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Development of a new recombineering system for Edwardsiella species.

Edwardsiella species are important aquaculture pathogens that also cause opportunistic infections in humans, necessitating efficient genome editing tools to study their pathogenesis and develop control strategies. In this study, we identified and characterized six endogenous recombinases pairs from Edwardsiella and its phages. Among these, the BAS_MS17 system exhibited the highest recombination efficiency in E. piscicida EIB202Δp. Extending homology arms from 150 bp to 200 bp improved editing efficiency by 2-fold, while the addition of Redg or Plug further enhanced recombination by 3-fold and 2.5-fold, respectively, without compromising accuracy (100%). More importantly, when applied to E. piscicida sdu12S, Redg or Plug improved the editing efficiency by 8-fold and 7-fold, respectively. Deletion of the phage-derived single-strand binding protein (SSB) reduced efficiency to 25% of the BAS_MS17 level, whereas expression of the endogenous RecA-family SSB (rSSB) increased recombinant yield by 5-fold, highlighting functional conservation. Furthermore, SSB proteins from heterologous hosts failed to enhance recombination efficiency. Using the optimized system, we successfully knocked out ten distinct genes, including virulence-associated loci, with editing accuracy exceeding 85%. Phenotypic analysis revealed that luxR, but not the other tested genes, contributes to biofilm formation. Virulence evaluation results showed that aroA, fur, and hfq are critical virulence-associated factors. Collectively, this streamlined recombineering system provides a simple, rapid, and efficient genetic tool for Edwardsiella, supporting mechanistic studies of virulence and the development of live attenuated vaccine candidates.

Edwardsiella piscicida

Molecular characterization and biological characteristics of a highly pathogenic recombinant ALV-J strain (HUE2023) with cross-clade gp85 recombination.

Avian leukosis virus subgroup J (ALV-J) has undergone extensive diversification into phylogenetically distinct clades, yet whether recombination between these clades within the gp85 envelope glycoprotein generates variants with altered pathogenicity has received little direct investigation. A field strain (HUE2023) was recovered from breeding roosters displaying vascular tumors. The viral genome was sequenced and subjected to phylogenetic and recombination analyses. The three-dimensional structure of gp85 was predicted with AlphaFold3; electrostatic surface potentials and surface hydrophobicity were computed using the Adaptive Poisson-Boltzmann Solver and the Eisenberg hydrophobicity scale, respectively. Pathogenicity and immunosuppressive effects were assessed in Hy-Line Brown chickens. Recombination analysis revealed that HUE2023 is an inter-clade recombinant derived from Clade 1.1 (major parent: JS14NT01) and Clade 1.2 (minor parent: JS09GY3). A single-residue deletion at position 61 within receptor-binding domain 1 (RBD-1), unique to the recombinant, induced a localized conformational rearrangement that generated a concentrated electronegative surface patch and a contiguous hydrophobic pocket not observed in either parental gp85. Animal challenge showed that HUE2023 is highly pathogenic: female chickens in the high-dose group reached only 61% survival and displayed significant growth retardation (P&#x202f;<&#x202f;0.05) together with marked immunosuppression. The recombination in the RBD-1 led to local conformational rearrangement, resulting in a concentrated and negatively charged surface area as well as a continuous hydrophobic pocket, which were never present in any of the parental gp85 sequences. These results indicate that gp85 recombination across clades can yield variants with fundamentally altered receptor-binding surfaces and argue for integrating structural surveillance into ALV-J monitoring programmes.

Animals

An Update on Inborn Errors of V(D)J Recombination.

