The emerging threat of multidrug-resistant Gram-negative bacteria in urology

In Vivo Activity Profiling of Biosynthetic Darobactin D22 against Critical Gram-Negative Pathogens

In recent years, naturally occurring darobactins have emerged as a promising compound class to combat infections caused by critical Gram-negative pathogens. In this study, we describe the in vivo evaluation of derivative D22, a non-natural biosynthetic darobactin analogue with significantly improved antibacterial activity. We found D22 to be active in vivo against key critical Gram-negative human pathogens, as demonstrated in murine models of Pseudomonas aeruginosa thigh infection, Escherichia coli peritonitis/sepsis, and urinary tract infection (UTI). Furthermore, we observed the restored survival of Acinetobacter baumannii-infected embryos in a zebrafish infection model. These in vivo proof-of-concept (PoC) in diverse models of infection against highly relevant pathogens, including drug-resistant isolates, highlight the versatility of darobactins in the treatment of bacterial infections and show superiority of D22 over the natural darobactin A. Together with a favorable safety profile, these findings pave the way for further optimization of the darobactin scaffold toward the development of a novel antibiotic.

Current and emerging strategies to curb antibiotic-resistant urinary tract infections

Rising rates of antibiotic resistance in uropathogenic bacteria compromise patient outcomes and prolong hospital stays. Consequently, new strategies are needed to prevent and control the spread of antibiotic resistance in uropathogenic bacteria. Over the past two decades, sizeable clinical efforts and research advances have changed urinary tract infection (UTI) treatment and prevention strategies to conserve antibiotic use. The emergence of antimicrobial stewardship, policies from national societies, and the development of new antimicrobials have shaped modern UTI practices. Future UTI management practices could be driven by the evolution of antimicrobial stewardship, improved and readily available diagnostics, and an improved understanding of how the microbiome affects UTI. Forthcoming UTI treatment and prevention strategies could employ novel bactericidal compounds, combinations of new and classic antimicrobials that enhance bacterial killing, medications that prevent bacterial attachment to uroepithelial cells, repurposing drugs, and vaccines to curtail the rising rates of antibiotic resistance in uropathogenic bacteria and improve outcomes in people with UTI.

The pattern of antibiotic resistance and distribution of the biofilm-producing Pseudomonas aeruginosa (PelD, PslB) isolated from infectious hospital departments

Background

The ability of Pseudomonas aeruginosa to produce biofilm has established it as one of the most significant pathogens. The purpose of this study was to evaluate antimicrobial resistance and conduct a molecular investigation of the virulence genes PslB and PelD in Pseudomonas aeruginosa species isolated from patients.

Methodology

One hundred clinical isolates were collected from patients of different age groups who were hospitalized in Kermanshah and Sonqor hospitals. The isolates were obtained through culture on specific media, biochemical confirmatory tests, and gram staining for confirmation. Biofilm production was assessed using an indirect quantification method with crystal violet. Additionally, antibiotic resistance was determined through the disc various method following Clinical and Laboratory Standards Institute guidelines. Finally, the presence of genes related to PlsB and PelD in resistant strains was examined using The polymerase chain reaction (PCR).

Results

The results indicate that the highest resistance and lowest sensitivity were related to nitrofurantoin 100 μg, while the lowest resistance and highest sensitivity were related to cefepime 30 mg. Biofilm phenotypes were categorized as weak in 7% (n = 7) of isolates, medium in 13% (n = 13), and high in 80% (n = 80). The PslB and PelD genes were identified in 86% (n = 86) and 38% (n = 38) of isolates, respectively, while 4% (n = 4) did not possess either of these two genes. Additionally, a majority of the isolates exhibited multidrug-resistance (87%) due to their moderate-to-high biofilm formation.

Conclusion

All isolates were capable of producing biofilm. A significant association were between strains with the high biofilm and multidrug-resistance species (p < 0.05). Multidrug-resistance (78%) isolates included 28% (n = 28) of isolates that were PslB+ PelD+, 45% (n = 45) of isolates that were only PslB+, and 5 (n = 5) isolates that were only PelD+. A significant relationship was found between the presence of the PslB gene multidrug-resistance and high producer (p < 0.05).

High-throughput screening identification of apigenin that reverses the colistin resistance of mcr-1-positive pathogens

The plasmid-mediated gene mcr-1 that makes bacteria resistant to the antibiotic colistin is spreading quickly, which means that colistin is no longer working well to treat Gram-negative bacterial infections. Herein, we utilized a computer-aided high-throughput screening drugs method to identify the natural product apigenin, a potential mcr-protein inhibitor, which effectively enhanced the antimicrobial activity of colistin. Several assays, including a checkerboard minimum inhibitory concentration assay, a time-kill assay, the combined disk test, molecular simulation dynamics, and animal infection models assay, were conducted to verify whether apigenin enhanced the ability of colistin to fight Gram-negative bacterial infections. The results showed that apigenin improved the antimicrobial activity of colistin against multidrug-resistant Enterobacteriaceae infection. Moreover, apigenin not only did not increase the toxic effect of colistin but also had the ability to effectively inhibit the frequency of bacterial resistance mutations to colistin. Studies clearly elucidated that apigenin could interfere with the thermal stability of the protein by binding to the mcr-1 protein. Additionally, the combination of apigenin and colistin could exert multiple effects, including disrupting bacterial membranes, the generation of bacterial nitric oxide and reactive oxygen species, as well as inhibiting bacterial adenosine triphosphate production. Furthermore, the addition of apigenin was able to significantly inhibit colistin-stimulated high expression levels of the bacterial mcr-1 gene. Finally, apigenin exhibited a characteristic anti-inflammatory effect while enhancing the antimicrobial activity of colistin against mcr-1-positive Escherichia coli (E. coli) infected animals. In conclusion, as a potential lead compound, apigenin is promising in combination with colistin in the future treatment of mcr-1-positive E. coli infections.IMPORTANCEThis study found that apigenin was able to inhibit the activity of the mcr-1 protein using a high-throughput virtual screening method. Apigenin effectively enhanced the antimicrobial activity of colistin against multidrug-resistant Enterobacteriaceae, including mcr-1-positive strains, in vitro and in vivo. This study will provide new options and strategies for the future treatment of multidrug-resistant pathogen infections.

Label-free single-cell antimicrobial susceptibility testing in droplets with concentration gradient generation

Bacterial communities exhibit significant heterogeneity, resulting in the emergence of specialized phenotypes that can withstand antibiotic exposure. Unfortunately, the existence of subpopulations resistant to antibiotics often goes unnoticed during treatment initiation. Thus, it is crucial to consider the concept of single-cell antibiotic susceptibility testing (AST) to tackle bacterial infections. Nevertheless, its practical application in clinical settings is hindered by its inability to conduct AST efficiently across a wide range of antibiotics and concentrations. This study introduces a droplet-based microfluidic platform designed for rapid single-cell AST by creating an antibiotic concentration gradient. The advantage of a microfluidic platform is achieved by executing bacteria and antibiotic mixing, cell encapsulation, incubation, and enumeration of bacteria in a seamless workflow, facilitating susceptibility testing of each antibiotic. Firstly, we demonstrate the rapid determination of minimum inhibitory concentration (MIC) of several antibiotics with Gram-negative E. coli and Gram-positive S. aureus, which enables us to bypass the time-consuming bacteria cultivation, speeding up the AST in 3 h from 1 to 2 days of conventional methods. Additionally, we assess 10 clinical isolates including methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Staphylococcus aureus (MDRSA) against clinically important antibiotics for analyzing the MIC, compared to the gold standard AST method from the United States Clinical and Laboratory Standards Institute (CLSI), which becomes available only after 48 h. Furthermore, by monitoring single cells within individual droplets, we have found a spectrum of resistance levels among genetically identical cells, revealing phenotypic heterogeneity within isogenic populations. This discovery not only advances clinical diagnostics and treatment strategies but also significantly contributes to the field of antibiotic stewardship, underlining the importance of our approach in addressing bacterial resistance.

Rational design and in vitro testing of new urease inhibitors to prevent urinary catheter blockage

Catheter associated urinary tract infections (CAUTI) caused by urease-positive organisms can lead to catheter blockage: urease metabolizes urea in urine to ammonia causing an increase in pH and hence precipitation of struvite and apatite salts into the catheter lumen and bladder leading to blockage. Acetohydroxamic acid (AHA) is the only urease inhibitor currently approved for patient use, however, it is rarely used owing to its side effects. Here, we report the identification and development of new urease inhibitors discovered using a rational in silico drug design approach. A series of compounds were designed, the compounds were screened and filtered to identify three compounds which were tested in in vitro urease activity assays. N,N'-Bis(3-pyridinylmethyl)thiourea (Bis-TU) outperformed AHA in activity assays and was tested in an in vitro bladder model, where it significantly extended the lifetime of the catheter compared to AHA. Bis-TU was delivered via a diffusible balloon catheter directly to the site of activity, thus demonstrating localized drug delivery. This cost-effective drug design approach allowed the identification of a potent urease inhibitor, which could be improved through iterative repeats of the method, and the process of design could be utilized to target other diseases.

Field-Deployable Colorimetric Array for On-Site Diagnosis of Urinary Tract Infection and Identification of Causative Pathogens

Urinary tract infection (UTI) is a common and prevalent disease caused by a spectrum of pathogens. Lack of access to rapid, portable, and high-quality diagnostics in resource-limited settings aggravates the improper treatment of UTIs, which is also a major driver of antibiotic misuse worldwide. Here, we describe a custom-made portable colorimetric array (PoCA) for reading out polymerase chain reaction (PCR) amplicons, the rationale of which is to transfer the previously developed dsDNA-based photosensitization colorimetric assay (solution) onto paper discs for detection. By integrating mini-LED irradiation and paper discs, the PoCA can read out 96 PCR tests in one pot, thus allowing diagnosis and identification of 12 prevailing UTI pathogens in less than 2 h, coupled with a portable thermal cycler for PCR. After analyzing 200 clinical urine samples, the pathogen profiling accuracy of the PoCA was demonstrated to be higher than the standard urine culture (confirmed with metagenomic next-generation sequencing). The PoCA platform could be used in primary care for rapid UTI diagnosis and pathogen identification.

