary tract infections (UTI) pose a global health problem and demands searching for alternative therapeutics. Antibiotics generate oxidative stress in bacteria which results in overexpression of the universal stress protein, UspA that helps in bacterial survival. An in silico study showed that two compounds ZINC000104153710, and ZINC000000217308 effectively bound bacterial UspA. This study aimed to determine the activity of ZINC000104153710, and ZINC000000217308 against bacterial UspA function in MDR-UPEC in vitro. Twenty-five highly MDR-UPEC were screened against ZINC000104153710, and, ZINC000000217308 either alone or in combination with the bactericidal antibiotics; ciprofloxacin (CIP), ceftazidime(CAZ), gentamicin(GEN) respectively by determining minimum inhibitory concentrations (MICs) using a broth microdilution assay. Additionally, the effect of ZINC000104153710, and ZINC000000217308 in the absence and presence of antibiotics on the bacteria was monitored by bacterial growth curve assays, ROS production, structure of the organism by scanning electron microscopy (FESEM) and quantitating UspA using a western blot technique. A 2-8 fold reduction in MIC values against ZINC000104153710, and ZINC000000217308 was observed against all 25 MDR-UPEC isolates in the presence of antibiotics with no alteration in intracellular ROS production. Discrete changes in cell morphology was evident in bacteria treated with ZINC000104153710 or ZINC000000217308 and antibiotics individually by FESEM compared with untreated control. Reduction in the level of UspA protein in bacteria treated with combination of ZINC000104153710 or ZINC000000217308 with individual antibiotics established their ability to inhibit UspA whose expression was elevated in presence of antibiotics alone. Therefore this study validated ZINC000104153710, and ZINC000000217308 as potent inhibitors of bacterial UspA function and indicated their potential as alternative therapeutics to combat the MDR-UPEC.

In vitro assessment of the antibacterial effects of the combinations of fosfomycin, colistin, trimethoprim and nitrofurantoin against multi-drug-resistant Escherichia coli

MDR UPEC has become a global health challenge. Our study investigates the pairwise interactions among FOS, COL, NIT and TRI against 29 UPEC strains using the checkerboard method. The synergistic combinations are further evaluated for their bactericidal effects against the most resistant strain (MRS) using the time-kill method. The results showed that 100% of these strains were resistant to TRI and NIT, whereas 75·86% of them were susceptible to FOS and COL. Among all tested strains, only seven strains were highly resistant to all used antibiotics. Remarkably, FOS/COL, COL/NIT and COL/TRI combinations represent the most effective synergistic (fractional inhibitory concentration index <1) combinations against the seven strains at MICs lower than the susceptible breakpoint ranges, followed by FOS/NIT and FOS/TRI, which achieved synergistic interactions against 1/7 and 2/7 of these strains. Importantly, the bactericidal effects (reduction ≥3·0 log₁₀  CFU per ml) were only observed with FOS/COL, COL/NIT and COL/TRI combinations against MRS after 24 h of post-treatment. Our data suggested that FOS/COL, COL/NIT and COL/TRI combinations could be a promising option against MDR UPEC infections. Additionally, FOS/NIT and FOS/TRI probably represent a good option for MDR UPEC with lower MICs.

Flagella, Type I Fimbriae and Curli of Uropathogenic Escherichia coli Promote the Release of Proinflammatory Cytokines in a Coculture System

BACKGROUND

Urinary tract infections (UTIs) are a public health problem in Mexico, and uropathogenic Escherichia coli (UPEC) is one of the main etiological agents. Flagella, type I fimbriae, and curli promote the ability of these bacteria to successfully colonize its host.

AIM

This study aimed to determine whether flagella-, type I fimbriae-, and curli-expressing UPEC induces the release of proinflammatory cytokines in an established coculture system.

METHODS

The fliC, fimH, and csgA genes by UPEC strain were disrupted by allelic replacement. Flagella, type I fimbriae, and curli were visualized by transmission electron microscopy (TEM). HTB-5 (upper chamber) and HMC-1 (lower chamber) cells cocultured in Transwell® plates were infected with these UPEC strains and purified proteins. There was adherence to HTB-5 cells treated with different UPEC strains and they were quantified as colony-forming units (CFU)/mL.

RESULTS

High concentrations of IL-6 and IL-8 were induced by the FimH and FliC proteins; however, these cytokines were detected in low concentrations in presence of CsgA. Compared with UPEC CFT073, CFT073ΔfimH, CFT073ΔfimHΔfliC, and CFT073ΔcsgAΔfimH strains significantly reduced the adherence to HTB-5 cells.

