Journal of invertebrate pathology最新文献

{"title":"Optimized cloning and expression workflow for Cry proteins from Bacillus wiedmannii biovar thuringiensis","authors":"Enrique E. Posada Vaquerano ,&nbsp;M. Florencia Gil ,&nbsp;Marina E. Battaglia ,&nbsp;Corina M. Berón","doi":"10.1016/j.jip.2026.108531","DOIUrl":"10.1016/j.jip.2026.108531","url":null,"abstract":"<div><div>Efficient heterologous expression of insecticidal Cry proteins, such as those produced by the bacterium <em>Bacillus thuringiensis</em> (<em>Bt</em>), remains essential for their structural and functional characterization. This article describes an optimized workflow for the amplification, cloning, and expression of <em>cry</em> genes identified in <em>Bacillus wiedmannii</em> biovar <em>thuringiensis</em> (<em>Bwt</em>). The <em>Bwt</em> genome harbors multiple <em>cry</em> genes that display high sequence conservation, especially in their flanking regions, and feature a high adenine/thymine content organized in short domains surrounding the start and stop codons. These regions often share homology with other <em>cry</em> genes, pseudogenes, or chromosomal fragments, making targeted amplification and cloning challenging. To overcome these difficulties, a nested PCR strategy was implemented to ensure high sequence specificity and fidelity. As a proof of concept, the <em>cry4Ea1</em> and <em>cry4Fa1</em> genes were cloned into the pSTAB vector, which combines the sporulation-dependent <em>cyt1Aa</em> promoter with the STAB-SD stabilizing sequence, and expressed in the <em>Bt</em>-derived acrystalliferous strain 4Q7. For genes containing internal restriction sites, the ligation-independent AQUA method provided an efficient alternative to conventional cloning. Optimization of the culture conditions demonstrated that inoculum physiology and nutrient availability significantly influenced biomass accumulation and Cry protein production, using the recombinant <em>Bacillus thuringiensis</em> subsp. <em>israelensis</em> 4Q7 strain expressing Cry4Fa1 as a representative case. This article analyzes these findings and compares them with other <em>Bt</em> expression systems, highlighting similarities, limitations, and complementary advances reported in other studies. Altogether, these approaches expand the molecular toolbox for Cry protein expression and characterization, offering promising biotechnological applications.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108531"},"PeriodicalIF":2.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Splicing factor SC35 inhibits Nosema bombycis proliferation by regulating the alternative splicing of Bmupp1","authors":"Qiong Yu ,&nbsp;Qingsheng Qu ,&nbsp;Shiyi Lu ,&nbsp;Pingyang Wang ,&nbsp;Li Sui ,&nbsp;Jie Cheng ,&nbsp;Xudong Tang ,&nbsp;Ping Qian","doi":"10.1016/j.jip.2026.108552","DOIUrl":"10.1016/j.jip.2026.108552","url":null,"abstract":"<div><div>Alternative splicing is a crucial mechanism in higher eukaryotes that enhances the structural complexity of the transcriptome and augments protein functional diversity. The regulation of alternative splicing is governed by splicing factors, which influence disease development by modulating this process. Pebrine disease, caused by <em>Nosema bombycis</em> (<em>N. bombycis</em>) infection, is a significant disease affecting the sericulture industry. Recent years have seen an increase in omics research, with numerous biochemical and molecular biological studies focusing on the complex interactions among various biomolecules (genes, RNA, proteins, metabolites) within the silkworm (<em>Bombyx mori</em>). However, there is a paucity of research on the alternative splicing gene response of silkworm during <em>N. bombycis</em> infection, and the role of alternative splicing genes in this process remains unclear. This study analyzes a differential alternative spliced gene <em>Bmupp1</em>, which responds to <em>N. bombycis</em> infection in silkworm. Subcellular localization revealed that Bmupp1-X1 is located in the cytoplasm, while Bmupp1-X2, X3, and X4 are localized in the nucleus. Overexpression of Bmupp1 demonstrated that Bmupp1-X2 and Bmupp1-X4 exhibit uridine phosphorylase (UPP) enzymatic activity. Bmupp1-X2 and Bmupp1-X4 inhibit <em>N. bombycis</em> replication, while Bmupp1-X1 and Bmupp1-X3 have no effect. Mini-gene assays and RNA interference of the splicing factor SC35 revealed that SC35 regulates the alternative splicing of <em>Bmupp1</em> in a dose-dependent manner, specifically influencing the splicing of Bmupp1-X2 and Bmupp1-X4. RT-qPCR analysis suggested that splicing factor SC35 may play distinct roles during the early and late stages of <em>N. bombycis</em> infection. In conclusion, during the early and late stages of <em>N. bombycis</em> infection, splicing factor SC35 regulates the alternative splicing of <em>Bmupp1</em>, thereby enhancing uridine phosphorylase enzymatic activity to suppress <em>N. bombycis</em> proliferation.