Amikacin treatment in urinary tract infection patients: evaluating the risk of acute kidney injury - a retrospective cohort study

The rise in ESBL-producing and carbapenem-resistant Gram-negative bacterial infections is alarming. Aminoglycosides remain attractive for treating urinary tract infections (UTIs). However, aminoglycosides-associated acute kidney injury (AKI) raises concerns, especially in patients with underlying renal impairment. We conducted a retrospective cohort study to evaluate the risk of AKI in patients with UTI empirically treated with amikacin. Among 395 patients (median age 41.9 years [IQR 28.3-67.1], 342 [86.6%] female), 162 (41.0%) received amikacin and 233 (59.0%) were empirically treated with other antibiotics. AKI incidence was low (5.6%) and not associated with amikacin exposure (OR 0.56, 95% CI 0.22-1.43, p = 0.23), even in those with pre-existing renal impairment or AKI on admission. The clinical outcomes (including cure by the third day, AKI, maximal creatinine, length of stay, mortality, and readmission) did not differ between the groups. Once-daily amikacin may offer a safe UTI treatment option amid increasing multi-drug resistance.

Unitary Tract Infection Treatment: When to Use What Agents including Beta-lactam Combination Agents

In this study, the authors review antibiotic treatment options for both acute uncomplicated and complicated urinary tract infection (UTI). In addition, they also review regimens used in the setting of drug-resistant pathogens including vancomycin resistant Enterococcus, extended spectrum beta-lactamase (ESBL) producing Enterobacterals, carbapenem-resistant Enterobacterals and carbapenem-resistant Pseudomonas, which are encountered with increasing frequency.

Exploring the Impact of Antibiotics on Fever Recovery Time and Hospital Stays in Children with Viral Infections: Insights from Advanced Data Analysis

Background: Antibiotic overuse in pediatric patients with upper respiratory tract infections (UR-TIs) raises concerns about antimicrobial resistance. This study examines the impact of antibiotics on hospital stay duration and fever resolution in pediatric patients diagnosed with viral infections via a multiplex polymerase chain reaction (PCR) respiratory panel. Methods: In the pediatric ward of Imam Abdulrahman Bin Faisal Hospital, a retrospective cohort analysis was conducted on pediatric patients with viral infections confirmed by nasopharyngeal aspirates from October 2016 to December 2021. Cohorts receiving antibiotics versus those not receiving them were balanced using the gradient boosting machine (GBM) technique for propensity score matching. Results: Among 238 patients, human rhinovirus/enterovirus (HRV/EV) was most common (44.5%), followed by respiratory syncytial virus (RSV) (18.1%). Co-infections occurred in 8.4% of cases. Antibiotic administration increased hospital length of stay (LOS) by an average of 2.19 days (p-value: 0.00). Diarrhea reduced LOS by 2.26 days, and higher albumin levels reduced LOS by 0.40 days. Fever and CRP levels had no significant effect on LOS. Time to recovery from fever showed no significant difference between antibiotic-free (Abx0) and antibiotic-received (Abx1) groups (p-value: 0.391), with a hazard ratio of 0.84 (CI: 0.57-1.2). Conclusions: Antibiotics did not expedite recovery but were associated with longer hospital stays in pediatric patients with acute viral respiratory infections. Clinicians should exercise caution in prescribing antibiotics to pediatric patients with confirmed viral infections, especially when non-critical.

Antibiotic Resistance Trends in Uropathogens during the COVID-19 Pandemic in Western Romania: A Cross-Sectional Study

The emergence and spread of antimicrobial resistance have been significant global health challenges, exacerbated by the COVID-19 pandemic. As healthcare systems faced unprecedented pressures, the management of non-COVID conditions, including urinary tract infections (UTIs), also encountered obstacles due to changes in microbial flora and antibiotic usage patterns. This cross-sectional study aimed to characterize the antimicrobial resistance trends among bacterial uropathogens isolated from patients in the Western region of Romania, between January 2020 and December 2022. The objectives were to map the resistance patterns and observe the pandemic's influence on antimicrobial resistance, particularly among enterobacterial Gram-negative species, to guide treatment and infection control strategies. From a total of 2472 urine samples collected during the study period, 378 positive samples were analyzed. This study found that Escherichia coli was the most commonly isolated uropathogen, making up 46.3% of the cases (n = 175), with Klebsiella pneumoniae at 20.6% (n = 78). There was a high resistance of Klebsiella pneumoniae to several antibiotics, while carbapenemase production increased to 52.5% and extended-spectrum beta-lactamase (ESBL) present in 24.3% of the strains. Escherichia coli showed high resistance rates to amoxicillin-clavulanic acid (from 45.4% in 2020 to 53.8% in 2022) and trimethoprim/sulfamethoxazole (from 27.5% in 2020 to 47.2% in 2022). The increasing trend of antimicrobial resistance noted during the pandemic, especially in Gram-negative enterobacterial species, highlights the urgent need for robust infection control measures and rational antibiotic use. This study underscores the critical importance of continuous surveillance to adapt antibiotic therapies effectively and prevent the further spread of resistance, thereby ensuring effective management of UTIs in the evolving healthcare landscape influenced by the pandemic.

Discovery of Salifungin as a Repurposed Antibiotic against Methicillin-Resistant Staphylococcus aureus with Limited Resistance Development

Exploring novel antimicrobial drugs and strategies has become essential to the fight MRSA-associated infections. Herein, we found that membrane-disrupted repurposed antibiotic salifungin had excellent bactericidal activity against MRSA, with limited development of drug resistance. Furthermore, adding salifungin effectively decreased the minimum inhibitory concentrations of clinical antibiotics against Staphylococcus aureus. Evaluations of the mechanism demonstrated that salifungin disrupted the level of H+ and K+ ions using hydrophilic and lipophilic groups to interact with bacterial membranes, causing the disruption of bacterial proton motive force followed by impacting on bacterial the function of the respiratory chain and adenosine 5'-triphosphate, thereby inhibiting phosphatidic acid biosynthesis. Moreover, salifungin also significantly inhibited the formation of bacterial biofilms and eliminated established bacterial biofilms by interfering with bacterial membrane potential and inhibiting biofilm-associated gene expression, which was even better than clinical antibiotics. Finally, salifungin exhibited efficacy comparable to or even better than that of vancomycin in the MRSA-infected animal models. In conclusion, these results indicate that salifungin can be a potential drug for treating MRSA-associated infections.

Reducing Recurrent Urinary Tract Infections in Women with MV140 Impacts Personal Burden of Disease: Secondary Analyses of a Randomized Placebo-controlled Efficacy Study

Background

Recurrent urinary tract infection (rUTI) remains a major health burden for women. A randomized, double-blind, placebo-controlled trial (RCT; NCT02543827) reported that female patients with rUTI receiving a sublingual vaccine, MV140, had a reduction in rUTI and increase in UTI-free rate compared with placebo.

Objective

To determine the impact of MV140 on the personal burden of disease in women with rUTI using secondary endpoint data from the pivotal RCT evaluating MV140.

Design setting and participants

In the primary RCT, female patients with rUTI enrolled in Spain and UK (from October 2015 to April 2019) were randomized to placebo (6 mo) or MV140 (3 or 6 mo), and followed for 12 mo. Individuals analyzed in this secondary analysis included those in the placebo and 3-mo (recommended dose) groups.

Intervention

A polybacterial sublingual vaccine, MV140 (four inactivated whole-cell bacteria-Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, and Enterococcus faecalis), or placebo.

Outcome measurements and statistical analysis

Symptom severity scoring, antibiotic use, safety, and multiple aspects of quality of life (QoL; Short-Form Questionnaire [SF-36]) were assessed.

Results and limitations

Compared with the placebo group (n = 76), the 3-mo vaccinated group (n = 74) experienced fewer overall UTI symptoms (mean symptom score 102.2 ± 222.9 vs 194.2 ± 178.8; p = 0.0002), fewer days on antibiotics (12.4 ± 17.7 vs 28.7 ± 25.2; p = 0.0001), and improved total, general, and physical SF-36 QoL improvement (differences in means for total SF-36 score 15.7; 95% confidence interval [CI] 8.80, 22.64; p < 0.0001), with only social function QoL showing no impact (4.07; 95% CI -4.93, 13.08; p = 0.3744).

Conclusions

Three months of MV140 is associated with a reduction of the personal burden of UTI by reducing overall UTI symptoms and antibiotic use, improving QoL in women with rUTI.

Patient summary

Three months of MV140 vaccine, which has previously been shown to reduce the risk of urinary tract infection safely, is associated with a reduction in the personal burden of disease.

Antibacterial efficacy and mechanism of Cyprinus carpio chemokine-derived L-10 against multidrug-resistant Escherichia coli infections

OBJECTIVES

Antimicrobial resistance has raised concerns regarding untreatable infections and poses a growing threat to public health. Rational design of new AMPs is an ideal solution to this threat.

METHODS

In this study, we designed, modified, and synthesised an excellent AMP, L-10, based on the original sequence of the Cyprinus carpio chemokine. All experimental data were presented as the mean ± standard deviation (SD), and the two-tailed unpaired T-test method was used to analyze all data.

