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Contribution of the Arg-33-His replacement in the histidine kinase CpxA to carbapenem and cefiderocol resistance in Serratia marcescens.

OBJECTIVE: The Serratia marcescens ROT_R clinical isolate, which was resistant to almost all β-lactams, including cefiderocol (4 mg/L), was recovered from a neonate 2 months after the isolation of the S. marcescens ROT_S strain that was susceptible to extended-spectrum cephalosporins (ESCs). In this study, we attempted to decipher the mechanism of resistance displayed by the ROT_R isolate. METHODS: The genomes of ROT_S and ROT_R were sequenced using the Illumina and the Oxford Nanopore Technologies. Long and short reads were assembled together, giving rise to a circularized hybrid genome. RESULTS: Genomic comparison between ROT_S and ROT_R disclosed only one mutation (G98A) in the cpxA gene of ROT_R, which led to the Arg-33-His substitution in the histidine kinase of the two-component system CpxA/CpxR. The cpxA alleles of ROT_S and ROT_R were amplified and cloned, thus giving rise to the pCpxA_WT and pCpxA_R33H recombinant plasmids, respectively, which were subsequently introduced into the S. marcescens HatR recipient strain, which lacks functional CpxA. The S. marcescens HatR (pCpxA_R33H) recombinant clone, which produced the altered CpxA_R33H variant, differed from the S. marcescens HatR (pCpxA_WT) recombinant clone, which produced the wild-type CpxA, by enhanced MICs of carbapenems and ESCs, including cefiderocol (1 mg/L). CONCLUSIONS: This study demonstrates that CpxA alteration, such as Arg-33-His substitution, can contribute to cefiderocol resistance. Although it increases slightly the MIC of cefiderocol without resulting per se in clinical resistance, it can contribute, in combination with other additional mechanisms, to achieve a high level of resistance to this siderophore cephalosporin.

Cefiderocol

The Long Road to Long-Acting: What Oral PrEP and CAB-LA Teach Us About Scaling Lenacapavir.

Despite significant biomedical advances, human immunodeficiency virus (HIV) remains a persistent global health crisis, with over 40 million people affected as of 2023, two-thirds of whom live in the World Health Organization (WHO) African Region. However, from an HIV prevention perspective, the more urgent concern is the continued occurrence of approximately 1.3 million new infections annually, particularly in sub-Saharan Africa and in settings where incidence is stable or increasing. This commentary explores the evolving landscape of HIV prevention, focusing on the trajectory of oral pre-exposure prophylaxis (PrEP), long-acting injectable cabotegravir (CAB-LA), and the newly emerging lenacapavir. While oral PrEP opened new possibilities, adherence challenges have limited its impact. CAB-LA demonstrated superior efficacy but encountered access, cost, and delivery barriers that restricted uptake. Lenacapavir, offering 6-monthly subcutaneous dosing with ≥ 99.9% efficacy in trials, holds the potential to overcome these hurdles. As of May 2026, lenacapavir had received regulatory approval in 17 countries, including several African nations, while regulatory reviews remained ongoing in multiple additional countries, reflecting the rapid global expansion of access to this long-acting HIV prevention option. However, its success depends on clinical promise, timely licensing, affordability, and integration into health systems. Drawing from real-world lessons of oral PrEP and CAB-LA, this paper argues that a proactive, coordinated rollout of lenacapavir could dramatically expand prevention reach. With global stakeholders aiming for 3 million users by 2028 and strategic licensing in 120 countries, the groundwork is in place. The recent release of WHO guidance recommending lenacapavir as an additional PrEP option further strengthens this momentum. Yet, equitable delivery, user-centred models, and strong policy backing will be critical. Ultimately, long-acting PrEP is not just a clinical breakthrough; it is a test of health systems' ability to deliver innovation at scale.

Humans

Herd-level heterogeneity of antimicrobial resistance in commensal Escherichia coli: A nationwide high-throughput survey of Australian pig herds.