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108552"},"PeriodicalIF":2.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146113300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biocontrol potential of Metarhizium spp. against Myzus persicae and beet mild yellowing virus in the post-neonicotinoid era","authors":"Ibtissem Ben Fekih ,&nbsp;Kenza Dessauvages ,&nbsp;Mathilde Scheifler ,&nbsp;Grégoire Noël ,&nbsp;Tariq M. Butt ,&nbsp;Joachim Carpentier ,&nbsp;Frédéric Francis","doi":"10.1016/j.jip.2026.108559","DOIUrl":"10.1016/j.jip.2026.108559","url":null,"abstract":"<div><div>Entomopathogenic fungi (EPF) are promising biocontrol agents that can also function as plant endophytes, mediating interactions within plant–insect–pathogen systems. Here, we evaluated four EPF isolates, two endemic (<em>Metarhizium brunneum</em> strain GxABT-2 and <em>Metarhizium majus</em> strain GxABT-3) and two reference strains (<em>M. brunneum</em> ARSEF4556 and V275), for their efficacy against the green peach aphid (<em>Myzus persicae</em>) and their ability to limit beet mild yellowing virus (BMYV) transmission. Concentration-dependent bioassays assessed aphid mortality, fecundity, and post-mortem fungal development, while seed treatments evaluated the endophytic colonization and impact on BMYV establishment. All isolates caused &gt; 80% aphid mortality at the highest concentration (1 × 10⁸ conidia ml⁻¹), whether applied directly (spray or immersion of aphids) or indirectly (spray or immersion of leaves), with GxABT-2 producing the greatest reduction in fecundity. Three post-mortem developmental stages (melanized, non-sporulating, and sporulating) were primarily observed at lower concentrations (1 × 10⁵ and 1 × 10⁶ conidia ml⁻¹). Overall, melanized aphid cadavers were more frequent with endemic isolates, whereas sporulating cadavers predominated in the V275 and ARSEF4556 treatments. Endophytically colonized plants exhibited significantly lower BMYV loads, with GxABT-2 being the most effective. These results highlight the potential of endemic <em>Metarhizium</em> spp. as sustainable biocontrol agents in a post-neonicotinoid era and underscore the importance of understanding isolate-specific variability in plant–fungus interactions for optimizing viral suppression.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108559"},"PeriodicalIF":2.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146131693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reducing the impact of HaHV-1 in Australian abalone: The role of age and immune priming","authors":"Jacinta R. Agius ,&nbsp;Danielle Ackerly ,&nbsp;Angus C. Watson ,&nbsp;Monique L Smith ,&nbsp;Lachlan Hulands ,&nbsp;Joshua McIntyre ,&nbsp;Travis Beddoe ,&nbsp;Karla J Helbig","doi":"10.1016/j.jip.2026.108554","DOIUrl":"10.1016/j.jip.2026.108554","url":null,"abstract":"<div><div>Abalone (<em>Haliotis sp</em>.) are marine organisms of significant ecological and economic importance. However, disease outbreaks, particularly caused by Haliotid herpesvirus (HaHV-1), pose a major threat to the global aquaculture industry. HaHV-1 causes Abalone Viral Ganglioneuritis (AVG) and has led to significant economic losses due to mass mortality in farmed and wild abalone in regions such as China, Taiwan, and Australia. The current study investigated the effect of age on the susceptibility of Australian hybrid abalone to HaHV-1 and the potential of immune priming as a strategy to protect abalone from HaHV-1 infection. Using a co-housed immersion challenge model, we found that abalone less than one year of age were significantly less susceptible to HaHV-1 infection and exhibit less pronounced clinical signs of HaHV-1 infection when compared to adults. Additionally, immune priming adult abalone with poly(I:C) prior to viral challenge provided protection against HaHV-1 when compared to abalone primed with a bacterial antigen, Flagellin-A and unprimed controls. We also determined that the use of pedal swabs is a less invasive method for confirming positive HaHV-1 infections, but not for determining comparative viral loads. These findings are pivotal in developing preventative strategies against HaHV-1 in aquaculture and highlight the need for further research on immune priming and age-related susceptibility in abalone.