Pub Date : 2026-01-20DOI: 10.1016/j.jip.2026.108545
Beth Okamura, Hanna Hartikainen
The ability to disperse and become established elsewhere is crucial for organisms as environmental quality varies over space and time. Many parasites produce resistant stages that can achieve dispersal independently from hosts. However, co-dispersal of parasites with hosts offers another means of dispersal. Here we focus on how dispersal and establishment of endoparasites with complex life cycles may promote invasion of freshwater environments. We review factors that could contribute to such invasion, present evidence for dispersal and invasions of malacosporean myxozoans, and consider how co-dispersal with their invertebrate hosts (freshwater bryozoans) may drive these processes. We develop this bryozoan/myxozoan association as a model system for assessing probability and risks of endoparasite invasion. Recurrent clonal reproduction in bryozoan hosts in concert with myxozoan traits (broad host ranges, host-condition dependent development) are proposed to particularly promote invasion. It is difficult to predict how global change may influence invasion and diseases caused by myxozoans in vertebrate hosts (fish) due to conflicting impacts and lack of knowledge. These include impacts of eutrophication and warming waters versus declines in migratory birds, poor knowledge of host ranges in parasites with complex life cycles, and recognition of hidden infections.
{"title":"Coinvasion biology of endoparasites and highly clonal hosts.","authors":"Beth Okamura, Hanna Hartikainen","doi":"10.1016/j.jip.2026.108545","DOIUrl":"https://doi.org/10.1016/j.jip.2026.108545","url":null,"abstract":"<p><p>The ability to disperse and become established elsewhere is crucial for organisms as environmental quality varies over space and time. Many parasites produce resistant stages that can achieve dispersal independently from hosts. However, co-dispersal of parasites with hosts offers another means of dispersal. Here we focus on how dispersal and establishment of endoparasites with complex life cycles may promote invasion of freshwater environments. We review factors that could contribute to such invasion, present evidence for dispersal and invasions of malacosporean myxozoans, and consider how co-dispersal with their invertebrate hosts (freshwater bryozoans) may drive these processes. We develop this bryozoan/myxozoan association as a model system for assessing probability and risks of endoparasite invasion. Recurrent clonal reproduction in bryozoan hosts in concert with myxozoan traits (broad host ranges, host-condition dependent development) are proposed to particularly promote invasion. It is difficult to predict how global change may influence invasion and diseases caused by myxozoans in vertebrate hosts (fish) due to conflicting impacts and lack of knowledge. These include impacts of eutrophication and warming waters versus declines in migratory birds, poor knowledge of host ranges in parasites with complex life cycles, and recognition of hidden infections.</p>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":" ","pages":"108545"},"PeriodicalIF":2.4,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146028862","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}
Pub Date : 2026-01-20DOI: 10.1016/j.jip.2026.108548
Dingfeng Wang , Liangde Li , Huiling Li , Jinyu Li , Jun Yang
The grey citrus weevil (GCW) Sympiezomias citri is a significant pest that causes extensive damage to various cash crops, including Citrus reticulata, Camellia sinensis, and Camellia oleifera. Control primarily relies on synthetic chemicals. However, biological control using fungal entomopathogens is a crucial alternative. This study demonstrated the first natural epizootic occurrence in polyphagous GCW (Sympiezomias citri; Coleoptera: Curculionidae) induced by Beauveria sp. in tea plantations in Southeast China. Motivated by the hypotheses that genetic diversity correlates with biocontrol potential and that dominant genetic lineages drive epizootics, we characterized the pathogenic fungi. Bayesian phylogenetic analysis of the nuclear intergenic Bloc region and translation elongation factor 1-α (TEF) revealed that all fifty-one pathogenic agents obtained from field-mycosed GCW adults as B. bassiana, and they were grouped into four subclades. Simple sequence repeat (SSR) genotyping revealed significant genotypic diversity and a heterogeneous population structure with clear dominance of one group (Group II, 78.43%), supporting the hypothesis of lineage dominance during outbreaks. The genetic differentiation index (Gst) among the three populations was 0.2697, and gene flow (Nm) was 0.9427, indicating restricted genetic exchange within the metapopulation. To test the hypothesis that genetic diversity is linked to biocontrol potential, we evaluated eight representative isolates for virulence, colony growth, sporulation, and thermotolerance. Contrary to this hypothesis, no strong correlation was found between genetic grouping and virulence or other key biocontrol traits; instead, superior performance was strain-specific. The DH42 strain was the most virulent, exhibiting the highest corrected mortality rate (100%), the highest mycosis rate (85.00%), and the lowest LT50 (4.76 d). DH42 also exhibited superior biological characteristics, including the highest hyphal growth rate, higher sporulation, germination rates, and thermotolerance compared with the other isolates. This study enhanced our understanding of the epizootic potential of B. bassiana in controlling coleopterous pests and revealed that while genetic diversity and lineage dominance are prominent features of the epizootic population, direct phenotypic screening remains essential for identifying effective biocontrol agents. The highly virulent isolate DH42 is a promising candidate for developing mycoinsecticides for biological control in tea plantations.