V(D)J recombination is the fundamental process by which developing T and B lymphocytes generate diverse antigen receptors, enabling adaptive immunity. This tightly regulated program operates exclusively in lymphoid precursors during G1 phase and depends on the lymphocyte-specific RAG1-RAG2 recombinase to introduce programmed DNA double-strand breaks at recombination signal sequences, followed by repair through the classical nonhomologous end joining (c-NHEJ) pathway. Disruption of any step in this molecular choreography compromises antigen receptor diversity and underlies a spectrum of inborn errors of immunity (IEIs), ranging from severe combined immunodeficiency (SCID) to immune dysregulation with autoimmunity and granulomatous disease. In this review, we place disorders of V(D)J recombination within the broader framework of T-cell development, detailing the temporal waves of recombinase activity, chromatin accessibility, and DNA damage responses that guide thymocyte differentiation. We discuss pathogenic variants affecting the cleavage phase [RAG1, RAG2, and the recently identified RAG cochaperone NudC domain-containing 3 (NUDCD3)], end processing (ARTEMIS), ligation and repair (LIG4, XLF, XRCC4, PRKDC), and genome surveillance pathways (ATM, MRN complex, RNF168), highlighting genotype-phenotype correlations and mechanisms driving immune deficiency and dysregulation. We briefly review recent diagnostic advances, including newborn screening using T-cell receptor excision circles, repertoire sequencing, and functional assays, alongside current therapeutic strategies. Finally, we outline key unanswered questions and argue that continued integration of clinical observation with molecular discovery is essential to improve outcomes and deepen understanding of adaptive immune development.

Humans

Safety and efficacy of recombinant botulinum toxin type A (Eveotox&#xae;) in patients with post-stroke upper limb spasticity: Results from a Phase Ib/II clinical trial.

Upper limb spasticity is a common and disabling complication of stroke. Botulinum toxin type A (BoNT-A) is widely used for focal spasticity treatment, but naturally derived products may present limitations related to immunogenicity and manufacturing variability. Recombinant botulinum toxin type A, produced by genetic engineering without complexing proteins, may provide improved product consistency. This Ib/II study evaluated the safety, tolerability, and preliminary efficacy of recombinant botulinum toxin type A in adults with post-stroke upper limb spasticity. This multicenter, seamless Ib/II clinical study included an open-label dose-escalation Ib phase and a randomized, double-blind, placebo-controlled II phase. Adult patients with post-stroke upper limb spasticity received a single intramuscular injection of recombinant botulinum toxin type A or placebo. The primary endpoint in Phase II was the change from baseline in the Modified Ashworth Scale (MAS) score of the primary target muscle group at Week 4. Secondary endpoints included MAS and Tardieu scale changes in individual muscle groups, Disability Assessment Scale (DAS), Physician's Global Assessment (PGA), and immunogenicity. The Ib phase showed improvements in MAS, DAS, and PGA, indicating an early efficacy signal. In Phase II, recombinant botulinum toxin type A produced a significant reduction in MAS score of the primary target muscle group at Week 4 compared with placebo, with effects sustained through Week 12. At Week 4, the PGA score in the Eveotox&#xae; group showed a statistically significant improvement compared with the placebo group. While MAS and PGA scores showed significant improvement, DAS functional scores did not differ statistically from the placebo group at week 4. The treatment was generally well tolerated, and low incidence of antibodies were observed. Recombinant botulinum toxin type A was safe and effective in reducing post-stroke upper limb spasticity after a single administration. These results support further Phase III clinical evaluation.

Humans

First evaluation of a novel recombinant eCG molecule in ewes reveals a discrepancy between ovulatory response and pregnancy outcome.