RESULTS

L-10 exhibited excellent antibacterial activity with negligible toxicity and improved the efficacy of a broad class of antibiotics against MDR Gram-negative pathogens, including tetracycline, meropenem, levofloxacin, and rifampin. Mechanistic studies have suggested that L-10 targets the bacterial membrane components, LPS and PG, to disrupt bacterial membrane integrity, thereby exerting antibacterial effects and enhancing the efficacy of antibiotics. Moreover, in animal infection models, L-10 significantly increased the survival rate of infected animals and effectively reduced the tissue bacterial load and inflammatory factor levels. In addition to its direct antibacterial activity, L-10 dramatically reduced pulmonary pathological alterations in a mouse model of endotoxemia and suppressed LPS-induced proinflammatory cytokines in vitro and in vivo. Lastly, L-10 was successfully expressed in Pichia pastoris and maintained antimicrobial activity against MDR Gram-negative pathogens in vivo and in vitro.

CONCLUSION

Collectively, these results reveal the potential of L-10 as an ideal candidate against MDR bacterial infections and provide new insights into the design, development, and clinical application of AMPs.

Photochemical inactivation as an alternative method to produce a whole-cell vaccine for uropathogenic Escherichia coli (UPEC)

Uropathogenic Escherichia coli (UPEC) is the primary causative agent of lower urinary tract infection (UTI). UTI presents a serious health risk and has considerable secondary implications including economic burden, recurring episodes, and overuse of antibiotics. A safe and effective vaccine would address this widespread health problem and emerging antibiotic resistance. Killed, whole-cell vaccines have shown limited efficacy to prevent recurrent UTI in human trials. We explored photochemical inactivation with psoralen drugs and UVA light (PUVA), which crosslinks nucleic acid, as an alternative to protein-damaging methods of inactivation to improve whole-cell UTI vaccines. Exposure of UPEC to the psoralen drug AMT and UVA light resulted in a killed but metabolically active (KBMA) state, as reported previously for other PUVA-inactivated bacteria. The immunogenicity of PUVA-UPEC as compared to formalin-inactivated UPEC was compared in mice. Both generated high UPEC-specific serum IgG titers after intramuscular delivery. However, using functional adherence as a measure of surface protein integrity, we found differences in the properties of PUVA- and formalin-inactivated UPEC. Adhesion mediated by Type-1 and P-fimbriae was severely compromised by formalin but was unaffected by PUVA, indicating that PUVA preserved the functional conformation of fimbrial proteins, which are targets of protective immune responses. In vitro assays indicated that although they retained metabolic activity, PUVA-UPEC lost virulence properties that could negatively impact vaccine safety. Our results imply the potential for PUVA to improve killed, whole-cell UTI vaccines by generating bacteria that more closely resemble their live, infectious counterparts relative to vaccines generated with protein-damaging methods.

IMPORTANCE

Lower urinary tract infection (UTI), caused primarily by uropathogenic Escherichia coli, represents a significant health burden, accounting for 7 million primary care and 1 million emergency room visits annually in the United States. Women and the elderly are especially susceptible and recurrent infection (rUTI) is common in those populations. Lower UTI can lead to life-threatening systemic infection. UTI burden is manifested by healthcare dollars spent (1.5 billion annually), quality of life impact, and resistant strains emerging from antibiotic overuse. A safe and effective vaccine to prevent rUTI would address a substantial healthcare issue. Vaccines comprised of inactivated uropathogenic bacteria have yielded encouraging results in clinical trials but improvements that enhance vaccine performance are needed. To that end, we focused on inactivation methodology and provided data to support photochemical inactivation, which targets nucleic acid, as a promising alternative to conventional protein-damaging inactivation methods to improve whole-cell UTI vaccines.

Collectin 11 has a pivotal role in host defense against kidney and bladder infection in mice

The urinary tract is constantly exposed to microorganisms. Host defense mechanisms in protection from microbial colonization and development of urinary tract infections require better understanding to control kidney infection. Here we report that the lectin collectin 11 (CL-11), particularly kidney produced, has a pivotal role in host defense against uropathogen infection. CL-11 was found in mouse urine under normal and pathological conditions. Mice with global gene ablation of Colec11 had increased susceptibility to and severity of kidney and to an extent, bladder infection. Mice with kidney-specific Colec11 ablation exhibited a similar disease phenotype to that observed in global Colec11 deficient mice, indicating the importance of kidney produced CL-11 for protection against kidney and bladder infection. Conversely, intravesical or systemic administration of recombinant CL-11 reduced susceptibility to and severity of kidney and bladder infection. Mechanism analysis revealed that CL-11 can mediate several key innate defense mechanisms (agglutination, anti- adhesion, opsonophagocytosis), and limit local inflammatory responses to pathogens. Furthermore, CL-11-mediated innate defense mechanisms can act on clinically relevant microorganisms including multiple antibiotic resistant strains. CL-11 was detectable in eight of 24 urine samples from patients with urinary tract infections but not detectable in urine samples from ten healthy individuals. Thus, our findings demonstrate that CL-11 is a key factor of host defense mechanisms in kidney and bladder infection with therapeutic potential for human application.

Discovery and Synthesis of a Gram-Negative-Active Cationic Lipopeptide Antibiotic Inspired by Primary Sequences from Underexplored Gram-Negative Bacteria

The emergence of multidrug-resistant Gram-negative pathogens poses a serious threat to global health. Gram-negative bacteria have become increasingly recognized as underexplored sources of Gram-negative-active cationic lipopeptide (CLP) antibiotics. We systematically screened 8982 sequenced genomes from 42 underexplored Gram-negative bacterial genera and identified eight potential CLP biosynthetic gene clusters. Their predicted products were rapidly accessed by solid-phase total synthesis, which led to the novel antibiotic chospeptin with good activities against clinically isolated colistin-resistant Gram-negative pathogens.

Ceftazidime-avibactam induced renal disorders: past and present

With the increasing prevalence of multidrug-resistant Gram-negative bacterial pathogens worldwide, antimicrobial resistance has become a significant public health concern. Ceftazidime-avibactam (CAZ-AVI) exhibited excellent in vitro activity against many carbapenemase-producing pathogens, and was widely used for the treatment of various complicated infections. CAZ-AVI is well tolerated across all dosing regimens, and its associated acute kidney injury (AKI) in phase II/III clinical trials is rare. However, recent real-world studies have demonstrated that CAZ-AVI associated AKI was more frequent in real-world than in phase II and III clinical trials, particularly in patients receiving concomitant nephrotoxic agents, with critically ill patients being at a higher risk. Herein, we reviewed the safety data related to renal impairment of CAZ-AVI, and discussed its pharmacokinetic/pharmacodynamic targets and dosage adjustment in patients with impaired renal function. This review aimed to emphasize the importance for healthcare professionals to be aware of this adverse event of CAZ-AVI and provide practical insights into the dosage optimization in critically ill patients with renal dysfunction.

Efficacy of fosfomycin compared to second generation cephalosporin flumarin as antimicrobial prophylaxis for transrectal ultrasound-guided prostate biopsy: a single center retrospective study

BACKGROUND

Fluoroquinolone has been the historic choice of antimicrobial prophylaxis for transrectal ultrasound (TRUS) guided prostate biopsy. However, increased fluoroquinolone resistance and recent restrictions of its use for antimicrobial prophylaxis has led to the emergence of alternative agents for antimicrobial prophylaxis for TRUS guided prostate biopsy including fosfomycin and cephalosporins. This study aimed to compare the efficacy of fosfomycin and a second-generation cephalosporin flumarin as alternative antimicrobials for TRUS-guided prostate biopsy in terms of the incidence of infectious complications after TRUS-guided prostate biopsy.

METHODS

A retrospective chart review of all patients who underwent TRUS-guided prostate biopsy between November 2009 to January 2023 was undertaken. Comparison of baseline characteristics and the incidence of infectious complications was done between those who received fosfomycin as antimicrobial prophylaxis for TRUS-guided prostate biopsy and those who received flumarin. Multivariate logistic regression analysis was conducted to identify risk factors for infectious complications after TRUS-guided prostate biopsy.

RESULTS

Of 2,900 patients identified as eligible candidates for analysis, 333 (11.5%) received fosfomycin and 2,567 (88.5%) received flumarin. The overall rate of infectious complications was approximately 3% lower in patients who received fosfomycin, although such difference did not reach statistical significance (5.7% vs. 8.6%, p = 0.074). Multivariate logistic regression analysis showed that history of operation done under general anaesthesia within six months of the biopsy (odds ratio [OR]: 2.216; 95% confidence interval [CI]: 1.042-4.713; p = 0.039) and history of prior antimicrobial use within six months (OR: 1.457; 95% CI: 1.049-2.024; p = 0.025) were significant risk factors for infectious complications after TRUS-guided prostate biopsy.

CONCLUSION

Fosfomycin was comparable to second-generation cephalosporin flumarin in preventing infectious complications after TRUS-guided prostate biopsy. Coupled with its properties such as ease of administration, low adverse effects, low resistance rate, and low collateral damage, fosfomycin might be an attractive alternative antimicrobial prophylaxis for TRUS-guided prostate biopsy.

Bactericidal and non-cytotoxic activity of bacteriocin produced by Lacticaseibacillus paracasei F9-02 and evaluation of its tolerance to various physico-chemical conditions

This study aims to explore novel lactic acid bacteria (LAB) from breast-fed infants' faeces towards characterizing their antimicrobial compound, bacteriocin. The LAB, Lacticaseibacillus paracasei F9-02 showed strong antimicrobial activity against clinical pathogens. Their proteinaceous nature was confirmed as the activity was completely abolished when treated with proteinaceous enzymes and retained during neutral pH and catalase treatment. The purified bacteriocin showed antimicrobial activity at the minimum inhibitory concentration (MIC) value of 7.56 μg/ml against vancomycin-resistant Enterococcus sp. [vancomycin-resistant enterococcal (VRE)], and methicillin-resistant Staphylococcus aureus (MRSA), 15.13 μg/ml against Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica subsp. enterica serotype typhi and 30.25 μg/ml against Shigella flexneri. Present study also proved the bactericidal, non-cytotoxic and non-hemolytic nature of bacteriocin. Additionally, bacteriocin retained their stability under various physico-chemical conditions, broad range of pH (2-10), temperature (40-121°C), enzymes (amylase, lipase and lysozyme), surfactants [Tween-20, 80, 100 and sodium dodecyl sulfate (SDS)], metal ions (CaCl2 , FeSO4 , ZnSO4 , MgSO4 , MnSO4 , CuCl2 ) and NaCl (2%-8%). The molecular weight of bacteriocin (~28 kDa) was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), functional and active groups were assessed by Fourier Transform-Infrared (FT-IR). To our knowledge, this is the first study reporting L. paracasei from breast-fed infants' faeces and assessing their antimicrobial compound, bacteriocin. The study results furnish the essential features to confirm the therapeutic potential of L. paracasei F9-02 bacteriocin.

