Global burden of bacterial antimicrobial resistance 1990-2021: a systematic analysis with forecasts to 2050

Antibiotic De-Escalation in the Intensive Care Unit: Rationale and Potential Strategies

Antibiotic de-escalation (ADE) is important to help optimize antibiotic use and balance the positive and negative effects of antimicrobial therapy. ADE should be performed promptly, and infections should be treated with the shortest course of antimicrobials as clinically feasible to avoid unnecessary use of broad-spectrum antimicrobials. Several tools have been developed to increase efficient ADE, including rapid diagnostic tests (ex. multiplex PCR), MRSA nasal PCR/culture, and biomarkers. Multiplex PCR and MRSA nasal PCR/culture have been associated with reductions in inappropriate antibiotic use. Procalcitonin, a biomarker, has been associated with shorter antimicrobial durations in some studies; however, widespread use may be limited by lack of specificity for bacterial infections, cost, and lack of set cut-off points. Additional biomarkers such as IL-6, HMGB1, presepsin, sTREM-1, CD64, PSP, proadrenomedullin, and pentraxin-3 are currently being studied. As technology improves, additional tools may be leveraged to better optimize ADE even better, such as antimicrobial spectrum scoring tools and artificial intelligence (AI). Spectrum scores, which quantify antibiotic activity using specific numeric values, could be incorporated into electronic health records to identify patients on unnecessarily broad antibiotics. AI modeling has the potential to predict personal antibiograms or provide the probability that an empiric regimen may cover a particular infection, among other potential applications. This review will discuss the literature associated with ADE in the ICU, selected tools to help guide ADE, and perspectives on how to implement ADE into clinical practice.

Antimicrobial peptides and their application to combat implant-associated infections - opportunities and challenges

Despite minimally invasive surgeries and advancements in aseptic techniques, implant-associated infections are a significant complication in post-surgical implantation of medical devices. The standard practice of systemic antibiotic administration is often ineffective due to the development of bacterial antibiotic resistance, poor antibiotic penetration into biofilms, and low antibiotic bioavailability at the infected site. Infected implants are typically salvaged by tissue resection and antibacterial reinforcements during revision surgery. Towards this end, antimicrobial peptides (AMPs) have emerged as a promising alternative to traditional antibiotics to combat infections. Herein, a comprehensive overview of antimicrobial peptides, their structure and function, comparison with conventional antibiotics, antimicrobial properties, mechanisms of action of AMPs, and bacterial resistance to AMPs in relation to antibiotics are discussed. Furthermore, stimuli-responsive AMP delivery and contact killing via AMP coatings on implant surfaces are deliberated. We discuss various methods of AMP immobilization and coatings on implant materials through physico-chemical coating strategies. The review also addresses the clinical status and current limitations of AMP coatings such as proteolytic instability and potential cytotoxicity. Finally, we conclude with future directions to develop small, effective AMP mimetics and encapsulation of AMPs within nanocarriers to improve antimicrobial properties and design-controlled release systems for sustained antimicrobial activity.

Cutting-edge tools for unveiling the dynamics of plasmid-host interactions

The plasmid-mediated transfer of antibiotic resistance genes (ARGs) in complex microbiomes presents a significant global health challenge. This review examines recent technological advancements that have enabled us to move beyond the limitations of culture-dependent detection of conjugation and have enhanced our ability to track and understand the movement of ARGs in real-world scenarios. We critically assess the applications of single-cell sequencing, fluorescence-based techniques and advanced high-throughput chromatin conformation capture (Hi-C) approaches in elucidating plasmid-host interactions at unprecedented resolution. We also evaluate emerging techniques such as CRISPR-based phage engineering and discuss their potential for developing targeted strategies to curb ARG dissemination. Emerging data derived from these technologies have challenged our previous paradigms on plasmid-host compatibility and an awareness of an emerging uncharted realm for ARGs.

Discovery of novel seven-membered ring derivatives of ONC212 as caseinolytic protease P protein activators using the ring expansion strategy: Rational design, synthesis, and antibacterial evaluation

Caseinolytic protease P (ClpP) protein is essential for prokaryotic and eukaryotic protein homeostasis, and has emerged as a promising bactericidal target for controlling bacterial infection and evading the emergent of drug-resistance risk. As the unique bactericidal mechanism, ClpP loses its substrate specificity and undergoes uncontrolled protein hydrolysis in the presence of an activator, leading to causing bacterial death. To further expand the chemotype of ClpP activator, a series of ONC212 derivatives were synthesized using a ring expansion strategy. Surprisingly, compound A14 showed optimal antibacterial activity against Xanthomonas oryzae pv. oryzae (Xoo) in vitro (EC50 value = 3.86 μg/mL), which was >6 × more potent than the EC50 value of ONC212 (26.42 μg/mL). Molecular docking, fluorescence titration and degradation experiments of the XooFtsZ protein indicated that compound A14 was a strong degrader of XooClpP towards XooFtsZ. In vivo assays showed that the control activity of compound A14 (200 μg/mL) reached 47.47 %, compared to 41.57 %, 36.72 %, and 30.43 % for ONC212, thiodiazole copper, and bismerthiazol, respectively. Overall, this study led to the identification compound A14, which not only showed improved antibacterial potency, and maintained the binding XooClpP, but also highlighted the ring expansion strategy as a promising approach for bactericide discovery.

In vitro activity and resistance mechanisms of novel antimicrobial agents against metallo-β-lactamase producers

The carbapenemase-producing Gram-negative organisms represent an urgent clinical and public health concern, as they have been associated with increased mortality and high dissemination in healthcare settings. Although overall incidence rates of infections sustained by metallo-β-lactamase (MβL)-producers have remained lower than those sustained by other carbapenemase-producers, albeit with substantial geographic differences, a significant increase in the prevalence of MβL-producers has been observed over the last decade. The recent development of new antimicrobials expanded the armamentarium to counter the challenge of metallo-β-lactamase (MβL)-producers. Cefiderocol and aztreonam/avibactam are already clinically available and recommended by international guidelines. In addition, two new classes of β-lactam/ β-lactamase combinations are under clinical evaluation: (i) combination of β-lactam with novel boronic-derived inhibitors (e.g. taniborbactam and xeruborbactam), (ii) combination of β-lactam with last generation diazabicyclooctane β-lactamase inhibitors (e.g. zidebactam and nacubactam), active on most of serine-β-lactamases but also showing strong intrinsic activity on PBP-2. This review aims to provide up-to-date data on the characteristics, activity and emerging resistance mechanisms of the armamentarium of clinically available or soon-to-be introduced drugs for the treatment of MβL-producing Gram-negative organisms.

Anti-staphylococcal fatty acids: mode of action, bacterial resistance and implications for therapeutic application

Novel strategies to counter multidrug-resistant pathogens such as methicillin-resistant Staphylococcus aureus are urgently required. The antimicrobial properties of fatty acids (FAs) have long been recognized and offer significant promise as viable alternatives to, or potentiators of, conventional antibiotics. In this review, we examine the interplay between FAs and S. aureus, specifically detailing the underlying molecular mechanisms responsible for FA-mediated inhibition and the counteracting staphylococcal systems evolved to withstand FA onslaught. Finally, we present an update on the recent therapeutic FA applications to combat S. aureus infection, either as a monotherapy or in combination with antibiotics or host-derived antimicrobial peptides. Given the frequency of interaction between FAs and S. aureus during host colonization and infection, understanding FA mode of action and deciphering S. aureus FA resistance strategies are central in rationally designing future anti-staphylococcal FAs and FA-combination therapies.

Cost-effectiveness of maintaining an active hospital microbiology laboratory service in Timor-Leste

Background

Maintaining an active hospital microbiology laboratory allows definitive antibiotic treatment for bacterial infections to be given in a timely manner. This would be expected to improve patient outcomes and shorten length of hospital stay. However, many hospitals in low- and middle-income countries lack access to microbiology services, and the cost-effectiveness of an active microbiology service is unknown.

Methods

We constructed a decision tree model and performed a cost-effectiveness analysis to determine whether maintaining an active microbiology laboratory service would be cost-effective in Timor-Leste, a lower middle-income country. The model was informed by local microbiology data, local patient treatment costs, results of an expert elicitation exercise and data from literature reviews.

Findings

Compared with no active microbiology laboratory, average patient care costs would be reduced by $165,469 (IQR: $134,834-200,902) for every 1000 hospitalised patients with suspected bloodstream infection. Maintaining an active microbiology laboratory was estimated to reduce deaths by between 34 and 51 per 1000 hospitalised patients. Similar results were found under various one-way sensitivity analyses. Accordingly, our results indicate that there is a high probability that maintaining an active microbiology laboratory is a cost-effective intervention that would both improve patient outcomes and reduce net costs (due to reduced intensive care admissions) compared to no microbiological testing, especially for the hospitalised paediatric patients with suspected primary bacteraemia.