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108554"},"PeriodicalIF":2.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Filling the gaps – New molecular and morphological data of gregarine apicomplexans colonising freshwater invertebrates","authors":"Anthony Allan-Cardoso ,&nbsp;Arne Schwelm ,&nbsp;Sonja Rückert","doi":"10.1016/j.jip.2026.108565","DOIUrl":"10.1016/j.jip.2026.108565","url":null,"abstract":"<div><div>Gregarines (Apicomplexa: Gregarinasina) are widespread protist symbionts of invertebrates, occupying roles across the symbiotic spectrum from mutualism to parasitism. Despite their ecological importance, they remain far less studied than other apicomplexans, leaving many aspects of their diversity, host specificity, and evolutionary history unresolved. This is particularly true for freshwater taxa for which only a handful of small subunit (SSU) rDNA sequences from species colonising freshwater hosts are available in public databases. In this study, we screened ten freshwater invertebrates (Arthropoda and Annelida) from streams and rivers in North-Rhine Westphalia, Germany, for gregarine infections. Nine eugregarine species were detected and described by combining light and electron microscopy with SSU rDNA sequencing data. We provide new host and locality records, ultrastructural observations, and molecular data for these gregarine species. The SSU phylogenetic analyses reveal a novel well-supported subclade within Gregarinoidea and support the reassignment of the family Metameridae to the Actinocephaloidea. Our findings expand the available molecular and morphological data for freshwater eugregarines and contribute to a clearer picture of their evolutionary relationships.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108565"},"PeriodicalIF":2.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146149824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacterial genotype and infection host shape the potential for cheating and evolution of virulence during passage in Bacillus thuringiensis","authors":"Peter Morwool ,&nbsp;Neil Crickmore ,&nbsp;Ben Raymond","doi":"10.1016/j.jip.2026.108564","DOIUrl":"10.1016/j.jip.2026.108564","url":null,"abstract":"<div><div>Understanding the evolution of pathogen host range is a challenging problem but one that is important for emerging infections and for biocontrol. Theory predicts that sequential selection in multiple host species should select for broad host range. Using two genotypes of <em>B. thuringiensis</em> we tested whether selection in alternating host environments would produce bacteria with increased virulence in both hosts, relative to bacteria passaged in single host species (fall armyworm, <em>Spodoptera frugiperda</em> or diamondback moth, <em>Plutella xylostella</em>). Since the Cry toxins of <em>B. thuringiensis</em> are public goods that benefit groups of bacteria, not individual cells, we employed a passage design which provided reproductive benefits to groups of pathogens, based on infectivity. Passage of one bacterial genotype (<em>Bt morrisoni)</em> led to the loss of virulence, while the second genotype (<em>Bt galleriae</em>) evolved virulence that was dependent on selection treatment. In contrast to expectation, selection in <em>P. xylostella</em> produced lineages with increases in virulence in both hosts; selection in <em>S. frugiperda</em> led to very low virulence and the alternating host treatment produced intermediate levels of virulence. Modest increases in virulence were accompanied by a reduction in fitness, consistent with a cost of increased investment in virulence factors. In contrast, infection in <em>S. frugiperda</em> selected for cheaters that had reduced investment in Cry toxins and high competitive fitness within hosts. In conclusion, the selection favouring cheaters depended strongly on both host species and bacterial genotype. Importantly, the host (<em>P. xylostella</em>) that favoured cooperation produced mutants with gains in virulence across multiple hosts.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108564"},"PeriodicalIF":2.