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

A simple two-dimensional metal-organic framework-based phototherapy nanoplatform with a triple-synergistic mechanism for enhanced wound infection treatment

Selecting an appropriate treatment for bacterial infections is critical. However, the rising prevalence of antimicrobial resistance has rendered many existing therapies less effective, highlighting the urgent need for novel antimicrobial strategies that are less prone to inducing antimicrobial resistance. Herein, we propose a simple, energy-efficient, photoresponsive antibacterial strategy based on metal-organic frameworks. Specifically, we developed an Au@Cu-THQ system activated by near-infrared laser irradiation, capable of exerting a synergistic triple-mode antibacterial effect-photothermal, photodynamic, and glutathione (GSH) depletion for the effective treatment of bacterial infections. The photothermal effect notably enhances the generation of reactive oxygen species and accelerates GSH depletion within bacterial cells, leading to a substantial disruption of their antioxidant defense systems and significantly amplifying the photodynamic therapeutic effect. Moreover, this material demonstrated excellent and stable photothermal performance both in vitro and in vivo, characterized by high photothermal conversion efficiency and effective GSH depletion activity. These features contribute to its potent antibacterial and anti-inflammatory effects, offering a promising multimodal strategy for the future development of in vivo anti-infective formulations.

Discovery of a novel sea snake antimicrobial peptide Hydrostatin-AMP3 with dual-mechanism against multidrug-resistant Klebsiella pneumoniae

Klebsiella pneumoniae (K. pneumoniae) has ranked in the top three pathogens responsible for bacteria-related mortal infections. The emergence of multi-drug resistant (MDR) K. pneumoniae strains highlights an urgent need for novel antimicrobial agents. In this study, a series of antimicrobial peptides (AMPs) were screened based on gene annotation and sequence profiling via high-quality whole genome maps of sea snakes Hydrophis curtus and Hydrophis cyanocinctus. The most potent Hydrostatin-AMP3 showed efficient antimicrobial capacity against a panel of pathogenic bacteria, particularly MDR K. pneumoniae strains. Moreover, Hydrostatin-AMP3 exhibited remarkable efficacy in infection models of MDR K. pneumoniae, while demonstrating favourable profiles in safety and resistance development both in vitro and in vivo studies. Mechanistically, Hydrostatin-AMP3 exerted a bactericidal effect through a unique dual-mechanism: bacterial membrane disruption and DNA-targeting. Overall, this study presented Hydrostatin-AMP3 as the potential antimicrobial candidate for the treatment of MDR K. pneumoniae infection.

Marine natural products as potential anti-Pseudomonas aeruginosa agents: challenges and advances

Antimicrobial resistance (AMR) has become a pressing need to address in the major global public health challenges, posing a serious threat to human health. Pseudomonas aeruginosa (PA) is one of the most concerning Gram-negative pathogens and is typically treated with broad-spectrum antibiotics. PA exhibits resistance to multiple antibiotics, multifactorial virulence, and dynamic hyperadaptation, which results in a particularly formidable challenge in eliminating PA from patients. The problem of drug resistance is becoming increasingly serious, and the development of new antibiotics is extremely lagging behind, resulting in no drug with a new structure and mechanism being approved for the treatment of infections caused by drug-resistant Gram-negative bacteria over the past half-century. Consequently, the development of new antibiotics is of utmost urgency and importance. Marine natural products (MNPs) have become an important source for developing new antibiotics due to their unique properties. So far, 44 potential molecules with significant anti-PA activity have been isolated from marine organisms, of which 19 have been reported as quorum-sensing system inhibitors (QSIs) with potential for further development. In this review, we provide a comprehensive summary of the current status of drug resistance, pathogenic mechanisms, and resistance mechanisms associated with PA infections. We also highlight the challenges and opportunities presented by MNPs in the development of anti-PA drugs, and offer recommendations to accelerate the antibiotic development process, thereby providing valuable insights for the study and exploitation of novel antibiotics.

Design and synthesis of benzothiazole aryl urea derivatives as potent anti-staphylococcal agents targeting autolysin-mediated peptidoglycan hydrolases

Novel benzothiazole aryl ureas were designed and synthesized as anti-MRSA agents targeting peptidoglycan (PG) hydrolases (autolysins). Structural simplification of prior benzothiazole-urea hybrids yielded compounds 4a, 7a and 11a bearing p-CF3 on phenyl ring demonstrating narrow-spectrum activity against Gram-positive bacteria including clinical methicillin-resistant S. aureus (MRSA). The primary autolysin in S. aureus, AtlA, mediates peptidoglycan hydrolase activity critical for bacterial growth, division, and cell wall remodeling. Mechanistic studies revealed that 4a down-regulated autolysin-related genes RNAIII and walR, disrupting peptidoglycan homeostasis. Knockout of atlA (a key autolysin gene) impaired 4a's efficacy, confirming autolysins as critical targets. Docking indicated that 4a binds to AtlA via hydrogen bonds, Pi-Pi, and hydrophobic interactions. In vivo, 4a significantly reduced bacterial load in a murine abdominal infection model, outperforming vancomycin at 10 mg/kg with lower cytotoxicity. Additionally, 4a disrupted MRSA biofilms, suppressed hemolytic toxin production, and alleviated inflammation in infected mice. These findings underscore AtlA as a promising therapeutic target and highlight benzothiazole phenyl urea as a scaffold for developing innovative anti-staphylococcal agents.

Exploring the correlation of linker structure and antimicrobial activities of pyridinium-based cationic biocides: Aromatic versus aliphatic architectures

Cationic biocides, particularly quaternary ammonium compounds (QACs), play a vital role in controlling microbial infections across various industries, healthcare facilities and households. As their widespread use increased drastically in the last few years due to COVID-19, there is growing concern about the development of resistance among microorganisms exposed to cationic biocides. It is crucial to recognize this threat in advance and respond by modifying and replacing the old generation of commercial biocides. Reported here is the pyridinium-based bis-QACs tuning via combination of two simple synthesis approaches to achieve novel biocide's architectures with mixed linkers. The obtained compounds were subjected to a broad bioactivity assay against a panel of 26 microbial pathogens, including multi-resistant bacterial ESKAPEE strains, fungi and biofilms. Novel hit-compounds showed improved antibacterial and antibiofilm action, rapid bacterial eradication within 15-30 min of exposure and 4.5-fold lower hemotoxicity, as well as lower potential for the development of bacterial resistance compared to commercial lead antiseptic octenidine. Highlighted findings and insights will serve as a good basis for further studies of bis-QACs as highly effective biocides.

Antibiotic resistance and bacterial spectrum in cerebrospial fluid cultures: Initial insights from Pakistan

Antimicrobial resistance (AMR) is a rising global health concern, especially in resource-limited countries like Pakistan, where indiscriminate and unregulated use of antibiotics has significantly worsened this problem. The study aimed to analyze the bacterial spectrum and antimicrobial resistance patterns in cerebrospinal fluid (CSF) cultures from patients with suspected bacterial meningitis, providing crucial insights for better infection control and treatment strategies.This retrospective study analyzed 1107CSF cultures were between 2019 and 2024 at the Lady Reading Hospital, MTI, Khyber Pakhtunkhwa, Pakistan, to assess bacterial profiles in patients with suspected bacterial meningitis and investigate the AMR patterns. Among the 106 positive growth cultures, gram-negative bacteria accounted for 84.9 %. Alarmingly, Acinetobacter baumannii was found to be completely resistant to all the nine antibiotics tested, while Salmonella typhi showed resistance to six out of seven tested antibiotics, highlighting their severe multi-drug resistance profile. Moreover, notable resistance was observed in Citrobacter freundii, Enterobacter species, and Staphylococcus aureus. The distribution results indicated that the Klebsiella pneumoniae is more prevalent in males and the 1-13 years age group. These findings highlight the necessity for urgent action on antibiotic stewardship, improved surveillance, and public awareness to mitigate the spread of AMR pathogens, particularly in life-threatening infections such as bacterial meningitis. Strengthening infection control measures and regulating antibiotic usage policies is imperative to curb the growing AMR crisis.