This study evaluated the reproductive performance and clinical safety of a novel recombinant eCG (r-eCG) in ewes. Two weeks prior to study onset (Day 0: intravaginal progesterone device insertion), 45 ewes were randomly assigned to negative control (NC; no eCG; n&#x202f;=&#x202f;10), positive control (PC; 400IU commercial non-recombinant eCG; n&#x202f;=&#x202f;20), or treatment group (T; 400IU r-eCG; n&#x202f;=&#x202f;15). Ewes were inseminated with fresh-diluted semen (200&#x202f;&#xd7;&#x202f;106 sperm). Ultrasonography assessed follicle count/diameter (days 11, 13), ovulation (day 13), corpus luteum (CL) number/characteristics (day 20), and pregnancy (day 44). Serum progesterone was measured on day 20; Group T underwent clinical/hematological evaluations (days 0, 20, and 44). Estrus signs were more frequent (P&#x202f;<&#x202f;0.01) in T (100%) than NC (50%), while PC (85%) did not differ. Ovulation rates were similar between T (93%) and PC (95%), but higher than NC (50%; P&#x202f;<&#x202f;0.05). On day 13, largest follicle diameter did not differ (P&#x202f;>&#x202f;0.05) among groups; however, fewer follicles > 2&#x202f;mm occurred in PC than NC and T (P&#x202f;<&#x202f;0.05). CL number was higher in T than PC (2.0&#x202f;&#xb1;&#x202f;0.3 vs. 1.0&#x202f;&#xb1;&#x202f;0.0, P&#x202f;<&#x202f;0.01), while NC did not differ (1.0&#x202f;&#xb1;&#x202f;0.25). Conversely, pregnancy rate was higher (P&#x202f;<&#x202f;0.05) in PC (70%) than T (28.6%) and NC (20%). Among ovulated ewes, progesterone concentration and progesterone/CL ratio did not differ among groups (P&#x202f;=&#x202f;0.92 and P&#x202f;=&#x202f;0.08, respectively). No relevant r-eCG-related clinical or hematological alterations occurred. In conclusion, 400IU r-eCG effectively induces estrus and ovulation without adverse effects; however, the discrepancy between ovulatory response and pregnancy rate underscores the need for further study refinement to improve fertility.

Animals

Recombinant Human Thrombopoietin Reduces the Need for Platelet Transfusion in Patients With Chronic Liver Disease and Thrombocytopenia.

Chronic liver disease (CLD)-related thrombocytopenia can limit the feasibility of invasive procedures. Recombinant human thrombopoietin (rhTPO) has demonstrated a favorable safety profile without hepatotoxicity. We evaluated the efficacy and safety of rhTPO in patients with CLD-related thrombocytopenia who were undergoing elective invasive procedures. In this multicenter, randomized (2:1), double-blind, placebo-controlled phase III trial, 120 adult Chinese patients with CLD-related thrombocytopenia (platelet count <&#x2009;50 &#xd7;&#x2009;109/L) received rhTPO (n =&#x2009;80) or placebo (n =&#x2009;40) once daily for up to 5 or 7&#x2009;days. The primary endpoint was the proportion of patients with sustained platelet counts &#x2265;&#x2009;50 &#xd7;&#x2009;109/L from 24 h before invasive procedure to 7&#x2009;days post-procedure, without requiring emergency bleeding management. The primary endpoint was achieved by 85.0% of patients in the rhTPO group versus 12.5% in the placebo group (p&#x2009;<&#x2009;0.0001). Preoperatively, platelet counts &#x2265;&#x2009;50 &#xd7;&#x2009;109/L were achieved in 92.5% and 20.0% of patients in the rhTPO and placebo groups, respectively (p&#x2009;<&#x2009;0.0001). Platelet transfusion was avoided in 92.5% of rhTPO-treated patients versus 25.0% of placebo-treated patients (p&#x2009;<&#x2009;0.0001). The median duration of platelet counts &#x2265;&#x2009;50 &#xd7;&#x2009;109/L was significantly longer with rhTPO than with placebo (21.0 vs. 3.0&#x2009;days, p =&#x2009;0.0007). Treatment-related treatment-emergent adverse events (TEAEs) occurred in 12.5% of patients in both the rhTPO and placebo groups. No treatment-related serious adverse events were reported. Overall, rhTPO was effective and well tolerated in patients with CLD-related thrombocytopenia and may represent a viable therapeutic option for those undergoing elective invasive procedures. Trial Registration: www.chinadrugtrials.org.cn: number CTR20230919.

Humans

Efficient rDNA-mediated multi-copy integration of gene clusters in Aureobasidium melanogenum.

