Transboundary and Emerging Diseases最新文献

{"title":"Characterization and Evaluation of the Pathogenicity of a Novel Alpha Family Chaperone-Usher Pilus Present on Porcine Enterotoxigenic Escherichia coli","authors":"Yi-Fang Lai,&nbsp;Yen-Chen Chang,&nbsp;Wei-Ting Lee,&nbsp;Shang-Te Danny Hsu,&nbsp;Chao-Nan Lin,&nbsp;Tzu-Ming Huang,&nbsp;Chien-Yu Chen,&nbsp;Dung-Chi Wu,&nbsp;Hao-Sen Chiang,&nbsp;Hui-Wen Chang","doi":"10.1155/tbed/9901219","DOIUrl":"10.1155/tbed/9901219","url":null,"abstract":"<p>Enterotoxigenic <i>Escherichia coli</i> (ETEC) is a leading cause of diarrhea in piglets, imposing significant economic burdens on swine production worldwide. Despite its impact, detailed characterization of intestinal colonization and comprehensive genomic profiling of virulent neonatal porcine ETEC strains remain limited. In this study, we isolated a β-hemolytic ETEC strain, PT4357, from a diarrheic neonatal piglet and conducted whole-genome sequencing (WGS) coupled with experimental infection in neonatal piglets to define its pathogenicity. The PT4357 belonged to serotype O8:H7 and sequence type ST2521 and harbored multiple virulence and antimicrobial resistance (AMR) genes, including the plasmid-borne colistin resistance gene <i>mcr-1</i>. Interestingly, a novel chaperone-usher (CU) assembly pathway pilus has a homolog of the α family usher gene that was identified in the chromosome of PT4357. Compared with the CS1 pilus on ETEC, structural superposition of the CU pathway pilus of PT4357, namely, CS33, showed strong conservation in the major subunit and chaperone and was relatively divergent in the N-terminal of usher and minor subunits while retaining essential core folds. Oral inoculation confirmed villi attachment of the ETEC PT4357, causing watery diarrhea in neonatal piglets without mucosal damage. Furthermore, the adherence of the ETEC PT4357 on porcine IPEC cells but not human Caco-2 cells suggests limited human tropism. Our results indicate that Taiwan porcine ETECs carried AMR genes and alternative CU pathway pilus. The role of the CS33 pilus on the pathogenicity or virulence of the pathogen requires further investigation and surveillance.</p>","PeriodicalId":234,"journal":{"name":"Transboundary and Emerging Diseases","volume":"2026 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13504359/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148811580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic and Pathogenic Characteristics of Novel PRRSV-1 Strain CH-JX-2504 and CH-SDTA-2506 in China","authors":"Yulin Xu,&nbsp;Qihang Xin,&nbsp;Kexin Li,&nbsp;Jianda Li,&nbsp;Luogang Ding,&nbsp;Yuyu Zhang,&nbsp;Hao Zeng,&nbsp;Fei Liu,&nbsp;Zhi Chen,&nbsp;Wenbo Sun,&nbsp;Jiang Yu,&nbsp;Jiaqiang Wu","doi":"10.1155/tbed/4674029","DOIUrl":"10.1155/tbed/4674029","url":null,"abstract":"<p>Porcine reproductive and respiratory syndrome virus (PRRSV) remains a leading cause of severe economic losses in the worldwide swine industry. In recent years, the geographic distribution of PRRSV-1 has been expanding, further complicating epidemic prevention and control. In 2025, two PRRSV-1 strains were successfully isolated from lung tissue samples of deceased pigs in Jiangxi and Shandong Provinces of China, named CH-JX-2504 and CH-SDTA-2506, respectively. Viral isolation was performed using primary porcine alveolar macrophages, and whole-genome sequencing was performed through metagenomic analysis. Subsequent phylogenetic analysis indicated that strain CH-JX-2504 belonged to the new subgroup 3, while CH-SDTA-2506 clustered within the BJEU06-1-like subgroup. Amino acid sequence analysis showed that CH-JX-2504 exhibits identical deletion patterns in the Nsp2, GP3, and GP4 proteins with the PRRSV-1 reference strain 180900-5. In contrast, distinct variations in these three proteins were identified in CH-SDTA-2506 compared with other representative PRRSV-1 strains, suggesting the emergence