{"title":"First record of epizootics in the grey citrus weevil (Sympiezomias citri; Coleoptera: Curculionidae) caused by Beauveria bassiana in tea plantations of Southeast China","authors":"Dingfeng Wang , Liangde Li , Huiling Li , Jinyu Li , Jun Yang","doi":"10.1016/j.jip.2026.108548","DOIUrl":"10.1016/j.jip.2026.108548","url":null,"abstract":"<div><div>The grey citrus weevil (GCW) <em>Sympiezomias citri</em> is a significant pest that causes extensive damage to various cash crops, including <em>Citrus reticulata</em>, <em>Camellia sinensis</em>, and <em>Camellia oleifera</em>. Control primarily relies on synthetic chemicals. However, biological control using fungal entomopathogens is a crucial alternative. This study demonstrated the first natural epizootic occurrence in polyphagous GCW (<em>Sympiezomias citri</em>; Coleoptera: Curculionidae) induced by <em>Beauveria</em> sp. in tea plantations in Southeast China. Motivated by the hypotheses that genetic diversity correlates with biocontrol potential and that dominant genetic lineages drive epizootics, we characterized the pathogenic fungi. Bayesian phylogenetic analysis of the nuclear intergenic Bloc region and translation elongation factor 1-α (TEF) revealed that all fifty-one pathogenic agents obtained from field-mycosed GCW adults as <em>B. bassiana</em>, and they were grouped into four subclades. Simple sequence repeat (SSR) genotyping revealed significant genotypic diversity and a heterogeneous population structure with clear dominance of one group (Group II, 78.43%), supporting the hypothesis of lineage dominance during outbreaks. The genetic differentiation index (<em>G</em><sub>st</sub>) among the three populations was 0.2697, and gene flow (<em>N<sub>m</sub></em>) was 0.9427, indicating restricted genetic exchange within the metapopulation. To test the hypothesis that genetic diversity is linked to biocontrol potential, we evaluated eight representative isolates for virulence, colony growth, sporulation, and thermotolerance. Contrary to this hypothesis, no strong correlation was found between genetic grouping and virulence or other key biocontrol traits; instead, superior performance was strain-specific. The DH42 strain was the most virulent, exhibiting the highest corrected mortality rate (100%), the highest mycosis rate (85.00%), and the lowest LT<sub>50</sub> (4.76 d). DH42 also exhibited superior biological characteristics, including the highest hyphal growth rate, higher sporulation, germination rates, and thermotolerance compared with the other isolates. This study enhanced our understanding of the epizootic potential of <em>B. bassiana</em> in controlling coleopterous pests and revealed that while genetic diversity and lineage dominance are prominent features of the epizootic population, direct phenotypic screening remains essential for identifying effective biocontrol agents. The highly virulent isolate DH42 is a promising candidate for developing mycoinsecticides for biological control in tea plantations.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108548"},"PeriodicalIF":2.4,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025471","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}
Pub Date : 2026-01-19DOI: 10.1016/j.jip.2026.108546
Min Jae Kim , Kwang Il Kim
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 (λai) peaked at 40–48 h post-infection (hpi, 0.24), approximately 24 h earlier than the transition from ill to deceased (λid) 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.
{"title":"Estimation of white spot syndrome virus severity grades dynamics in whiteleg shrimp (Penaeus vannamei) during the disease transition process","authors":"Min Jae Kim , 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<sub>ai</sub></em>) peaked at 40–48 h post-infection (hpi, 0.24), approximately 24 h earlier than the transition from ill to deceased (<em>λ<sub>id</sub></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":"2026-01-19","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}
Pub Date : 2026-01-17DOI: 10.1016/j.jip.2026.108535
Paula Parada , Ciro Invernizzi , Juan Pablo Campá , Ivanna Tomasco
Varroa destructor mites are the main biotic threat to honey bees. Mites entered Uruguay in 1978, but remarkably, for the next 20 years, it was not a significant problem for honey bees. Sequencing partially the mitochondrial cytochrome oxidase I gene and genotyping two hypervariable nuclear loci of mite samples from the 1980s and 1990s showed that these correspond to the Korean haplotype and did not differ from current mite samples. These results contribute to the discussion on the spread of V. destructor in South America and its increased virulence in Uruguay.