Modified Zhibai Dihuang pill alleviated urinary tract infection induced by extended-spectrum β-lactamase Escherichia coli in rats by regulating biofilm formation

CONTEXT

Zhibai Dihuang pill (ZD), a traditional Chinese medicine nourishes Yin and reduces internal heat, is believed to have therapeutic effects on urinary tract infections (UTIs).

OBJECTIVE

To explore the effects and mechanism of modified ZD (MZD) on UTI induced by extended-spectrum β-lactamase (ESBLs) Escherichia coli.

MATERIALS AND METHODS

Thirty Sprague-Dawley rats were randomly divided into control, model (0.5 mL 1.5 × 108 CFU/mL ESBLs E. coli), MZD (20 g/kg MZD), LVFX (0.025 g/kg LVFX), and MZD + LVFX groups (20 g/kg MZD + 0.025 g/kg LVFX), n = 6. After 14 days of treatment, serum biochemical indicators, renal function indicators, bladder and renal histopathology, and urine bacterial counts in rats were determined. Additionally, the effects of MZD on ESBLs E. coli biofilm formation and related gene expression were analyzed.

RESULTS

MZD significantly decreased the count of white blood cells (from 13.12 to 9.13), the proportion of neutrophils (from 43.53 to 23.18), C-reactive protein (from 13.21 to 9.71), serum creatinine (from 35.78 to 30.15), and urea nitrogen (from 12.56 to 10.15), relieved the inflammation and fibrosis of bladder and kidney tissues, and reduced the number of bacteria in urine (from 2174 to 559). In addition, MZD inhibited the formation of ESBLs E. coli biofilms (2.04-fold) and decreased the gene expressions of luxS, pfS and ompA (1.41-1.62-fold).

DISCUSSION AND CONCLUSION

MZD treated ESBLs E. coli-induced UTI inhibited biofilm formation, providing a theoretical basis for the clinical application of MZD. Further study on the clinical effect of MZD may provide a novel therapy option for UTI.

External validation of biochemical recurrence definition to predict oncologic outcomes following focal therapy for localized prostate cancer using high intensity focused ultrasound

PURPOSE

This is an external validation of several biochemical recurrence definitions based on prostate specific antigen criteria (PSA). The purpose is to predict the need of additional treatment and failure after focal therapy using high intensity focused ultrasound (HIFU) for localized prostate cancer (PCa).

MATERIALS AND METHODS

A total of 343 consecutive patients who underwent HIFU with Ablatherm® and Focal One® devices between June 2001 and November 2020 were identified. Treatment failure was defined as clinically significant PCa on postoperative biopsy, the need for salvage radical or systematic treatment, metastasis, or PCa-related death. The biochemical recurrence definitions tested were PSA nadir, time to PSA nadir, percentage of PSA reduction, Huber et al. criteria defined as PSA nadir + 1 ng/mL at 12 months or PSA nadir + 1.5 ng/mL at 24-36 months. Multivariable Cox regression analysis and decision-curve analysis were used to validate and compare criteria. Kaplan-Meier analysis was used to assess criteria associated with the highest accuracy.

RESULTS

One hundred seventy-eight patients met the inclusion criteria and were analyzed. Overall, 61 (34%) and 41 (23%) patients had an additional treatment and failure with a median follow-up of 52 months. At multivariable analysis, model including Huber et al. criteria exhibited the highest Harrell's C-index for the prediction of the need of additional treatment (hazard ratio [HR]: 10, p < 0.001, c-index: 84%) and treatment failure (HR: 9.1, p < 0.001, c-index: 82%) as well as higher net benefit. The 60-months need of additional treatment and treatment failure-free survival were 89% and 98% compared to 26% and 49%, respectively, when stratified according to Huber et al. criteria (Log-rank test, p < 0.001). Similar results were found after excluding patient with non-clinically significant PCa at initial biopsy.

CONCLUSIONS

We report an external validation of biochemical recurrence definitions predicting the need of additional treatment and failure after focal therapy using HIFU for localized PCa. Huber et al. criteria were identified as the most accurate and could be used to guide clinicians toward further evaluation and salvage treatments.

N-acetylcysteine prevents catheter occlusion and inflammation in catheter associated-urinary tract infections by suppressing urease activity

Introduction

Proteus mirabilis is a key pathobiont in catheter-associated urinary tract infections (CA-UTIs), which is well known to form crystalline biofilms that occlude catheters. Urease activity alkylates urine through the release of ammonia, consequentially resulting in higher levels of Mg2+ and Ca2+ and formation of crystals. In this study, we showed that N-acetyl cysteine (NAC), a thiol antioxidant, is a potent urease inhibitor that prevents crystalline biofilm formation.

Methods

To quantify urease activity, Berthelot's method was done on bacterial extracts treated with NAC. We also used an in vitro catheterised glass bladder model to study the effect of NAC treatment on catheter occlusion and biofilm encrustation in P. mirabilis infections. Inductively-coupled plasma mass spectrometry (ICP-MS) was performed on catheter samples to decipher elemental profiles.

Results

NAC inhibits urease activity of clinical P. mirabilis isolates at concentrations as low as 1 mM, independent of bacterial killing. The study also showed that NAC is bacteriostatic on P. mirabilis, and inhibited biofilm formation and catheter occlusion in an in vitro. A significant 4-8log10 reduction in viable bacteria was observed in catheters infected in this model. Additionally, biofilms in NAC treated catheters displayed a depletion of calcium, magnesium, or phosphates (>10 fold reduction), thus confirming the absence of any urease activity in the presence of NAC. Interestingly, we also showed that not only is NAC anti-inflammatory in bladder epithelial cells (BECs), but that it mutes its inflammatory response to urease and P. mirabilis infection by reducing the production of IL-6, IL-8 and IL-1b.

Discussion

Using biochemical, microbiological and immunological techniques, this study displays the functionality of NAC in preventing catheter occlusion by inhibiting urease activity. The study also highlights NAC as a strong anti-inflammatory antibiofilm agent that can target both bacterial and host factors in the treatment of CA-UTIs.

Uropathogen and host responses in pyelonephritis

Urinary tract infections (UTIs) are among the most common bacterial infections seen in clinical practice. The ascent of UTI-causing pathogens to the kidneys results in pyelonephritis, which can trigger kidney injury, scarring and ultimately impair kidney function. Despite sizable efforts to understand how infections develop or are cleared in the bladder, our appreciation of the mechanisms by which infections develop, progress or are eradicated in the kidney is limited. The identification of virulence factors that are produced by uropathogenic Escherichia coli to promote pyelonephritis have begun to fill this knowledge gap, as have insights into the mechanisms by which kidney tubular epithelial cells oppose uropathogenic E. coli infection to prevent or eradicate UTIs. Emerging data also illustrate how specific cellular immune responses eradicate infection whereas other immune cell populations promote kidney injury. Insights into the mechanisms by which uropathogenic E. coli circumvent host immune defences or antibiotic therapy to cause pyelonephritis is paramount to the development of new prevention and treatment strategies to mitigate pyelonephritis and its associated complications.

Management of uncomplicated urinary tract infection in the post-antibiotic era: select non-antibiotic approaches

BACKGROUND

Given the high frequency of patients presenting with urinary tract infections (UTIs) and the ensuing high degree of antibiotic prescription, UTI is a critical point of intervention for non-antibiotic treatments to curb the further development of antimicrobial resistance and provide risk-appropriate care for patients.

OBJECTIVES

To highlight several select non-antibiotic therapies for the treatment of uncomplicated UTI and relevant indications (prevention and complicated UTI) from recent literature.

SOURCES

PubMed, Google Scholar, and clinicaltrials.gov were searched for clinical trials published in the English language corresponding to non-antibiotic treatments for UTI.

CONTENT

The focus of this narrative review centres on a limited number of non-antibiotic therapies for the treatment of UTI based on (a) herbal extracts or (b) antibacterial strategies (e.g. bacteriophage therapy and D-mannose). The experience of treatment with non-steroidal anti-inflammatory drugs is also used to fuel discussion on the risk of developing pyelonephritis without antibiotics-compared with the projected harms of continuing their widespread use.

IMPLICATIONS

Non-antibiotic treatment strategies for UTI have shown varying results in clinical trials, and the current evidence does not yet indicate a clear, better alternative to antibiotics. However, the collective experience with non-antibiotic treatments suggests that there is a need to weigh the actual benefits/risks of unfettered, non-culture-confirmed antibiotic use in uncomplicated UTI. Given the different mechanisms of action of proposed alternatives, more in-depth knowledge on microbiological and pathophysiological factors influencing UTI susceptibility and prognostic indicators are highly needed to stratify patients most likely to benefit. The feasibility of alternatives in clinical practice should also be considered.

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.