of a novel deletion pattern. In vivo challenge experiments showed that both CH-JX-2504 and CH-SDTA-2506 could induce typical clinical symptoms in piglets, including fever, retarded weight gain, and pathological lesions, including interstitial pneumonia with lymphocyte infiltration, obvious damage to intestinal villi, and disruption of the intestinal microbiota structure. Notably, one piglet in the CH-JX-2504 group died at 10 days postinfection (dpi), indicating that CH-JX-2504 exhibits higher pathogenicity than CH-SDTA-2506. Therefore, strengthened surveillance of PRRSV-1 in China is essential to prevent its further spread.</p>","PeriodicalId":234,"journal":{"name":"Transboundary and Emerging Diseases","volume":"2026 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13501167/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148808215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Epidemiological and Operational Constraints on the Feasibility of Peste des Petits Ruminants Eradication Target by 2030: Necessity for a New Pragmatic Road Map","authors":"Kadir Yeşilbağ,&nbsp;Mevlüt Yaşar","doi":"10.1155/tbed/4504556","DOIUrl":"10.1155/tbed/4504556","url":null,"abstract":"<p>Peste des petits ruminants (PPR) remains a major constraint to small ruminant production and food security, and a global eradication target for 2030 have been set by FAO/WOAH. This review analyses recent evidence on the feasibility of that target by integrating epidemiological indicators, operational performance of vaccination and surveillance systems, and structural drivers that sustain transmission. We find that the main barriers to eradication are not either virological/methodological or programmatic: achieving and sustaining high population immunity in pastoral and highly mobile systems; cold-chain and logistics constraints that reduce effective vaccine delivery; uneven surveillance sensitivity, timeliness, and data quality that limit detection of residual foci; and persistent reseeding via informal trade and transboundary movements. Multihost dynamics at wildlife–livestock interfaces, together with fragility factors such as conflict and climate-driven mobility, further complicate the endgame. Recent incursions into previously free territories highlight that progress is reversible when borders and surveillance systems are stressed. The dominance of PPR virus (PPRV) lineage IV in global spatiotemporal distribution has become increasingly evident in the last 10 years. We conclude that global freedom by 2030 is unlikely without rapid, synchronized improvements in coverage, surveillance performance, and cross-border coordination. A pragmatic pathway beyond 2030 should prioritize risk-based vaccination targeting high-connectivity corridors and markets, routine postvaccination seromonitoring as a decision trigger, strengthened endgame-grade surveillance (including targeted genomic investigation), and regional compacts that align implementation with broader resilience and economic development goals. We suggest that a new, revised global planning consisting of three consecutive phases would be more appropriate and predictable.</p>","PeriodicalId":234,"journal":{"name":"Transboundary and Emerging Diseases","volume":"2026 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13501124/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148808034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly Virulent Getah Virus Subgroup GIII-c Emerging in Pigs in China","authors":"Zhaoying Xiang,&nbsp;Xingchen Wang,&nbsp;Yuchen Huang,&nbsp;Xinyu Gao,&nbsp;Lei Zhou,&nbsp;Xinna Ge,&nbsp;Jun Han,&nbsp;Yongning Zhang,&nbsp;Hanchun Yang","doi":"10.1155/tbed/3201005","DOIUrl":"https://doi.org/10.1155/tbed/3201005","url":null,"abstract":"<p>Getah virus (GETV) is an emerging mosquito-borne zoonotic alphavirus that poses a threat to multiple animal species, particularly pigs, and carries significant public health