Ciprofloxacin-loaded electrosprayed lactose particles

Bacterial infections persist as a major global health challenge, underscoring the need for the development of advanced drug delivery systems. This study firstly explored the use of electrospraying to generate lactose microparticles loaded with ciprofloxacin (cipro), using polyvinyl alcohol (PVA) as an additive to enhance particle formation. Following optimization, spherical electrosprayed (ES) lactose microparticles were successfully produced with various cipro loadings (in the range of 0.25 %-1.07 % w/w). The electrosprayed particles did not contain any detectable crystalline material. Additionally, it was observed that the ES particles contained residual water, primarily originating from the production process. In terms of drug release, the ES particles exhibited rapid release kinetics within 5 h, suggesting their potential utility in treating acute bacterial infections. Notably, the formulations displayed concentration-dependent antibacterial activity against both Staphylococcus aureus and Pseudomonas aeruginosa, effectively delaying and inhibiting bacterial growth.

Tedizolid for osteoarticular infections: Evaluation of the published evidence

INTRODUCTION

Tedizolid phosphate, an oxazolidinone antibiotic, has been approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). However, its off-label use has been reported in various infections, including osteoarticular infections.

METHODS

A systematic review of data from PubMed, Scopus, and Web of Science was conducted to evaluate the antimicrobial activity, safety, and effectiveness of tedizolid in patients with bone and joint infections, including prosthetic joint infections, osteomyelitis, and septic arthritis. The review encompassed clinical trials, prospective and retrospective studies, and case reports.

RESULTS

A total of 6 in vitro antimicrobial and 15 clinical studies were included in the review. Tedizolid demonstrated high antimicrobial activity across all in vitro studies. In 106 patients from the included clinical studies, tedizolid showed high effectiveness, with therapy success ranging from 76.5 % to 100 % in 4 cohort studies. Additionally, favorable outcomes were reported in 7 of 9 case reports. Tedizolid exhibited a favorable safety profile, with 11 of 15 clinical studies reporting no adverse events in 37 patients. Adverse events leading to therapy discontinuation were observed in 9 out of 124 patients included in the remaining studies.

CONCLUSION

The current appraisal suggests that tedizolid is a promising antibiotic for the treatment of bone and joint infections. Nonetheless, its use should be reserved for multi-drug resistant infections when other approved therapeutic options are limited. Further clinical studies are warranted to substantiate the effectiveness and safety of tedizolid in this patient population.

Synthesis and antimicrobial evaluation of novel quaternary quinolone derivatives with low toxicity and anti-biofilm activity

To overcome the increasing global drug resistance, the development of novel antimicrobial drugs is a top priority in the fight against multidrug resistant (MDR) and persistent bacteria. In this work, we report the synthesis of novel single quaternary quinolone antibacterial agents. The majority of the tested compounds exhibited significant antimicrobial efficacy against Gram-negative pathogens (E. coli and S. maltophilia). Notably, the selected compound (4e) was highly inhibitory with a MIC value of 0.25 μg/mL against E. coli. Additionally, compound 4e demonstrated excellent stability in complex biological fluids with low hemolytic activity (HC50 > 1280 μg/mL) and a significantly lower propensity to induce bacterial resistance. Encouragingly, 4e showed not only rapid bactericidal activity and inhibition of bacterial biofilms, but also low toxicity to erythrocytes and RAW 264.7 cells compared to the clinical drug ciprofloxacin. Mechanism studies have found that compound 4e has a relatively weak destructive effect on the cell membrane of E. coli. However, it can effectively inhibit the activity of glutathione (GSH), promote the massive accumulation of intracellular reactive oxygen species (ROS), and then disrupt the antioxidant defense system of bacteria, achieving a bactericidal effect. In addition, compound 4e has a certain binding effect with bacterial DNA.

Imide-based enones: A new scaffold that inhibits biofilm formation in Gram-negative pathogens

We prepared a series of enones containing different substituents as potential antibiofilm molecules. The design considered the structural features previously found in N-acylhomoserine lactones, but it replaced the labile furanone with different imides portions. After evaluation, some of the analogs inhibited 50 % or more the formation of the biofilm from P. aeruginosa or A. baumannii; moreover, substituents attached at the phenyl ring, the size of the enone as well as the type of imide seemed relevant for the selectivity against the tested pathogens. In the end, we performed a molecular docking study using the crystallized LasR to describe the main interactions of the ligand-receptor complex and propose a plausible mechanism of action.

Unravelling AMR dynamics in the rumenofaecobiome: Insights, challenges and implications for One Health

Antimicrobial resistance (AMR) is a critical global threat to human, animal and environmental health, exacerbated by horizontal gene transfer (HGT) via mobile genetic elements. This poses significant challenges that have a negative impact on the sustainability of the One Health approach, hindering its long-term viability and effectiveness in addressing the interconnectedness of global health. Recent studies on livestock animals, specifically ruminants, indicate that culturable ruminal bacteria harbour AMR genes with the potential for HGT. However, these studies have focused predominantly on using the faecobiome as a proxy to the rumen microbiome or using easily isolated and culturable bacteria, overlooking the unculturable population. These unculturable microbial groups could have a profound influence on the rumen resistome and AMR dynamics within livestock ecosystems, potentially holding critical insights for advanced understanding of AMR in One Health. In order to address this gap, this review of current research on the burden of AMR in livestock was undertaken, and it is proposed that combined study of the rumen microbiome and faecobiome, termed the 'rumenofaecobiome', should be performed to enhance understanding of the risks of AMR in ruminant livestock. This review discusses the complexities of the rumen microbiome and the risks of AMR transmission in this microbiome in a One Health context. AMR transmission dynamics and methodologies for assessing the risks of AMR in livestock are summarized, and future considerations for researching the impact of AMR in the rumen microbiome and the implications within the One Health framework are discussed.

Qingfei Litan decoction alleviated Klebsiella pneumoniae-induced pneumonia by targeting the TLR4/MyD88/NF-κB axis via miR-146a-5p

ETHNOPHARMACOLOGICAL RELEVANCE

Klebsiella pneumoniae (Kp) is a significant pathogen responsible for various clinical bacterial infections, including pneumonia, sepsis, and even death. However, effective treatment options remain limited due to the rising prevalence of antimicrobial resistance. Traditional Chinese medicine (TCM) has shown potential in the treatment of bacterial pneumonia. Qingfei Litan decoction (QFLT) has been reported to alleviate symptoms in patients with bacterial pneumonia, though its precise mechanisms in regulating pulmonary inflammation remain unclear.

AIM OF THE STUDY

This study aimed to investigate the therapeutic potential of QFLT in Kp-induced pneumonia and to elucidate its underlying molecular mechanisms.

MATERIAL AND METHODS

In vivo, a murine pneumonia model was established through intratracheal instillation of Kp, and QFLT was administered by oral gavage. miR-146a-5p expression was downregulated by tail vein injection of an antagomir. The therapeutic effects of QFLT on pulmonary pathology, inflammatory factors, and miR-146a-5p expression were evaluated using qRT-PCR, flow cytometry, and other methods. Bioinformatics tools were employed to predict miR-146a-5p targets and associated inflammatory pathways. In vitro, an alveolar macrophage inflammation model was established by stimulating MH-S cells with heat-inactivated Klebsiella pneumoniae (iKp), followed by QFLT treatment. Inhibition of miR-146a-5p was achieved through transfection with specific inhibitors. The effects of QFLT on inflammatory responses, miR-146a-5p expression, and TLR4/MyD88/NF-κB signaling were assessed using qRT-PCR, Western blotting (WB) and other methods.