Pharmacokinetic/Pharmacodynamic Target Attainment of Continuous Infusion Piperacillin-Tazobactam or Meropenem and Microbiological Outcome among Urologic Patients with Documented Gram-Negative Infections

(1) Objectives: To describe the relationship between pharmacokinetic/pharmacodynamic (PK/PD) target attainment of continuous infusion (CI) piperacillin-tazobactam or meropenem monotherapy and microbiological outcome in a case series of urological patients with documented Gram-negative infections. (2) Methods: Patients admitted to the urology ward who were treated with CI piperacillin-tazobactam or meropenem monotherapy for documented Gram-negative infections and underwent real-time therapeutic drug monitoring (TDM)-guided expert clinical pharmacological advice (ECPA) program from June 2021 to May 2023 were retrospectively retrieved. Average steady-state (Css) piperacillin-tazobactam and meropenem concentrations were determined, and the free fractions (fCss) were calculated. Optimal PK/PD target attainments were defined as an fCss/MIC ratio >4 for CI meropenem and an fCss/MIC ratio of piperacillin >4 coupled with an fCss/CT ratio for tazobactam >1 for piperacillin-tazobactam (joint PK/PD target). The relationship between beta-lactam PK/PD targets and microbiological outcome was explored. (3) Results: Sixteen urologic patients with documented Gram-negative infections (62.5% complicated urinary tract infections (cUTI)) had 30 TDM-guided ECPAs. At first TDM assessment, beta-lactam dosing adjustments were recommended in 11 out of 16 cases (68.75%, of which 62.5% decreases and 6.25% increases). Overall, beta-lactam dosing adjustments were recommended in 14 out of 30 ECPAs (46.6%). Beta-lactam PK/PD target attainments were optimal in 100.0% of cases. Microbiological failure occurred in two patients, both developing beta-lactam resistance. (4) Conclusion: A TDM-guided ECPA program may allow for optimizing beta-lactam treatment in urologic patients with documented Gram-negative infections, ensuring microbiological eradication in most cases.

The safety of ceftolozane/tazobactam for the treatment of complicated urinary tract infections

INTRODUCTION

Ceftolozane is a cephalosporin similar to ceftazidime in its structure, which is marketed in combination with tazobactam, a well-known β-lactamase inhibitor.

AREAS COVERED

After a brief introduction on the drug characteristics and efficacy, we focused on available data from randomized controlled trials and post-marketing observational studies pertaining to the safety of ceftolozane/tazobactam (C/T) for the treatment of complicated urinary tract infections (cUTI). A search was conducted in PubMed from January 2010 to February 2023.

EXPERT OPINION

The use of C/T for the treatment of cUTI is supported by solid efficacy and safety data, especially for the treatment of those pathogens where it can represent a first-line approach due to some peculiar characteristics: (i) treatment of cUTI caused by multidrug-resistant Pseudomonas aeruginosa, in view of its frequent activity against carbapenem-resistant isolates when resistance mechanisms other than production of carbapenemases are concerned; (ii) treatment of cUTI caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacterales in those settings where the selective pressure for carbapenem resistance needs to be relieved, as a suitable and effective carbapenem-sparing option. Although development of resistance to C/T during or after treatment has been reported, this has been reported very rarely in patients receiving C/T for the treatment of cUTI.

Extended-spectrum beta-lactamase in Escherichia coli isolated from humans, animals, and environments in Bangladesh: A One Health perspective systematic review and meta-analysis

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli has been linked to both life-threatening hospital- and community-acquired infections across the globe. Here, we conducted a systematic review and meta-analysis to evaluate the prevalence of ESBL in E. coli isolated from humans, animals, and environments in Bangladesh. Following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, the current systematic review and meta-analysis was taken into account for studies published between 2010 and 2021 in peer-reviewed journals. The meta-analysis was performed on "R" version 4.2.2. A total of 36 studies were included in this systematic review and meta-analysis; among them, 22 were human, seven were animal, four were environmental, and three were multidisciplinary studies. The meta-analysis revealed that the pooled prevalence of ESBL-producing E. coli in Bangladesh was 21% (95% CI: 15%-27%). On the sample basis, the pooled prevalence of ESBL-producing E. coli in humans, animals, and environments was 17% (95% CI: 11%-23%), 22% (95% CI: 9%-34%), and 39% (95% CI: 16%-62%), respectively. All the pooled prevalence of ESBL-producing E. coli showed substantial heterogeneity (I2 > 75%; p < 0.05) among the selected studies. This systematic review reported 13 different types of resistance genes encoding ESBL, such as blaTEM-1 (37.5%), blaCMY (34.6%), blaCTX-M-1 (20.7%), blaCTX-M-15 (16.1%), blaTEM (12.3%), blaCTX-M and blaOXA (9.6%), blaOXA-1 (5.8%), blaampC (3.9%), blaSHV (3.8%), blaCMY-2 (2.3%), blaCTX-M-14 (1.3%), and blaCTX-M-9 (0.3%). Moreover, 39 types of epidemiologically important clones (including ST10 and ST131) were detected in ESBL-producing E. coli isolated from humans, animals, and environments in Bangladesh. To the best of our knowledge, this is the first systematic review and meta-analysis of integrated studies on ESBL-producing E. coli using the One Health approach in Bangladesh. The high prevalence of ESBL-producing E. coli, their resistance genes, and epidemiologically important clones in humans, animals, and environments highlights the importance of implementing comprehensive antimicrobial resistance (AMR) surveillance under a One Health perspective to mitigate the AMR consequences in Bangladesh.

Bacterial profile, antimicrobial resistance, and molecular detection of ESBL and quinolone resistance gene of uropathogens causing urinary tract infection in the southeastern part of Bangladesh

Humans frequently contract urinary tract infections (UTIs), which can be brought on by uropathogens (UPs) that are multi-drug resistant. Treatment for UTIs brought on by pathogenic UPs that produce extended-spectrum lactamases (ESBLs) is more costly and potentially fatal. As a result, the objective of this study was to use culture, biochemical, and 16S rRNA sequencing to identify and characterize UPs isolated from outpatients in Noakhali, Bangladesh, who had symptoms of UTIs. ESBL gene identification and quinolone resistance gene typing were then performed on the isolates using polymerase chain reaction (PCR). Throughout the trial's 8-month duration, 152 (76%) of 200 urine samples were positive for the presence of UPs. The overall number of UPs recovered was 210, with 39 individuals having multiple UPs present in their samples. Among all of the isolates, Escherichia coli (45.24%, 95/210; 95% confidence interval (CI): 35.15-57.60%), Enterobacter spp. (24.76%, 52/210; CI: 19.15-35.77%), Klebsiella spp. (20.95%; 44/210; CI: 15.15-30.20%), and Providencia spp. (9.05%; 19/210; CI: 4.95-19.25%) were the four most prevalent bacteria found in the isolates. The UPs displayed a very high level of resistance to piperacillin 96.92% (126/130), ampicillin 90% (117/130), nalidixic acid 77.69% (101/130), cefazolin 70% (91/130), amoxicillin 50% (55/130), cefazolin 42.31% (55/130), nitrofurantoin 43.08% (56/130), and ciprofloxacin 33.08% (43/130), whereas resistance to netilmicin (3.85%), amikacin (4.62%), and imipenem (9.23%) was low. Individually, every species of E. coli and Providencia spp. showed greater ampicillin, amikacin, cefazolin, cefazolin, and nalidixic acid resistance than the others. The bivariate results indicate several antibiotic pairings, and isolates had meaningful associations. All MDR isolates were subjected to PCR, which revealed that blaCTX-M-15 genes predominated among the isolates, followed by the blaTEM class (37%). Isolates also had the qnrS, aac-6´-Ib-cr, and gyrA genes. The findings provide worrying indications of a major expansion of MDR isolates in the study locations, particularly the epidemiological balCTX-M 15, with the potential for the transmission of multi-drug-resistant UP strains in the population.

Cinnamaldehyde Restores Ceftriaxone Susceptibility against Multidrug-Resistant Salmonella

In recent years, infections caused by multidrug-resistant (MDR) bacteria have greatly threatened human health and imposed a burden on global public health. To overcome this crisis, there is an urgent need to seek effective alternatives to single antibiotic therapy to circumvent drug resistance and prevent MDR bacteria. According to previous reports, cinnamaldehyde exerts antibacterial activity against drug-resistant Salmonella spp. This study was conducted to investigate whether cinnamaldehyde has a synergistic effect on antibiotics when used in combination, we found that cinnamaldehyde enhanced the antibacterial activity of ceftriaxone sodium against MDR Salmonella in vitro by significantly reduced the expression of extended-spectrum beta-lactamase, inhibiting the development of drug resistance under ceftriaxone selective pressure in vitro, damaging the cell membrane, and affecting its basic metabolism. In addition, it restored the activity of ceftriaxone sodium against MDR Salmonella in vivo and inhibited peritonitis caused by ceftriaxone resistant strain of Salmonella in mice. Collectively, these results revealed that cinnamaldehyde can be used as a novel ceftriaxone adjuvant to prevent and treat infections caused by MDR Salmonella, mitigating the possibility of producing further mutant strains.

A 2-Year Audit on Antibiotic Resistance Patterns from a Urology Department in Greece

PURPOSE

The high incidence of urinary tract infections (UTIs), often in nosocomial environments, is a major cause of antimicrobial resistance (AMR). The dissemination of antibiotic-resistant infections results in very high health and economic burdens for patients and healthcare systems, respectively. This study aims to determine and present the antibiotic resistance profiles of the most common pathogens in a urology department in Greece.

METHODS

During the period 2019-2020, we included 12,215 clinical samples of blood and urine specimens that tested positive for the following pathogens: Escherichia coli, Enterococcus faecium, Enterococcus faecalis, Proteus mirabilis, Klebsiella pneumoniae, or Pseudomonas aeruginosa, as these are the most commonly encountered microbes in a urology department.