Antimicrobial resistance in commensal Escherichia coli provides a useful indicator for overall antimicrobial resistance burden. We applied this approach to assess antimicrobial resistance within and between commercial pig herds across Australia. A high-throughput robotic workflow was used to isolate 2730 E. coli colonies from rectal contents collected in 2022 from healthy slaughter pigs (n = 300) representing 30 herds (∼70% of national production). Up to 94 isolates per herd underwent antimicrobial susceptibility testing using the Robotic Antimicrobial Susceptibility Platform. Isolate- and herd-level antimicrobial resistance indices were calculated, weighting antimicrobials by their human health importance. Resistance to first-line agents was widespread: ampicillin 77% and tetracycline 79%. By contrast, resistance to critically important antimicrobials was rare (ciprofloxacin 0.11%; extended-spectrum cephalosporins 0.04%), and no clinical resistance to carbapenems or colistin was detected. Overall, 56.9% of isolates were multi-class resistant. Herd-level antimicrobial resistance within indices ranged from 1.51 to 5.76, revealing substantial between-herd heterogeneity. Three herds carried critically important antimicrobials-resistant isolates that would likely have been missed using conventional, lower-density sampling approaches. Whole-genome sequencing identified fluoroquinolone-resistant isolates belonging to ST10 and ST69 (both qnrS1), and ST744 (Quinolone Resistance Determining Region mutations plus blaCTX-M-27). By testing approximately tenfold more isolates than conventional surveys, we uncovered considerable antimicrobial resistance with heterogeneity within and between animals and herds, including farm-specific variability. This expanded sampling also enabled detection of critically important antimicrobial resistance at very low prevalence. In conclusion, high-throughput, high-density testing offers a practical early-warning system and herd-level benchmark to inform surveillance and targeted interventions.

Animals

Comparing the efficacy of chlorhexidine and povidone-iodine for surgical site disinfection: a systematic review and meta-analysis from randomized controlled trials.

BACKGROUND: Randomized controlled trials report conflicting evidence on the efficacy of different skin disinfectants for preventing surgical site infection (SSI). METHODS: We systematically searched PubMed, Web of Science, Cochrane Library, and Embase for RCTs published up to February 2025 comparing preoperative skin disinfection with povidone-iodine (PVI) versus chlorhexidine (CH). Primary outcomes were overall, superficial, deep, and organ/space SSI rates. Secondary outcomes included hospital stay, readmission, and reoperation. RESULTS: CH was superior to PVI in preventing overall SSI (26 studies, n = 29,356; RR: 0.89; 95% confidence interval [CI]: 0.80 to 0.99). The overall SSI incidence rate in the CH group was 7.1% (1,045/14,677), compared with 7.8% (1,152/14,679) in the PVI group, equating to an 11% reduction in relative risk and a 0.7% reduction in absolute risk. The number needed to treat to prevent one SSI was 143. CH demonstrated superiority over PVI in preventing superficial SSI (13 studies, n = 16,867; RR: 0.77; 95% CI: 0.64 to 0.92), but not for deep SSI (11 studies, n = 15,842; RR: 1.00; 95% CI: 0.77 to 1.29) or organ SSI (9 studies, n = 9,471; RR: 1.17; 95% CI: 0.89 to 1.53). No significant differences were found in hospital stay, readmission, or reoperation rates between the two groups. CONCLUSION: CH demonstrates statistical superiority over PVI in preventing overall and superficial SSI, though the absolute clinical benefit is modest. No significant differences were observed for deep or organ/space SSI, nor for secondary outcomes including hospital length of stay, readmission, or reoperation rates.

Humans

Diverse structures of mcr-10-bearing plasmids and high colistin resistance in Enterobacter cloacae complex clinical isolates from South Korea.

BACKGROUND: The emergence of mcr-mediated colistin resistance in Enterobacter cloacae complex (ECC) poses a significant threat to antimicrobial therapy. Among mcr variants, mcr-10 has been identified in various environments, but its genetic diversity, structural context, and functional role in colistin resistance remain unclear. METHODS: We investigated 183 ECC isolates and identified 60 colistin-resistant strains through minimum inhibitory concentration (MIC) testing. The presence of mcr-10 was screened using reference genomes from NCBI, and whole plasmid sequencing was conducted on mcr-10-positive isolates. The genetic environment of mcr-10 was analyzed via synteny and structural annotation. RESULTS: Whole-plasmid sequencing of eight mcr-10-positive ECC isolates identified three replicon types among the mcr-10-harboring plasmids: IncFIB (n=3), IncFII (n=3), and IncFII/IncFIB (n=2). Although all plasmids shared the xerC-mcr-10 cassette, they lacked a conserved backbone and showed diverse genetic contexts with variable insertion sequences near mcr-10, indicating marked structural heterogeneity. No additional antimicrobial resistance genes were detected on these plasmids. When introduced into E. coli DH5α, the plasmids increased colistin MICs only modestly, whereas representative plasmids transferred into colistin-susceptible E. roggenkampii and E. kobei conferred high-level resistance comparable to that of the parental mcr-10-positive isolates. Consistently, qRT-PCR showed higher mcr-10 expression in ECC transformants than in E. coli under colistin exposure, supporting a hostdependent effect on mcr-10-mediated colistin resistance. CONCLUSION: These findings highlight the diversity of mcr-10-carrying plasmids and suggest that mcr-10-mediated colistin resistance is shaped by the host genetic background. Further studies are needed to clarify the mechanisms underlying mcr-10 expression.