CONCLUSION

The FimH and FliC proteins are involved in IL-6 and IL-8 release in a coculture model of HTB-5 and HMC-1 cells.

Challenges to Early Discharge of Patients with Upper Urinary Tract Infections by ESBL Producers: TMP/SMX as a Step-Down Therapy for Shorter Hospitalization and Lower Costs

Background

Urinary tract infections (UTIs) caused by extended spectrum beta-lactamase (ESBL) producing pathogens have increased and are treated with carbapenem in general. Carbapenem use is associated with prolonged hospitalization or daily outpatient visit. The aim of this study was to investigate patients with UTIs by ESBL-producing pathogens for early discharge using an old oral antibiotic, trimethoprim-sulfamethoxazole (TMP-SMX), which is susceptible to ESBL-producing pathogens.

Methods

Data on UTIs caused by ESBL-producing pathogens from a single tertiary hospital were collected retrospectively. Patients who had been treated with intravenous carbapenems or oral TMP/SMX were included. Patients’ clinical and microbiological outcomes were compared between oral TMP/SMX and ertapenem treatment groups.

Results

A total of 103 patients were included, 21 of whom had been treated with TMP/SMX, whereas 82 with ertapenem. Clinical outcomes between the two groups were not significantly different (TMP/SMX: 90.5%; ertapenem: 84.1%, p = 0.73). The microbiological cure rate was higher in the TMP/SMX group than in the ertapenem group (90.5% vs 58.5%, respectively, p = 0.01). The mean duration of hospitalization was significantly shorter in the TMP/SMX group than in the ertapenem group (8.00 ± 10.50 days vs 14.00 ± 37.00 days, p = 0.07). The mean duration of antibiotic treatment was longer in the ertapenem group than in the TMP/SMX group (16.45 ± 4.77 vs 12.76 ± 5.37 days, p = 0.006).

Conclusion

For susceptible pathogens, TMP/SMX may enable early discharge as an effective oral antibiotic treatment option for UTIs caused by ESBL-positive pathogens. Additionally, use of oral antibiotics can shorten hospital stays and reduce medical costs.

Recurrent Urinary Tract Infections: Unraveling the Complicated Environment of Uncomplicated rUTIs

Urinary tract infections (UTIs) are frequent in humans, affecting the upper and lower urinary tract. Present diagnosis relies on the positive culture of uropathogenic bacteria from urine and clinical markers of inflammation of the urinary tract. The bladder is constantly challenged by adverse environmental stimuli which influence urinary tract physiology, contributing to a dysbiotic environment. Simultaneously, pathogens are primed by environmental stressors such as antibiotics, favoring recurrent UTIs (rUTIs), resulting in chronic illness. Due to different confounders for UTI onset, a greater understanding of the fundamental environmental mechanisms and microbial ecology of the human urinary tract is required. Such advancements could promote the tandem translation of bench and computational studies for precision treatments and clinical management of UTIs. Therefore, there is an urgent need to understand the ecological interactions of the human urogenital microbial communities which precede rUTIs. This review aims to outline the mechanistic aspects of rUTI ecology underlying dysbiosis between both the human microbiome and host physiology which predisposes humans to rUTIs. By assessing the applications of next generation and systems level methods, we also recommend novel approaches to elucidate the systemic consequences of rUTIs which requires an integrated approach for successful treatment. To this end, we will provide an outlook towards the so-called 'uncomplicated environment of UTIs', a holistic and systems view that applies ecological principles to define patient-specific UTIs. This perspective illustrates the need to withdraw from traditional reductionist perspectives in infection biology and instead, a move towards a systems-view revolving around patient-specific pathophysiology during UTIs.

Strategies to Tackle Antimicrobial Resistance: The Example of Escherichia coli and Pseudomonas aeruginosa

Traditional antimicrobial treatments consist of drugs which target different essential functions in pathogens. Nevertheless, bacteria continue to evolve new mechanisms to evade this drug-mediated killing with surprising speed on the deployment of each new drug and antibiotic worldwide, a phenomenon called antimicrobial resistance (AMR). Nowadays, AMR represents a critical health threat, for which new medical interventions are urgently needed. By 2050, it is estimated that the leading cause of death will be through untreatable AMR pathogens. Although antibiotics remain a first-line treatment, non-antibiotic therapies such as prophylactic vaccines and therapeutic monoclonal antibodies (mAbs) are increasingly interesting alternatives to limit the spread of such antibiotic resistant microorganisms. For the discovery of new vaccines and mAbs, the search for effective antigens that are able to raise protective immune responses is a challenging undertaking. In this context, outer membrane vesicles (OMV) represent a promising approach, as they recapitulate the complete antigen repertoire that occurs on the surface of Gram-negative bacteria. In this review, we present Escherichia coli and Pseudomonas aeruginosa as specific examples of key AMR threats caused by Gram-negative bacteria and we discuss the current status of mAbs and vaccine approaches under development as well as how knowledge on OMV could benefit antigen discovery strategies.