Interpretation

Our findings indicate that investment in the maintenance and expansion of local diagnostic capacity is likely to be cost-effective in resource-limited settings.

Funding

This project is funded by the Department of Health and Social Care (DHSC)'s Fleming Fund using UK aid.

Copper(II) enhances the antibacterial activity of nitroxoline against MRSA by promoting aerobic glycolysis

Nitroxoline (NIT) is an FDA-approved antibiotic with numerous pharmacological properties. However, the intricate connections between its metal-chelating ability and antimicrobial efficacy remain incompletely understood. The specific interactions of NIT with different metal ions were measured via UV-vis absorption spectroscopy. Here, we found that NIT can bind to various metal ions, including Cu2+, Fe2+, Zn2+ and Mn2+. However, the antimicrobial activity of NIT against methicillin-resistant Staphylococcus aureus (MRSA) was significantly enhanced by the inclusion of Cu2+ as determined by a minimal inhibitory concentration (MIC) assay in Mueller-Hinton broth. The enhanced antibacterial effect was not influenced by the availability of oxygen. Mechanistically, Cu2+ promoted bacterial proliferation, increased the bacterial transmembrane electrical potential, and increased intracellular acidification. In addition, Cu2+ rewired bacterial metabolism, promoting the uptake of glucose with a lower level of ATP production. Pharmacological upregulation of glycolysis by VLX600 could potentiate the susceptibility of MRSA to NIT. Moreover, Cu2+ also significantly increased the survival rate of acutely infected larvae. These collective results underscore that the enhanced antibacterial efficacy of NIT by Cu2+ intricately involves aerobic glycolysis in MRSA.

Incidence and prevalence of antimicrobial resistance in outpatients with cancer: a multicentre, retrospective, cohort study

BACKGROUND

Infections are the second leading cause of death in patients with cancer and are often caused by resistant bacteria. However, the frequency of antimicrobial resistance (AMR) in outpatients with cancer is not well understood. We aimed to compare the frequency of AMR bacterial pathogens in outpatients with and without cancer.

METHODS

This retrospective cohort study evaluated antimicrobial susceptibility of bacteria isolated from adults (aged ≥18 years) with and without cancer seeking care in 198 outpatient health-care settings in the USA. Data were collected using the BD Insights Research Database. Patients who were not prescribed cancer medications or not admitted to an inpatient cancer unit in the predefined period were categorised as patients without cancer. Patients were included in the cancer cohort if they received medication solely or sometimes indicated for cancer. Data on gender and race or ethnicity were not collected. Non-duplicate and non-contaminant pathogens collected from various samples (ie, blood, intra-abdominal, respiratory, urine, skin or wound, and other) in outpatients were used to assess the coprimary outcomes: overall and source-specific proportions of non-susceptible pathogen isolates with corresponding AMR odds ratios (ORs); and rates of AMR pathogens per 1000 isolates with corresponding AMR incidence rate ratio (IRR) in patients with and without cancer.

FINDINGS

Data were collected between April 1, 2018, and Dec 31, 2022. 53 006 (3·2%) of 1 655 594 pathogens identified were from 27 421 patients with cancer and 1 602 588 (96·8%) were from 928 128 patients without cancer. For Pseudomonas aeruginosa, carbapenem non-susceptibility was higher in pathogen isolates from patients with cancer (816 [14·4%] of 5683) than patients without cancer (10 709 [11·3%] 94 419; OR 1·22 [95% CI 1·13-1·32]). For Enterobacterales, fluoroquinolone non-susceptibility was higher in pathogen isolates from patients with cancer (8662 [28·0%] of 30 867) than patients without cancer (238 479 [21·8%] of 1 095 996; OR 1·44 [1·40-1·47]), as was carbapenem non-susceptibility (472 [1·5%] of 30 867 vs 9165 [0·8%] of 1 095 996; OR 1·89 [1·72-2·07]), multidrug-resistant pathogens (2672 [8·7%] of 30 867 vs 48 962 [4·5%] of 1 095 996; OR 2·03 [1·95-2·11]), and extended-spectrum β-lactamase producers (4343 [16·5%] of 26 327 vs 93 977 [9·4%] of 996 853; OR 1·96 [1·90-2·03]). For Staphylococcus aureus, meticillin resistance was higher in pathogen isolates from patients with cancer (4747 [53·0%] of 8959) than patients without cancer (129 291 [48·3%] of 267 520; OR 1·20 [1·15-1·25]). For Enterococcus spp, vancomycin resistance was higher in pathogen isolates from patients with cancer (1329 [18·6%] of 7145) than patients without cancer (12 333 [9·1%] of 135 772]; ORR 2·20 [2·06-2·34). The rates and corresponding IRRs of AMR pathogens per 1000 isolates was also higher in patients with cancer compared with patients without cancer, particularly for carbapenem non-susceptible P aeruginosa (IRR 2·06 [1·91-2·21]) and vancomycin-resistant enterococci (IRR 3·06 [2·89-3·24]). For all comparisons, p<0·0001.

INTERPRETATION

AMR proportions and IRRs for most key pathogens were up to three-times higher in isolates from outpatients with cancer than those without cancer, highlighting the need for enhanced surveillance, infection prevention, and timely diagnostic stewardship to improve antibiotic prescribing in this population.

FUNDING

AMR Action Fund.

NorA Efflux Pump Inhibitors: Expanding SAR Knowledge of Pyrazolo[4,3-c][1,2]benzothiazine 5,5-Dioxide Derivatives

Antimicrobial resistance (AMR) represents a significant global concern, driven by the overuse of antibiotics. One of the principal mechanisms contributing to AMR is the activity of microbial efflux pumps (EPs), which expel diverse antibiotics out of bacterial cells, thereby rendering them ineffective. Our research aimed to expand the range of molecular classes that inhibit the Staphylococcus aureus EP NorA. In this study, starting from the hit compound pyrazolo[4,3-c][1,2]benzothiazine 5,5-dioxide 1, previously reported as a NorA efflux pump inhibitor (EPI), we undertook medicinal chemistry efforts, which involved the iterative combination of the design and synthesis of new analogues with data obtained through ethidium bromide efflux inhibition assays. Subsequent synergistic assays with ciprofloxacin (CPX) against the resistant strain SA-1199B led to the identification of three potent compounds (3, 10, and 19). The evaluation of these compounds in combination with CPX against NorA-overexpressing and NorA-knockout strains (SA-K2378 and SA-K1902, respectively) confirmed that the observed synergy with CPX is dependent on the presence of NorA. Additionally, the combination of NorA EPIs with CPX reduced biofilm production in NorA-overexpressing strains. These findings enhance our understanding of the structure-activity relationship of pyrazolobenzothiazine derivatives and support the use of EtBr efflux assays for rapid NorA inhibitors' identification.

Drinking water plumbing systems are a hot spot for antimicrobial-resistant pathogens

BACKGROUND

Antimicrobial-resistant (AMR) pathogens in drinking water plumbing systems represent a significant yet underestimated public health threat.

METHODS

This is the first study to use qPCR and culture-based methods to investigate the prevalence of key AMR threats, meticillin resistant Staphylococcus aureus (MRSA) and carbapenem resistant Pseudomonas aeruginosa and Acinetobacter baumannii, in Australian hospital and residential drinking water and biofilm samples.

FINDINGS

Seventy-three per cent of residential water and biofilm samples were qPCR positive for at least one target pathogen compared with 38% of hospital samples, and 45% of residential plumbing fixtures harboured at least two target pathogens. Thirty-seven per cent of water and biofilm samples were qPCR positive for P. aeruginosa, 22.3% for A. baumannii and 21.7% for S. aureus. Using culture, 10% of samples were positive for P. aeruginosa, 8% for A. baumannii and 7% for S. aureus. Of these, 29% of P. aeruginosa and 28% of A. baumannii culture isolates were carbapenem resistant, and 54% of S. aureus isolates were identified as MRSA. Drain biofilms were the most common reservoir for AMR A. baumannii, S. aureus and P. aeruginosa. Carbapenem resistance genes including blaNDM-1, blaOXA-48, blaKPC-2 and blaVIM were found in biofilm samples otherwise negative for P. aeruginosa, indicating plumbing biofilms may act as eDNA reservoirs.

CONCLUSIONS

These findings underscore the critical role of plumbing biofilms as hotspots for diverse AMR pathogens, amplifying risks for vulnerable populations, particularly in home healthcare settings. This study highlights an urgent need for enhanced surveillance and targeted interventions to mitigate AMR risks in drinking water plumbing systems.

Necrotizing Soft Tissue Infections

Necrotizing soft tissue infections are a diverse group of severe infections of the skin, fascia, and musculature. These infections are characterized by the rapid and progressive destruction of soft tissue, as well as high incidence of morbidity and mortality. Prompt diagnosis, appropriate antimicrobial choice, and aggressive surgical interventions are essential in effecting a clinical cure and optimal outcomes for patients. Despite advances in medical care since necrotizing soft tissue infections were first described, the morbidity and mortality associated with them remains high. The etiology, pathophysiology, clinical presentation, diagnostic options, and treatment approach will be reviewed in this article.