Colistin

A Randomized Clinical Trial to Compare Moxifloxacin Versus Azithromycin for the Treatment of Mycoplasma genitalium: The FARTHEST Study.

BACKGROUND: Mycoplasma genitalium (MG) is increasingly characterized by high rates of macrolide and fluoroquinolone resistance. International guidelines recommend resistance-guided therapy; however, access to genotypic testing is limited, and randomized trial evidence is lacking. We assessed the efficacy of moxifloxacin and azithromycin without resistance assays. METHODS: This monocentric, open-label, superiority, randomized controlled trial enrolled adults with MG infection detected by multiplex PCR, randomized 1:1 to receive moxifloxacin 400 mg daily for 10 days or azithromycin 500 mg daily for 6 days. A test of cure was performed ≥28 days after treatment completion. The primary endpoint was microbiological cure in the intention-to-treat (ITT) and per-protocol (PP) populations. Subgroup analyses assessed symptomatic versus asymptomatic infections, doxycycline exposure, re-treatment, and sexual behavior. RESULTS: Among 358 randomized participants, 87.0% of those treated with moxifloxacin and 61.2% of those treated with azithromycin achieved microbiological cure in the ITT analysis (absolute risk difference 25.8%, 95% CI 16.5, 35.2). The superiority of moxifloxacin was confirmed in the ITT and PP populations. Moxifloxacin remained superior across most subgroups, whereas azithromycin showed comparable efficacy only among heterosexual individuals. Doxycycline coadministration did not improve outcomes. Both regimens were well tolerated, with only one case of discontinuation. CONCLUSIONS: Moxifloxacin demonstrated superior efficacy compared to azithromycin for treating MG infection in the absence of resistance testing. These randomized data support the use of moxifloxacin as a first-line option when resistance assays are unavailable and may inform treatment strategies.

Humans

Pharmacokinetic and Pharmacodynamic Bio-Similarity of ADL-018 to Innovator Omalizumab: A Randomized Study in Healthy Adults.

Bioequivalence and safety of ADL-018, an omalizumab biosimilar, were compared with United States-licensed omalizumab (US-OMA) and European Union-approved omalizumab (EU-OMA), both approved for allergies. Healthy adults were randomized (1:1:1) to receive a dose of ADL-018, US-OMA, or EU-OMA (150 mg/mL). Pharmacokinetic (PK) parameters, including AUC(0-last), AUC(0-∞), and Cmax, were considered equivalent if 90% CIs of geometric mean ratios (GMRs) were within predefined equivalence margin (0.80-1.25) using ANCOVA model. Other PK parameters, pharmacodynamics (PD) (free/total immunoglobulin E [IgE]), immunogenicity, and safety were compared. Overall, 306 participants (n = 102 per arm) were dosed; 287 completed the study. Equivalence of primary PK parameters was confirmed for pairwise comparisons, with 90% CIs within the predefined margin (GMRs of ADL-018 vs US-OMA: AUC(0-last)-1.08, AUC(0-∞)-1.07, Cmax-1.05; GMRs of ADL-018 vs EU-OMA: AUC(0-last)-1.06, AUC(0-∞)-1.06, Cmax - 1.05; and GMRs of US-OMA vs EU-OMA: AUC(0-last)-0.99, AUC(0-∞)-0.99, Cmax-1.00). PK/PD parameters were comparable across arms. Increase in total IgE (AUEC ∼30,000 to 35,000 h IU/mL) and decrease in free IgE (AUEC ∼29,000 to 35,000 h IU/mL) were comparable across arms. Similar incidence of adverse events across arms (treatment-emergent adverse events: ADL-018, n = 6; US-OMA, n = 5; EU-OMA, n = 4) was observed. ADL-018 demonstrated PK/PD equivalence and comparable safety profile to reference omalizumab.

Humans

A prospective pharmacokinetic interaction study between rifampicin and fusidic acid for the treatment of staphylococcal infections.