Aureobasidium melanogenum is a promising non-conventional yeast chassis for synthetic biology. However, techniques recombining large genetic fragments, such as gene clusters, are still unavailable, hindering further metabolic reprogramming in this chassis. To achieve multi-copy integration of genes, we employed highly repetitive ribosomal DNA (rDNA) sequences in A. melanogenum as homologous recombination sites for large genetic fragments. First, integration efficiency of three different regions of A. melanogenum rDNA were investigated: RNA polymerase I promoter region (rDNA1, 1.0&#x202f;kb), partial 26S rDNA region (rDNA2, 1.0&#x202f;kb), and RNA polymerase I terminator region (rDNA3, 1.0&#x202f;kb). Our findings revealed that the highest copy numbers and expression stability were observed for the short heterologous green fluorescent protein gene (gfp, 0.7&#x202f;kb) and the long native polyketide synthase gene (pks, 7.0&#x202f;kb) after rDNA1-mediated integration. Specifically, the copy numbers reached 7.0 and 8.0 for gfp and pks, respectively, and they remained stably expressed in the genome after 120-h subculturing. Furthermore, an 11.0&#x202f;kb gene cluster (comprising the native pks, phosphopantetheinyl transferase (npg1), and scytalone dehydratase genes (scd) responsible for melanin biosynthesis) was integrated at the rDNA1 site, resulting in stable recombination with 15.0 copies and an approximately 12-fold increase in melanin production. Overall, the convenience and efficiency of the proposed rDNA-mediated multi-copy insertion strategy will facilitate superior metabolic engineering of A. melanogenum chassis cells.

Multigene Family

Inducible flocculation in Komagataella phaffii enables enhanced biomass separation for biopharmaceutical production.

Biomass separation represents a critical bottleneck in Komagataella phaffii-based biopharmaceutical processes, as typically high cell densities of 40 - 50&#x202f;% create significant operational, technical and economic challenges for harvest operations. Yeast cell aggregation (flocculation) provides a solution to accelerate cell sedimentation by increasing particle size, thus allowing to improve biomass-supernatant separation efficiency during both natural gravity settling and (continuous) centrifugation operations. This study demonstrates successful engineering of K. phaffii strains with an inducible flocculation phenotype using CRISPR/Cas9-based genome editing to integrate the Saccharomyces cerevisiae FLO1 (ScFLO1) gene under control of various regulatory elements, including methanol-inducible and derepressible promoters. Flocculation strength could be enhanced by implementing transcriptional positive feedback circuits based on the methanol-inducible AOX1 promoter. To address methanol-free production requirements, we developed alternative systems to retrofit PAOX1-based ScFLO1 expression and exploited the derepressible PDF promoter, offering broader compatibility with biopharmaceutical manufacturing facilities. Flocculating cells cultivated in a bioreactor demonstrated significantly improved sedimentation behavior, with considerably lower supernatant turbidity after short low-speed centrifugation or gravity sedimentation compared to non-flocculating controls. Crucially, cell flocculation had no negative impact on product amount and quality when expressing a multivalent NANOBODY&#xae; VHH molecule with pharmaceutical relevance. Thus, this work establishes the first genetically engineered flocculation system in K. phaffii compatible with recombinant protein production, providing the basis for an innovative approach to streamline harvest operations in biopharmaceutical processes.

Flocculation

Bioprospecting microbial genomes to expand the biocatalytic toolbox of rubber oxygenases.

A set of rubber oxygenases was discovered through phylogenetic analysis and AI-based structural modeling of complexes of the putative enzymes with a substrate mimicking cis-1,4-polyisoprene. Sixteen candidate proteins were selected from thermophilic microorganisms, all sequence-related to the Latex clearing protein from Streptomyces sp. K30 (LcpK30). Sequence truncation and solubility tags were then evaluated to enhance protein expression, with the SUMO tag proving to be the most effective. Including LcpK30, nine heme-containing oxygenases were successfully expressed in E. coli NEB 10-beta cells, purified (35-157 mg L-1 yield) and characterized. Steady-state kinetics revealed significant rubber latex-degrading properties for six of them, with the truncated SUMO-fused LcpK30 (SUMO-LcpK30T) showing activity in agreement with literature. Notably, the catalytic efficiencies of all the expressed homologs lay within one order of magnitude and the oxygenase from Thermomonospora echinospora was found to be particularly promising in terms of activity, especially at high latex concentrations (more than 1% w/v). The analysis of reaction mixtures by both HPLC and HPLC-MS confirmed the oxidation of cis-1,4-polyisoprene to form the expected isoprenoid oligomers (n&#x202f;=&#x202f;2-12), whose distribution was consistent with the usual endo-type cleavage pattern in all but one case. This bioprospecting effort afforded a platform of new rubber-degrading enzymes with diverse efficiencies and product profiles, capable of adapting to targeted applications.