Biological assessments of novel ultrasound-synthesized 2-arylbenzimidazole derivatives: antiproliferative and antibacterial effects

This paper describes ultrasound synthesis, structural characterization and biological activity of new derivatives of 2-arylbenzimidazole 12-27 and 1,2,3-triazole derivatives of 2-arylbenzimidazole 28-33. The tautomeric structures of the prepared target compounds were confirmed by 1H- and 13C-NMR spectroscopy as well as by two-dimensional NOESY, HSQC and HMBC methods. The synthesized compounds underwent in vitro antiproliferative assays, revealing that compound 23 exhibited the highest potency against chronic myeloid leukemia cells (K-562, IC50 = 2.0 μM) and non-Hodgkin's lymphoma cells (Z-138, IC50 = 2.0 μM). Compound 23 was further evaluated for cytotoxicity on normal peripheral blood mononuclear cells (PBMC), and its mechanism of action was investigated. The antibacterial properties of the synthesized compounds were assessed against both Gram-positive and Gram-negative bacterial strains. Derivatives 15-17 exhibited significant selective antibacterial activity against the Gram-positive bacterium Enterococcus faecalis (MIC = 0.25-1 μg mL-1). Additionally, among the 1,2,3-triazole derivatives of 2-arylbenzimidazole, compounds 28 and 30 demonstrated strong selective activity against Enterococcus faecalis (MIC = 0.25 μg mL-1).

Microbicidal Activity of Extract Larrea tridentata (Sessé and Moc. ex DC.) Coville on Pseudomonas syringae Van Hall and Botrytis cinerea Pers

Due to their secondary metabolite content, plant extracts are an alternative method for controlling pathogenic organisms in agriculture and post-harvest operations. Botrytis cinerea and Pseudomonas syringae are among the causative agents of diseases and losses in agricultural production. The species Larrea tridentata is abundant in the arid and semi-arid zones of Mexico and has no defined use; however, it contains secondary metabolites with microbicidal potential that could aid in biological control and enhance its harvest status. Growth inhibition (halo) of B. cinerea and P. syringae was evaluated by applying alcoholic extract of L. tridentata leaves at doses of 50, 100, 250, 500, 750, 1000, and 2000 µg mL-1 in vitro, using poisoned medium and potato dextrose agar for the fungus and the agar well method for the bacteria, in a completely randomized design with five replicates. The flavonoids quercetin, apigenin, narigenin, kaempferol, and galangin were identified as possible agents of microbicidal activity. The extract inhibited the growth of B. cinerea from 100 µg mL-1 and completely inhibited it with 1000 and 2000 µg mL-1. For P. syringae, inhibition was observed from 250 µg mL-1, demonstrating that the higher the concentration, the greater the growth inhibitory effect. The secondary metabolite content of the L. tridentata extract is sufficient to have an impact on microorganisms with economic impact in agriculture.

Association between national action and trends in antibiotic resistance: an analysis of 73 countries from 2000 to 2023

The world's governments have agreed on actions to address the challenge of antibiotic resistance. This raises the question of what level of national action is associated with improved outcomes, including both slower growth and lower levels of antibiotic resistance. Answering this question is challenged by variation in data availability and quality as well as disruptive events such as the COVID-19 pandemic. We investigate the association between level of national action and temporal trends in multiple indicators related to health system capacity, antibiotic use (ABU), absolute rates of resistance (ABR) and a Drug Resistance Index (DRI). Using the Global Database for Tracking Antimicrobial Resistance (TrACSS) to construct an index of national action, we apply cross-sectional regression across 73 countries to estimate the association between the level of action in 2016 and trends in national indicators (2000-2016). We find that national action is consistently associated with improved linear or categorical trends in all groups of indicators. Reductions are associated with a relatively high action index (range 0-4) for ABU (median 2.8, 25-75% quartile 2.6-3.3), ABR (3.0, 2.4-3.4), and DRI (3.5, 3.1-3.6). These associations are robust to the inclusion of other contextual factors related to socio-economic conditions, human population density, animal production and climate. Since 2016, a majority of both Low- and Middle-Income Countries (LMICs) and High-Income Countries (HICs) report increased action on repeated questions, while one third of countries report reduced action. The main limitations in interpretation are heterogeneity in data availability and in when actions have been implemented. Our findings highlight the importance of national action to address the domestic situation related to antibiotic resistance and indicate the value of both incremental changes in reducing adversity of outcomes and the need for high levels of action in delivering reduced levels of resistance.

Resveratrol inhibits the formation of Staphylococcus aureus biofilms by reducing PIA, eDNA release, and ROS production

Introduction

Staphylococcus aureus is a zoonotic pathogen that is difficult to control. Resveratrol (RES) has been shown to have significant antibacterial effects. The present study aimed to investigate the inhibitory effect of RES on the formation of Staphylococcus aureus biofilms and their molecular mechanism.

Methods

First, the minimum inhibitory concentration and inhibitory action curve of RES against Staphylococcus aureus were obtained through testing. Second, we found that RES can inhibit biofilm formation by reducing the release of polysaccharide intercellular adhesion (PIA) and extracellular DNA (eDNA) from Staphylococcus aureus.

Results

RES treatment significantly reduced the production of reactive oxygen species (ROS) and nicotinamide adenine dinucleotide phosphate (NADPH) in Staphylococcus aureus, indicating that ROS and NADPH are closely related to biofilm formation.

Conclusion

This study demonstrates that RES inhibits the formation of Staphylococcus aureus biofilms by reducing PIA, eDNA release, and ROS production, and these results provide new ideas for the clinical application of RES in the treatment of Staphylococcus aureus infection.

Estimated undertreatment of carbapenem-resistant Gram-negative bacterial infections in eight low-income and middle-income countries: a modelling study

BACKGROUND

Carbapenem-resistant Gram-negative (CRGN) bacterial infections are an urgent health threat, especially in low-income and middle-income countries (LMICs), where they are rarely detected and might not be treated appropriately given inadequate health system capacity. To understand this treatment gap, we estimated the total number of CRGN bacterial infections requiring an active agent and the number of individuals potentially initiated on appropriate treatment in eight large LMICs.

METHODS

For eight selected countries (Bangladesh, Brazil, Egypt, India, Kenya, Mexico, Pakistan, and South Africa), we estimated deaths associated with CRGN bacterial infections (that were not susceptible to other antibiotics) in 2019 using data from the Global Burden of Disease 2021 study on antimicrobial resistance. We used estimates from the literature to establish infection type-specific case fatality rates and an overall case fatality rate for CRGN bacterial infections. The total number of CRGN bacterial infections requiring an active agent could then be calculated by dividing the total number of CRGN bacterial infection-related deaths by the overall case fatality rate. We estimated the treatment gap (ie, the number of individuals with CRGN bacterial infections who were not appropriately treated) by subtracting from the total number of infections the number of individuals who initiated appropriate treatment, which was estimated using 2019 IQVIA sales data for six antibiotics active against CRGN bacteria, corrected to account for IQVIA's partial data coverage for each country and dose-adjusted by age.

FINDINGS

In 2019, in the eight selected countries, we estimated that there were 1 496 219 CRGN bacterial infections (95% CI 1 365 392-1 627 047) but that only 103 647 treatment courses were procured. The resulting treatment gap (1 392 572 cases [95% CI 1 261 745-1 523 400]) meant that only 6·9% of patients were treated appropriately. The treatment gap persisted even when we used more restrictive assumptions. The most-procured antibiotic was tigecycline (intravenous; 47 531 [45·9%] of 103 647 courses). India procured most of the treatment courses (83 468 [80·5%] courses), with 7·8% of infections treated appropriately (treatment gap 982 848 cases [95% CI 909 291-1 056 405]). The rates of appropriate treatment coverage were highest in Mexico (5634 [5·4%] courses procured; treatment gap 32 141 cases [30 416-33 867]) and Egypt (7572 [7·3%] courses procured; treatment gap 43 258 cases [38 742-47 774]), both with 14·9% of infections treated appropriately.

INTERPRETATION

Infections caused by CRGN bacteria are likely to be significantly undertreated in LMICs. To close this treatment gap, improved access to diagnostics and antibiotics, strengthening of health systems, and research to identify gaps in the treatment pathway are needed.

FUNDING

Global Antibiotic Research and Development Partnership, supported by the Governments of Canada, Germany, Japan, Monaco, the Netherlands, Switzerland, and the UK, and by the Canton of Geneva, the EU, the Bill & Melinda Gates Foundation, Global Health EDCTP3, GSK, the RIGHT Foundation, the South African Medical Research Council, and Wellcome.