RESULTS

The analysis revealed a 22.30% mean resistance rate of E. coli strains with a 76.42% resistance to ampicillin and a 54.76% resistance rate to ciprofloxacin in the two-year period. It also showed an approximately 19% resistance rate of P. mirabilis strains and a mean resistance rate of 46.205% of K. pneumoniae strains, with a decreasing trend during the four semesters (p-value < 0.001), which presented an 80% resistance rate to ampicillin/sulbactam and 73.33% to ciprofloxacin. The resistance to carbapenems was reported to be 39.82%. The analysis revealed a 24.17% mean resistance rate of P. aeruginosa with a declining rate over the two-year period (p-value < 0.001). The P. aeruginosa strains were 38% resistant to fluoroquinolones and presented varying resistance against carbapenems (31.58% against doripenem and 19.79% against meropenem). Regarding the Enteroccocal strains, a 46.91% mean resistance was noted for E. faecium with 100% resistance to ampicillin, and a 24.247% mean resistance rate for E. faecalis strains that were 41% resistant to ciprofloxacin. Both types showed 100% sensitivity to linezolid.

CONCLUSIONS

The dissemination of antibiotic-resistant pathogens poses the need to implement surveillance programs and, consequently, to develop strategies to prevent the emergence of such pathogens in order to optimize patient outcomes.

High prevalence of β-lactam and fluoroquinolone resistance in various phylotypes of Escherichia coli isolates from urinary tract infections in Jiroft city, Iran

BACKGROUND

Urinary tract infection (UTI) is one of the most prevalent infectious diseases with worldwide health threatening. Antimicrobial resistant strains of Escherichia coli (E. coli) are a common cause of UTI which were identified as a treatment challenge. This study aimed to assay the prevalence of common β-lactam resistance genes including blaTEM, blaSHV, blaCTX-M and blaCMY and phenotypic resistance to commonly used β-lactam and fluoroquinolone antibiotics in UTIs. These factors were evaluated in various phylogenetic groups (phylotypes) of E. coli isolates. Real-time PCR was applied to detect β-lactam resistance genes and conventional PCR was used to determine the phylotypes. Phenotypic resistance against β-lactams (ceftazidime, cefotaxime, aztreonam and ceftriaxone) and fluoroquinolones (ciprofloxacin) were identified by the disc diffusion technique. The ability of extended spectrum β-lactamases (ESBLs) production in E. coli isolates was detected using the combined disc diffusion method.

RESULTS

The prevalence of resistance genes were 89.6% for blaTEM, 44.3% for blaCTX-M, 6.6% for blaSHV and 0.9% for blaCMY. The two high prevalent phylotypes were B2 (29.2%) and D (17.9%) followed by E (14.1%), F (9.4%), C (6.6%) and 10.3% of isolates were unknown in phylotyping. Disc diffusion results showed high prevalence of antibiotic resistance to cefotaxime (88.6%), aztreonam (83%), ceftireaxon (77.3%), ceftazidime (76.4%) and ciprofloxacin (55.6%). Totally, 52.8% of isolates were found as phenotypical ESBL-producers.

CONCLUSIONS

This study's results confirmed an explosion of antibiotic resistance amongst E. coli isolates from UTI against β-lactams and fluoroquinolones. Findings explain the necessity of deep changes in quantity and quality of drug resistance diagnosis and antibiotic therapy strategies. More studies are suggested to better and confident evaluations.

The Use and Effectiveness of Ceftazidime-Avibactam in Real-World Clinical Practice: EZTEAM Study

INTRODUCTION

Ceftazidime-avibactam has proven activity against multidrug-resistant (MDR) bacteria in clinical trials and real-world studies. This study was conducted to describe the patterns of use of ceftazidime-avibactam (including indications and associated antibiotics), and the effectiveness and safety of ceftazidime-avibactam in real-world clinical practice.

METHODS

This non-interventional medical chart review study was conducted in 11 countries across the European and Latin American (LATAM) regions. Consecutive patients treated in clinical practice with at least one dose of ceftazidime-avibactam for an approved indication per country label since 01 January 2018 (or launch date in the country if posterior) were enrolled. Effectiveness analyses were conducted in patients treated with ceftazidime-avibactam for at least 72 h.

RESULTS

Of the 569 eligible patients enrolled, 516 (90.7%) were treated for at least 72 h (354 patients from Europe and 162 patients from LATAM); 390 patients (75.7%) had switched from another antibiotic line for Gram-negative coverage. Infection sources were intra-abdominal, urinary, respiratory, bloodstream infections, and other infections (approximately 20% each). K. pneumoniae was the most common microorganism identified in the latest microbiological evaluation before starting ceftazidime-avibactam (59.3%). Two-thirds of microorganisms tested for susceptibility were MDR, of which 89.3% were carbapenem-resistant. The common MDR mechanisms for K. pneumoniae were carbapenemase (33.9%), oxacillinase 48 (25.2%), extended-spectrum beta-lactamase (21.5%), or metallo-beta-lactamase (14.2%) production. Without prior patient exposure, 17 isolates (mostly K. pneumoniae) were resistant to ceftazidime-avibactam. Treatment success was achieved in 77.3% of patients overall (88.3% among patients with urinary infection), regardless of first or second treatment line. In-hospital mortality rate was 23.1%. Adverse events were reported for six of the 569 patients enrolled.

CONCLUSION

This study provides important real-world evidence on treatment patterns, effectiveness, and safety of ceftazidime-avibactam in clinical practice through its recruitment in the European and LATAM regions. Ceftazidime-avibactam is one of the antibiotics to consider for treatment of MDR bacteria.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03923426.

An Effective Sublingual Vaccine, MV140, Safely Reduces Risk of Recurrent Urinary Tract Infection in Women

Uncomplicated recurrent urinary tract infections (rUTIs) in women are associated with episodic bothersome symptoms and have a significant impact on the mental and physical quality of life. Treatment with antibiotics (short- and long-term dosing) results in acute and chronic side effects and costs and promotes general antibiotic resistance. Improved nonantibiotic management of rUTI in women represents a true, unmet medical need. MV140 is a novel sublingual mucosal-based bacterial vaccine developed for the prevention of rUTI in women. Based on observational, prospective, and randomized placebo-controlled studies, MV140 has been shown to safely prevent (or reduce the risk of) UTIs, reduce antibiotic use, overall management costs, and patient burden while improving the overall quality of life in women suffering from rUTIs.

SAR investigation and optimization of benzimidazole-based derivatives as antimicrobial agents against Gram-negative bacteria

Antibiotic-resistant bacteria represent a serious threat to modern medicine and human life. Only a minority of antibacterial agents are active against Gram-negative bacteria. Hence, the development of novel antimicrobial agents will always be a vital need. In an effort to discover new therapeutics against Gram-negative bacteria, we previously reported a structure-activity-relationship (SAR) study on 1,2-disubstituted benzimidazole derivatives. Compound III showed a potent activity against tolC-mutant Escherichia coli with an MIC value of 2 μg/mL, representing a promising lead for further optimization. Building upon this study, herein, 49 novel benzimidazole compounds were synthesized to investigate their antibacterial activity against Gram-negative bacteria. Our design focused on three main goals, to address the low permeability of our compounds and improve their cellular accumulation, to expand the SAR study to the unexplored ring C, and to optimize the lead compound (III) by modification of the methanesulfonamide moiety. Compounds (25a-d, 25f-h, 25k, 25l, 25p, 25r, 25s, and 26b) exhibited potent activity against tolC-mutant E. coli with MIC values ranging from 0.125 to 4 μg/mL, with compound 25d displaying the highest potency among the tested compounds with an MIC value of 0.125 μg/mL. As its predecessor, III, compound 25d exhibited an excellent safety profile without any significant cytotoxicity to mammalian cells. Time-kill kinetics assay indicated that 25d exhibited a bacteriostatic activity and significantly reduced E. coli JW55031 burden as compared to DMSO. Additionally, combination of 25d with colistin partially restored its antibacterial activity against Gram-negative bacterial strains (MIC values ranging from 4 to 16 μg/mL against E. coli BW25113, K. pneumoniae, A. baumannii, and P. aeruginosa). Furthermore, formulation of III and 25d as lipidic nanoparticles (nanocapsules) resulted in moderate enhancement of their antibacterial activity against Gram-negative bacterial strains (A. Baumannii, N. gonorrhoeae) and compound 25d demonstrated superior activity to the lead compound III. These findings establish compound 25d as a promising candidate for treatment of Gram-negative bacterial infections and emphasize the potential of nano-formulations in overcoming poor cellular accumulation in Gram-negative bacteria where further optimization and investigation are warranted to improve the potency and broaden the spectrum of our compounds.

Antimicrobial usage and associated residues and resistance emergence in smallholder beef cattle production systems in Nigeria: A One Health challenge

Livestock intensification has facilitated antimicrobial use (AMU) with consequent antimicrobial resistance (AMR) development. We assessed AMU in beef farms, pathways for residues and resistance dissemination to humans, risk status, residues identification, and drivers for antimicrobial residues and resistance emergence in beef cattle production systems. A cross-sectional survey was conducted in randomly selected beef farms of Northern Nigeria, between 2018 and 2019. Traffic Light model and Disc Diffusion Test were used to assess risk status and determined residues, respectively. Data was analyzed using descriptive statistics and logistic regression models at 95% confidence level. About 92% (n = 608) farmers participated. The majority of farmers managing intensive (78.9%) and semi-intensive (76.6%) farms did not follow antimicrobial dosage instructions. Also, 72.4% and 83.9% of the farmers on intensive and semi-intensive systems, respectively, did not observed withdrawal periods after AMU. Furthermore, 71.5% farmers in intensive and 53.2% in semi-intensive farms used antimicrobials as growth promoters. Antimicrobials frequently used include tetracyclines, sulfonamides and penicillin. Antimicrobial residues and resistance dissemination pathways from beef herds were: consumption of contaminated meat with residues (p = 0.007); contacts with contaminated cattle and fomites (p < 0.001); and contaminated manure and aerosols in farm environment (p = 0.003). Significant drivers of residues and resistance emergence were antimicrobial misuse and overuse (OR = 2.72; 95% CI:1.93-3.83), non-enforcement of laws (OR = 2.98; 95% CI:2.11-4.21), poor education and expertise (OR = 1.52; 95% CI:1.09-2.12), and husbandry management system (OR = 10.24; 95% CI:6.75-15.54). The majority of intensive (63.6%) and semi-intensive (57.63%) farm systems belonged to Class 3 (Red risk) status. Antimicrobial residues were detected in 48.4% intensively and 34.4% semi-intensively managed farms. The study revealed poor practices of AMU in beef cattle production. Many factors were found to influenced antimicrobial residues and resistance occurrence and dissemination. A 'One Health' approach mitigation with adequate sanitation, hygiene, and good biosecurity measures will assure food safety, public and environmental health.