RESULTS

Kp infection significantly exacerbated pulmonary inflammation and downregulated miR-146a-5p expression in both lung tissues and MH-S cells. QFLT treatment alleviated inflammatory responses and upregulated miR-146a-5p expression. Bioinformatics analysis demonstrated that miR-146a-5p targeted TRAF6, a key mediator of the TLR4/MyD88/NF-κB pathway. Western blot analysis further confirmed that QFLT reduced Kp-induced upregulation of the TLR4/MyD88/NF-κB pathway in MH-S cells. Moreover, inhibition of miR-146a-5p exacerbated inflammatory responses in both lung tissues and MH-S cells, whereas QFLT treatment effectively attenuated these inflammatory effects. Furthermore, miR-146a-5p suppression resulted in elevated expression of proteins in the TLR4/MyD88/NF-κB signaling pathway in MH-S cells, while QFLT administration significantly reduced the expression levels of these signaling components.

CONCLUSIONS

These findings demonstrated that QFLT ameliorated Kp-induced pneumonia by modulating the TLR4/MyD88/NF-κB axis via miR-146a-5p.

Burden of bacterial antimicrobial resistance in China: a systematic analysis from 1990 to 2021 and projections to 2050

INTRODUCTION

Antimicrobial resistance (AMR) has emerged as a critical health challenge; however, there is a paucity of in-depth reports outlining its burden and trends in China.

OBJECTIVES

This study aimed to systematically assess the burden of bacterial AMR in China from 1990 to 2021 and project future trends up to 2050, providing critical insights for AMR control and policy-making.

METHODS

We analyzed data from the Global Burden of Disease Study 2021, encompassing 12 infectious syndromes, 64 pathogens (including 22 with AMR), and 84 pathogen-drug combinations. The burden was quantified by deaths and disability-adjusted life years under two counterfactual scenarios: deaths associated with AMR and those attributable to AMR, respectively. Trends were assessed using joinpoint regression analysis, and future projections up to 2050 were modeled using an autoregressive integrated moving average approach.

RESULTS

In 2021, AMR was attributable to approximately 160,268 (95% uncertainty intervals [UI]: 132,375-188,160) deaths in China, with up to 711,852 (95% UI: 586,447-837,256) fatalities associated with AMR. The most lethal infectious syndrome was bloodstream infections, with key pathogen-drug combinations including methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Streptococcus pneumoniae, and carbapenem-resistant Acinetobacter baumannii. Between 1990 and 2021, there was a substantial decrease in the burden among children under the age of five, primarily due to a decline in fatalities caused by carbapenem-resistant S. pneumoniae. In contrast, the burden increased among individuals aged 45 and older, with MRSA identified as the principal contributor. Projections indicate that by 2050, AMR could be associated with 769,432 deaths in China, of which 180,123 directly attributable to AMR.

CONCLUSION

Our findings provide a comprehensive evaluation of AMR burden in China, highlighting the urgent need for targeted interventions to prevent and control resistant infections, particularly among older adults.

Incidence of catheter-related infection in cancer patients receiving parenteral nutrition: A retrospective cohort study of French administrative claims data

Data confirming parenteral nutrition (PN) as an independent risk factor for catheter-related infection (CRI) are scarce and not recent. This study aims to estimate the effect of PN on CRI in cancer patients after catheter placement. A retrospective cohort analysis of the French National Health Data System was conducted. A total of 5300 gastric, 5975 pancreatic, and 15,102 lung cancer patients with central venous catheter insertion between 2012 and 2016 were included. Potential confounders for CRI were evaluated using Poisson regression. Incidence rates (IRs) of CRI were calculated. Incidence rate ratio (IRR) was estimated to assess the effect of exposure to PN on infection occurrence in all patients and among patients receiving chemotherapy (CT). The independent risk factors found to be associated with CRI were age, sex, Charlson Comorbidity Index, PN, CT, metastasis, and history of infection. After adjustment, there was an increased risk of CRI in patients with versus without PN in gastric (IRR: 1.1165; 95% confidence interval [95% CI]: 1.0119-1.2319), pancreatic (IRR: 1.2071; 95% CI: 1.0985-1.3265), and lung cancer (IRR: 1.1850; 95% CI: 1.0832-1.2962). In patients who received PN, IRs of CRI were higher than in those who did not, for gastric (34.84% vs 29.69%, respectively; P = .0001), pancreatic (38.89% vs 28.58%, respectively; P < .0001), and lung (23.64% vs 22.13%, respectively; P = .0967) cancer cohorts. The results of this National administrative claims database analysis suggested that PN might be one of the independent risk factors for CRI. However, the risk was smaller than previously reported, regardless of whether the patient was receiving CT or not.

Removal of antibiotic resistance from wastewater in aquatic ecosystems dominated by submerged macrophytes

Submerged macrophytes in constructed wetlands (CWs) can effectively improve wastewater quality. However, the effectiveness of different submerged macrophytes in removing antibiotic-resistant genes (ARGs) from wastewater remains unexplored. Additionally, wastewater loading in wetlands can fluctuate due to climate change, potentially affecting ARG removal efficiency. In this study, we systematically constructed microscale wetlands using three submerged plants: Vallisneria natans (VN), Sagittaria pygmaea (SP), and Myriophyllum spicatum (MS). Their effectiveness in ARGs removal was analyzed at hydraulic retention times (HRTs) of 0, 3, 6, and 9 days under high (HWL) and low (LWL) wastewater loading. The results indicated that under LWL conditions, all ecosystems exhibited a higher reduction rate of ARG diversity and relative abundance (RS) compared to HWL conditions. The efficiency of all ecosystems in reducing ARG diversity and abundance followed the order: MS > VN > SP. The sul resistance gene exhibited the highest RS and was degraded most rapidly in all samples. Additionally, sulfadimidine concentrations significantly decreased under LWL conditions, which was significantly correlated with sul reduction. Chemical oxygen demand, total phosphorus, total nitrogen, ammonium nitrogen, and nitrate nitrogen were identified as key factors influencing bacterial and ARG profiles. The increase in rhizobial bacteria and decrease in aerobic denitrifying bacteria likely contributed significantly to ARGs removal. This study offers new insights into ARG removal by submerged macrophytes in CWs, emphasizing the role of wastewater loading and the potential of MS in enhancing ARG degradation. These findings enhance CW design and management to mitigate ARG contamination in wastewater.

Mass spectrometry-based identification reveals the polymicrobial nature of canine urinary tract infections

Canine urinary tract infections (UTIs) are common in veterinary practice and often have a complex etiology. Typically, diagnoses rely on classical phenotypic tests or are limited to identifying the genus of the pathogen. Treatments are frequently administered without prior in vitro antimicrobial susceptibility testing. This study analyzed 389 urine samples from dogs with clinical signs of UTI, collected by cystocentesis, through microbiological culture. Species-level identification of bacteria and yeasts was performed using mass spectrometry, while bacterial isolates underwent antimicrobial susceptibility testing via the disk diffusion method. Of the 389 samples, 170 (43.7%) showed microbial growth, with 192 microorganisms identified. Among these, 98.4% (189/192) were bacteria, and 1.6% (3/192) were fungi/yeasts. The predominant pathogens included Enterobacteria (116/192 = 60%), enterococci (26/192 = 13.5%), and staphylococci (24/192 = 12.5%). Novel pathogens, such as Lactobacillus murinus and Stenotrophomonas maltophilia, were identified as primary agents of canine UTIs. Coinfections commonly involved E. coli with either E. faecalis (5/21 = 23.8%) or S. canis (4/21 = 19%). Amoxicillin/clavulanic acid was the most effective antimicrobial (≥ 70%), followed by amikacin and marbofloxacin (≥ 60%). Observed antimicrobial resistance rates included enterobacteria (18%), enterococci (> 40%), staphylococci (18%), streptococci (30%), Pseudomonas aeruginosa (60%), and other organisms (> 30%). Multidrug resistance affected 18% (34/189) of bacterial isolates. This study highlights the polymicrobial nature of canine UTIs and emphasizes concerns about multidrug-resistant bacteria. These findings contribute to improving molecular diagnostics and monitoring antimicrobial resistance in domestic animals, a critical global issue.