Antibiotic Resistance of Uropathogens Isolated from Patients Hospitalized in District Hospital in Central Poland in 2020

The aim of this study was to determine antibiotic resistance patterns and the prevalence of uropathogenes causing urinary tract infections (UTIs) in patients hospitalized in January–June 2020 in central Poland. Antimicrobial susceptibility testing was performed using the disk-diffusion method. Escherichia coli (52.2%), Klebsiella pneumoniae (13.7%), Enterococcus faecalis (9.3%), E. faecium (6.2%), and Proteus mirabilis (4,3%) were most commonly isolated from urine samples. E. coli was significantly more frequent in women (58.6%) (p = 0.0089) and in the age group 0–18, while K. pneumoniae was more frequent in men (24.4%) (p = 0.0119) and in individuals aged 40–60 and >60. Gram-negative species showed resistance to ampicillin. K. pneumoniae were resistant to amoxicillin plus clavulanic acid (75.0%), piperacillin plus tazobactam (76.2%), cefotaxime (76.2%), cefuroxime (81.0%), ciprofloxacin (81.0%), and trimethoprim plus sulphamethoxazole (81.0%). Carbapenems were effective against all E. coli and P. mirabilis. Some K. pneumoniae (13.6%) produced metallo-β-lactamases (MBLs). E. coli (22.6%), K. pneumoniae (81.8%), and all E. faecium were multidrug-resistant (MDR). Some E. coli (26.2%), K. pneumoniae (63.6%), and P. mirabilis (14.3%) isolates produced extended-spectrum beta-lactamases (ESBL). Vancomycin-resistant E. faecium was also found. This study showed that the possibilities of UTIs therapy using available antibiotics become limited due to the increasing number of antibiotic-resistant uropathogens.

Distribution of phylogenetic groups, adhesin genes, biofilm formation, and antimicrobial resistance of uropathogenic Escherichia coli isolated from hospitalized patients in Thailand

Background

Urinary tract infections (UTIs) are the most common bacterial infections and are often caused by uropathogenic Escherichia coli (UPEC). We investigated the distribution of phylogenetic groups, adhesin genes, antimicrobial resistance, and biofilm formation in E. coli isolated from patients with UTIs.

Methods

In the present study, 208 UPEC isolated from Thai patients were classified into phylogenetic groups and adhesin genes were detected using multiplex PCR. Antimicrobial susceptibility testing was performed using agar disk diffusion. The Congo red agar method was used to determine the ability of the UPEC to form biofilm.

Results

The most prevalent UPEC strains in this study belonged to phylogenetic group B2 (58.7%), followed by group C (12.5%), group E (12.0%), and the other groups (16.8%). Among adhesin genes, the prevalence of fimH (91.8%) was highest, followed by pap (79.3%), sfa (12.0%), and afa (7.7%). The rates of resistance to fluoroquinolones, trimethoprim-sulfamethoxazole, and amoxicillin-clavulanate were  65%, 54.3%, and 36.5%, respectively. The presence of adhesin genes and antibiotic resistance were more frequent in groups B2 and C compared to the other groups. Of the 129 multidrug-resistant UPEC strains, 54% were biofilm producers. Our findings further indicated that biofilm production was significantly correlated with the pap adhesin gene (p ≤ 0.05).

Conclusion

These findings provide molecular epidemiologic data, antibiotic resistance profiles, and the potential for biofilm formation among UPEC strains that can inform further development of the appropriate prevention and control strategies for UTIs in this region.

Phage Therapy as a Novel Strategy in the Treatment of Urinary Tract Infections Caused by E. Coli

Urinary tract infections (UTIs) are regarded as one of the most common bacterial infections affecting millions of people, in all age groups, annually in the world. The major causative agent of complicated and uncomplicated UTIs are uropathogenic E. coli strains (UPECs). Huge problems with infections of this type are their chronicity and periodic recurrences. Other disadvantages that are associated with UTIs are accompanying complications and high costs of health care, systematically increasing resistance of uropathogens to routinely used antibiotics, as well as biofilm formation by them. This creates the need to develop new approaches for the prevention and treatment of UTIs, among which phage therapy has a dominant potential to eliminate uropathogens within urinary tract. Due to the growing interest in such therapy in the last decade, the bacteriophages (natural, genetically modified, engineered, or combined with antibiotics or disinfectants) represent an innovative antimicrobial alternative and a strategy for managing the resistance of uropathogenic microorganisms and controlling UTIs.