Bacterial lectins: multifunctional tools in pathogenesis and possible drug targets

Glycans are vital macromolecules with diverse biological roles, decoded by lectins - specialized carbohydrate-binding proteins crucial in pathogenesis. The WHO identifies bacterial antimicrobial resistance (AMR) as a critical global health challenge, necessitating innovative strategies that also target non-antibiotic pathways. Recent studies highlight bacterial lectins as key players in pathogenesis and promising therapeutic targets, with early clinical success using glycomimetics and vaccines to treat and prevent AMR-related infections. This review covers the current knowledge on bacterial lectins, their classifications, and roles in host recognition and adhesion, biofilm formation, cytotoxicity, and host immune evasion, with examples of well-characterized lectins. It also explores their therapeutic potential and highlights novel lectins with unknown functions, encouraging further research.

Epidemiology of clinical antimicrobial-resistant Enterobacterales in Togo over three decades: a systematic review and meta-analysis, with recommendations and alternative solutions

BACKGROUND

According to the World Health Organization (WHO), surveillance programs have become essential at national, regional, and global levels to adjust empirical treatments and target interventions to prevent and control the emergence of antimicrobial resistance (AMR). Therefore, this study aimed to conduct the first systematic review and meta-analysis of clinical Enterobacterales resistance to 11 representative antimicrobials from the WHO AWaRe (Access, Watch, Reserve) list, and to provide recommendations to tackle AMR more efficiently in Togo.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (The PRISMA 2020) were used to conduct this study and the protocol was registered with PROSPERO (CRD42024606897). Keywords were used to conduct a systematic literature review of electronic databases. Data analysis was conducted using Stata software version 17.0.

RESULTS

Twenty research articles reporting 9,327 clinical Enterobacterales isolates obtained from 1991 to 2020 were included in this review and were mainly Escherichia coli (6,639; 71.2%), and Klebsiella spp. (2,542; 27.3%), mainly isolated from urine (14 studies; 70%), and pus/wounds (12; 60%). The pooled Enterobacterales resistance rates ranged from 1% (95% CI: 0, 2) imipenem, 3% (95% CI: 1, 5) amikacin, 4% (95% CI: 2, 7) fosfomycin, 50% (95% CI: 40, 60) chloramphenicol, 55% (95% CI: 45, 64) gentamicin, 68% (95% CI: 59, 76) ciprofloxacin, 73% (95% CI: 66, 80) amoxicillin/clavulanic acid (AMC), 79% (95% CI: 71, 86) third-generation cephalosporins (3GC), to 90% (95% CI: 86, 93) sulfamethoxazole/trimethoprim (SXT). The most significant upward trend over 30 years was reported for SXT (R2 = 73.24%, p < 0.001), ciprofloxacin (R2 = 61.44%, p < 0.001), and 3GC (R2 = 18.49%, p < 0.001). Klebsiella spp. strains were significantly more resistant to chloramphenicol (p = 0.03) than E. coli isolates, whereas E. coli isolates were significantly more resistant to amikacin (p = 0.04) than Klebsiella spp. isolates.

CONCLUSION

This study revealed high first-line AMR rates with drastic upward trends in clinical Enterobacterales isolated in Togo over the past 30 years. Thus, the adjustment of empirical antimicrobial treatments in Togo becomes crucial. Moreover, the implementation of prevention policies, whole-genome sequencing approaches, and the promotion of antibiotic stewardship must be enhanced. Finally, alternative therapeutic approaches, such as phytotherapy and phage therapy, were discussed.

CLINICAL TRIAL

Not applicable.

Accelerated detection of carbapenem resistance in Klebsiella pneumoniae via single-cell Raman spectroscopy

Antibiotic resistance poses a significant global public health challenge, particularly concerning carbapenem-resistant Klebsiella pneumoniae (CRKP). A Raman-based antimicrobial susceptibility testing (R-AST) method was developed, utilizing D₂O-labeled single-cell Raman spectroscopy alongside the Metabolic Inhibition Level (MIL) for rapid CRKP antimicrobial susceptibility testing and carbapenemase enzyme typing. By analyzing 30,000 single-cell Raman spectra from 57 K. pneumoniae strains, the R-AST accurately detected CRKP within two hours. Furthermore, R-AST was able to differentiate between amikacin-sensitive and amikacin-resistant strains within the CRKP category, thereby providing potential treatment options. Notably, both R-AST classifications demonstrated 100% category agreement with the Vitek®-2 Compact system. The R-AST demonstrated greater accuracy in distinguishing carbapenemase types compared to the carbapenemase inhibitor enhancement test in K. pneumoniae, achieving an overall accuracy of 95.74% (95% CI: 85.46-98.77%) in enzyme typing. However, it misclassified 2 out of 21 KPC-producing CRKP strains as KPC and NDM-coproducing CRKP strains. Conversely, the overall accuracy of the carbapenemase inhibitor enhancement test was 93.62% (95% CI: 82.69-97.66%), with 3 out of 9 KPC and NDM-coproducing strains being missed. By delivering reliable results within 2 h, the R-AST provides an efficient, dependable, and broadly applicable approach to rapid antimicrobial susceptibility testing in clinical settings, potentially mitigating antibiotic misuse and the spread of drug-resistant bacteria.

Prevalence, Antimicrobial Resistance, and Virulence Potential of Staphylococcus aureus in Donkeys from Nigeria

BACKGROUND

Animal-associated antimicrobial-resistant staphylococci pose a One Health concern, as they can spread into the environment and cause serious infections. Yet, donkeys in Nigeria have been largely overlooked as potential reservoirs of these pathogens.

AIM/OBJECTIVES

To isolate Staphylococcus aureus from donkeys in Obollo-Afor, southeast Nigeria, assess their antimicrobial resistance profiles, and evaluate their virulence potential.

MATERIALS AND METHODS

Staphylococci were isolated from the nasal swabs of 250 donkeys, using mannitol salt agar, confirmed biochemically, with Staphylococcus aureus identified via a latex agglutination test and mass spectrometry. The resistance profiles of the isolates, including in regard to methicillin, inducible clindamycin, and β-lactamase production, were determined using disc diffusion, while vancomycin resistance was assessed through the use of agar dilution. The virulence factors were evaluated phenotypically.

RESULTS

Of the 250 samples, 11 (4.4%) contained S. aureus and 239 (95.6%) grew other Staphylococcus species. The resistance rates of the 11 S. aureus isolates to gentamicin, penicillin, tigecycline, cefoxitin, linezolid, and chloramphenicol were 45.5%, 66.7%, 54.5%, 27.3%, 36.4%, and 18.1%, respectively. The phenotypic methicillin-resistant S. aureus prevalence was 1.2%. Additionally, 23.5% of the S. aureus isolates were multidrug resistant, with a mean antibiotic resistance index of 0.25. All the S. aureus isolates exhibited virulence factors like clumping factor expression, catalase, caseinase, lecithinase, and gelatinase activity, while the occurrence of haemagglutinin, biofilm, pellicle, and hemolysin occurred in 27.3%, 54.5%, 36.4%, 72.2%, respectively.

CONCLUSION

Although a small percentage of donkeys in Nigeria may harbor S. aureus, these animals are potentially spreading antimicrobial resistance, including multidrug and methicillin resistance, to humans and the environment.

A self-assembled and H2O2-activatable hybrid nanoprodrug for lung infection and wound healing therapy

Background: The pursuit of effective antibacterial strategies aimed at mitigating pathogenic bacterial infections while minimising drug resistance remains of paramount importance. A combinational therapeutic strategy that integrates distinct treatment components can enhance overall efficacy and mitigate undesired effects, thereby exhibiting considerable promise in combating bacterial infections. Methods: In this study, a meticulously engineered self-assembling hybrid nanoprodrug (CPBP NPs) has been devised, functioning as a hybrid prodrug of Ciprofloxacin (Cip) and hydroxybenzyl alcohol (HBA). Results: CPBP molecules can generate nanoassemblies via self-assembly and subsequently undergo decomposition to synchronously release Cip and HBA upon hydrogen peroxide (H2O2) exposure. The CPBP NPs exert antibacterial and anti-inflammatory properties through the controlled release of Cip and HBA, while also facilitating the scavenging of reactive oxygen species. These CPBP NPs exhibit broad-spectrum antibacterial activity against both Gram-negative bacteria (E. coli, 98.4%) and Gram-positive bacteria (S. aureus, 98.5%). Notably, CPBP NPs not only accumulate in the lungs to facilitate organ-specific infection treatment but also expedite the healing process of infected wounds. Conclusions: Consequently, this H2O2-activatable hybrid nanoprodrug, possessing excellent biocompatibility, holds substantial promise for advancing clinical applications in managing bacterial infections.