implications. Nevertheless, the molecular evolution and pathogenicity of circulating GETV strains in China remain incompletely defined. In this study, three GETV strains were isolated from diseased piglets during concurrent outbreaks on three geographically distinct commercial pig farms in China in August 2025. The isolates shared 99.67%–99.91% genomic nucleotide (nt) identity and were phylogenetically classified into subgroup GⅢ-c. Amino acid sequence alignment against 136 reference strains from the GenBank database identified four substitutions in Nsp1 and Nsp3 that were absent from all reference strains, along with six conserved residues largely concentrated in a distinct subclade formed by the three isolates and five related reference strains. Pathogenicity evaluation using a representative isolate (GETV-YY/2025) in 7-day-old piglets revealed that the infected animals developed severe clinical signs, including fever, diarrhea, ataxia, and hindlimb paralysis, with a high mortality rate of 77.8% (7/9). The strain exhibited broad tissue tropism, with high viral loads detected in pharyngeal and rectal swabs, serum, and multiple visceral organs as early as 1 day postinoculation, accompanied by obvious cerebral vascular congestion and pulmonary hemorrhage. Notably, efficient contact transmission to sentinel piglets was observed, resulting in one fatality among the three contact animals (33.3%). Collectively, these findings characterize the emergence of a highly virulent GETV subgroup GⅢ-c circulating in Chinese pig populations, highlighting its capacity for efficient contact transmission and severe pathogenesis in neonatal pigs. This study provides critical insights into the evolutionary dynamics of GETV and informs the urgent development of prevention and control strategies against this re-emerging veterinary pathogen.</p>","PeriodicalId":234,"journal":{"name":"Transboundary and Emerging Diseases","volume":"2026 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/tbed/3201005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to “Glycosylation Deletion of Hemagglutinin Head in the H5 Subtype Avian Influenza Virus Enhances Its Virulence in Mammals by Inducing Endoplasmic Reticulum Stress”","authors":"","doi":"10.1155/tbed/9847165","DOIUrl":"https://doi.org/10.1155/tbed/9847165","url":null,"abstract":"<p>Y. Yin, S. Yu, Y. Sun, et al., “Glycosylation Deletion of Hemagglutinin Head in the H5 Subtype Avian Influenza Virus Enhances Its Virulence in Mammals by Inducing Endoplasmic Reticulum Stress,” <i>Transboundary and Emerging Diseases</i>, 2020;67:1492–1506. https://doi.org/10.1111/tbed.13481.</p><p>These corrections do not affect the interpretation of the results or the conclusions of the article. The corrected Figures 3 and 6 are shown below:</p><p>We apologize for these errors.</p>","PeriodicalId":234,"journal":{"name":"Transboundary and Emerging Diseases","volume":"2026 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/tbed/9847165","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Emerging DTMUV Variant Remains Restricted in Mammals but Acquires Olfactory Route-Mediated Neuroinvasion Following Limited Adaptive Mutations","authors":"Qing Yang,&nbsp;Ting Zhou,&nbsp;Zhengzheng Li,&nbsp;Kang Yang,&nbsp;Chenyang Song,&nbsp;Qingqing Du,&nbsp;Yingqi Zhu,&nbsp;Guijun Wang","doi":"10.1155/tbed/4857491","DOIUrl":"https://doi.org/10.1155/tbed/4857491","url":null,"abstract":"<p>Duck Tembusu virus (DTMUV), a mosquito-borne flavivirus, has caused widespread outbreaks in poultry and has exhibited an expanding host range among avian species, accompanied by ongoing genetic variation and adaptation. As many mosquito-borne flaviviruses can infect mammals and cross species barriers, it remains unclear whether recently emerged DTMUV variants have acquired similar potential. To address this, we assessed whether the circulating variant AQ-19 can establish infection in mammals