OBJECTIVE: Fusidic acid with rifampicin is used for the treatment of severe staphylococcal infection, particularly prosthetic joint infections. Previous studies using twice daily fusidic acid showed rifampicin increases fusidic acid clearance, potentially causing sub-therapeutic concentrations. It is uncertain whether this occurs with three-times daily dosing. This study sought to re-evaluate this potential drug-drug interaction. METHODS: In this prospective, open-label drug-drug interaction population pharmacokinetic (PK) study, participants were randomized to receive fusidic acid or rifampicin for 24 hours, followed by combination therapy for the duration of treatment. Drug concentration assays used liquid-chromatography mass spectroscopy on dried blood spots. Population PK models were built for fusidic acid, rifampicin and 25-desacetyl rifampicin. RESULTS: Ten participants were recruited. Inter-individual variability for both absorption (98.1%) and clearance (77.8%) were high for fusidic acid. A population pharmacokinetic model for fusidic acid revealed that early autoinhibition dominated over later rifampicin-mediated induction, resulting in a net decrease in fusidic acid clearance. The mean fusidic acid area under the curve during each dosing interval (AUCτ) at steady state was 1.76-fold [0.049, 34.918] higher relative to Day 1, despite high uncertainty.Large inter-individual (110%) variability in absorption was observed for rifampicin. There was no apparent effect on rifampicin metabolism by fusidic acid co-administration, however, fusidic acid decreased clearance of 25-desacetyl rifampicin. CONCLUSION: In patients treated with fusidic acid three times daily in combination with rifampicin, autoinhibition potentially counteracted rifampicin induction such that fusidic acid concentrations were not reduced. Rifampicin clearance was not affected by fusidic acid, but 25-desacetyl rifampicin clearance was decreased. There was large inter-individual variability in the observed concentrations and final parameter estimates.

Fusidic Acid

"Clinical efficacy and expression of antimicrobial resistance genes after using a novel herbal mouthwash compared to chlorhexidine: A Randomised controlled trial in generalised gingivitis patients".

OBJECTIVES: Chlorhexidine, the gold-standard mouthwash, has several disadvantages, like promotion of antimicrobial resistance. Herbal mouthwashes are emerging as alternatives to chlorhexidine. However, its impact on antimicrobial resistance remains unclear. The aim of the study was to compare the clinical efficacy and the expression of antimicrobial resistance genes of chlorhexidine with a novel herbal mouthwash. DESIGN: Sixty patients with generalised gingivitis were randomly assigned to two groups using block randomisation. After professional mechanical plaque removal patients were instructed to use either chlorhexidine or a novel herbal mouthwash (patented composition) for two weeks. Tetracycline resistance (tetM) and macrolide efflux (mefI) gene expression in subgingival plaque were analysed using real-time polymerase chain reaction. Intragroup comparisons were performed with a paired t-test and Wilcoxon signed-rank test for parametric and nonparametric data. Intergroup comparisons employed unpaired t-test, chi-square test, and Mann-Whitney test. RESULTS: A significant reduction in bleeding, plaque, pocket depth and and patient reported outcomes were noticed in both groups. But reduction in plaque was more significant in chlorhexidine group. tetM and mefI genes significantly upregulated in the chlorhexidine group, while it was downregulated with herbal mouthwash (fold change 1.79 ± 0.74 and 0.60 ± 0.43 for tetM, and 1.83 ± 0.87 and 0.51 ± 0.44 for mefI). However, patients' perception of taste, freshness, and overall satisfaction was better in the chlorhexidine group. CONCLUSIONS: The increased expression of antimicrobial resistance genes following chlorhexidine use warrants careful consideration. Herbal mouthwash is an effective, safer alternative with comparable clinical benefits and less impact on antimicrobial resistance.

Humans

Acceptability of alcohol-based hand rub during neonatal care in rural Ugandan households: a qualitative study nested within the BabyGel trial.