Oxygenases

Reprogrammed Komagataella phaffii for enhanced secretory expression of human lactoferrin.

Human lactoferrin (hLF) is a multifunctional glycoprotein of the transferrin family derived from milk and mucosal secretions, which exhibits antibacterial, anti-tumor, and immunomodulatory functions, and is an important component of infant formula. Conventional methods for lactoferrin expression are often inefficient, primarily due to inadequate protein synthesis capabilities and poor stability within microbial hosts. Herein, a Komagataella phaffii yeast strain capable of high-level secretory expression of hLF was constructed by reprogramming the endoplasmic reticulum (ER) and vacuole using CRISPR/Cas9 technology. A dual-expression cassette containing the AOX1 promoter, an &#x3b1;-secretion signal peptide, the hLF gene, and a terminator was integrated into three different sites of the K. phaffii genome. The stepwise strategy combining expansion of the ER membrane involved in protein synthesis with knockout of vacuolar proteases further enhanced hLF production. Subsequently, 0.1&#x202f;g/L FeCl&#x2083; was added to the medium to reduce the toxicity of hLF and improve its stability. After high-density cultivation of K. phaffii through optimization of cultivation conditions in shake flasks and a 5&#x202f;L bioreactor, the secretory intact hLF titer reached 2214&#x202f;mg/L, representing a 76.3-fold increase achieved through these engineering strategies. In addition, antibacterial experiments demonstrated that this secretory hLF had a significant inhibitory effect on Escherichia coli, Staphylococcus aureus, and yeast. Overall, the developed K. phaffii protein expression platform enabled efficient production of lactoferrin, demonstrating its potential for expressing other lactoproteins.

Lactoferrin

Genetic diversity and recombination of&#xa0;NA-PRRSV field strains in Vietnam: Implications for vaccine efficacy.

Porcine reproductive and respiratory syndrome (PRRS) causes severe reproductive losses in pregnant sows and piglets, resulting in substantial economic impact on the swine industry worldwide. However, due to the significant genetic diversity and rapid evolutionary changes of the pathogen, continuous surveillance and detailed genetic analysis of circulating strains are essential. The current study aimed to evaluate the genetic diversity of the hypervariable (HV) region of non-structural protein 2 (nsp2) among North American PRRSV strains isolated from swine farms in Vietnam. Phylogenetic analysis and multiple sequence alignment were conducted to determine subtype classification and assess genetic variability. A total of 48 field isolates were obtained, of which 12.5% belonged to classical NA-PRRSV, 16.6% to NADC30-like and 70.9% to HP-PRRSV, primarily distributed across sublineages 1.4, 5.1, 8.7 and 8.9. Amino acid comparisons found multiple insertions, deletions and substitutions at various positions within the hypervariable region of nsp2. The study revealed substantial genetic variation in the HV region of nsp2 among NA-PRRSV field strains, largely associated with recombination and immune escape. These findings highlight epidemiological risks to vaccine efficacy and underscore the need for continuous molecular surveillance to support effective PRRSV control in Vietnam.

PRRSV

Duration and characteristics of hypoglycemia with once-weekly insulin efsitora alfa versus once-daily basal insulins in adults with type 2 diabetes: Exploratory safety analysis of QWINT 2-4.

AIMS: Efsitora is a novel once-weekly basal insulin. Efsitora demonstrated similar efficacy and safety compared with once-daily basal insulin comparators across four phase 3 clinical trials for type 2 diabetes. This exploratory safety analysis further characterizes hypoglycemia events in the efsitora and once-daily treatment groups in three of these trials (QWINT-2, -3, and -4). METHODS: Median duration of hypoglycemia events was assessed with masked continuous glucose monitoring. Incidence of persistent-recurrent (PR) hypoglycemia was assessed by investigators and by a pre-specified algorithm using SMBG e-diary data. Factors contributing to hypoglycemia, characteristics of hypoglycemia, and treatment methods were reported by participants and assessed across groups. RESULTS: Across the three trials, durations of hypoglycemic events for efsitora vs once-daily basal insulin comparators were: Level 1 and 2 [<70&#xa0;mg/dL]: 40-42.5 vs 40&#xa0;min; Level 2 [<54&#xa0;mg/dL]: 35-39.9 vs 35&#xa0;min. Few incidences of PR hypoglycemia were reported for efsitora or once-daily comparators. No major descriptive differences were observed between hypoglycemia contributing factors, characteristics, or treatment methods in efsitora and once-daily treatment groups. CONCLUSIONS: No clinically relevant differences were observed between the duration or characteristics of hypoglycemic events in efsitora and once-daily treatment groups in the QWINT-2, -3, and -4 trials.