Beyond clinical genomics: addressing critical gaps in One Health AMR surveillance

Antimicrobial resistance (AMR) poses an escalating global threat that demands comprehensive surveillance approaches beyond traditional clinical contexts. Although next-generation sequencing (NGS), particularly whole-genome sequencing (WGS), has revolutionized AMR surveillance, current implementation predominantly targets clinical isolates, largely neglecting critical environmental and animal reservoirs. Consequently, significant gaps persist in our understanding of AMR dynamics across diverse ecosystems. This Perspective emphasizes the urgent need to adopt an integrated genomic framework, combining isolate-based WGS with shotgun metagenomics within a cohesive One Health strategy. Such an integrated approach would significantly enhance the detection, tracking, and containment of resistance determinants, facilitating proactive rather than reactive AMR management. Achieving this vision requires global standardization of sequencing methods, harmonization of bioinformatics pipelines, and strengthened cross-sectoral collaboration to ensure timely interventions against AMR threats worldwide.

Factors influencing the frequency, knowledge, attitudes and practices of antibiotic use in commercial layer chicken farms, Tanzania

Introduction

Indiscriminate use of veterinary antibiotics significantly contributes to the current antibiotic resistance in the world. The primary objective of this study was to explore the factors that could influence knowledge, attitudes and practices of antibiotic use in commercial layer farms.

Methods

A cross-sectional study was conducted to evaluate antibiotic use patterns and their associated factors among layer chicken farmers in Tanzania. The study surveyed 205 farmers randomly selected from three regions: Unguja, Morogoro, and Dar es Salaam. Data were analysed using descriptive statistics, while negative binomial and multiple linear regression models were employed to identify factors influencing antibiotic usage patterns.

Results

A widespread use of antibiotics was revealed, with 97.1% of farmers using antibiotics for treatment, prophylaxis and/or increasing egg productivity. The most commonly used antibiotics were oxytetracycline (63%), doxycline-tylosin combination (29.8%) and enrofloxacin (22.4%). Notably, 95.6% of farmers reported that they do not observe withdrawal periods. Assessment of farmers' knowledge, attitudes, and practices yielded mean scores of 55.5%, 69.1% and 50.9% respectively. Furthermore, older adults and individuals with primary education were more likely to have higher attitude scores. Geographic location and flock size are among other factors that are likely to influence knowledge and attitudes towards antibiotic use. Higher frequency of antibiotic use was significantly associated with young adults, medium-scale farm operators, and farmers in Morogoro region (compared to the other two regions).

Conclusion

The frequency, knowledge, attitude and practices related to the use of antibiotics were affected by scale of production, location, age, and education. These findings provide insights into antibiotic stewardship among layer farmers that could suggest future multifaceted interventions to promote prudent use of antibiotics, hence mitigating risk of antibiotic resistance.

Standardizing multidrug resistance definitions and visualizations to support surveillance across One Health

OBJECTIVE

This study aimed to understand the current use of visualizations for multidrug resistance (MDR) data across the One Health spectrum and the visualization preferences and definitions of MDR used by antimicrobial resistance experts, with emphasis on the animal health sector of One Health, which lacks standardized MDR definitions.

METHODS

A rapid scoping review was conducted to synthesize current approaches to visualize MDR. Six databases and grey literature were searched with antimicrobial, resistance, surveillance, and figure or dashboard terms. An active machine learning model was used for the initial screening of references. An online survey was distributed to self-identified antimicrobial resistance experts, including questions about respondents' country of employment, job position, definitions of MDR, and preferences for MDR metrics and visualizations.

RESULTS

Bar charts, visual antibiograms, heat maps, and network graphs were the most common visualizations employed in peer-reviewed publications, websites, and reports. Survey respondents preferred simplistic visualizations, such as line graphs and heat maps. Respondents used a variety of MDR definitions, although resistance to three or more antimicrobial categories was the most common. Some respondents advocated for the exclusion of intrinsic resistance in the definition, while others argued for its inclusion.

CONCLUSIONS

Despite historic proposals for standardizing international definitions of MDR, a lack of consensus remains. Respondents also expressed different preferences for MDR visualizations. Some visualizations currently in use, such as network graphs, are complex and may be challenging to interpret. Harmonization of MDR definitions and optimization of visualizations are essential to facilitate comparisons across populations and studies.

Changing climate and socioeconomic factors contribute to global antimicrobial resistance

Climate change poses substantial challenges in containing antimicrobial resistance (AMR) from a One Health perspective. Using 4,502 AMR surveillance records involving 32 million tested isolates from 101 countries (1999-2022), we analyzed the impact of socioeconomic and environmental factors on AMR. We also established forecast models based on several scenarios, considering antimicrobial consumption reduction, sustainable development initiatives and different shared socioeconomic pathways under climate change. Our findings reveal growing AMR disparities between high-income countries and low- and middle-income countries under different shared socioeconomic pathway scenarios. By 2050, compared with the baseline, sustainable development efforts showed the most prominent effect by reducing AMR prevalence by 5.1% (95% confidence interval (CI): 0.0-26.6%), surpassing the effect of antimicrobial consumption reduction. Key contributors include reducing out-of-pocket health expenses (3.6% (95% CI: -0.5 to 21.4%)); comprehensive immunization coverage (1.2% (95% CI: -0.1% to 8.2%)); adequate health investments (0.2% (95% CI: 0.0-2.4%)) and universal access to water, sanitation and hygiene services (0.1% (95% CI: 0.0-0.4%)). These findings highlight the importance of sustainable development strategies as the most effective approach to help low- and middle-income countries address the dual challenges of climate change and AMR.

Anti-Staphylococcus aureus Activity and Structural Characterization of Rationally Designed Peptides

Background/Objectives: Microbial infections represent a significant threat to public health due to the emergence and spread of antimicrobial resistance. Adjunctive and alternative therapeutic strategies are explored to tackle this issue, including the use of natural or synthetic antimicrobial peptides. Previous research showed that antibody-derived peptides possess antimicrobial, antiviral, and immunomodulatory properties. This study aimed to characterize newly designed antibody-derived peptides and evaluate their effectiveness against representative strains of Staphylococcus aureus, including drug-resistant isolates. Methods: Colony-forming unit assays and confocal microscopy studies were performed to evaluate peptide activity against planktonic microbial cells. Cytotoxicity tests were performed on THP-1 human monocytic cells. Circular dichroism (CD) and nuclear magnetic resonance (NMR) were employed for the conformational characterization of peptides. Results: The half-maximal effective concentrations of the peptides against bacterial reference strains and drug-resistant isolates ranged from 0.17 to 18.05 µM, while cytotoxic effects were not observed against mammalian cells. A killing kinetics analysis and observation by confocal microscopy of the interaction between peptides and bacteria suggested a mechanism of action involving membrane perturbation. CD studies showed that all peptides predominantly exhibit a random coil arrangement in aqueous solution. NMR spectroscopy revealed that the most active peptide adopts a helical conformation in the presence of membrane mimetics. Conclusions: The structural characterization and evaluation of the newly designed peptides' antimicrobial activity may lead to the selection of a candidate to be further studied to develop an alternative treatment against microbial infections caused by drug-resistant strains.

Revitalizing the ICPD Programme of Action on the International Development Agenda: Toward a Path Forward for Reproductive Health and Rights in Troubled Times

Since the 1994 International Conference on Population and Development (ICPD), there have been notable improvements in reproductive health and rights. However, these overall gains obscure deep inequalities, and recent setbacks during and after the COVID-19 pandemic highlight the fragility of this progress. The reproductive health agenda is extensive yet remains underfunded and underperforming. Careful thought is needed on how to retain reproductive health and rights as a priority in the global development framework that will replace the Sustainable Development Goals in 2030. This paper examines the evolution of reproductive health, drawing lessons and recommendations for revitalizing and future-proofing its agenda and enhancing progress. Key recommendations include encouraging bolder thinking in research engaging with the field's multiple challenges, including nontechnical aspects; improving dissemination and utilization of policy-relevant research; presenting a stronger business case to influence policymakers; and employing broader, inclusive rights-based arguments that emphasize social justice and equity. Additionally, reevaluating the global reproductive health architecture is necessary, particularly the influential yet inconsistent role of the USA. Relevant lessons from maternal and child health and HIV efforts are distilled to further assist in this process of developing a more effective path forward, ensuring the ICPD's vision is achieved beyond 2030.

Chemical Proteomics Reveals Human Off-Targets of Fluoroquinolone Induced Mitochondrial Toxicity

Fluoroquinolones (FQs) are an important class of potent broad-spectrum antibiotics. However, their general use is more and more limited by adverse side effects. While general mechanisms for the fluoroquinolone-associated disability (FQAD) have been identified, the underlying molecular targets of toxicity remain elusive. In this study, focusing on the most commonly prescribed FQs Ciprofloxacin and Levofloxacin, whole proteome analyses revealed prominent mitochondrial dysfunction in human cells, specifically of the complexes I and IV of the electron transport chain (ETC). Furthermore, global untargeted chemo-proteomic methodologies such as photo-affinity profiling with FQ-derived probes, as well as derivatization-free thermal proteome profiling, were applied to elucidate human protein off-targets of FQs in living cells. Accordingly, the interactions of FQs with mitochondrial AIFM1 and IDH2 have been identified and biochemically validated for their contribution to mitochondrial dysfunction. Of note, the FQ induced ETC dysfunction via AIFM1 activates the reverse carboxylation pathway of IDH2 for rescue, however, its simultaneous inhibition further enhances mitochondrial toxicity. This off-target discovery study provides unique insights into FQ toxicity enabling the utilization of identified molecular principles for the design of a safer FQ generation.