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146125299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of two quantitative real-time PCRs for the detection of Perkinsus beihaiensis and P. marinus","authors":"Kamila dos Santos Bezerra,&nbsp;Natanael Dantas Farias,&nbsp;Sofia Lucena de Oliveira Coutinho,&nbsp;Darlânia Santos da Silva,&nbsp;Patricia Mirella da Silva","doi":"10.1016/j.jip.2026.108530","DOIUrl":"10.1016/j.jip.2026.108530","url":null,"abstract":"<div><div>Oyster production is an expanding aquaculture activity worldwide. Protozoan parasites such as <em>Perkinsus</em> spp. affects bivalve populations in the Americas, Europe, and Asia, causing mass mortality in both cultured and wild populations. Their impact contributed to the depletion of natural resources, resulting in significant economic losses. A recent concern is the rapid spread of <em>Perkinsus</em> into regions far from their natural geographical areas, posing a threat to native mollusk populations. Since 2008, <em>Perkinsus</em> spp. has been detected among bivalves from Brazil. Two species (<em>P. olsenii</em> and <em>P. chesapeaki</em>) were sporadically observed. In contrast, two others (<em>P. marinus</em> and <em>P. beihaiensis</em>) are frequently detected in oyster populations, reaching high infection intensities and prevalences depending on the populations and species (<em>Crassostrea gasar, C. rhizophorae,</em> and <em>Magallana gigas</em>). Diagnosis based on molecular techniques, such as qPCR, has been developed to detect protozoan parasites, including <em>Perkinsus</em> spp.. However, the qPCRs developed for the diagnosis of <em>P. marinus</em> and <em>P. beihaiensis</em> have limitations; because they were not designed to distinguish among the seven species within the genus, they are neither fully specific nor validated. Considering the spread of <em>Perkinsus</em> spp. over the continents, prompted by several factors (environmental or anthropogenic), there is an urgent need to accurately detect <em>Perkinsus</em> species infecting hosts in areas of co-occurrence or coinfection. In the present study, we developed two species-specific qPCRs for the detection of these protozoan parasites <em>P. marinus</em> and <em>P. beihaiensis</em> that are spreading worldwide.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108530"},"PeriodicalIF":2.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145966340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elevated virulence in TCP-PAI carrying strains indicates the pathogenicity island’s important role in Vibrio mediterranei pathogenicity to bivalves","authors":"Xiaohui Zou ,&nbsp;Haiyan Zhang ,&nbsp;Sheng Liu ,&nbsp;Junchao Xu ,&nbsp;Zhihua Lin ,&nbsp;Qinggang Xue","doi":"10.1016/j.jip.2026.108551","DOIUrl":"10.1016/j.jip.2026.108551","url":null,"abstract":"<div><div>Several <em>Vibrio</em> spp. are important shellfish pathogens. <em>Vibrio mediterranei</em>, notorious for its pathogenicity to bivalve larvae, contains a pathogenicity island, TCP-PAI, homologous to the <em>Vibrio cholerae</em> TCP gene cluster. This study explored the role of TCP-PAI in <em>V. mediterranei</em> pathogenicity by comparing TCP-PAI (+) and TCP-PAI (−) strains isolated from larval and juvenile Chinese razor clams (<em>Sinonovacula constricta</em>) and blood clams (<em>Tegillarca granosa</em>). Three independent PCR assays were developed to detect TCP-PAI, <em>tcpA</em>, and <em>tcpB</em>, respectively. The assay amplified a 949 bp band for TCP-PAI (−) strains, a 13375 bp band for TCP-PAI (+) strains, a 415 bp band for <em>tcpA</em>, and a 400 bp band for <em>tcpB</em>, with detection limits of 1.98 × 10³ copies/µL for TCP-PAI and 1.38 × 10³ copies/µL for <em>tcpA</em> and <em>tcpB</em>. A total of 352 <em>Vibrio</em> spp. isolates were collected from larval clams, including 300 from healthy razor clams, 6 from healthy blood clams, and 46 from diseased blood clams. Three isolates (1% of total) from healthy razor clams were identified as <em>V. mediterranei</em> and all were determined to be TCP-PAI (−). Ten isolates (21.7% of total) from diseased blood clams were identified as <em>V. mediterranei</em> and all were TCP-PAI (+). No <em>V. mediterranei</em> was detected in healthy blood clams. Infection experiments showed TCP-PAI (+) strains were associated with up to 99% and 96.67% mortality in razor clams and blood clams, respectively, significantly higher than TCP-PAI (−) strains (71% and 48.89%). These findings highlight TCP-PAI as a key virulence factor in <em>V. mediterranei</em> pathogenicity. The developed PCR assays provide a tool for further studies on TCP-PAI’s role and transmission, offering insights into <em>V. mediterranei</em> pathogenesis in bivalves.