Adult

Efficacy of NAs in combination with Peg-IFN for functional cure in patients with CHB: a meta-analysis of RCTs.

BACKGROUND: The goal of treating chronic hepatitis B (CHB) is to achieve functional cure. We aimed to evaluate the efficacy of the combination of nucleoside (acid) analogues (NAs) and pegylated interferon (Peg-IFN) on the functional cure of CHB patients at the EOT and at the EOF. METHOD: PubMed, Embase, and Web of Science were searched systematically up to March 15, 2025. Sixteen RCTs on CHB patients receiving combination or monotherapy were included. RESULT: Compared with NAs treatment, the NAs combined with Peg-IFN treatment group significantly improved HBsAg clearance rate (RR: 14.05, 95% CI 6.13-32.20) and HBsAg seroconversion rate (RR: 12.82, 95% CI 5.08-32.33) at the EOT. Moreover, compared with NAs treatment, the NAs combined with Peg-IFN treatment group significantly improved HBsAg clearance rate (RR: 7.70, 95% CI 4.24-13.98), HBsAg seroconversion rate (RR: 11.93, 95% CI 5.14-27.67) at the EOF. However, compared with Peg-IFN monotherapy, the combination therapy group did not show any improvement in HBsAg clearance rate, HBsAg seroconversion rate, and the rate of qHBsAg decrease > 1 log10&#x2009;IU/mL at the EOT and the EOF. Moreover, in terms of safety, the Peg-IFN monotherapy group showed more ALT flares (ALT > 5&#x2009;&#xd7;&#x2009;ULN) during the treatment process. CONCLUSION: Compared with NAs therapy, Peg-IFN combined with NAs therapy significantly improves functional cure rate. However, combination therapy shows no additional advantage over Peg-IFN monotherapy in achieving functional cure. The Peg-IFN monotherapy group has a higher incidence of ALT flares than the combination therapy group.

Humans

Seventeen-year follow-up of hypophosphatasia diagnosed in middle-aged siblings harboring a novel intronic and a rare missense ALPL gene mutation.

Hypophosphatasia (HPP) is the rare inborn-error-of-metabolism that features impaired mineralization of the skeleton and teeth due to a deactivating mutation or mutations of the gene ALPL which encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). We report 17-year follow-up of twin sisters and a brother referred in middle-age for painful proximal femoral "stress fractures" and then diagnosed with HPP. They reported generalized muscle and bone pain, metatarsal fractures, arthropathy and, since childhood, tooth loss. Their concordant findings were explained by compound heterozygosity in ALPL for a rare maternal missense mutation (c.1403C&#xa0;>&#xa0;T, p.Ala468Val) in exon 12, together with a novel presumably paternal change (c.863-14G&#xa0;>&#xa0;A) predicting a cryptic mRNA splice site in intron 8. Fractures continued during follow-up until one sister received a three-and-one-half-year course of hydroxyapatite-targeted TNSALP supplementation therapy (asfotase alfa) during which substantial improvement occurred in her clinical, biochemical, and functional parameters as well as quality of life. Following subsequent unplanned treatment cessation she suffered significant clinical deterioration, including new fractures and loss of mobility. Her bone histopathology documented osteomalacia. Treatment resumption restored its benefits. Among ten asymptomatic family members evaluated in this four-generation kindred, eight were carriers heterozygous for either ALPL mutation. Those harboring the maternal missense defect manifested mild hypophosphatasemia, suggesting a dominant-negative mutation effect. This experience underscores the importance of in-depth phenotyping and then clinical follow-up to characterize ALPL variant combinations, and for maintaining effective asfotase alfa treatment.