Pollution by antimicrobials and antibiotic resistance genes in East Africa: Occurrence, sources, and potential environmental implications

The escalating burden of antimicrobial pollution in East Africa poses severe threats to public health, environmental integrity, and economic stability. Environmental compartments such as soil and water serve as reservoirs for these pollutants such as antimicrobials and antibiotic resistance genes, creating selective pressure that accelerates the emergence of antimicrobial resistance (AMR). These dynamic fosters the proliferation of multidrug-resistant pathogens, or "superbugs," complicating infection management and amplifying health risks in a region already challenged by inadequate healthcare and sanitation infrastructure. Furthermore, pollution by antimicrobials and antibiotic resistance genes critically disrupts ecological processes, such as nutrient cycling and organic matter degradation, diminishing soil fertility, water quality, and agricultural productivity, thereby threatening food security and overall ecological health. Current surveillance efforts, including the Global Antimicrobial Resistance and Use Surveillance System (GLASS) and the East Africa Public Health Laboratory Networking Project (EAPHLNP), have made strides in tracking AMR trends and guiding policy decisions. However, these efforts remain insufficient to address the growing crisis. This study highlights the urgent need for integrated strategies, including stringent antibiotic usage regulations, advanced wastewater treatment technologies, and comprehensive environmental surveillance. Therefore, there is a need to address the intersections of health, agriculture, and environment, to mitigate AMR and its far-reaching consequences to ensure public health safety and sustainability.

Design framework to develop sustainable innovations for addressing One Health challenges

The complexity of global health challenges requires integrated approaches that crosses traditional boundaries. One Health (OH) offers a holistic approach to address health issues at the crossroads of human, animal, and environmental domains. Antimicrobial Resistance (AMR), a prime example of a cross-sectoral issue and OH challenge, highlights the need for coordinated interventions that consider multiple stakeholders. Current approaches to improve OH challenges and AMR have limited success, often due to a lack of a structured theoretical approach that informs the design and development of solutions for long-term sustainability. Existing frameworks focus primarily on human or veterinary sectors in isolation, leaving a gap in comprehensive, integrated approaches that align with OH principles. The proposed framework addresses this gap by offering a structured approach to both implementing and evaluating interventions that consider all three sectors. This paper proposes the HEARTf of OHC (Holistic Engagement and Adaptive Responses Theoretical framework of One Health challenges), a user-centered design approach aimed at developing sustainable and innovative OHC interventions. The HEARTf of OHC integrates knowledge from social sciences, computer science, industrial design, pedagogy, and health sciences to create context specific solutions that address the specific needs of end-users in the human, animal, and environmental sectors. Additionally, this paper reviews existing frameworks addressing AMR, identifies limitations and outlines the need for a transdisciplinary approach when tackling OHC. By emphasizing the importance of the user-centered design, transdisciplinarity, and continuous evaluation, the HEARTf of OHC aims to bridge the gap between current strategies and improve the development and evaluation of innovative solutions or services. The HEARTf of OHC is a generalizable framework for the design, implementation, and evaluation of OH interventions, where we use AMR as a case study to demonstrate its application.

Shelter dogs as reservoirs of international clones of Escherichia coli carrying mcr-1.1 and blaCTX-M resistance genes in Lima, Peru

Antimicrobial resistance (AMR) poses a critical public health threat worldwide, particularly at the human-animal interface where cross-transmission of critical priority Enterobacterales, such as Escherichia coli, have become increasingly reported. Worryingly, E. coli encoding extended-spectrum β-lactamases (ESBLs) has been documented in companion animals worldwide. Conversely, the presence of mcr genes, which confer resistance to polymyxins, in bacteria from pets remains more infrequent. In this study, we sequenced and reported on the first genomic data of E. coli strains carrying mcr-1 and/or blaCTX-M genes isolated from rectal swabs of stray dogs in a shelter in the city of Lima, Peru. Antimicrobial susceptibility revealed that E. coli strains exhibited a multidrug resistance profile. In addition to mcr-1 and blaCTX-M genes, other clinically relevant resistance determinants were identified, with notably presence of blaTEM-176 and the novel blaSCO-2 variant. The association of mcr-1.1 and IncI2 plasmid was confirmed. Several virulence genes were detected, classifying strains as putative extraintestinal pathogenic E. coli. Multilocus sequence typing prediction recognized diverse sequence types (ST), including ST155, ST189, ST657, ST746, ST1140, ST3014, and ST7188. This study represents the first report of mcr-positive E. coli in dogs from Peru, emphasizing the need for continuous surveillance and genomic characterization to better understand the transmission dynamics of these critical resistance genes at the human-animal interface. Furthermore, our results provide evidence that stray, and shelter dogs could be a reservoir for the spread of WHO priority pathogens, and/or polymyxin and β-lactam resistance genes, which is a public health and One Health concern that requires appropriate management strategies.

Effect of oxygen on antimicrobial resistance genes from a one health perspective

Bacteria must face and adapt to a variety of physicochemical conditions in the environment and during infection. A key condition is the concentration of dissolved oxygen, proportional to the partial pressure of oxygen (PO2), which is extremely variable among environmental biogeographical areas and also compartments of the human and animal body. Here, we sought to understand if the phenotype of resistance determinants commonly found in Enterobacterales can be influenced by oxygen pressure. To do so, we have compared the MIC in aerobic and anaerobic conditions of isogenic Escherichia coli strains containing 136 different resistance genes against 8 antibiotic families. Our results show a complex landscape of changes in the performance of resistance genes in anaerobiosis. Certain changes are especially relevant for their intensity and the importance of the antibiotic family, like the large decreases in resistance observed against ertapenem and fosfomycin among blaVIM β-lactamases and certain fos genes, respectively; however, the blaOXA-48 β-lactamase from the clinically relevant pOXA-48 plasmid conferred 4-fold higher ertapenem resistance in anaerobiosis. Strong changes in resistance patterns in anaerobiosis were also conserved in Klebsiella pneumoniae. Our results suggest that anaerobiosis is a relevant aspect that can affect the action and selective power of antibiotics for specific AMRs in different environments.

Fitness trade-off and the discovery of a novel missense mutation in the PmrB sensor kinase of a colistin-resistant Pseudomonas aeruginosa strain developed by adaptive laboratory evolution

Pseudomonas aeruginosa is a prominent bacterial pathogen that causes several nosocomial infections and is notorious for its environmental resilience and rapid development of resistance to frontline antibiotics. A major cause of mortality and morbidity among cystic fibrosis patients, multidrug-resistant P. aeruginosa is often targeted with the antibiotic colistin as a last option. However, increasing reports of colistin resistance among P. aeruginosa is a significant concern. Though the molecular mechanisms responsible for the development of colistin resistance are well known, the evolutionary trajectory to colistin resistance is an important area of investigation. In this work, using the adaptive laboratory evolution (ALE) approach we have evolved a colistin-sensitive P. aeruginosa ancestral strain to a resistant one. During the process of laboratory evolution in 106 generations, colistin MIC was increased 32-fold. The evolved strain had lower fitness than the ancestral strain, as evidenced by a lower growth rate. Moreover, the evolved strain produced more biofilm and less pyocyanin pigment. Interestingly, the evolved strain showed collateral sensitivity to several antibiotics, including ampicillin, tetracycline, streptomycin, gentamycin, nalidixic acid, trimethoprim, rifampicin, and chloramphenicol. On analysing various TCS modules involved in the development of colistin resistance, a novel missense mutation (V136G) was detected in the PmrB sensor kinase. In silico analysis indicated that the V136G substitution would destabilize the PmrB kinase structure, making the mutation deleterious. However, the functionality of the PmrB mutant remains to be validated experimentally.