via peripheral routes. Despite its enhanced virulence in avian species, this variant failed to establish infection in mice following peripheral inoculation, indicating that a substantial barrier still restricts cross-species transmission to mammals. We next investigated whether additional adaptive changes are required for DTMUV to overcome this barrier. Through serial intracranial passage in Institute of Cancer Research (ICR) mice, we generated a mouse-adapted strain (F13) that exhibited markedly enhanced virulence and, notably, acquired the ability to invade the central nervous system (CNS) via intranasal (i.n.) inoculation, resulting in lethal infection. This neuroinvasive phenotype was strictly route-dependent, as infection remained ineffective via intraperitoneal (i.p.) and subcutaneous (s.c.) routes. We found that the adapted virus invades the CNS via the olfactory route and disseminates broadly, exhibiting strong neurotropism and inducing severe neural damage. Functional disruption of the olfactory epithelium using ZnSO₄ significantly delayed disease onset and reduced viral burden in the brain, supporting its role as a major route for nasal-to-brain transmission. Importantly, genomic analysis identified only four nonsynonymous amino acid substitutions in the adapted strain, suggesting that a limited number of mutations may be sufficient to confer enhanced neurovirulence and enable neuroinvasion in a mammalian host. Collectively, these findings demonstrate that the emerging DTMUV variant AQ-19 remains restricted in mammals, whereas limited adaptive changes acquired during experimental mouse adaptation are associated with the acquisition of neuroinvasive capacity, providing new insights into the evolutionary potential of DTMUV for mammalian adaptation.</p>","PeriodicalId":234,"journal":{"name":"Transboundary and Emerging Diseases","volume":"2026 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/tbed/4857491","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genomic and Clinicopathological Characterization of a Reassortant HPAI H5N1 (Clade 2.3.4.4b) in an Endangered Cinereous Vulture (Aegypius monachus) in South Korea, 2026","authors":"Chang-Gi Jeong,&nbsp;Seongwon Hwang,&nbsp;Taeyeong Jung,&nbsp;Su-Beom Chae,&nbsp;Tae-Nam Kim,&nbsp;Nchimunya Siamulonga,&nbsp;Serin Sim,&nbsp;Geonwoo Baek,&nbsp;Jun-Soo Park,&nbsp;Won-Il Kim,&nbsp;Jae-Ik Han,&nbsp;Sang-Ik Oh,&nbsp;Jae-Ku Oem","doi":"10.1155/tbed/2623621","DOIUrl":"https://doi.org/10.1155/tbed/2623621","url":null,"abstract":"<p>Clade 2.3.4.4b highly pathogenic avian influenza viruses (HPAIVs) continue to circulate widely in East Asia and undergo frequent reassortment in wild birds. Raptors are regarded as spillover hosts that may be exposed through predation or scavenging, yet integrated clinicopathologic and genomic investigations in cinereous vultures remain limited. Here, we describe a fatal H5N1 HPAIV infection in a cinereous vulture (<i>Aegypius monachus</i>) found in South Korea on January 17, 2026. On presentation, the cinereous vulture showed severe neurologic dysfunction, including inability to stand, right-sided head tilt with pathologic nystagmus, reduced oculocephalic and palpebral reflexes, and intermittent bilateral leg tremors. The cinereous vulture died within 2 days after rescue, and a complete necropsy was performed. Hematologic and biochemical testing revealed marked heterophil predominance, severe lymphopenia, mild monocytosis, and globulin values near the upper end of the reference interval. An oropharyngeal swab tested positive for influenza A virus, and a virus isolate, designated A/Cinereous_Vulture/Korea/26-JBN47/2026(H5N1), was recovered in embryonated chicken eggs. Histopathology showed nonsuppurative encephalitis and necrotizing myocarditis, and influenza A nucleoprotein was detected immunohistochemically in neurons and cardiomyocytes. Tissue real-time RT-PCR showed the lowest