Unmet Needs in Complicated Urinary Tract Infections: Challenges, Recommendations, and Emerging Treatment Pathways

While urinary tract infections (UTIs) are one of the most common types of infections globally, the wide variety of presentations and of severity of disease can make it difficult to manage. The definition for uncomplicated UTIs (uUTIs) is generally regarded as UTIs in healthy, non-pregnant women whereas all other UTIs are considered complicated. There is, however, a lack of consensus definition of complicated UTIs (cUTIs), leading to global differences in management. In addition, the patients who develop complicated UTIs generally have other comorbidities that warrant more urgent intervention. One of the biggest challenges in treating cUTIs is the rise of antimicrobial resistance (AMR). While there have been recent drug approvals for new antibiotic to treat these resistant organisms, a multidisciplinary approach, including regulatory frameworks, provider education and public awareness campaigns, is crucial to limiting unnecessary treatments for asymptomatic bacteriuria (ASB) and uUTIs that can ultimately lead to more severe infections.

Magnitude and antimicrobial susceptibility profiles of Gram-Negative bacterial isolates among patients suspected of urinary tract infections in Arba Minch General Hospital, southern Ethiopia

The emergence of drug-resistant Gram-negative bacterial uropathogens poses a grave threat worldwide, howbeit studies on their magnitude are limited in most African countries, including Ethiopia. Therefore, measuring the extent of their drug resistance is essential for developing strategies to confine the spread. A cross-sectional study was conducted at title hospital from 01 June to 31 August 2020. Midstream urine specimens were collected and inoculated onto MacConkey agar. Positive urine cultures showing significant bacteriuria as per the Kass count (>105 CFU/mL) were further subjected to biochemical tests to identify the type of uropathogens. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disk diffusion technique, and potential carbapenemase producers were phenotypically determined by the modified carbapenem inactivation method as per the CLSI guidelines. Data were analyzed using SPSS version 26; P-value <0.05 was considered statistically significant. Totally, 422 patients were included, and the majority were females (54.7%). The prevalence of carbapenem-resistant Gram-negative uropathogens was 12.9%, and 64.7% of them were carbapenemase producers. Klebsiella pneumoniae (n = 5) was the predominant carbapenemase producer, followed by Pseudomonas aeruginosa (n = 4). Consumption of antibiotics prior to six months of commencement of the study, the presence of chronic diseases and hospitalizations were statistically associated with UTI caused by carbapenem-resistant Gram-negative uropathogens. Carbapenemase producers were resistant to most of the antibiotics tested. Our findings highlight the need for periodic regional bacteriological surveillance programs to guide empirical antibiotic therapy of UTI.

Bacterial infections epidemiology and factors associated with multidrug resistance in the northern region of Ghana

Bacterial infections caused by multidrug resistant organisms are a major global threat. There is still a knowledge gap on this situation in the Northern Region of Ghana. This study determined the prevalence and resistance profile of bacterial infections. It also identified factors associated with multidrug resistance in the study area. This was a retrospective cross-sectional design and it analyzed data from the samples received at the Tamale Zonal Public Health Reference Laboratory from June 2018 to May 2022. The data were analyzed using the R software version 4.2.0. Univariate and multivariable binary logistic regression analyses were used to determine the factors associated with multidrug resistance. The samples included all specimen types possible. The specimens were collected for the purpose of clinical bacteriology diagnostics. Overall a total of 1222 isolates were obtained. The three (3) main bacteria responsible for infections were: Klebsiella spp. (27%), Moraxella spp. (22%), Escherichia spp. (16%). High resistance levels were found against the tested antibiotics and about 41.60% of the bacterial strains isolated were multidrug resistant. Hospitalization was associated with multidrug resistance in univariate (COR 1.96; 95% CI 1.43-2.71; P-value < 0.001) and multivariable analyses (AOR 1.78; 95% CI 1.28-2.49; P-value < 0.001). There is the need for further research on the molecular epidemiology of antibiotic resistance genes in the study area to effectively control the spread of multidrug resistant pathogens. In addition, efforts to build the capacity of health professionals on infection prevention and control as well as diagnostic and antimicrobial stewardship needs urgent attention.

MAP3K7 is an innate immune regulatory gene with increased expression in human and murine kidney intercalated cells following uropathogenic Escherichia coli exposure

Understanding the mechanisms responsible for the kidney's defense against ascending uropathogen is critical to devise novel treatment strategies against increasingly antibiotic resistant uropathogen. Growing body of evidence indicate Intercalated cells of the kidney as the key innate immune epithelial cells against uropathogen. The aim of this study was to find orthologous and differentially expressed bacterial defense genes in human versus murine intercalated cells. We simultaneously analyzed 84 antibacterial genes in intercalated cells enriched from mouse and human kidney samples. Intercalated cell "reporter mice" were exposed to saline versus uropathogenic Escherichia coli (UPEC) transurethrally for 1 h in vivo, and intercalated cells were flow sorted. Human kidney intercalated cells were enriched from kidney biopsy using magnetic-activated cell sorting and exposed to UPEC in vitro for 1 h. RT² antibacterial PCR array was performed. Mitogen-activated protein kinase kinase kinase 7 (MAP3K7) messenger RNA (mRNA) expression increased in intercalated cells of both humans and mice following UPEC exposure. Intercalated cell MAP3K7 protein expression was defined by immunofluorescence and confocal imaging analysis, was consistent with the increased MAP3K7 mRNA expression profiles defined by PCR. The presence of the orthologous innate immune gene MAP3K7/TAK1 suggests that it may be a key regulator of the intercalated cell antibacterial response and demands further investigation of its role in urinary tract infection pathogenesis.

The effect of anal hygiene method in prevention from recurrent lower urinary tract infections in women

Aim: To evaluate the effects stopping the use of water and hands on preventing urinary tract infections (UTI) for a group of female patients having recurrent UTIs (rUTI). Material and Method: A retrospective observational study conducted in a tertiary care hospital between February 2017 and March 2018. 273 female patients which had rUTIs without any concomitant risk factors were included. In the study, 2 or more bacteriologically documented UTIs in the last 6 months were accepted as rUTI. The groups of the study defined as using their hands, using water only and using toilet paper (using either one of these two methods and then using toilet paper). Patients were observed for an average time of 10.4 months after stopping the use of water and hands for anal cleansing after defecation. Instead they were all given toilet education and started wiping for anal hygiene. Results: There was a statistically significant relationship between previous history of UTI and washing with hands + water (p=0.021). The rate of previous UTIs were significantly higher in the group of patients using their hands for anal washing (69% vs 31%). No relation was found between previous UTI history variable for using toilet paper and flushing with water only (p>0.05). Our results showed a statistically significant decrease of UTIs after stopping the use of water and hands in the patient group who had a previous UTI history (p=0.001). Conclusion: We managed to underline that washing with hands for anal cleansing as a risk factor for rUTIs in women. Also showed the positive effect of stopping the use of water and hands for anal cleansing after defecation for prevention from rUTIs. We encourage all clinicians for further studies to investigate this issue in the future.

Novel and Structurally Diversified Bacterial DNA Gyrase Inhibitors Discovered through a Fluorescence-Based High-Throughput Screening Assay

Bacterial DNA gyrase, a type IIA DNA topoisomerase that plays an essential role in bacterial DNA replication and transcription, is a clinically validated target for discovering and developing new antibiotics. In this article, based on a supercoiling-dependent fluorescence quenching (SDFQ) method, we developed a high-throughput screening (HTS) assay to identify inhibitors targeting bacterial DNA gyrase and screened the National Institutes of Health's Molecular Libraries Small Molecule Repository library containing 370,620 compounds in which 2891 potential gyrase inhibitors have been identified. According to these screening results, we acquired 235 compounds to analyze their inhibition activities against bacterial DNA gyrase using gel- and SDFQ-based DNA gyrase inhibition assays and discovered 155 new bacterial DNA gyrase inhibitors with a wide structural diversity. Several of them have potent antibacterial activities. These newly discovered gyrase inhibitors include several DNA gyrase poisons that stabilize the gyrase-DNA cleavage complexes and provide new chemical scaffolds for the design and synthesis of bacterial DNA gyrase inhibitors that may be used to combat multidrug-resistant bacterial pathogens. Additionally, this HTS assay can be applied to screen inhibitors against other DNA topoisomerases.

UTI assessment tool for intermittent catheter users: a way to include user perspectives and enhance quality of UTI management

BACKGROUND

Urinary Tract Infections (UTIs) are among the most severe complications for users of intermittent catheterisation (IC), with numerous risk factors contributing to their occurrence. The aim of this study was to develop a tool to assess UTI risk factors among IC users in a systematic way that considers the perspective of the individual user.

METHODS

The Design Thinking Process was used to guide the development of the content and format of the tool. The UTI Risk Factors model by Kennelly et al. was used as a basis for developing the content. Insights on the appropriate content and format were collected via the Coloplast Nurse Advisory Boards and by conducting a qualitative evidence synthesis on user perspectives and practices in relation to UTIs.