Long-term forecast for antibacterial drug consumption in Germany using ARIMA models

The increasing supply shortages of antibacterial drugs presents significant challenges to public health in Germany. This study aims to predict the future consumption of the ten most prescribed antibacterial drugs in Germany up to 2040 using ARIMA (Auto Regressive Integrated Moving Average) models, based on historical prescription data. This analysis also evaluates the plausibility of the forecasts. Our findings represent one of the first long-term national forecasts for antibacterial drug consumption. ARIMA(0,1,0), a random walk model with drift, is the best-fitting model to capture trends across all antibacterial drugs. While more complex models offer greater detail, they seem less suitable for long-term forecasting. In a short-term forecast of 5 and 10 years, predictions between significant models vary very little. Predictions indicate increasing DDD-prescriptions for amoxicillin, cefuroxime axetil, amoxicillin clavulanic acid, clindamycin, azithromycin, nitrofurantoin, and ciprofloxacin, while declines are forecasted for doxycycline, phenoxymethylpenicillin, and sulfamethoxazole-trimethoprim. The reliability of the predictions varies. Forecasts for azithromycin, phenoxymethylpenicillin, and sulfamethoxazole-trimethoprim are likely accurate, whereas uncertainties exist for doxycycline, amoxicillin clavulanic acid, nitrofurantoin, and ciprofloxacin, though general trends appear valid. Potential discrepancies may arise in the predictions for amoxicillin, cefuroxime axetil, and clindamycin. These forecasts highlight the urgent need for proactive healthcare planning to prevent future shortages, a problem underscored by recent supply disruptions in Germany. Future research should extend this analysis to the development of bacterial resistance and other frequently used drug classes.

Overproduction of secondary metabolites in Photorhabdus noenieputensis through rpoB mutations

Specific mutations of the rpoB gene, which encodes the β subunit of bacterial RNA polymerase, can enhance the production of secondary metabolites in bacteria such as actinomycetes. Entomopathogenic bacteria Photorhabdus and Xenorhabdus species produce a variety of secondary metabolites. Recently, these genera have attracted attention as a promising source for novel antibiotics. In this study, the effect of rpoB mutations on secondary metabolite production in Photorhabdus noenieputensis DSM 25462, a known producer of the antituberculosis antibiotic evybactin, was evaluated. Spontaneous rifampicin-resistant mutants, frequently carrying rpoB mutations, were generated by plating cells on agar medium containing four times the minimum inhibitory concentration (MIC) of rifampicin and evaluated their antibacterial production using Escherichia coli WO153 as a test strain. Among 190 spontaneous rifampicin-resistant mutants of P. noenieputensis, strain designated R191, which harbors the rpoB Q148K mutation (C442A), displayed higher antibacterial activity than that of the parental strain DSM 25462. The real-time quantitative RT-PCR analysis of 20 putative secondary metabolite biosynthetic gene clusters (BGCs) identified using antiSMASH revealed that seven of these BGCs were overexpressed in the strain R191. Furthermore, comparative high-pressure liquid chromatography (HPLC) analysis of the metabolite profile indicated that the strain R191 produced several compounds that were not detectable in the DSM 25462 culture. These findings suggest that the introduction of rpoB mutations into Photorhabdus strains is an effective strategy for enhancing secondary metabolite production and may lead to the discovery of novel antibiotics.

Fighting Antibiotic Resistance: Insights Into Human Barriers and New Opportunities: Antibiotic Resistance Constantly Rises With the Development of Human Activities. We discuss Barriers and Opportunities to Get It Under Control

The public health issue of bacterial multi-resistance to antibiotics has gained awareness among the public, researchers, and the pharmaceutical sector. Nevertheless, the spread of antimicrobial resistance has been considerably aggravated by human activities, climate change, and the subsequent increased release of antibiotics, drug-resistant bacteria, and antibiotic resistance genes in the environment. The extensive use of antibiotics for medical and veterinary purposes has not only induced increasing resistance but also other health problems, including negative effects on the patient's microbiome. Preventive strategies, new treatment modalities, and increased surveillance are progressively set up. A comprehensive approach is, however, lacking for urgently tackling this adverse situation. To address this challenge, we discussed here the main causes driving antimicrobial resistance and pollution of the environment by factors favorable to the emergence of drug resistance. We next propose some key priorities for research, prevention, surveillance, and education to supervise an effective clinical and sustainable response.

Applying Antimicrobial Strategies in Wound Care Practice: A Review of the Evidence

Antimicrobial resistance is increasing due to an overreliance on antimicrobials to treat and manage infections. Chronic wounds are particularly vulnerable to infections and harbour complex microbial communities, increasing the risk of secondary infections caused by antimicrobial resistant bacteria. Accurate and early diagnosis of infection ensures appropriate treatment interventions and a reduction in the likelihood that antibiotic use is required. Despite this, the overuse of antibiotic treatment in wound care is still evident. Antimicrobial stewardship describes a structured approach to managing antimicrobial resistance through educating healthcare professionals about antimicrobial use to improve patient outcomes and minimise the spread of infections. However, the evidence suggests that healthcare professionals experience barriers when attempting to implement such strategies in their practice. It is essential that the principles of antimicrobial stewardship are embedded into wound care treatment and management. This review aimed to explore the current barriers to antimicrobial stewardship in wound care clinical practice and discuss the strategies that can be applied to successfully maximise infection prevention. There is a need to further educate wound care practitioners about antimicrobial stewardship and future research should concentrate on understanding how healthcare professionals can work collaboratively to implement such strategies in their practice.

Specialist training in infectious diseases in Europe

OBJECTIVES

The objectives were to determine the structure of training programmes and assessment of physicians training to become infectious disease (ID) specialists in Europe in early 2024 and to document the provision of specialists, trainees and training centres in each country.

METHODS

Delegates to the ID Section and Board of the European Union of Medical Specialists entered national data on a web-based survey tool in late 2023-early 2024. Results were compared with European Union of Medical Specialists recommendations on the structure and content of postgraduate training in ID in Europe (2018), and to results of a similar survey in early 2021.

RESULTS

Responses were received from all 35 countries; 27/35 (77%) recognize ID as an independent speciality and 7/35 (20%) as a subspeciality. Spain does not officially recognize the speciality. In Cyprus, Iceland, and Luxembourg, despite official recognition of the sub-/speciality, ID training must be completed abroad. Paediatric ID was recognized in 16/35 (46%) countries. The number of adult ID specialists varied from 78.8 per million inhabitants in Sweden to 0.6 in Germany. Only 7/31 (23%) national programmes provide the minimum recommended 6 months of training in medical microbiology. Assessment methods included logbooks/portfolios in 25/31 (81%), final examinations in 25/31 (81%) and workplace-based assessments in 21/31 (68%).

DISCUSSION

There has been little change since 2021 in speciality status or in structure and content of training programmes across Europe. There have been large increases in training position numbers in several countries, possibly in response to COVID-19. Continued low compliance with the 2018 recommendations to increase exposure to medical microbiology during training highlights the slow pace of change. Logistic barriers to change and to harmonization across Europe remain and are discussed in the context of published concerns of trainees.

Immune-based strategies for the treatment of biofilm infections

Biofilms are bacterial communities surrounded by a polymeric matrix that can form on implanted materials and biotic surfaces, resulting in chronic infection that is recalcitrant to immune- and antibiotic-mediated clearance. Therefore, biofilm infections present a substantial clinical challenge, as treatment often involves additional surgical interventions to remove the biofilm nidus, prolonged antimicrobial therapy to clear residual bacteria, and considerable risk of treatment failure or infection recurrence. These factors, combined with progressive increases in antimicrobial resistance, highlight the need for alternative therapeutic strategies to circumvent undue morbidity, mortality, and resource strain on the healthcare system resulting from biofilm infections. One promising option is reprogramming dysfunctional immune responses elicited by biofilm. Here, we review the literature describing immune responses to biofilm infection with a focus on targets or strategies ripe for clinical translation. This represents a complex and dynamic challenge, with context-dependent host-pathogen interactions that differ across infection models, microenvironments, and individuals. Nevertheless, consistencies among these variables exist, which could facilitate the development of immune-based strategies for the future treatment of biofilm infections.