Adaptation and validation of the scale for the prevention and control of healthcare-associated infections among nursing students: an exploratory factor analysis approach

This study aimed to adapt and validate the HAInnovPrev scale, a tool for assessing the prevention and control of healthcare-associated infections (HAIs) among nursing students. HAIs are a significant global health concern, particularly in healthcare education, where student training and institutional protocols must align to prevent infections effectively. The development process employed a quantitative approach, utilizing exploratory factor analysis (EFA) on data collected from 347 nursing students across two universities in Peru. This method refined the instrument, reducing the original 15 dimensions to 11 well-defined factors, encompassing key aspects such as institutional compliance, personal motivation, emotional exhaustion, and adherence to hygiene protocols. The results demonstrated that the instrument's 11-dimensional structure was statistically valid, with measures such as the Kaiser-Meyer-Olkin (KMO) test and Bartlett's sphericity indicating suitability for factor analysis. Internal consistency reliability, evaluated through omega coefficients, showed strong reliability for most dimensions (ω > 0.70). The findings suggest that the HAInnovPrev scale is a valid and reliable tool to assess critical areas of knowledge, attitudes, and practices regarding HAI prevention among nursing students. Streamlining the scale from 15 to 11 dimensions improves its practical applicability and clarity, focusing on the most relevant factors influencing students' adherence to infection control practices. Future research should broaden the sample and include observational measures to validate these findings further.

Plasma-Activated Water Against Carbapenem-Resistant Klebsiella pneumoniae and Vancomycin-Resistant Enterococcus faecalis

The scope of the antibacterial effects of plasma-activated water (PAW) is not yet fully comprehended. We investigated the activity of PAW produced by the in-house 3-pin atmospheric pressure plasma jet against carbapenem-resistant Klebsiella pneumoniae and vancomycin-resistant Enterococcus faecalis, with a focus on PAW's potential to promote susceptibility to conventional antibiotics in these bacteria. Bacterial inactivation was determined by the colony count after 15 and 60 min PAW treatments. Minimum inhibitory concentrations (MICs) measured following repeated exposures to PAW across multiple generations of bacteria enabled the assessment of changes in susceptibility to antibiotics. The PAW's efficacy was also analyzed through the detection of intracellular reactive oxygen and nitrogen species in treated bacteria. Time-dependent significant inactivation efficiency against K. pneumoniae was observed (log reduction 6.92 ± 0.24 after 60 min exposure), while effects on E. faecalis were limited. PAW demonstrated potential to decrease the MICs of crucial antibiotics. Namely, a 50 to 62.5% decrease in the MICs of colistin against K. pneumoniae and a 25% reduction in the MICs of vancomycin against enterococci were recorded. We found a significant increase in the superoxide anion concentration in K. pneumoniae and E. faecalis cells after PAW treatments. This study indicates that PAW's inactivating efficacy coupled with the capacity for the potentiation of antibiotic effects is a promising combination against multidrug-resistant bacteria.

A Systematic Literature Review of the Epidemiology of Complicated Urinary Tract Infection

INTRODUCTION

Urinary tract infections (UTIs) are common bacterial infections and present with heterogeneous clinical phenotypes. Whereas many uncomplicated UTIs resolve spontaneously or with antibiotic treatment, a complicated UTI (cUTI) presents with greater morbidity and a higher risk of treatment failures. The goal of this study was to estimate the real-world epidemiology of cUTI, including acute pyelonephritis (AP) and catheter-associated UTIs (CAUTIs), and its associated mortality internationally.

METHODS

A systematic literature search was conducted using PubMed, Embase, Cochrane, and EconLit databases for relevant articles published between July 2013 and July 2023 covering Europe and the following countries: France, Italy, Germany, Spain, the UK, China, Japan, and the US (US). Search terms relating to cUTI, AP, CAUTI, outcomes of interest (epidemiology), and real-world research designs were used. There were no language limitations (protocol registry: PROSPERO-CRD42023454794).

RESULTS

Database searches yielded 1014 unique records, of which 91 met the prespecified inclusion criteria; bibliography and conference abstract searches yielded 27 additional records for a total of 118 records for inclusion. Disease presentation and reported outcomes varied widely across studies, and most studies reporting incidence and prevalence of cUTI were from the US (21 of 29). No studies reporting incidence or prevalence rates of cUTI in China, Germany, or the UK were identified. Overall, high antibiotic resistance rates were reported in both inpatient and outpatient settings. The inpatient cohort mortality rates were highly variable (0-50%) depending on the patient population.

CONCLUSIONS

While disease presentation and reported outcomes varied widely across studies, cUTIs represent a considerable burden in terms of incidence, prevalence, drug resistance, and mortality, yet vast knowledge gaps remain in the literature. There is a crucial need to address these gaps to effectively evaluate new treatments and improve future analyses of cUTI burden and outcomes.

Comparative analysis of virulence-associated genes in ESBL-producing Escherichia coli isolates from bloodstream and urinary tract infections

The prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) is a global health concern due to the multidrug antimicrobial resistance in extraintestinal pathogenic E. coli (ExPEC). ExPEC causes severe infections such as bloodstream infections, meningitis, and sepsis. Uropathogenic E. coli (UPEC), a subset of ExPEC, is responsible for urinary tract infections (UTIs), ranging from asymptomatic bacteriuria and cystitis to more severe conditions, such as pyelonephritis, bacteremia, and sepsis (urosepsis). Although ESBL-producing E. coli may have a significant impact on patient outcomes, comparisons of genotype and virulence factors between ESBL-producing and non-ESBL-producing E. coli have not fully elucidated the factors influencing its pathogenicity. Therefore, in the present study, we analyzed the genotypes and virulence-associated genes of ESBL-producing strains isolated from the blood of patients with UTIs to determine the characteristics of ESBL-producing UPEC strains associated with severe infections. Most of the clinical isolates belonged to phylogroup B2, with the exception of three strains from phylogroup D. The MLST was ST131, followed by ST73, ST95, and ST38, which are commonly found in UPEC strains. Intriguingly, ST131 strains were associated with fewer sepsis cases compared to non-ST131 strains (8 of 38 cases by ST131 and 5 of 8 cases by non-ST131 [OR, 0.16; 95% CI, 0.038-0.873; p = 0.031]). In silico analysis of 23 clinical isolates revealed that the genes detected in all strains may play a significant role in the pathogenesis of invasive UTIs. Clustering and gene locus analysis highlighted the genotype-MLST dependence of UPEC-specific virulence-associated genes. ST38-specific strains were atypical, characterized by the absence of several UPEC-specific genes, including pap loci, pathogenicity island marker (malX), and ompT, as well as the presence of genes encoding Ycb fimbriae and a Type 3 secretion system, which are typically found in enteropathogenic E. coli (EPEC). These results suggest that the virulence of clinical isolates causing invasive infections can vary, and that the pathogenicity of UPEC should be considered when analyzing the correlation between MLST and the repertoire of virulence-associated genes.

Application of [99mTc]Tc-GSA in the diagnosis of Staphylococcus aureus infections

INTRODUCTION

Staphylococcus aureus can cause a variety of conditions such as bacteremia, sepsis, toxic shock syndrome, pneumonia, and infective endocarditis; therefore, a rapid and accurate diagnosis should be made to pinpoint the site of infection. This study aimed to use the existing nuclear medicine tracer [99mTc]Tc-dimercaptosuccinic acid galactosyl human serum albumin ([99mTc]Tc-GSA) as a simple technique for the early diagnosis of S. aureus infection.

METHODS

The in vitro studies evaluated the accumulation of [99mTc]Tc-GSA in S. aureus. In addition, the effect of metabolic and vital activity and inhibition of asialoglycoprotein receptors on [99mTc]Tc-GSA accumulation were evaluated. In vivo studies were performed on the biodistribution and imaging of [99mTc]Tc-GSA in the S. aureus SR3637 mouse thigh infection model.

RESULTS

In vitro studies have confirmed that [99mTc]Tc-GSA accumulates to the same extent as 2-deoxy-2-[18F]fluoro-d-glucose, and it was thought that [99mTc]Tc-GSA binds to the receptors that recognize the saccharide molecules and glycan chains expressed in S. aureus. In addition, in the distribution and imaging of [99mTc]Tc-GSA, it was confirmed that the latter accumulates at the infection site and shows a clear contrast with the non-infected site.