Cefaclor as a first-line treatment for acute uncomplicated cystitis: a retrospective single-center study

Background

Wide-spectrum antibiotics have been favored to treat acute uncomplicated cystitis (AUC) for a long time, leading to the emergence of multi-drug resistant bacteria. We hypothesize that narrow-spectrum antibiotics might mitigate the issue and aim to investigate the clinical efficacy of cefaclor in patients with AUC.

Methods

We retrospectively reviewed the clinical data of female outpatients with AUC treated with cefaclor and evaluated the safety and clinical efficacy. Clinical cure was defined as the elimination of clinical symptom under 4 white blood cells (WBCs) per high power field on microscopy.

Results

Overall, 223 women with AUC were enrolled. Escherichia coli was the dominant pathogen (n = 160; 68.6%), followed by Klebsiella species and E. coli-extended spectrum β-lactamase (ESBL) (n = 19; 8.1% and n = 18; 7.7%). Overall success rate was 94.0% (n = 219) and susceptibility rate of cefazolin was 84.1%, which was close to that of levofloxacin (82.9%). Ampicillin showed the lowest rate of 63.7% with a significantly greater resistance rate of 35.3% among all antibiotics (P < 0.001). In the subgroup analysis, the success rate in patients with resistance to levofloxacin or cefazolin was 100% (n = 24) or 93.3% (n = 14). The rate in patients with resistance to both antibiotics was 60.0% (n = 9), and the pathogens in the other 40.0% (n = 6) of patients with treatment failure were E. coli-ESBL.

Conclusion

Cefaclor showed excellent efficacy in AUC patients, even in those with in vitro resistance to cefazolin or levofloxacin. Cefaclor may be considered as a first-line option in patients with AUC and a second-line option for those with levofloxacin treatment failure.

Antibiotic Resistance Among Uropathogenic Escherichia coli

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

Prevalence and antimicrobial susceptibility of bacterial pathogens isolated from urine specimens received in rizgary hospital - Erbil

BACKGROUND

Urinary tract infection (UTI) is a common health-associated problem worldwide. Like other medical conditions, UTI patients may suffer from poor treatment outcomes due to the emergence of antimicrobial resistance. Determining patterns of antimicrobial susceptibility in uropathogens will guide physicians to choose the best antibiotics for treating affected patients. In this project we aimed to evaluate the frequencies of pathogens associated with UTI and their antimicrobial susceptibility patterns.

METHODS

This study was conducted on 2692 urine samples of patients visited Rizgary Teaching Hospital in Erbil city. Aerobic bacterial growth identification and antimicrobial susceptibility tests were performed using VITEK^®2 compact system.

RESULTS

Our data show that more than 20% of all studied samples were negative for bacterial growth; only 16.72% of them were pathogenic bacteria in which 82.44% of them were Gram negative bacteria (GNB) and the rest were Gram positive bacteria (GPB). Escherichia coli was the most frequent, and Acinetobacter baumannii was the most resistant GNB. Staphylococcus haemolyticus was the most frequent, and Enterococcus faecalis was the most resistant GPB. In general GNB were highly resistant to Ticarcillin and Cefepime, and GPB were also resistant to Ticarcillin, and Tigecycline antibiotics.

CONCLUSIONS

The amount of negative culture growth indicates that symptoms only based diagnosis for UTI detection is unreliable. E. coli is the most UTI related pathogen, E. faecalis and A. baumannii were among highly antibiotic resistant bacteria. Finally, since many of GNG and GPB isolates were resistant to several antibiotics, there might be a high possibility for multi drug resistant among local population in Erbil.

Community-Acquired Urinary Tract Infection by Escherichia coli in the Era of Antibiotic Resistance

Urinary tract infections (UTIs) caused by Escherichia coli (E. coli) are the most common types of infections in women. The antibiotic resistance of E. coli is increasing rapidly, causing physicians to hesitate when selecting oral antibiotics. In this review, our objective is to ensure that clinicians understand the current seriousness of antibiotic-resistant E. coli, the mechanisms by which resistance is selected for, and methods that can be used to prevent antibiotic resistance.