Update on multidrug-resistant tuberculosis preventive therapy toward the global tuberculosis elimination

Multidrug-resistant tuberculosis (MDR-TB), the deadliest form of tuberculosis (TB), has been included in the 2024 World Health Organization (WHO) priority list of antibiotic-resistant bacterial pathogens owing to its severe public health implications. Almost two billion people worldwide are infected with Mycobacterium tuberculosis; however, the share of MDR-M.tuberculosis remains uncertain. Mathematical modeling estimates that MDR-TB affects nearly three in every 1000 people worldwide, highlighting the urgent need to address TB preventive treatment (TPT) for contacts of MDR-TB cases. Before 2018, close monitoring of contacts of people with MDR-TB was recommended rather than TPT. However, considering the ethical and public health concerns associated with leaving infected individuals untreated, the WHO updated its guidelines in 2018, 2020, and 2022. Despite the limited evidence at the time, the WHO suggested considering quinolone-based TPT for selected high-risk cases. To close this gap in evidence, two large-scale prospective randomized controlled trials were conducted: VQUIN (VQUIN MDR Australia New Zealand Clinical Trials Registry number, ACTRN12616000215426) and TB-CHAMP (TB-CHAMP ISRCTN Registry number, ISRCTN92634082). Both trials evaluated the efficacy of levofloxacin (Lfx) compared with a placebo for MDR-TB after household exposure in adults and children. A combined meta-analysis of the two trials showed a 60% reduction in TB incidence in the Lfx group, and the difference was statistically significant. Based on these results, in 2024, the WHO recommended the use of 6 months of daily Lfx as a TPT for contacts exposed to MDR/rifampicin-resistant TB. This regimen is cost-effective, safe, demonstrates good efficacy, and does not interact with HIV therapies. Despite these promising results, pre-extensively drug-resistance (XDR)-TB (MDR-TB with documented resistance to quinolones) remains an emerging concern. Two ongoing trials will address this challenge: the PHOENIx trial (PHOENIx-MDR TB NCT03568383), which will evaluate the efficacy of delamanid compared with isoniazid for preventing M/XDR-TB after household exposure, and the BRANCH-TB trial (NCT0656848), which will assess the efficacy and safety of 1 month of bedaquiline regimen compared with WHO-recommended TPT regimens. Preventing MDR/rifampicin-resistant TB remains a significant challenge for the global elimination of TB. Although the recent WHO recommendation for 6 months of daily Lf is a promising step, expanding the TPT options for pre-XDR TB and addressing drug intolerance are critical. Ongoing and new trials are essential to develop alternative treatment and achieve TB elimination.

Nutritional Deficiencies and Management in Tuberculosis: Pharmacotherapeutic and Clinical Implications

Tuberculosis is an infectious condition caused by Mycobacterium tuberculosis, primarily targeting the pulmonary system, with the potential to disseminate to various other organs via the haematogenous pathway, ranking among the top ten causes of global mortality. Tuberculosis remains a serious public health problem worldwide. This narrative review aims to emphasise the clinical importance of the inter-relationships between nutrition, pharmacotherapy, and the most common drug-nutrient interactions in the context of tuberculosis and multi-drug-resistant tuberculosis management. Nowadays, pharmacologic approaches utilise polytherapeutic regimens that, although showing increased efficacy, prominently affect the nutritional status of patients and modify multiple metabolic pathways, thus influencing both the effectiveness of therapy and the patient outcomes. There is much evidence that antituberculosis drugs are associated with deficiencies in essential vitamins and various micronutrients, leading to serious adverse consequences. Moreover, poor nutrition exacerbates TB outcomes, and TB further exacerbates nutritional status, a vicious cycle that is particularly prevalent in low-resource environments. Nutritional support is necessary, and clinicians ought to evaluate it on a patient-by-patient basis, as empirical evidence has shown that it can improve immune recovery, decrease tuberculosis-associated morbidity, and increase adherence to therapy. However, drug-food interactions are increasingly prevalent, and patients with tuberculosis require personalised dietary and pharmacological regimens. In this context, antituberculosis treatment requires a holistic approach, based on the collaboration of the prescribing physician, pharmacist, and nutritionist, to assess the patient's needs from a nutritional and pharmacological perspective, with the ultimate goal of decreasing mortality and improving the prognosis of patients through personalised therapies.

A solution to the postantibiotic era: phages as precision medicine

Antibiotic-resistant bacterial infections pose a significant global health challenge. Phage therapy provides a promising alternative to antibiotics that enables the specific targeting of pathogenic bacteria while preserving the healthy microbiome. Recent advances in genetic engineering, synthetic biology, and artificial intelligence have rekindled interest in phage therapy, as they move phages into the realm of precision medicine. Engineered phages can be customized to have a broader host range, encode counter-defenses that overcome bacterial immune systems, or express other proteins that modulate the bacterial host to their advantage. Innovations in artificial intelligence and machine learning promise to speed up the identification of optimal phage candidates and create tailored cocktails for individualized therapies - advances that will transform phage therapy and provide a solution to the antibiotic resistance crisis.

Enterobacterales abundance in oral cancer patients and elevated clindamycin resistance rates in head and neck infections at a Hungarian Tertiary Hospital

BACKGROUND

Oral bacteria have been associated with several systemic diseases, and studies have highlighted their potential role in carcinogenesis. A biofilm is considered an antimicrobial resistance gene reservoir, and the oral cavity provides an excellent environment for biofilm formation. The aim of this study was to evaluate the pathogen spectrum and antimicrobial resistance rates of clinical isolates from head and neck infections in the Hungarian population.

METHODS

A total of 5185 bacterial isolates were analyzed from 1978 patients between 2018 and 2023. Antimicrobial resistance rates were reported according to the EUCAST guidelines. The primary diagnoses of the patients were categorized into three major groups: abscesses, necrotizing lesions and surgical site infections of patients treated for malignant tumors. Pearson's chi-square test was used to compare the percentages of bacteria in the different patient groups.

RESULTS

The most frequently isolated bacteria were Streptococcus (18.8%) and Prevotella spp. (13.5%), followed by Staphylococcus (13.2%) and Fusobacterium spp. (9.1%). Differences in the pathogen spectrum of three patient groups ('abscess', 'necrosis' and 'tumor') were also evaluated. Compared with the other two patient groups, cancer patients had significantly greater percentages of Enterobacter spp., Enterococcus spp., Pseudomonas spp. and beta-hemolytic streptococci. Substantial resistance rates to clindamycin were observed for Prevotella, Streptococcus and Staphylococcus spp. at 40.9% (95% CI [37.3-44.7%]), 34.8% (95% CI [31.8-37.9%]) and 32.3% (95% CI [28.8-35.9%]), respectively. The percentage of methicillin-resistant Staphylococcus aureus isolates was 13.8% (95% CI [9.2-19.5%]). The percentage of vancomycin-resistant Enterococcus spp. isolates was 2.8% (95% CI [0.6-8.0%]), and the percentages of extended-spectrum beta-lactamase-producing E. coli and Klebsiella spp. isolates were 1% (95% CI [0.02-5.6%]) and 2.6% (95% CI [0.8-5.9%]), respectively.

CONCLUSION

Our evaluation revealed high percentages of Enterobacterales in patients with diseases such as osteonecrosis or oral cancer. Further investigation of the role of the oral microbiota and its potential impact on the morbidity of patients with advanced disease is needed. Substantial antimicrobial resistance rates, particularly to clindamycin, pose a major concern for treating bacterial infections in the head and neck region.