cycle threshold value in the brain. Whole-genome sequencing demonstrated that 26-JBN47 belonged to clade 2.3.4.4b and contained a polybasic HA cleavage site (PLREKRRKR/GLF). Segment-level phylogenetic analysis revealed a reassortant genome constellation comprising a maintained H5N1 backbone in HA, NA, and M; low PAIV (LPAIV)-associated but H5N1-incorporated PA and NP segments; flyway-associated PB2 and NS segments; and a PB1 segment phylogenetically linked to regional LPAIV lineages. Molecular marker analysis identified multiple substitutions previously reported to be associated with receptor-binding properties, polymerase-related fitness, virulence, and host-response modulation, whereas canonical PB2 mammalian-adaptive markers were absent. These findings show that 26-JBN47 was a reassortant clade 2.3.4.4b H5N1 HPAIV associated with systemic disease and clinicopathological findings consistent with neurotropic and cardiotropic infection in a cinereous vulture. They also support the potential value of scavenging raptors as sentinels of local or regional HPAIV circulation involving reassortant viruses in East Asia.</p>","PeriodicalId":234,"journal":{"name":"Transboundary and Emerging Diseases","volume":"2026 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/tbed/2623621","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gut Microbiota-Derived Butyrate Strengthens Blood-Brain Barrier Integrity and Attenuates Streptococcus suis SC19-Induced Meningitis: Involvement of the Gut-Brain Axis","authors":"Wangyuan Yao,&nbsp;Meili Chen,&nbsp;Huachun Pan,&nbsp;Md. F. Kulyar,&nbsp;Jialu Zhang,&nbsp;Hongkai Ren,&nbsp;Qingqing Luo,&nbsp;Hongdou Liu,&nbsp;Qinghua Wang,&nbsp;Xuyuan Wang,&nbsp;Rendong Fang","doi":"10.1155/tbed/5502623","DOIUrl":"https://doi.org/10.1155/tbed/5502623","url":null,"abstract":"<p><i>Streptococcus suis</i> serotype 2 (<i>SS2</i>) is a major zoonotic pathogen that causes severe meningitis and high mortality in both humans and swine. Growing evidence shows that metabolites generated along the gut-brain axis regulate neuroinflammation. In this study, we demonstrate that oral administration of sodium butyrate (NaB) (300 or 600 mg/kg/day) for 28 days lowered mortality and lessened neuropathological signs in mice infected with <i>SS2</i> (<i>SC19</i> strain). Butyrate prophylaxis was associated with lower bacterial loads in the blood and brain tissue, preserved expression of tight junction proteins (ZO-1, Claudin-5, and Occludin) in the brain, and maintained blood-brain barrier (BBB) integrity and permeability. 16S rRNA sequencing analysis revealed that <i>SC19</i> infection significantly diminished the diversity and richness of the gut microbiota, notably depleting key short-chain fatty acid (SCFA)-producing bacterial taxa. Butyrate intervention restored microbial homeostasis and enriched SCFA-producing communities. Mechanistically, butyrate was associated with upregulated expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream antioxidant effectors (heme oxygenase 1 [HO-1] and NQO1), while inhibiting phosphorylation of NF-κB p65 and the secretion of proinflammatory cytokines (interleukin-1β [IL-1β], interleukin-6 [IL-6], and tumor necrosis factor-α [TNF-α]) in human cortical microvessels endothelial cells/D3 (hCMEC/D3) cells. Critically, these protective effects were abrogated upon pharmacological inhibition of Nrf2, indicating the critical role of Nrf2 in butyrate-mediated attenuation of neuroinflammation and oxidative stress. Our findings highlight the prophylactic potential of modulating the gut-brain axis as a novel strategy to mitigate central nervous system (CNS) infections associated with foodborne pathogens.