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108551"},"PeriodicalIF":2.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ascosphaera apis invasion alters the expression pattern, alternative splicing and alternative polyadenylation of transcripts in the eastern honeybee larval gut","authors":"Jianfeng Qiu ,&nbsp;Fangji Wang ,&nbsp;Xiang Li ,&nbsp;Tao Wu ,&nbsp;Xin Jing ,&nbsp;Zhenzhen Zuo ,&nbsp;Jing Tian ,&nbsp;Dafu Chen ,&nbsp;Rui Guo","doi":"10.1016/j.jip.2026.108549","DOIUrl":"10.1016/j.jip.2026.108549","url":null,"abstract":"<div><div>The <em>Ascosphaera apis</em> infects the honeybee larval gut and causes chalkbrood disease, which impacts colony health and beekeeping production. Currently, the innate immune mechanisms by which honeybee larvae resist <em>A. apis</em> infection remain unclear. This study utilized nanopore sequencing technology to analyze differentially expressed transcripts (DETs) in <em>A. apis</em>-infected and uninfected <em>Apis cerana cerana</em> larval guts, and identified alternative splicing (AS) and alternative polyadenylation (APA) in honeybee genes. The results showed that 1,642, 1,281, and 1,377 DETs were detected on 1–3 days post-infection, respectively. Ten DETs were randomly selected from each group for RT-qPCR validation, and 26 DETs exhibited expression trends consistent with the nanopore sequencing results. A total of 5,476 AS events from 2,430 genes were identified in the larval guts during 1–3 days post-infection, with the number of AS events in the <em>A. apis</em>-infected group being higher than in the control group. Five randomly validated AS events matched the sequencing results. Additionally, 7,310 genes containing APA sites were identified, with the majority having more than five APA sites. Three genes were randomly selected, and their APA sites were validated. These findings provide preliminary insights into the roles of AS and APA at the transcript level in honeybee responses to <em>A. apis</em> infection.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108549"},"PeriodicalIF":2.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of white spot syndrome virus severity grades dynamics in whiteleg shrimp (Penaeus vannamei) during the disease transition process","authors":"Min Jae Kim ,&nbsp;Kwang Il Kim","doi":"10.1016/j.jip.2026.108546","DOIUrl":"10.1016/j.jip.2026.108546","url":null,"abstract":"<div><div>White spot syndrome virus (WSSV), the causative agent of white spot disease (WSD), is a major threat to global shrimp aquaculture. Regular WSSV monitoring is essential for disease management, and severity grades may serve as indicators for evaluating shrimp health and anticipating the risk of outbreaks. This study aimed to elucidate the relationships among WSSV replication properties, severity grades, and disease transition dynamics in whiteleg shrimp using an intramuscular challenge (Exp. 1) to establish a controlled infection and immersion challenge (Exp. 2) to simulate the natural transmission. In Exp. 1, severity grades were associated with distinct viral replication phases, with the eclipse, logarithmic, and plateau phases corresponding to G0–G1, G2–G3, and G4 grades. In Exp. 2, the transition rate from asymptomatic to ill (<em>λ_ai</em>) peaked at 40–48 h post-infection (hpi, 0.24), approximately 24 h earlier than the transition from ill to deceased (<em>λ_id</em>) at 64–72 hpi (0.28). Collectively, shrimp remained asymptomatic but shed virus during the eclipse phase (G0–G1; 0–48 hpi), whereas anorexia and moribundity appeared during the logarithmic phase (G2–G3; 48–72 hpi), followed by extensive mortality in the plateau phase (G4; 72–120 hpi). Accordingly, the results of the present study suggest that shrimp exhibiting G0–G1 grades are likely to represent chronic infection, whereas grades ≥ G2 indicate ongoing disease progression. The correlations identified between severity grades and disease transition provide a practical framework for interpreting longitudinal WSSV monitoring data and improving risk assessment and management in shrimp aquaculture.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108546"},"PeriodicalIF":2.4,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146018632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}