BACKGROUND: Poor access to water, sanitation and hygiene exacerbates the spread of infections among newborns. The BabyGel cluster randomised trial assessed the effectiveness of a community-level alcohol-based hand rub with a training component in reducing infection or death rates among newborns in Uganda. OBJECTIVE: Nested in the BabyGel trial, this study investigated the acceptability of the BabyGel intervention among mothers and household members in Eastern Uganda, using the Theoretical Framework of Acceptability. METHODS: In 2022, we conducted individual semistructured interviews with mothers, and group interviews with mothers and other household members, all recruited from intervention-arm clusters. Thematic analysis combined inductive and deductive coding, structured by the framework's seven constructs: affective attitude, burden, ethicality, intervention coherence, opportunity costs, perceived effectiveness and self-efficacy. RESULTS: Twenty mothers and 14 household members participated in 10 individual and 10 small group interviews. Participants found the intervention generally acceptable, appreciating its convenience and perceived protection against infection. Many described hand hygiene changes that persisted beyond the intervention period. However, concerns related to its harmful effects, spiritual beliefs and social tensions with visitors occasionally influenced its use. CONCLUSION: Alcohol-based hand rub combined with a training component was generally well accepted, driven by perceived health and practical benefits, although concerns related to safety, belief systems and social dynamics remained. Because data collection coincided with the COVID-19 pandemic, a period of heightened hygiene awareness, the acceptability observed could differ in nonpandemic periods. Culturally adapted education, community engagement and reinforcement of correct use may enhance acceptability and sustainability in similar settings.

Humans

Ecr positively regulates activity of the PhoQ/PhoP signalling system in Klebsiella pneumoniae.

BACKGROUND: The rising prevalence of polymyxin resistance in multidrug-resistant Klebsiella pneumoniae presents a critical situation with limited therapeutic options. METHODS: Methods Genomic sequencing of 15 clinical polymyxin-resistant K. pneumoniae strains with multidrug resistance revealed that MgrB inactivation, predominantly disrupted by insertion sequences (ISs) in the IS1, IS4, and IS5 families, was the leading cause of polymyxin resistance. Comparative transcriptomics of wild-type, ΔmgrB, and ΔmgrBΔphoP were performed to elucidate the MgrB-PhoPQ regulatory network. RESULTS: This study conducted a system-wide analysis of the regulatory network and identified a species-specific PhoPQ regulon in K. pneumoniae.Beyond the classical MgrB-PhoPQ-ArnBCADTEF pathway, we identified a previously unannotated PhoPQ-regulated gene, 144 bp LN739_RS09850, encoding an Ecr homologue from Enterobacter cloacae. This protein has been reported to confer colistin heteroresistance, with the underlying mechanism not yet functionally validated. This study revealed that overexpression of Ecr homologues decreased colistin susceptibility in both K. pneumoniae and E. cloacae, but this phenotype was abolished upon phoP deletion, confirming PhoP's essential role. Consistent with this dependency, comparative transcriptomics of Ecr-overexpressing K. pneumoniae vs. control revealed significant upregulation of mgrB, phoPQ, arnBCADTE, and pmrD. Two-hybrid bacterial assays further demonstrated direct Ecr-PhoQ interaction. Electrophoretic mobility shift assay confirmed that PhoP directly binds to the ecr promoter in vitro, and a β-galactosidase reporter assay demonstrated that PhoP enhanced ecr promoter activity, indicating that PhoP regulates ecr expression by directly controlling its transcription. CONCLUSION: Collectively, these findings suggest that PhoP may directly activate the transcription of Ecr, with Ecr feedback activating the PhoPQ system via interaction with PhoQ, leading to induction of the arn operon and consequent polymyxin resistance.

Klebsiella pneumoniae

Antibiotic-impregnated bone graft to prevent infection after total hip arthroplasty (ABOGRAFT): protocol for a randomised, double-blind, placebo-controlled trial.

INTRODUCTION: Studies have shown promising results using bone graft as a carrier for local administration of antibiotics to reduce the risk of prosthetic joint infection (PJI). The objective of this clinical trial is to determine if tobramycin and vancomycin-impregnated bone graft is safe and effective in reducing the rate of PJI after total hip arthroplasty (THA). METHODS AND ANALYSIS: This study is an international, randomised, double-blinded, placebo-controlled clinical drug trial. Patients scheduled for THA (n=1100) requiring bone grafting (excluding revisions due to an ongoing infection) are randomised in a 1:1 ratio to prophylactic treatment with tobramycin and vancomycin or placebo-impregnated bone graft.The primary outcome is the time to reoperation due to infection or diagnosis of PJI, expressed as a relative risk difference between the two groups. A risk reduction of at least 50% is considered clinically relevant. Secondary outcomes are time to and reason for reoperation and implant revision, type of micro-organism and antibiotic susceptibility pattern within 2 and 5 years after surgery. Safety outcomes are the number of adverse events and revision rate due to aseptic loosening. The primary analysis will be performed using proportional hazard models. ETHICS AND DISSEMINATION: The study has been approved under the Clinical Trial Regulation No 536/2014 (EU CT; 2024-510921-25-00). Results will be published in open-access peer-reviewed journals and disseminated to patient organisations and the media, and de-identified individual participant data will be curated and shared on reasonable request in accordance with the Findability, Accessibility, Interoperability and Reuse principles, subject to the laws and regulations governing data protection in each participating country. TRIAL REGISTRATION NUMBER: NCT05169229.

