Mpox, a zoonotic disease caused by the mpox virus (MPXV), has seen a significant shift in its epidemiological status since 2022, evolving from an initial local outbreak to a global epidemic. This recent outbreak of MPXV mainly emerged in several European and American countries and subsequently spread to over 100 countries and regions worldwide. The rapid evolution of MPXV, coupled with increased international interactions, has led to a gradual rise in mpox cases in certain regions of Asia, mostly involving MPXV clade II and its branch strains. In contrast, the more pathogenic and clinically severe MPXV clade Ib has been relatively rare, with no reports in China to date. Here, we analyzed the whole gene sequence of imported MPXV clade Ib variant from the first infection case detected in China. Through whole genome sequencing, we successfully obtained a full-length MPXV genome of 195,405 base pairs (bp). Phylogenetic analysis revealed that the genetic sequence of the MPXV in this case was predominantly clustered with MPXV clade Ib sequences previously reported from multiple African and European countries. Compared with the MPXV clade Ib reference strain DQ011155.1, there are 127 nucleotide alterations and 57 amino acid mutations in the MPXV genome of this case. Given that the MPXV clade Ib has started to appear in China, we must pay more attention to the prevention of and control measures for the spread of mpox.

Introduction: Salmonella is an important cause of foodborne diarrheal diseases worldwide. The emergence of bla_NDM-positive carbapenem-resistant Salmonella enterica isolates in recent years poses a huge public health challenge.Methods: In this study, two clinical S. enterica isolates carrying bla_NDM–5: a serotype 4,[5],12:i:- strain (2023JX045) and a serovar Stanley strain (2024–406) were analyzed using antimicrobial susceptibility testing and whole genome sequencing.Results: Both isolates were multidrug resistant, with insusceptibility to ampicillin, ampicillin/sulbactam, amoxicillin/clavulanic acid, cefuroxime, ceftiofur, cefazolin, cefoxitin, cefotaxime, ceftazidime, cefepime, ceftazidime/avibactam, meropenem, imipenem, ertapenem, tetracycline, gentamicin, trimethoprim/sulfamethoxazole, florfenicol, chloramphenicol, ciprofloxacin, colistin, and polymixin B. The bla_NDM–5-carrying plasmids in 2023JX045 and 2024–406 were named p23045-NDM5 and p2024406-NDM5, respectively, with both belonging to the incompatibility (Inc)HI2/IncHI2A group and sequence type ST3. In 2023JX045, bla_NDM–5 was flanked by two same-oriented copies of IS26 elements (IS26-dsbC-trpF-ble_MBL-bla_NDM–5-IS5-ΔIS3000-ΔISKox3-umuC-umuD-IS26). In 2024–406, p2024406-NDM5 was found to carry two copies of bla_NDM–5, possibly resulting from duplication of IS26-dsbC-trpF-ble_MBL-bla_NDM–5-IS5-ΔISAba125-ΔIS3000-ΔISKox3-umuC-umuD-IS26 and interrupted by mobile element IS1 at the upstream region of ΔIS3000.Discussion: This is the first report to describe the presence of two bla_NDM–5 copies on an IncHI2/IncHI2A plasmid carried by serovar Stanley, as well as the dissemination of bla_NDM–5 in Salmonella in Jiaxing City, China. IS26-flanked composite transposons appeared to play an important role in the formation of this region. The dissemination of blaNDM in Salmonella isolates and the complexity of the bla_NDM–5 region highlight the urgent need to monitor carbapenem-resistant S. enterica.

Nontyphoidal Salmonella (NTS) is a cause of foodborne diarrheal diseases worldwide. Important emerging NTS serotypes that have spread as multidrug-resistant high-risk clones include S. Typhimurium monophasic variant and S. Kentucky. In this study, we isolated Salmonella in 5019 stool samples collected from patients with clinical diarrhea and 484 food samples. Antibiotic susceptibility testing and whole-genome sequencing were performed on positive strains. The detection rates of Salmonella among patients with diarrhea and food samples were 4.0% (200/5019) and 3.1% (15/484), respectively. These 215 Salmonella isolates comprised five main serotypes, namely S. Typhimurium monophasic variant, S. Typhimurium, S. London, S. Enteritidis, and S. Rissen, and were mainly resistant to ampicillin, tetracycline, chloramphenicol, and trimethoprim/sulfamethoxazole. The MDR rates of five major serotypes were 77.4%, 56.0%, 66.7%, 53.3%, and 80.0%, respectively. The most commonly acquired extended-spectrum β-lactamase-encoding genes were bla_TEM−1B, bla_OXA-10, and bla_CTX-M-65. The S. Typhimurium monophasic variant strains from Jiaxing City belonged to a unique clone with broad antibiotic resistance. S. Kentucky isolates showed the highest drug resistance, and all were MDR strains. The discovery of high antibiotic resistance rates in this common foodborne pathogen is a growing concern; therefore, ongoing surveillance is crucial to effectively monitor this pathogen.