</p>","PeriodicalId":234,"journal":{"name":"Transboundary and Emerging Diseases","volume":"2026 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/tbed/5502623","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resolving the Phylogenetic Placement of the FSfaCV/PCV5-Related Viruses Within the Genus Macochavirus","authors":"Wenqiang Wang,&nbsp;Liping Jiang,&nbsp;Tingting Niu,&nbsp;Miaojie Zhang,&nbsp;Lulu Chen,&nbsp;Xiaoye Jia,&nbsp;Lin Yuan,&nbsp;Kegong Tian,&nbsp;Xiangdong Li","doi":"10.1155/tbed/8481347","DOIUrl":"https://doi.org/10.1155/tbed/8481347","url":null,"abstract":"<p>Metagenomic analysis of fecal samples from diarrheic pigs in China identified 10 complete circular single-stranded DNA viral genomes previously designated as putative porcine circovirus 5 (PCV5)–like viruses. Genome characterization revealed a typical cressdnavirus organization with bidirectionally oriented Rep and Cap genes. Phylogenetic analyses based on complete genomes and encoded proteins showed that these viruses do not cluster with members of Circoviridae but instead form a distinct lineage within the family Pecoviridae, closely related to the genus <i>Macochavirus</i>. Sequence identity, genetic distance, and nucleotide diversity analyses supported their classification as a coherent viral group. Comparative analyses indicated greater sequence divergence in the Rep region than in the Cap region. These findings support reclassification of putative PCV5 as a porcine-associated lineage within the genus <i>Macochavirus</i>, designated porcine <i>Macochavirus</i> (PMV), thereby resolving their long-standing taxonomic ambiguity and expanding the recognized diversity of cressdnaviruses within the family Pecoviridae.</p>","PeriodicalId":234,"journal":{"name":"Transboundary and Emerging Diseases","volume":"2026 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/tbed/8481347","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization and Therapeutic Potential of a Novel Lytic Bacteriophage vB_Kp_H122 Targeting Multidrug-Resistant Hypervirulent Klebsiella pneumoniae of K57 Capsular Type","authors":"Cuilong Fan,&nbsp;Qiu Xu,&nbsp;Stefan Schwarz,&nbsp;Yaowei Liu,&nbsp;Susu Du,&nbsp;Xiaofeng Lu,&nbsp;Yuxuan Yuan,&nbsp;Longhua Lin,&nbsp;Shuangyu Xie,&nbsp;Fang Xie,&nbsp;Wanjiang Zhang","doi":"10.1155/tbed/8429457","DOIUrl":"10.1155/tbed/8429457","url":null,"abstract":"<p><i>Klebsiella pneumoniae</i> is an important zoonotic opportunistic pathogen. Of particular concern is the emergence of multidrug-resistant hypervirulent <i>K. pneumoniae</i> (MDR-hvKP), which represents a serious public health threat. Bacteriophage (phage) therapy has emerged as a promising solution to combat antibiotic-resistant <i>K. pneumoniae</i> infections. Here, we characterize a novel lytic phage, vB_Kp_H122, that specifically targets K57 capsular-type MDR-hvKP. vB_Kp_H122 exhibited the characteristic morphology of a siphovirus and demonstrated efficient infection kinetics, with an optimal multiplicity of infection (MOI) of 0.001 and a latent period of ~5 min. It also demonstrated considerable stability across a pH range of 4–11 and at temperatures from 4°C to 50°C, as well as potent activity against <i>K. pneumoniae</i> biofilms. The phage has a linear double-stranded DNA genome of 46,077 bp with a G + C content of 47.61% and belongs to a novel species within the genus <i>Roufvirus</i>. Its genome contained no identifiable genes associated with lysogeny, virulence, or antibiotic resistance, supporting its therapeutic safety. In a mouse infection model, a single dose of vB_Kp_H122 at 2 × 10⁶ PFU significantly reduced bacterial loads in organs, alleviated pathological damage, and provided complete protection against lethal challenge with K57 MDR-hvKP. These findings suggest that vB_Kp_H122 may have potential as an antibacterial candidate against K57 MDR-hvKP isolates.</p>","PeriodicalId":234,"journal":{"name":"Transboundary and Emerging Diseases","volume":"2026 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/tbed/8429457","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148719790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}