Humans

Copper-Containing Surface Engineering for Soft-Tissue Biomedical Devices: Structure-Function Relationships and Ion Release-Driven Biological Performance, A Systematic Review.

Copper and copper-based materials have gained increasing attention for the functional modification of implantable medical devices intended for prolonged soft-tissue contact, including vascular stents, catheters, and intrauterine devices. Owing to their broad-spectrum antimicrobial activity, redox reactivity, and involvement in angiogenesis and cellular signaling, copper-based systems offer significant potential for multifunctional surface engineering. However, achieving a balance between antibacterial efficacy, corrosion behavior, controlled ion release, and cytocompatibility remains a critical challenge. This PRISMA-compliant systematic review analyzes copper-containing materials and surface modification strategies for soft-tissue biomedical applications. A structured search of Scopus, Web of Science, and PubMed (2015-2025) identified 65 eligible studies. The review encompasses bulk copper-containing alloys, electrochemical and chemical surface modification techniques, physical vapor deposition approaches, and advanced hybrid systems integrating copper with polymers, hydrogels, or metal-phenolic networks. Across the reviewed literature, antibacterial performance was strongly dependent on copper concentration, microstructural distribution, and spatiotemporal ion release profiles. Moderate, well-controlled copper incorporation frequently improved antibacterial efficacy while maintaining acceptable hemocompatibility and cytocompatibility, particularly in vascular and blood-contacting devices. In contrast, excessive copper loading often accelerated corrosion and induced adverse cellular responses. Emerging multifunctional architectures demonstrated improved regulation of biological interactions, enabling simultaneous antibacterial, antithrombotic, and proendothelial effects. Overall, copper-based surface technologies represent a versatile platform for soft-tissue implant modification. Future translational progress will require precise control of copper release kinetics and comprehensive long-term in vivo validation to ensure safety and sustained therapeutic performance. From the authors' perspective, the most promising future direction involves multifunctional copper-based hybrid coatings capable of dynamically regulating ion release, host tissue integration, and antibacterial performance simultaneously. Strategies integrating hierarchical architectures, stimulus-responsive release systems, and clinically scalable fabrication methods are expected to play a key role in translating copper-containing surfaces from experimental concepts toward commercially viable soft-tissue biomedical devices.

Copper

From buffalo to human: Klebsiella pneumoniae in high-somatic cell count milk as an overlooked link in the one health chain.

High somatic cell count (SCC) is a critical indicator of udder health and milk quality in buffalo milk production. However, in many low-income regions, SCC monitoring is often underemphasized, allowing a proportion of high-SCC buffalo milk to enter the food chain and potentially compromising food safety and public health. Klebsiella pneumoniae (K. pneumoniae) is a common zoonotic pathogen found in high-SCC milk, yet systematic investigations into the prevalence and characteristics in high-SCC buffalo milk remain limited. In this study, 23 K. pneumoniae strains were screened out from 460 bacterial isolates obtained from high-SCC buffalo milk samples from Guangxi, China, with an isolation rate of 5.0%. These isolates were comprehensively characterized using whole-genome sequencing and comparative genomic analyses. The results revealed that 78.26% (18/23) of the isolates shared high genomic similarity with the human reference strain ATCC 13883, and the ST37 clone exhibited a pronounced potential of cross-species transmission. All isolates harbored core adhesion factors and intrinsic resistance genes. Notably, several strains displayed high-risk features: strain 419 carried the K1 capsular serotype, strain 326 possessed a complete yersiniabactin synthesis gene cluster, and strain 320 exhibited a multidrug-resistant phenotype. Phenotypic assays further demonstrated a positive correlation between biofilm formation capacity and virulence in Galleria mellonella. Metabolic pathway enrichment analyses suggested that K. pneumoniae has undergone substantial adaptation to the nutrient-rich buffalo milk environment. Collectively, these findings confirm that raw high-SCC buffalo milk serves as a significant reservoir for high-risk zoonotic K. pneumoniae. While industrial thermal processing effectively eliminates viable pathogens, the resilient antimicrobial resistance determinants within these isolates pose a persistent risk of horizontal gene dissemination along the food chain, providing critical evidence for enhancing pre-processing milk quality regulations within a One Health framework.