Following the lifting of COVID-19 pandemic control measures, a progressive increase in influenza A virus activity, particularly the H1N1 subtype, has been observed in Jiaxing. This study systematically characterized the genomic evolution of influenza A(H1N1) viruses circulating in Jiaxing, China during the 2023–2024 epidemic seasons through whole-genome sequencing and phylogenetic analysis. Viral RNA was detected by quantitative real-time PCR (qPCR) and 83 influenza A(H1N1) isolates (48 from 2023 and 35 from 2024 surveillance) were selected for whole-genome sequencing. Launch RDP4, MEGA11 and iTOL were used to analyze the homology, molecular evolutionary clusters and resistance sites of influenza A(H1N1) virus. The positivity rates of influenza A(H1N1) virus in Jiaxing were 10.66% in 2023 and 5.09% in 2024, respectively. Compared with vaccine strain A/Wisconsin/67/2022, the influenza A(H1N1) virus in 2023 and 2024 showed high homology, with the nucleotide homology of hemagglutinin gene ranging from 97.9% to 99.2% and that of neuraminidase gene ranging from 98.3% to 99.1%. Among 83 Jiaxing strains, 80 were classified as clade 6B.1A.5a.2a and 3 were assigned to clade 6B.1A.15a.2a.1. These strains were further categorized into subclades C.1 (45), C.1.9(17), C.1.9.3 (18), and D (3). Additionally, an HA/NA reassortant strain (A/ZJNH/SWL1331/2023) was identified in 2023, followed by an oseltamivir-resistant strain (A/ZJPH/SWL1544/2024) carrying the H275Y substitution in 2024. A total of 31 amino acid substitutions were identified in the HA1 segment of Jiaxing influenza A(H1N1) strains, affecting three antigenic sites: Ca (S137P, A139D, A141T/V, R142K, D222G), Cb (L70F, S71F), and Sb (I185S, D187N, S190G), plus an additional Ca1 substitution (K169Q). During 2023–2024, multiple genomic sites of influenza A(H1N1) viruses in Jiaxing have acquired mutations, underscoring the need for enhanced continuous surveillance and prevention of H1N1 influenza.

Molecular diagnostic assays for cholera detection have superior sensitivity to conventional assays and are now being accepted as the new standard method, especially the real-time PCR/RT-PCR. However, limited throughput capacity and long detection duration prevent them from detecting more specimens and more targets in one turnaround time simultaneously. In this study, we utilized nucleic acid extraction-free, direct RT-PCR and high-speed amplification to develop a novel multiplex assay, a quadplex direct one-tube real-time RT-PCR assay, for rapid detection of the serogroup and cholera toxin toxigenicity of Vibrio cholerae targeting the epsM, ctxA, rfb-O1, and rfb-O139 genes. Performance of the multiplex assay was evaluated by comparison with the monoplex real-time PCR assay according to the China Cholera Prevention Manual. Detection data from clinical specimens showed that the new assay had good diagnostic sensitivities for epsM (100%, n = 301), ctxA (100%, n = 125), rfb-O1 (100%, n = 85), and rfb-O139 (97.87%, n = 49). Analysis of the analytical sensitivities with serial dilutions of positive standards showed that the detection limits of the new assay for Vibrio cholerae epsM,ctxA,rfb-O1, and rfb-O139 were up to 200, 590, 115, and 1052 copies per mL lower than the monoplex real-time PCR (910, 345, and 1616 copies/mL respectively, for ctxA,rfb-O1, and rfb-O139). The results indicate that the multiplex assay is a rapid, sensitive, specific, and easy-to-use detection tool for Vibrio cholerae, especially suitable for rapid identification and screening detection of mass specimens.

Background/Objectives: Multidrug-resistant Salmonella enterica serovar Enteritidis, especially those isolated from humans, remains a public concern. In the present study, S. Enteritidis strain 31404 was obtained clinically from a fecal sample of a fifteen-year-old girl, who was positive for bla_NDM-13. Methods: Antibiotic susceptibility testing and whole genome sequencing were performed. Core genome MLST and hierarchical clustering (HierCC) were performed using EnteroBase. Population structure analysis of 57 S. Enteritidis isolates collected between 2023 and 2025 in Jiaxing city was conducted. A comparative structure analysis of bla_NDM-13-positive plasmids was also performed. Results: S. Enteritidis strain 31404 was resistant to 13 antimicrobial agents. We found that strain 31404 belonged to ST11 and carried resistance genes, such as bla_NDM-13, bla_CTX-M-14, ble_MBL, fosA3, qnrS, and tet (A). bla_NDM-13 was located on an IncI1-I (α) plasmid designated as p31404-NDM13. S. Enteritidis isolate 31404 was closely related to PNUSAS514422, which was isolated from the United States in 2025. Comparative genetic environment related to bla_NDM-13-positive plasmids available in the NCBI database indicates that ΔTn125-mediated contexts were commonly associated with bla_NDM-13. IS1294 (IS91 family), which replaces ISAba125, is likely to mobilize bla_NDM-13. Conclusions: The findings in this study provide insights into the molecular characterization and diversification of bla_NDM-13. The identification of bla_NDM-13-containing transferable plasmids in different serotypes of Salmonella isolates (such as S. Rissen, S. Typhimurium, and S. Enteritidis) in different cities in China highlights the risk of the spread of carbapenem-resistant genes among Salmonella isolates.