Humans

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 &#x3b2;-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

Weight regain following discontinuation of glucagon-like peptide-1 receptor agonists in adults who are overweight or obese: a systematic review and meta-analysis.

OBJECTIVE: This study aims to explore the effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs) on weight changes and the occurrence of adverse reactions in overweight or obese adults after drug withdrawal. METHODS: Computerized searches were conducted in evidence-based databases such as PubMed, Embase, Cochrane Library and Scopus. The search period was from the establishment of the database to December 2025. Collect randomised controlled trials (RCTs) and controlled trials on GLP-1RAs, including tirzepatide, semaglutide, liraglutide, and dulaglutide, for the treatment of overweight or obese adult patients. The risk of bias in the included studies was assessed using the Cochrane Risk of Bias V2.0 tool provided by the Cochrane Collaboration, and meta-analysis was performed using the R programming language. RESULTS: A total of 699 studies were initially retrieved. Eventually, six studies involving 8,993 patients were included in the quantitative analysis, comprising 5,553 patients in the discontinuation group and 3,440 in the continued treatment group. The results of the meta-analysis showed that, compared with the continued treatment group, the weight difference in the discontinuation group was mean difference (MD) = 17.90%, 95% confidence interval (CI) [14.11-21.69], P&#xa0;<&#xa0;0.0001. It can be seen that there was a significant rebound in weight after drug withdrawal, and there was statistical heterogeneity among the studies (P&#xa0;=&#xa0;0.0082). Subgroup analysis further revealed that the weight rebound amplitude after discontinuation of tirzepatide was significantly higher than that of semaglutide. This result suggests that the differences in the mechanism of action of different GLP-1RAs may be the reason for the differences in weight changes after discontinuation. In addition, the percentage difference in body weight between after and before drug withdrawal was MD = 9.11%, 95% CI [7.91-10.30], P&#xa0;<&#xa0;0.0001, further verifying the trend of weight rebound after drug withdrawal. The summary of adverse reaction reports analyzed and studied indicates that after drug withdrawal, the overall adverse reactions of patients decreased, gastrointestinal adverse reactions decreased, and the incidence of cardiovascular events was not affected by drug withdrawal. CONCLUSION: There is a significant weight rebound phenomenon after discontinuation of GLP-1RAs, and the rebound magnitudes vary among different types of drugs. At the same time, there is a risk of adverse reactions during the use of such drugs.

Humans

Bivalirudin Versus Heparin in Low and Non-Low Bleeding Risk Patients Undergoing Primary PCI for STEMI: The BRIGHT-4 Trial.

BACKGROUND: In the BRIGHT-4 trial, among 6,016 patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) with a radial artery approach, procedural anticoagulation with bivalirudin plus a post-PCI high-dose infusion for 2 to 4 hours reduced the 30-day primary composite outcome of all-cause death or Bleeding Academic Research Consortium (BARC) types 3 to 5 bleeding, as well as death and bleeding individually, compared with heparin monotherapy. OBJECTIVES: We sought to determine whether the benefits of bivalirudin apply principally to patients who are at low bleeding risk (LBR) as well as non-LBR. METHODS: In a prespecified analysis from BRIGHT-4, outcomes were examined by baseline bleeding risk, with LBR defined as a CRUSADE score <30. RESULTS: At baseline, 4,581 patients (76.1%) were categorized as LBR. Non-LBR patients had higher rates of the 30-day primary endpoint (8.6% vs 2.2%; HR: 4.08 [95% CI: 3.14-5.31]; P < 0.0001), driven by both greater mortality and BARC types 3 to 5 bleeding. In non-LBR patients, the primary outcome occurred in 8.1% of patients randomized to bivalirudin vs 9.2% of those randomized to heparin (difference: -1.1% [95% CI: -4.0% to 1.8%]; HR: 0.88 [95% CI: 0.62-1.26]). In LBR patients, the primary outcome occurred in 1.4% of patients randomized to bivalirudin vs 2.9% of those randomized to heparin (difference: -1.5% [95% CI: -2.3% to -0.6%]; HR: 0.49 [95% CI: 0.32-0.75]) (Pabsolute interaction = 0.81; Prelative interaction = 0.04). The effects of bivalirudin compared with heparin in reducing all-cause death were as robust in LBR patients compared with non-LBR patients (Pabsolute interaction = 0.67; Prelative interaction = 0.06). CONCLUSIONS: Among patients with STEMI undergoing primary PCI with radial artery access, procedural anticoagulation with bivalirudin plus a high-dose post-PCI infusion for 2 to 4 hours reduced the 30-day risk of all-cause death and major bleeding in patients at low bleeding risk as well as in patients at higher-risk of bleeding. (Bivalirudin With Prolonged Full Dose Infusion Versus Heparin Alone During Emergency PCI [BRIGHT-4; NCT03822975]).