Animals

Comparison of Keverprazan-based versus esomeprazole-based dual therapy for initial treatment of Helicobacter pylori infection: a prospective, multicenter, randomized controlled trial.

BACKGROUND: Keverprazan offers a new perspective for Helicobacter pylori eradication. This study compared 14-day keverprazan-amoxicillin therapy with esomeprazole-amoxicillin therapy to explore a superior treatment strategy. METHODS: This was a prospective, open-label, multicenter, randomized controlled trial in adult patients with treatment-naive H. pylori infection. Participants were randomly assigned to receive either 14-day of KA therapy (Keverprazan 20&#x2009;mg b.i.d plus amoxicillin 1&#x2009;g t.i.d) or 14-day of EA therapy (Esomeprazole 40&#x2009;mg b.i.d plus amoxicillin 1&#x2009;g t.i.d). The primary outcome was the H. pylori eradication rate. Secondary outcomes were the incidence of adverse events and patient adherence. RESULTS: A total of 264 patients were enrolled in the study. In the intention-to-treat (ITT) analysis, the eradication rates for the 14-day KA group and the 14-day EA group were 87.9% and 80.3%, respectively (p&#x2009;=&#x2009;0.092); in the modified intention-to-treat (mITT) analysis, the eradication rates were 92.1% and 86.2%, respectively (p&#x2009;=&#x2009;0.135); and in the per-protocol (PP) analysis, the eradication rates were 93.5% and 88.3%, respectively (p&#x2009;=&#x2009;0.155). Non-inferiority was confirmed between the two groups (all p&#x2009;<&#x2009;0.001). Adverse events and patient adherence were similar between the two groups. CONCLUSION: For treatment-naive H. pylori infection, the 14-day KA therapy is non-inferior to EA therapy. Given its good tolerability, pharmacogenomic independence, and potent acid suppression, KA is a rational first-line alternative to EA in the Chinese population.

Humans

Genomic and food-safety evaluation of Staphylococcus chromogenes in Chinese dairy milk.

Non-aureus staphylococci and mammaliicocci (NASM) cause mastitis and may contaminate milk and dairy products. Milk samples (n&#xa0;=&#xa0;1916) from cows with subclinical or clinical mastitis (SCM and CM, respectively) were collected from 28 large-scale (> 500 lactating cows) Chinese dairy farms. Overall, 999 NASM isolates representing 19 species were identified by MALDI-TOF MS and cpn60 sequencing, with Staphylococcuschromogenes, Mammaliicoccus sciuri and Staphylococcus haemolyticus being most prevalent. Antimicrobial resistance (AMR) was determined with disc diffusion; non-susceptible to penicillin was most common (SCM, 30% and CM, 29%) whereas cefoxitin non-susceptible NASM accounted for 8-10% of isolates; among these, 12.5% carried mecA but none carried mecC. Galleria mellonella was used to assess virulence of 78 strains of S. chromogenes, a dominant species; subsequently, 32 strains, representing higher- and lower-virulence in the Galleria model, were selected for whole-genome sequencing and comparative genomics. S. chromogenes isolates from CM had higher virulence (p&#xa0;<&#xa0;0.05) than those from SCM. The 32 genomes comprised 20 sequence types, indicating high genetic diversity. No robust genomic marker of Galleria virulence phenotype was identified in this selected WGS subset. Acquired resistance genes (n&#xa0;=&#xa0;5) were detected, including a first report of fusC in S. chromogenes; the fusC-positive isolate had an elevated fusidic acid MIC (8&#xa0;mg/L). Although S. chromogenes persisted in milk at 4&#xa0;&#xb0;C, pasteurization (64&#xa0;&#xb0;C for 30&#xa0;min) reduced viable counts to below detection. This study provided new insights into the prevalence, AMR, genomic diversity, and dairy-chain relevance of milk-derived NASM, particularly S. chromogenes. However, the genomic findings were based on an intentionally selected WGS subset and should be interpreted as hypothesis-generating rather than population-representative.

Animals

Cefiderocol susceptibility rates in carbapenem-resistant Gram-negative bacteria in a comparative, multicenter surveillance study in China.