CONCLUSION

The application of [99mTc]Tc-GSA to the imaging diagnosis of S. aureus infection is expected to non-invasively detect the localization of S. aureus in real time, pinpoint the site of infection and determine the number of viable bacteria, and help in the selection of optimal therapeutic agents and treatments.

Molecular Differentiation and Detection of AMR Genes from Nosocomial Staphylococcus spp

Staphylococcus spp. is a major nosocomial pathogen, particularly affecting immunocompromised patients and infants. It is associated with bacteremia, endocarditis, and co-infections. Methicillin-resistant Staphylococci (MRS) carry the mecA gene, encoding PBP2a, which confers resistance to beta-lactam antibiotics. The aim of this study is to investigate resistance profiles and develop a molecular method to identify nosocomial Staphylococcus spp. strains. A total of 64 strains from public hospitals in Rio de Janeiro were analyzed using phenotypic and molecular methods, with 17 classified as MDR. Different melting temperatures (Tm) were obtained through qPCR-HRM analysis, to identify S. aureus- (70.4 °C), S. haemolyticus- (79 °C), S. epidermidis- (74.1 °C) and mecA (70.5 °C)-positive strains (MRS). The mecA gene was detected in 51 strains, with 22 showing SCCmec type IV. The spread of MRSA and MDR Staphylococci, particularly MDR S. haemolyticus, is a growing concern. In our study, among 64 Staphylococci strains, only 11 were susceptible to methicillin, showing the continuous emergence of resistant strains. qPCR-HRM is a cost-effective, sensitive and fast method for rapid Staphylococcus spp. identification, aiding in nosocomial infection control.

Off-label use of intravenous rifampicin during surgery: analysis of Australian surveillance data and retrospective audit at a tertiary hospital

Objective

To investigate the use of rifampicin vials in Australian operating theaters (OT) to determine the method of administration and rationale for use.

Methods

Retrospective (2022 and 2023) OT usage data for rifampicin 600 mg vials were analyzed to compare trends in use between Australian hospitals and between jurisdictions. An audit of rifampicin vials used in OT during 2023 was conducted at a large tertiary hospital.

Results

Fifty-nine of 248 hospitals (24%) contributing data to the National Antimicrobial Utilisation Surveillance Program recorded OT use of rifampicin vials during 2022 and 2023. Excluding hospitals with no usage, the median use was 7 vials/annum/per hospital (IQR: 2-32). A wide variation in use was seen between Australian states and territories. An audit of OT use in 2023 at a large tertiary hospital found poor documentation of topical use; in most cases, documentation was in the operation note only, with no documentation on the medication charts, medical notes, or the anesthetic record. Of 33 rifampicin vials used in 2023, documented topical use was identified for 10 individual patients only, 4 of whom had a confirmed Staphylococcus aureus infection (1 methicillin-resistant and 3 methicillin-susceptible).

Conclusion

Off-label, topical use of rifampicin during surgery is not uncommon in some Australian hospitals despite limited evidence of safety or efficacy. Given the potential for resistance, surgical use of rifampicin should be restricted to a named-patient basis, under the guidance of an infectious disease specialist/clinical microbiologist. Documentation of all medication use is recommended for patient safety.

Research and predictive analysis of the disease burden of bloodstream infectious diseases in China

BACKGROUND

Bloodstream Infection(BSI) are one of the leading causes of infection-related mortality worldwide. However, epidemiological data related to BSI in China remain very limited.

METHODS

Based on the Global Burden of Disease(GBD) database, a systematic analysis was conducted on the epidemic trends, pathogen spectrum, and the current status of Antimicrobial Resistance(AMR) related to BSI in China for the year 2021. Additionally, an Autoregressive Integrated Moving Average(ARIMA) time series model was constructed to predict the trend of the disease burden associated with BSI in China from 2022 to 2035.

RESULTS

In terms of pathogens, the top five pathogens causing deaths due to BSI in China are as follows: Staphylococcus aureus, Escherichia coli, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. There are significant differences in the pathogens causing BSI across different age groups. The disease burden is heaviest in the elderly population aged 70 and above. Among children under five years old, Staphylococcus aureus, Streptococcus pneumoniae, and Candida species are predominant. From 1990 to 2021, although there has been a gradual decline in mortality rates due to BSI across different age groups (with an approximately 52.4% reduction in age-standardized rates), the disease burden of BSI increases with age. This is especially evident in the population aged 70 and above, where the burden of disease is significantly higher than in other age groups. For instance, in 2021, the mortality rate for individuals aged 70-74 was 149.29 (per 100 K), while for those aged 95 and older, the mortality rate reached as high as 896.71 (per 100 K). On a global scale, the disease burden caused by BSI in China is at a moderate level. According to time series model projections, the mortality burden of BSI in China shows a complex trend toward 2035: the crude mortality rate across all age groups is expected to increase by approximately 14.26%, whereas the age-standardized mortality rate and Disability-Adjusted Life Years(DALYs) are projected to decrease significantly. Notably, the mortality burden is expected to decline most prominently in the 70 + and under 5 age groups, while the 25-44 age group is projected to see minimal change. Conversely, the mortality rates for the 5-49 age group are anticipated to increase slightly.

CONCLUSION

Staphylococcus aureus and Escherichia coli are key pathogens contributing to the high mortality burden of BSI. Additionally, the heavy burden associated with AMR poses significant challenges to clinical treatment. From 1990 to 2021, the age-standardized mortality rate mortality of BSI patients is gradually decreasing, and the change in BSI mortality will be mainly affected by the changes in population size and age structure. The forecast analysis for 2022-2035 finds that the death burden of the elderly will be the heaviest, and the mortality of people aged 5-49 years will increase slightly. BSI and its related health problems are still major challenges and need continuous attention.

CLINICAL TRIAL

Inapplicability.

Bacterial abundance and antimicrobial resistance prevalence carried by adult house flies (Diptera: Muscidae) at Kansas dairy and beef cattle operations

House flies (Musca domestica L.) are filth-breeding pests of urban and rural environments around the world. Frequenting microbe-rich substrates for nutritional and reproductive needs, house flies pose a risk to human and animal health through their carriage and transmission of pathogenic and antimicrobial resistant bacteria (AMR). Adult house flies were collected from Kansas beef and dairy cattle operations to assess factors influencing bacterial abundance and AMR incidence flies. Aerobic culturable bacteria and suspected coliforms (SC) were enumerated from fly homogenate cultured on nonselective (tryptic soy agar) and selective (violet-red bile agar VRBA) media, respectively. Unique morphotypes of SC isolates were screened for tetracycline resistance and tested for resistance to 4 additional antibiotics to identify multi-drug resistant (MDR) isolates. Female house flies carried greater abundances of both culturable bacteria and SC than male flies. Abiotic factors such as ambient and soil temperatures correlated with culturable bacteria and SC abundances in flies, but farm type correlated only with SC abundance and trends of resistance phenotypes observed in SC isolates. Male and female flies from both farm types carried one or more AMR and MDR SC isolates (73.02% AMR and 31.09% MDR). The majority of AMR and MDR bacteria were Escherichia/Shigella sp., which possessed the widest range of phenotypic resistance variability found in our study. Our results further emphasize the role house flies play in harboring bacteria of risk to human and animal health and identified factors of potential use for the development of strategies to mitigate house fly transmission of bacterial pathogens and AMR within confined cattle operations.

Development of antibiotic resistome in premature infants

Preterm birth is a major concern in neonatal care, significantly impacting infant survival and long-term health. The gut microbiome, essential for infant development, often becomes imbalanced in preterm infants, making it crucial to understand the effects of antibiotics on its development. Our study analyzed weekly, 6-month, and 1-year stool samples from 100 preterm infants, correlating clinical data on antibiotic use and feeding patterns. Comparing infants who received no antibiotics with those given empirical post-birth treatment, we observed notable alterations in the gut microbiome's composition and an increase in antibiotic resistance gene abundance early in life. Although these effects diminished over time, their long-term clinical impacts remain unclear. Human milk feeding was associated with beneficial microbiota like Actinobacteriota and reduced antibiotic resistance genes, underscoring its protective role. This highlights the importance of judicious antibiotic use and promoting human milk to foster a healthy gut microbiome in preterm infants.