Aircraft lavatory wastewater surveillance for movement of antimicrobial resistance genes: a proof-of-concept study

Long-haul flight aircraft wastewater may serve as a representative microbial footprint, often of mixed country origin, offering valuable insight into the movement of pathogens and antimicrobial resistance (AMR) on a global scale. Herein, we present a proof-of-concept for aircraft-based surveillance of AMR by investigating lavatory wastewater samples from 44 repatriation flights to Australia departing from nine countries. Profiles of pathogens including ESKAPE pathogens (Salmonella spp., Mycobacterium spp., Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa) and antibiotic resistance genes (ARGs) (aph(3')-IIIa, blaNDM-1, blaCTX_M-1, blaKPC, ermB, qnrS, sul1, tetM, and vanA) were investigated along with traditional fecal indicator bacteria (Escherichia coli and Enterococcus spp.) and fecal/urine marker genes (Bacteroides HF183, Carjivirus, human polyomavirus, and a cryptic plasmid pBI143) using quantitative PCR (qPCR). Two fecal indicator bacteria (FIB) and four human fecal/urine marker genes were detected in all aircraft wastewater samples. Detection rates for ESKAPE pathogens ranged from 6.8% (S. aureus) to 84.1% (K. pneumoniae). Of all ARG targets, aph(3')-IIIa, ermB, qnrS, sul1, and tetM were detected in all wastewater samples, whereas blaKPC and vanA were not detected in any of the samples. Results reflected geographic differences in ARG abundance originating from departure countries/continents and suggested a potential risk of importing ARGs that might be rare in local wastewater systems. The loss of nucleic acid targets was less than 10% over a 24 h incubation in the presence of disinfectants, suggesting that nucleic acids are resilient enough to persist in aircraft wastewater over the maximum duration of a flight.IMPORTANCEIn the context of international connectedness, aircraft-based wastewater surveillance should be viewed as a beyond-national tool to enhance global AMR management and foster international cooperation.

Rapid antimicrobial susceptibility tests performed by self-diluting microfluidic chips for drug resistance studies and point-of-care diagnostics

Antimicrobial resistance (AMR) is a global public health issue. Rapid and accurate antimicrobial susceptibility tests (AST) on bacteria isolates would facilitate appropriate choice of antibiotics, in which patients receive appropriate treatment and the emergence of multidrug-resistant organisms could be prevented simultaneously. In this study, we have developed a microfluidic device named Self Dilution for Faster Antimicrobial Susceptibility Testing (SDFAST). This SlipChip-based device consists of two layers of microchips, allowing injection of bacterial suspension and antibiotics by simply connecting the two chips. By slipping one microchip against another in a single press of the microchip, the antibiotics can be diluted within seconds and be well mixed with bacterial samples. By combining SDFAST with a water-soluble tetrazolium salt-8 (WST-8) assay, a range of clinically prevalent bacteria, including Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Staphylococci species, were tested under various antibiotics. Color analysis after 4-6 h of incubation showed an abrupt change in the WST-8 color of certain wells with diluted antibiotics, proving that instrument-free and immediate identification of minimum inhibitory concentration (MIC) could be achieved. The testing on 51 clinical isolates had an agreement of 92%, proving the accuracy of our method. These results validated its advantages of simple operation, rapid testing, and low sample consumption comparing to conventional methods, which require 16-24 h of incubation. Therefore, our method shows great potential to be further developed into a medical instrument for automated medical testing and point-of-care diagnosis.

[Antibiotic stewardship-an update : Ongoing development of an initiative]

The burden of disease caused by infections with antibiotic-resistant bacteria is increasing worldwide. The reason for this is the inappropriate use of antibiotics. In addition to the development of new antibiotics, their rational use is crucial to slowing down the development of resistance. Antibiotic stewardship makes an important contribution to reducing the use of antibiotics by implementing programs, particularly in hospitals. In addition, "diagnostic stewardship" supports the targeted use of infectiological diagnostics to avoid mis- and overdiagnosis, thereby optimizing anti-infective therapy. The critical review of suspected penicillin allergies ("delabeling") also promotes the sensible use of antibiotics. Findings from healthcare research on antibiotics and diagnostic stewardship are increasingly being incorporated into infectiology and sector-specific guidelines.

Synergistic combination of next-generation polymyxin MRX-8 and meropenem against carbapenem-resistant A. baumannii

MRX-8 is a new next-generation polymyxin with potent antibacterial activity against carbapenem-resistant Acinetobacter baumannii (CRAB). This study evaluated the MRX-8 and meropenem combination and their dosing regimens against CRAB in clinics. Seven CRAB strains isolated from Huashan Hospital were tested. Two strains of AB21-3881 and AB21-3759 were selected for static time-kill and the Hollow Fiber Infection Model (HFIM). Adaptive resistance to MRX-8 was assessed via population analysis profiling (PAP) at 2 mg/L of MRX-8. Multilocus sequence typing identified all seven strains as ST2. Minimum inhibitory concentration values for MRX-8 ranged from 0.5 to 1 mg/L. Synergy was observed in six out of seven (85.7%) strains. The combination of 1 mg/L MRX-8 with 1 mg/L meropenem completely inhibited bacterial growth within 24 h for both selected strains. In HFIM, the combination of MRX-8 (0.75 mg/kg q8h continuous infusion) and meropenem (1 g q6h continuous infusion) achieved synergistic killing over 72 h for AB21-3759, while single treatment of MRX-8 (0.75 mg/kg q8h continuous infusion) achieved bactericidal effect (lower than the detect limitation) over 72 h. PAP analysis demonstrated that the combinational therapy could delay the emergence of adaptive resistance sub-populations by 12-24 h. The combination of MRX-8 and meropenem demonstrated synergistic bactericidal activity by checkerboard and static time-kill curves. Additionally, in HFIM, MRX-8 at 1 mg/kg q12h combined with meropenem at 2 g q12h, as well as MRX-8 at 0.75 mg/kg q8h continuous infusion combined with meropenem at 1 g q6h continuous infusion, achieved bacteriostatic killing at 72 h compared to the initial inoculum.

Point-of-caRE DiagnostICs for respiraTOry tRact infectionS (PREDICTORS) study: developing guidance for using C-reactive protein point-of-care tests in the management of lower respiratory tract infections in primary care using a Delphi consensus technique

OBJECTIVE

Antimicrobial resistance is a significant global health challenge, exacerbated by unnecessary antibiotic prescribing. Respiratory tract infections (RTIs) are common reasons for antibiotic prescribing in primary care, despite most being viral or bacterial infections that are self-limiting. C-reactive protein (CRP) point-of-care tests (POCTs) are promising tools to support antibiotic stewardship by guiding the management of lower RTIs (LRTIs). The aim of this study was to develop best practice guidance for using CRP POCT in the management of LRTIs in primary care.

DESIGN

Scoping review findings informed guidance statements, which were then evaluated through a three-round Delphi process with an expert panel via web-based questionnaires. Statements focused on intended use, detection of bacterial LRTIs, communication strategies, device features, performance and ease of use of CRP POCT.

SETTING AND PARTICIPANTS

The panel of experts included 19 healthcare professionals across several specialties, including general practitioners, community pharmacists, hospital pharmacists and respiratory physicians.

MAIN OUTCOME MEASURES

Panellists rated each guidance statement using a 5-point Likert scale, with acceptance, revision or rejection determined using predefined cut-off scores for medians and interquartile ranges. Statements were revised between rounds using the feedback provided by panellists.

RESULTS

In the first round, 49 statements were evaluated; 16 were accepted, nine removed and 24 revised for the second round. Of the 24 statements evaluated in the second round, 17 were accepted and seven were revised. In the third round, consensus was reached on four of the seven statements presented, resulting in 37 final guidance statements. These statements covered key areas, including the appropriate use of CRP POCTs to guide antibiotic prescribing, CRP cut-off values, integration with clinical decision rules, device performance and operational considerations, training requirements and financial reimbursement. The panel emphasised the need for structured guidelines to align CRP POCT use with clinical context and highlighted its role in improving diagnostic confidence while supporting antibiotic stewardship.