BACKGROUND: Cefiderocol is a siderophore cephalosporin with potent, broad spectrum of activity against carbapenem-resistant (CR) Gram-negative bacteria. The objective of this surveillance study was to assess cefiderocol susceptibility in molecularly characterized CR Gram-negative pathogens collected from hospitalized patients across China. METHODS: Susceptibility testing was performed by the broth microdilution method according to Clinical and Laboratory Standards Institute guidelines, using pre-prepared frozen 96-well microtiter Thermo Fisher plates. Susceptibilities to cefiderocol and most comparators were determined by Clinical and Laboratory Standards Institute breakpoints, to tigecycline by US Food and Drug Administration breakpoints, and to colistin by European Committee on Antimicrobial Susceptibility Testing criteria. Carbapenemases were identified by whole-genome sequencing and polymerase chain reaction. RESULTS: Of 149 CR Klebsiella pneumoniae, 95.3% were susceptible to cefiderocol (OXA-48-positive 100% [n = 15]; IMP-positive 100% [n = 9]; KPC-positive 95.4% [n = 108]; NDM-positive 88.2% [n = 17]) and against 103 NDM-positive CR Escherichia coli, cefiderocol susceptibility was 45.6%. Among comparator antibiotics, ceftazidime-avibactam was only active against K. pneumoniae carbapenemase-positive and OXA-48-positive K. pneumoniae isolates. Susceptibilities to tigecycline and colistin were between 22.2% and 97.1% and between 88.2% and 100% across CR Enterobacterales with different carbapenemases, respectively. High cefiderocol susceptibility rates were found for CR Pseudomonas aeruginosa (98.4%), CR Acinetobacter baumannii (99.6%), and Stenotrophomonas maltophilia (99.6%). Among comparator antibiotics, only colistin showed high activity against CR P. aeruginosa (99.2%) and CR A. baumannii (99.2%). CONCLUSIONS: Cefiderocol susceptibility rates were &#x2265;88% against a collection of carbapenemase-positive CR Gram-negative isolates, except for lower susceptibility in NDM-positive CR E. coli isolates. Continuous monitoring of cefiderocol susceptibility is warranted.

Cefiderocol

Predictors of Treatment Failure in Children With HIV Starting First-line Antiretroviral Therapy in the ODYSSEY Trial.

BACKGROUND: Data on predictors of treatment failure in children starting antiretroviral therapy (ART) are limited, particularly on dolutegravir-based regimens (DTG). METHODS: ODYSSEY demonstrated superior efficacy of DTG versus standard-of-care (SOC). We assessed predictors at ART initiation of treatment failure by 96 weeks. RESULTS: Three hundred and eighty-one children started first-line ART (82% African). At ART-initiation, median age was 10.5 years (IQR: 6.5, 14.0, 67 < 3 years), CD4% 20% (IQR: 12, 28), BMI-for-age Z-score -.58 (IQR:-1.48, +.25). One hundred and eighty-nine children started DTG, 192 started SOC (91% &#x2265;3 years started efavirenz; 79% <3 years started lopinavir). Seventy-five children experienced treatment failure (24 DTG, 51 SOC). Failure risk was lower on DTG than SOC (hazard ratio [HR] = 0.47, 95% CI: 0.29-0.77, P = .002). Lower BMI-for-age Z-score (HR = 0.82 for each unit gain, 95% CI: 0.70-0.96, P = .01) and being at an African site (HR = 2.09, 95% CI: 0.82-5.31, P = .09) were associated with higher failure risk. Risk was also higher at younger ages with the steepest increase in the youngest children and increased at lower CD4%, with a stronger CD4% effect at younger ages. At CD4% = 20, HRs relative to age 10 years were 2.40 (95% CI: 1.58-3.65) at age 1 year, 1.30 (95% CI: 1.15-1.48) at age 5 years, and 0.80 (95% CI: 0.72-0.89) at age 18 years. At age 1 year, HRs relative to CD4% = 20 were 1.39 (95% CI: 1.16-1.66) at CD4% = 15, and 0.52 (95% CI: 0.36-0.75) at CD4% = 30; at age 10, corresponding estimates were 1.07 (95% CI: 0.94-1.20) at CD4% = 15, and 0.88 (95% CI: 0.69-1.13) at CD4% = 30. CONCLUSIONS: Young age, low BMI-for-age, and low CD4% at ART initiation predicted higher risk of treatment failure and can guide targeted support.

Humans