Bimetallic Metal-Organic Framework Microneedle Array for Wound Healing through Targeted Reactive Oxygen Species Generation and Electron Transfer Disruption

The development of reactive oxygen species (ROS)-based antibacterial strategies that overcome ROS's ultrashort diffusion distance and disrupt bacterial electron transfer represents a promising yet underexplored avenue for nonantibiotic therapies. In this study, we introduce an iron-copper bimetallic metal-organic framework (MOF) with peroxidase (POD)-like enzymatic activity engineered to integrate dual functionalities: bactericidal recognition and electron transfer disruption to synergistically enhance antibacterial efficacy. Mechanistic investigations reveal that boronic-acid-cis-diol interactions enable the MOF to selectively bind to bacterial membranes, where it generates localized ROS, effectively killing bacteria. Concurrently, the alignment of MOF energy levels with the bacterial redox potential facilitates efficient electron transfer from the bacterial membrane to the MOFs, disrupting membrane integrity and inhibiting critical processes such as electron transport and ATP synthesis. When incorporated into biodegradable microneedle patches, the MOF effectively penetrates biofilms and wound exudates, delivering potent antibacterial effects directly to infection sites while simultaneously promoting tissue repair. This strategic combination of bactericidal targeting, electron transfer disruption, and microneedle-mediated delivery highlights the potential of this approach to advance nonantibiotic antibacterial therapies.

Cranberry-Derived Phenolic Compounds Contribute to the Inhibition of FimH-Mediated Escherichia coli Hemagglutination

Background/Objectives: FimH adhesin, located at the tips of type 1 pili in Escherichia coli (E. coli), plays a crucial role in bacterial adhesion to the surface urothelial cells-a key step in the pathogenesis of urinary tract infections (UTIs). Given the rising concern over antimicrobial resistance (AMR), and considering that E. coli is one of the pathogens with the largest AMR burdens on a global scale, alternative strategies targeting bacterial adhesion are gaining increasing attention. Products that contain D-mannose and cranberry-derived phenolic compounds have shown promise in preventing E. coli colonization and infection. The aim of this study was to investigate the antiadhesive effects of cranberry-related phenolic compounds on FimH-mediated E. coli adhesion using a cellular hemagglutination inhibition assay, as well as to assess the synergistic effects of mannose and phenolic compounds on biofilm formation. Methods: A range of phenolic acids (benzoic, chlorogenic, hippuric, p-coumaric, ferulic and caffeic), resveratrol, (+)-catechin and procyanidin A, as well as a Vaccinium macrocarpon extract, were evaluated for their ability to inhibit FimH-mediated adhesion. A binocular microscope was used to observe agglutination, and we also evaluated the biofilm inhibition potential of the phenolic compounds in the presence of D-mannose. Results: Our results demonstrated that these compounds significantly reduced hemagglutination, with benzoic acid, chlorogenic acid, caffeic acid and resveratrol exhibiting strong inhibitory effects at concentrations as low as 0.25 mM. Furthermore, the addition of 1 mM solutions of these phenolic compounds to D-mannose resulted in a twofold reduction in the inhibition titer, suggesting synergistic interactions. In addition to their antiadhesive properties, the tested phenolic compounds contributed slightly to the inhibition of FimH-mediated biofilm formation, further supporting their potential roles in UTI prevention. Conclusions: These findings highlight the potential of cranberry-derived phenolics as natural antiadhesive agents against E. coli and warrant further investigation into their mechanisms of action and possible applications in infection control.

CIWARS: A Web Server for Antibiotic Resistance Surveillance Using Longitudinal Metagenomic Data

The rise of antibiotic resistance (AR) poses a substantial threat to human and animal health, food security, and economic stability. Wastewater-based surveillance (WBS) has emerged as a powerful strategy for population-level AR monitoring, providing valuable data to guide public health and policy decisions. Metagenomic sequencing is especially promising, as it can yield comprehensive profiles of antibiotic resistance genes (ARGs) and other genes relevant to AR in a single run. However, online analytical platforms to facilitate analysis of longitudinal metagenomic data are lacking. To address this, we introduce CyberInfrastructure for Waterborne Antibiotic Resistance Surveillance (CIWARS), a web server configured for characterizing key AR trends from longitudinal metagenomic WBS data. CIWARS offers comprehensive profiling of ARGs and taxonomic profiling of pathogen-associated bacterial taxonomic groups, identifies potential associations of ARGs with mobile genetic elements (MGEs) and pathogen-containing taxa, and assesses resistome risk based on the co-occurrence of ARGs, MGEs, and pathogen-like sequences. Additionally, it detects anomalous AR indicators over time, aiding in identifying potential events of concern, such as the emergence of resistant strains or outbreaks. Through interactive temporal data visualization, CIWARS enables AR monitoring and can serve as a tool to inform effective and timely interventions to mitigate the spread and transmission of AR. Here, CIWARS is demonstrated using longitudinal metagenomic data from a wastewater treatment plant (WWTP) influent and effluent, but it can be extended to any environment. CIWARS provides a valuable tool to support global efforts to combat the evolution and spread of AR, while also guiding agricultural and public health efforts aimed at optimizing antibiotic use. The web server is freely available at https://ciwars.cs.vt.edu/.

Methicillin-Resistant Staphylococcus aureus Inhibitory Activity of some New Thiazole-Based Schiff Bases: One-pot Synthesis and In Vitro Screening

Twelve thiazole-based Schiff bases derived from salicylaldehyde derivatives are efficiently prepared in the current study. A typical Hantzsch thiazole reaction was used to prepare the targeted molecules in 80%-92%. Therefore, a one-pot protocol was developed involving the reaction of salicylaldehydes, thiosemicarbazide, and the appropriate hydrazonyl chlorides in dioxane at reflux for 5-6 h in the presence of one equivalent of triethylamine. The new products were tested against six different American Type Culture Collection bacterial strains with the reference ciprofloxacin. In general, integrating an aryldiazenyl unit into the structure of the tested 4-methylthiazole-based Schiff bases at thiazole-C5 resulted in improved antibacterial activity. Moreover, Schiff bases linked to 5-((4-chlorophenyl)thio)methyl units outperformed their analogs linked to 5-(phenyl)thio)methyl units by 2-fold. Thiazole-based Schiff base linked to 5-((4-chlorophenyl)thio)methyl and 5-((4-methoxyphenyl)diazenyl) units showed the highest activity against all strains tested, particularly Staphylococcus aureus and Enterococcus faecalis. It had minimum inhibitory concentration/minimum bactericidal concentration (MIC/MBC) up to 7.4/14.9 µM. Moreover, it demonstrated comparable Methicillin-resistant S. aureus (MRSA) inhibitory activity to linezolid against two MRSA strains with MIC/MBC up to 7.4/29.8 µM.

Silver Nanoparticles and Antibiotics: A Promising Synergistic Approach to Multidrug-Resistant Infections

The escalating threat of antibiotic resistance demands innovative strategies against multidrug-resistant (MDR) microorganisms, particularly in hospital settings where such infections represent a major global health challenge. Since the rapid growth of nanotechnology interdisciplinary research and funding programs in the 2000s, silver ions have re-emerged as potent antimicrobial agents, offering a promising complement to conventional therapies. This therapeutic potential is nowadays explored through the use of silver nanoparticles (AgNPs) as sources for silver ions release. Recent studies have shown that controlled silver ion release enhances the efficacy of common antibiotics. This can be attributed to the energetically demanding nature of the bacterial response to silver, which weakens bacterial metabolism and, in turn, overwhelms bacterial defenses and increases antibiotic effectiveness. Herein, historical insights into the use of colloidal silver and AgNPs are combined with a review of recent research on the exploitation of the synergistic effect between AgNPs and antibiotics as a promising strategy against MDR pathogens.

Impact of Multiplex PCR on Diagnosis of Bacterial and Fungal Infections and Choice of Appropriate Antimicrobial Therapy

Multiplex Polymerase Chain Reaction (PCR) has significantly impacted the field of infectious disease diagnostics, offering rapid and precise identification of bacterial and fungal pathogens. Unlike traditional culture methods, which may take days to yield results, multiplex PCR provides diagnostic insights within hours, enabling faster, targeted antimicrobial therapy and reducing the delay in treating critical infections like sepsis. The technique's high sensitivity and broad pathogen coverage make it ideal for both single and polymicrobial infections, improving outcomes across respiratory, bloodstream, and bacterial/fungal infections. However, multiplex PCR is not without challenges; initial high costs and the need for specialized training can limit its adoption, especially in low-resource settings. This review discusses the clinical advantages and limitations of multiplex PCR, highlighting its influence on diagnostic accuracy, antimicrobial stewardship, and the global fight against antimicrobial resistance (AMR). Furthermore, recent innovations in multiplex PCR, such as digital PCR and portable devices, are explored as potential tools for expanding access to rapid diagnostics worldwide.

METTL3-mediated m6A modification in sepsis: current evidence and future perspectives

Sepsis, a severe systemic inflammatory condition triggered by infection, is associated with high morbidity and mortality worldwide. While medical diagnosis and treatment have advanced in recent years, a specific therapy remains unavailable. Recently, significant progress has been made in studying the epigenetic RNA modification N6-methyladenosine (m6A) and its core methyltransferase METTL3. The role of m6A in sepsis has also been increasingly elucidated. This review aims to explore the pathological mechanisms of sepsis and its relationship with m6A, focusing on the role of the key m6A writer, METTL3, in sepsis.