CONCLUSIONS

This study provides a set of best practice guidance statements to support the use of CRP POCT in the management of LRTIs in primary care. Dissemination and further research are required to assess their impact.

Target-Guided Design and Synthesis of Aryl-Functionalized Promysalin Analogs

The development of new narrow-spectrum antibiotics is a promising approach to combat antibiotic resistance. Promysalin, a secondary metabolite isolated from Pseudomonas putida, exhibits potent species-specific inhibition of the pathogen P. aeruginosa (IC50 21 nM). Herein, the total synthesis and stereochemical assignment of promysalin, structure-activity relationship studies, and the identification of its molecular target, succinate dehydrogenase, are previously reported by the group. These findings enable computational studies of promysalin's interactions with succinate dehydrogenase, revealing a novel binding site region primed for π-π stacking interactions with a nearby tryptophan residue. It is hypothesized that new aromatic analogs of promysalin can target this beneficial interaction, potentially leading to more potent inhibitors of P. aeruginosa growth. Herein, the in silico design of these analogs, a scalable and general synthetic route to access them, and characterization of their activity against a panel of clinically relevant P. aeruginosa strains are reported.

Prospective Genomic Surveillance of Severe Febrile Illness in Tanzanian Children Identifies High Mortality and Resistance to First-Line Antibiotics in Bloodstream Infections

We evaluated the prevalence, pathogen profile, and antimicrobial resistance (AMR) patterns of bloodstream infections (BSIs) among 392 children with severe febrile illness who presented (July 26, 2022-September 20, 2023) to a referral hospital in Tanzania. We identified a causative pathogen in 9.8% (n=38) of participants. Blood culture analysis confirmed BSI in 5.2% (n=20) of participants with a case fatality rate of 45%. Whole genome sequencing (WGS) of blood culture isolates identified gram-negative bacteria ( Escherichia coli, Klebsiella pneumoniae ) as the predominant pathogens, many exhibiting extended-spectrum beta-lactamase (ESBL) resistance genes (CTX-M-15, CTX-M-27), rendering them resistant to first-line antimicrobials. We also observed probable nosocomial transmission in ventilated patients based on phylogenetic analyses of tracheal aspirate isolates. There is an urgent need for enhanced AMR surveillance, empiric antibiotic regimens tailored to local AMR patterns, culture-independent diagnostics, and robust infection control practices in resource-limited settings to mitigate BSI-related mortality and minimize nosocomial transmission risk.

Funding

NIAID K23AI144029 (TBK), NIAID K23AI185326 (VTC), Chan Zuckerberg Biohub (JLD, CRL).

Article Summary Line

Genomic surveillance of severe febrile illness in Tanzanian children reveals high mortality rates and widespread resistance to first-line antibiotics, highlighting the urgent need for tailored treatments and enhanced antimicrobial resistance monitoring.

The rise and global spread of IMP carbapenemases (1996-2023): a genomic epidemiology study

Background

IMP carbapenemases confer extensive drug resistance and are increasingly noted worldwide. Despite this, little is known regarding the global epidemiology of IMP carbapenemases.

Methods

We comprehensively identified bla IMP genes in all publicly available bacterial genomes, then systematically analysed the distribution of variants across species, lineages, plasmids and mobile elements, examining patterns over time, across geographic regions and by source. Structural analysis of IMP variants was performed.

Findings

4,556 bla IMP -containing genomes were identified from 1996-2023, including 52 bla IMP variants across 93 bacterial species. Key variants ( bla IMP-1 , bla IMP-4 , bla IMP-7 , bla IMP-8 and bla IMP-13 ) achieved global endemicity, while bla IMP-26 and bla IMP-27 were regionally endemic in Southeast Asia and North America, respectively. bla IMP dissemination was driven by horizontal gene transfer, facilitating inter-species spread. Proliferation of multidrug-resistant Enterobacter hormaechei , Pseudomonas aeruginosa and Klebsiella pneumoniae lineages led to local outbreaks. Dereplication removed 3,175/4,556 (69.9%) genomes, indicating that most bla IMP -containing genomes were highly related. bla IMP variants were associated with mobile genetic element combinations including class 1 integrons and insertion sequences (99.7%), aiding mobilisation into ≥52 plasmid clusters, predominantly IncHI2A, IncN, IncL/M and IncC. Genomes of environmental and animal origin accounted for 10.0% and 1.1% of the dataset, respectively. Evidence of cross-source transmission was limited, with most spillover occurring between genomes of human and environmental origin. Structural analysis revealed a conserved carbapenemase structure (mean lDDT 0.977), with convergent missense mutations at seven catalytically relevant sites.

Interpretation

Global analysis enabled us to historically reconstruct the emergence and variant-specific epidemiologies of bla IMP carbapenemase genes. Intersecting mobile elements enabled bla IMP genes to spread across multiple plasmids and bacterial genera, facilitating global and multi-source spread within a One Health framework. Additionally, convergent evolutionary patterns indicate that IMP variants may continue evolving, potentially evading novel beta-lactam antimicrobial agents.

Funding

NHMRC EL1 (APP1176324) to N.M.; NHMRC PF (APP1117940) to A.Y.P.; NIH/NIAID R01AI175414 to A.G-S.

Research in context panel

Evidence before this study: Despite being a major cause of carbapenem resistance in Gram negative infections, little is known about the global epidemiology of IMP carbapenemases. IMP carbapenemases are metallo-beta-lactamases that were first identified in 1991 and have evolved into 96 different IMP variants. On May 21 2025, we searched all published reports available in PubMed using the terms "'IMP' and 'carbapenemase' genomics NOT (Review[Publication Type]) NOT (Case Reports[Publication Type]) NOT PCR" with no language restrictions and no publication date restrictions. We identified 223 articles, 62 and 121 of which reported single species or a single study centre/country, respectively. Only 6 articles employed genomics to examine multi-species and multi-geographical isolates, though this was in the context of carbapenem resistance more broadly rather than IMP carbapenemases specifically. The most relevant study included 38 globally distributed genomes across four species and tracked seven blaIMP variants across mobile genetic elements.Added value of this study: To our knowledge, this global characterisation provides the most comprehensive account of bla IMP carbapenemase gene epidemiology. To analyse the global distribution and diversity of bla IMP genes, we compiled all available public genome data resulting in a dataset of 4,646 genomes. This has allowed us to identify local, regional and international spread of bla IMP variants and determine the contributions of clonal expansion, plasmid proliferation and co-localised mobile genetic elements. We demonstrated that key bla IMP variants display global (IMP-1, IMP-4, IMP-7, IMP-8 and IMP-13) and regional (IMP-26 within Southeast Asia and IMP-27 within North America) endemicity and that these patterns have been previously unacknowledged, reframing the previous understanding that IMP carbapenemases were largely confined to the Asia-Pacific region. Our observation of convergent evolutionary patterns raise concern that IMP variants may continue to evolve, potentially evading new β-lactam antimicrobials. This analysis has revealed the under-recognised contribution IMP carbapenemases make to global carbapenem resistance. Implications of all the available evidence: These findings provide the first comprehensive atlas of bla IMP carbapenemase gene dissemination and underscore the silent global spread of IMP carbapenemases. We note the critical need for enhanced surveillance systems, particularly in low- and middle-income countries, that can detect complex plasmid-mediated and mobile genetic element-associated spread, as we noted with bla IMP carbapenemase genes. Moreover, our analyses show that systematic sampling across human, animal, and environmental reservoirs is crucial to address the One Health dimensions of emerging antimicrobial resistance threats. The study provides a framework for future interventions aimed at tracking and stopping the spread of IMP carbapenemases and calls for co-ordinated, real-time public health responses to this growing challenge.