Humans

Aflibercept With Versus Without Reduced-Fluence Photodynamic Therapy for Polypoidal Choroidal Vasculopathy: Optical Coherence Tomography Angiographic Changes From a Randomized Clinical Trial.

OBJECTIVES: To report the longitudinal optical coherence tomography angiography (OCTA) changes in polypoidal choroidal vasculopathy (PCV) treated with intravitreal aflibercept monotherapy or in combination with reduced-fluence PDT. DESIGN: Image analysis of a double-masked, sham-controlled, randomized clinical trial. SUBJECTS: 55 eyes of 55 treatment-na&#xef;ve participants with symptomatic macular PCV completing 52 weeks of follow-up. METHODS: Participants underwent protocolized, multimodal imaging, including OCT, OCTA, fluorescein angiography, and indocyanine green angiography at baseline, week 12, and week 52. Quantitative OCTA parameters included total lesion area, branching neovascular network (BNN) area, and BNN vessel density (VD). Qualitative features included trunk vessel presence and OCTA signal within the polypoidal lesion (PL). Eyes were categorized by treatment arm and PL closure at week 52. MAIN OUTCOME MEASURES: Longitudinal OCTA changes and predictors of PL closure at week 52. RESULTS: We included 55 eyes (28 combination therapy and 27 monotherapy). Total lesion area decreased at week 12 but returned toward baseline at week 52 (combination: 3.72 &#xb1; 3.01mm2 at baseline, 2.86 &#xb1; 2.50mm2 at week 12, 3.59 &#xb1; 3.26mm2 at week 52; monotherapy: 3.77 &#xb1; 2.23mm2 at baseline, 3.27 &#xb1; 2.36mm2 at week 12, and 3.47 &#xb1; 2.58mm2 at week 52). BNN area decreased at week 12 and remained reduced at week 52 in both treatment arms (combination: 2.29 &#xb1; 2.08 mm2 at baseline, 1.46 &#xb1; 1.36mm2 at week 12, and 1.53 &#xb1; 1.32mm2 at week 52; monotherapy: 2.39 &#xb1; 1.85mm2 at baseline, 1.87 &#xb1; 1.68mm2 at week 12, and 1.82 &#xb1; 1.38mm2 at week 52). BNN VD reduction was greater in the combination arm at week 12 (-10 &#xb1; 15% vs - 3 &#xb1; 12%, P = .02). The proportion of eyes with trunk vessels increased over time in both arms (combination: 35.7% at baseline, 59.3% at week 12, and 67.8% at week 52; monotherapy: 25.9% at baseline, 44.4% at week 12, and 71.4% at week 52). In multivariable analysis, baseline BCVA predicted BCVA change at week 52 (&#x3b2;=-0.96 [-1.21 to -0.72], P < .01), and baseline CST predicted CST change (&#x3b2;=0.93 [0.75 to 1.10], P < .01). Greater reduction in BNN VD at week 12 was independently associated with PL closure at week 52 (OR 0.62 [0.39 to 0.97], P = .03). CONCLUSIONS: Early reduction in BNN vessel density, rather than reduction in lesion size, was associated with subsequent PL closure. OCTA-derived vascular changes may serve as noninvasive biomarkers for predicting treatment response in PCV.

Humans