RESULTS

The literature search identified a total of 3544 articles, out of which 22 met the inclusion criteria. Additionally, three rounds of meetings were conducted with approximately 90 nurses from the Nurse Advisory Boards across Europe. The qualitative evidence synthesis showed that users describe their UTI symptoms in different terms and that personal needs and priorities impact their adherence and catheter selection. Furthermore, some users lack relevant and updated knowledge about IC and UTIs. The nurses described that correct UTI diagnosis is essential. They pointed that they would assess the user's general condition, adherence, technique, and catheter type as potential areas of risk factors and emphasised the importance of adequate support for users. The study resulted in the development of the UTI assessment tool for intermittent catheter users, which comprises three elements: a guide for healthcare professionals, a dialogue board, and a notepad. The tool starts with a confirmation of the UTI incidence, and then assesses risk factors via questions on health, adherence, technique, and catheter, and concludes with a support section.

CONCLUSIONS

The UTI assessment tool for intermittent catheter users is designed to help healthcare professionals assess UTI risk factors in a systematic way, while engaging users and taking their perspective into account. By identifying the relevant risk factors, the use of this tool has the potential to reduce the occurrence of UTIs for the individual IC user.

Risk of Sepsis in Retrograde Intrarenal Surgery: A Systematic Review of the Literature

Context

Objective

Evidence acquisition

Evidence synthesis

Conclusions

Patient summary

Electro-fulguration for extensive inflammatory bladder lesions in post-menopausal women with antibiotic-recalcitrant recurrent urinary tract infections

INTRODUCTION AND HYPOTHESIS

To evaluate how women with uncomplicated antibiotic-recalcitrant recurrent urinary tract infections (RUTIs) and extensive inflammatory bladder lesions on office cystoscopy responded to electro-fulguration (EF) to eliminate these chronic bladder sites.

METHODS

After IRB approval, a retrospective study of non-neurogenic women with RUTIs, inflammatory lesions on cystoscopy, and who underwent EF was performed. Lesions were classified through a simplified staging system based on the extent of bladder wall involvement. Only those with extensive bladder wall involvement (stages 3 and 4) at the time of EF were analyzed in this report. Six months after EF, an office cystoscopy was performed, with endoscopic success defined as no lesions seen. The primary clinical outcome was number of symptomatic UTIs after EF, defined as cure (0/year), improvement (1-2/year), and failure (≥3/year).

RESULTS

From 2007 to 2019, a total of 57 women met the study criteria, 30 stage 3 and 27 stage 4. Nineteen (63%) were endoscopically successful in stage 3 and 11 (41%) in stage 4. Mean follow-up was 2.9 years (stage 3) and 3.1 years (stage 4). All had at least a 6-month UTI follow-up after the 6 months of office cystoscopy, with 15 patients cured, 37 improved, and 5 failed (all stage 4).

CONCLUSIONS

Although EF only resulted in 63% complete endoscopic resolution, the majority experienced a decrease in the frequency of UTIs, suggesting that EF can be durably effective even in women with very extensive cystitis lesions.

Antimicrobial susceptibility of bacteria isolated from urine cultures in Southern Turkey

Background

Pathogen spectrum and antibiotic susceptibility patterns vary in different regions and should consider the empirical treatment of urinary tract infections (UTIs). Information on susceptibility is the basis for providing reliable treatment. This study aimed to determine the antibiotic susceptibility of bacteria isolated from urine cultures at Çukurova State Hospital, which is located south of Turkey and east of the Mediterranean region.

Materials and methods

Urine culture results were retrospectively evaluated between April 2018 and January 2021. Variables, such as age, sex, and medical department, were also recorded. Inclusion criteria were patients aged at least 18 years with pathogenic bacterial growth in their urine cultures. Antibiotic susceptibility testing and bacterial identification were performed using the VITEK 2 automated system.

Results

Of 12,288 urine samples, 2033 (16.5%) had pathogenic growth. The rates of bacterial and yeast growth were 93.3% and 6.7%, respectively. Gram-negative pathogens constituted 91.6% of the cohort. The most prevalent bacteria were Escherichia coli with a 66% rate, followed by Klebsiella (14.2%). According to our results, ciprofloxacin, trimethoprim-sulfamethoxazole, and ampicillin are not suitable for empirical treatment of UTIs, whereas nitrofurantoin and fosfomycin are rational options.

Conclusions

Uropathogens exhibit an increased resistance rate against ampicillin, trimethoprim-sulfamethoxazole, and ciprofloxacin. Nitrofurantoin, fosfomycin, and ceftazidime have better efficacy than other investigated antibiotics in urine culture against common uropathogens and are suitable for empirical treatment of UTI.

Raw Meat Contaminated with Cephalosporin-Resistant Enterobacterales as a Potential Source of Human Home Exposure to Multidrug-Resistant Bacteria

The prevalence of cephalosporine-resistant (3GC-R) strains among United States community-related research samples ranged from 5.6 to 10.8%, while, in the European countries, it was 1.2% to 10.1%. Several studies suggest that meat of animal origin could be one of the reservoirs of 3GC-R bacteria. Here, 86 raw meat samples (turkey, pork, chicken and beef) were collected randomly and verified for the presence of 3GC-R bacteria. The 3GC-R bacteria were isolated, identified and characterized phenotypically (antibiotic resistance, motility and biofilm) and genotypically (repetitive-sequence-based rep-PCR) to elucidate any correlations with principal component analysis (PCA). From 28 3GC-R positive samples, 41 strains were isolated, from which the majority belonged to Serratia fonticola (39%), followed by Escherichia coli (19.5%), Enterobacter cloacae (17.1%) and Klebsiella pneumoniae (14.6%). The isolates of E. coli and S. fonticola presented diverse profiles in rep-PCR. Generally, 3GC-R strains were more resistant to antibiotics used in veterinary medicine than in human medicine. PCA derived from antibiotic resistance, motility and biofilm formation of S. fonticola and E. coli strains showed that resistance to beta-lactams was separated from the resistance to other antibiotic classes. Moreover, for the S. fonticola, E. coli and En. cloacae, the type of meat can create a specific tendency towards antibiotic resistance and phenotypic characteristics for S. fonticola, while these relationships were not found for other tested species.

Ucl fimbriae regulation and glycan receptor specificity contribute to gut colonisation by extra-intestinal pathogenic Escherichia coli

Extra-intestinal pathogenic Escherichia coli (ExPEC) belong to a critical priority group of antibiotic resistant pathogens. ExPEC establish gut reservoirs that seed infection of the urinary tract and bloodstream, but the mechanisms of gut colonisation remain to be properly understood. Ucl fimbriae are attachment organelles that facilitate ExPEC adherence. Here, we investigated cellular receptors for Ucl fimbriae and Ucl expression to define molecular mechanisms of Ucl-mediated ExPEC colonisation of the gut. We demonstrate differential expression of Ucl fimbriae in ExPEC sequence types associated with disseminated infection. Genome editing of strains from two common sequence types, F11 (ST127) and UTI89 (ST95), identified a single nucleotide polymorphism in the ucl promoter that changes fimbriae expression via activation by the global stress-response regulator OxyR, leading to altered gut colonisation. Structure-function analysis of the Ucl fimbriae tip-adhesin (UclD) identified high-affinity glycan receptor targets, with highest affinity for sialyllacto-N-fucopentose VI, a structure likely to be expressed on the gut epithelium. Comparison of the UclD adhesin to the homologous UcaD tip-adhesin from Proteus mirabilis revealed that although they possess a similar tertiary structure, apart from lacto-N-fucopentose VI that bound to both adhesins at low-micromolar affinity, they recognize different fucose- and glucose-containing oligosaccharides. Competitive surface plasmon resonance analysis together with co-structural investigation of UcaD in complex with monosaccharides revealed a broad-specificity glycan binding pocket shared between UcaD and UclD that could accommodate these interactions. Overall, our study describes a mechanism of adaptation that augments establishment of an ExPEC gut reservoir to seed disseminated infections, providing a pathway for the development of targeted anti-adhesion therapeutics.

ExPEC infection of the urinary tract and bloodstream is frequently seeded from an intestinal reservoir, necessitating an understanding of the mechanisms that promote gut colonisation. Here we employed molecular and structural approaches to define the regulation and function of ExPEC Ucl fimbriae as a gut colonisation factor. We describe how mutations in the non-coding regulatory region of the ucl promoter cause increased Ucl fimbriae expression and promote enhanced gut colonisation via tuned induction by a global regulator that senses oxygen stress. We further define the glycan receptor targets of Ucl fimbriae and characterise the structural features of the Ucl adhesin that facilitate these interactions. These findings explain how ExPEC can adapt to survival in the gut to seed extra-intestinal infection.

Determining risk factors for symptomatic urinary tract infection following trial of void: A retrospective analysis

Objective:

To investigate the incidence and risk factors for symptomatic urinary tract infection (UTI) following trial of void (TOV) to guide patient selection for antibiotic prophylaxis.

Methods:

A retrospective study considered all patients who underwent successful TOV across two separate 12-month periods at a tertiary hospital. Routine prophylactic antibiotics were not administered.

Results:

The 183 patients included were mostly men (91.3%) aged ⩾ 65 years (78.7%). Thirty-seven (20.3%) had recent urological surgery. The incidence of UTI following TOV was 12.6% (23/183); median duration of onset was 3 days (interquartile range = 2–9). Cystitis was most common (17/183; 9.3%), while four patients (2.2%) suffered urosepsis. There were no singular statistically significant risk factors for increasing the risk of UTI following TOV, however, ⩾ 2 risk factors showed numerically higher odds of UTI compared to ⩽ 1 risk factor (15.6% vs 4.2%; odds ratio = 4.24, 95% confidence interval = 0.96–18.80, p = 0.058). Atypical organisms resistant to most oral antibiotics were predominantly cultured, however, 89% sensitivity to ciprofloxacin was observed.

Conclusion:

The incidence of UTI following TOV was higher than anticipated. Reliable identification of at-risk patients for antibiotic prophylaxis is likely to be complicated. Further research is needed to confirm patient selection prior to confirmatory trials.

Level of evidence:

2b