Myroides odoratimimus urinary tract infection in an immunocompromised patient: an emerging multidrug-resistant micro-organism

Background

Myroides spp. are common environmental organisms and they can be isolated predominantly in water, soil, food and in sewage treatment plants. In the last two decades, an increasing number of infections such as urinary tract infections and skin and soft tissue infections, caused by these microorganisms has been reported. Selection of appropriate antibiotic therapy to treat the infections caused by Myroides spp. is difficult due to the production of a biofilm and the organism's intrinsic resistance to many antibiotic classes.

Case presentation

We report the case of a 69-year-old immunocompromised patient who presented with repeated episodes of macroscopic haematuria, from Northern Italy.A midstream urine sample cultured a Gram negative rod in significant amounts (> 105 colony-forming units (cfu)/mL), which was identified as Myroides odoratimimus. The patient was successfully treated with trimethoprim/sulfamethoxazole after antibiotic susceptibility testing confirmed its activity.

Conclusion

This case underlines the emergence of multidrug resistant Myroides spp. which are ubiquitous in the environment and it demands that clinicians should be more mindful about the role played by atypical pathogens, which may harbour or express multidrug resistant characteristics, in immunocompromised patients or where there is a failure of empiric antimicrobial therapy.

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.

A systematic review of non-antibiotic measures for the prevention of urinary tract infections in pregnancy

Background

Urinary tract infections (UTIs) are common in pregnancy and account for the highest proportion of primary care antibiotic prescriptions issued to pregnant women in the UK. It is well known that antibiotic use is associated with increased antimicrobial resistance and therefore measures to minimise antibiotic use for UTI prevention have been studied. The efficacy and safety of these measures in pregnancy have not been addressed and therefore the aim of this study was to systematically review the literature to identify and evaluate potential measures to prevent UTIs in pregnant women.

Methods

Ten databases (EMBASE, AMED, BNI, CINAHL, Medline, PubMed, PsycINFO, Cochrane Trials, Scopus and Science Direct) were systematically searched in July 2017 for studies reporting non-antibiotic measures to prevent UTIs in pregnancy. The terms (“urinary tract infection” or UTI or bacteriuria or cystitis) AND (prevention) AND (pregnan*) were used. The quality of the publications was appraised using the Critical Appraisal Skills Programme (CASP) checklists for cohort study, case-control study and randomised controlled trial. The results were synthesised using a textual narrative approach.

Results

Search results yielded 3276 publications and after reviewing titles and removing duplicates, 57 full text articles were assessed for eligibility and eight were included in the review. Five different approaches (hygiene measures, cranberry juice, immunisation, ascorbic acid and Canephron® N) have been identified, all of which are reported to be safe in pregnancy.

Conclusion

The quality of the evidence varied considerably and only hygiene measures were supported by evidence to be recommended in practice. Future work needs to concentrate on strengthening the evidence base through improved design and reporting of studies with a focus on immunisation, ascorbic acid and Canephron® N.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-1732-2) contains supplementary material, which is available to authorized users.

Use of Lactobacillus spp. to prevent recurrent urinary tract infections in females

Urinary tract infections (UTIs) are the most common bacterial infections seen in the community, especially amongst females. The widespread use of antibiotics has led to the increased occurrence of E. coli resistant isolates worldwide. A promising non-antibiotic approach is the use of probiotic lactobacilli strains. This paper hypothesizes that Lactobacillus spp. containing products are able to prevent recurrent urinary tract infections in females. Using the keywords [lactobacillus OR lactobacilli OR probiotic] and [urinary tract infection OR UTI OR cystitis], a preliminary search on the PubMed, Ovid, Google Scholar and ClinicalTrials.gov database yielded 1,647 papers published in English between 1-Jan-1960 and 1-May-2017. 9 clinical trials with a total of 726 patients were reviewed. Different lactobacilli strains (in either oral or suppository formulation) were utilized and they demonstrated varying efficacy in the prevention of recurrent UTIs. Using a random-effects model, pooled risk ratio of at least one recurrent UTI episode during the entire study duration was 0.684 (95% CI 0.438 to 0.929, p < 0.001), per-protocol analysis. However, key limitations include significant inter-study variability and the limited duration of follow-up of most studies. Our hypothesis on the chemoprophylactic effects of probiotics for UTIs is plausible and supported by current data. Lactobacillus rhamnosus GR1 and Lactobacillus reuteri RC14 were the most commonly studied lactobacilli strains. Further and more robust randomized controlled trials with standardized lactobacilli strains and formulation are required for confirmation of effects.

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

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