{"title":"Analysis of 1980s and 1990s Varroa destructor samples from Uruguay provides insights into its spread and increasing virulence","authors":"Paula Parada , Ciro Invernizzi , Juan Pablo Campá , Ivanna Tomasco","doi":"10.1016/j.jip.2026.108535","DOIUrl":"10.1016/j.jip.2026.108535","url":null,"abstract":"<div><div><em>Varroa destructor</em> mites are the main biotic threat to honey bees. Mites entered Uruguay in 1978, but remarkably, for the next 20 years, it was not a significant problem for honey bees. Sequencing partially the mitochondrial cytochrome oxidase I gene and genotyping two hypervariable nuclear loci of mite samples from the 1980s and 1990s showed that these correspond to the Korean haplotype and did not differ from current mite samples. These results contribute to the discussion on the spread of <em>V. destructor</em> in South America and its increased virulence in Uruguay.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108535"},"PeriodicalIF":2.4,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146003629","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}
Pub Date : 2026-01-13DOI: 10.1016/j.jip.2026.108531
Enrique E. Posada Vaquerano , M. Florencia Gil , Marina E. Battaglia , Corina M. Berón
Efficient heterologous expression of insecticidal Cry proteins, such as those produced by the bacterium Bacillus thuringiensis (Bt), remains essential for their structural and functional characterization. This article describes an optimized workflow for the amplification, cloning, and expression of cry genes identified in Bacillus wiedmannii biovar thuringiensis (Bwt). The Bwt genome harbors multiple cry 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 cry 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 cry4Ea1 and cry4Fa1 genes were cloned into the pSTAB vector, which combines the sporulation-dependent cyt1Aa promoter with the STAB-SD stabilizing sequence, and expressed in the Bt-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 Bacillus thuringiensis subsp. israelensis 4Q7 strain expressing Cry4Fa1 as a representative case. This article analyzes these findings and compares them with other Bt 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.
{"title":"Optimized cloning and expression workflow for Cry proteins from Bacillus wiedmannii biovar thuringiensis","authors":"Enrique E. Posada Vaquerano , M. Florencia Gil , Marina E. Battaglia , 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":"2026-01-13","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}
Pub Date : 2026-01-13DOI: 10.1016/j.jip.2026.108532
Ke Wu, Clebson S. Tavares, Bryony C. Bonning
Diaphorina citri transmits the causal agent of huanglongbing. We previously established three continuous D. citri cell lines, two of which (Dici1 and Dici5) harbor Wolbachia and Diaphorina citri reovirus (DcRV). Here we demonstrate that Wolbachia infection of these cell lines is associated with marked cytopathological effects, including culture collapse. Doxycycline treatment reduced Wolbachia titers and prevented further collapse, while DcRV levels remained unchanged, indicating that Wolbachia does not influence DcRV replication. Prolonged doxycycline treatment nearly eliminated Wolbachia, resulting in increased stability of the Dici1 and Dici5 cell lines. These cell lines with reduced Wolbachia loads represent improved systems for investigating host-microbe interactions.
{"title":"Doxycycline-mediated clearance of Wolbachia is associated with the long-term survival of Diaphorina citri cell lines","authors":"Ke Wu, Clebson S. Tavares, Bryony C. Bonning","doi":"10.1016/j.jip.2026.108532","DOIUrl":"10.1016/j.jip.2026.108532","url":null,"abstract":"<div><div><em>Diaphorina citri</em> transmits the causal agent of huanglongbing. We previously established three continuous <em>D. citri</em> cell lines, two of which (Dici1 and Dici5) harbor <em>Wolbachia</em> and <em>Diaphorina citri reovirus</em> (DcRV). Here we demonstrate that <em>Wolbachia</em> infection of these cell lines is associated with marked cytopathological effects, including culture collapse. Doxycycline treatment reduced <em>Wolbachia</em> titers and prevented further collapse, while DcRV levels remained unchanged, indicating that <em>Wolbachia</em> does not influence DcRV replication. Prolonged doxycycline treatment nearly eliminated <em>Wolbachia</em>, resulting in increased stability of the Dici1 and Dici5 cell lines. These cell lines with reduced <em>Wolbachia</em> loads represent improved systems for investigating host-microbe interactions.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"216 ","pages":"Article 108532"},"PeriodicalIF":2.4,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986724","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}
Pub Date : 2026-01-11DOI: 10.1016/j.jip.2026.108530
Kamila dos Santos Bezerra, Natanael Dantas Farias, Sofia Lucena de Oliveira Coutinho, Darlânia Santos da Silva, Patricia Mirella da Silva
Oyster production is an expanding aquaculture activity worldwide. Protozoan parasites such as Perkinsus 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 Perkinsus into regions far from their natural geographical areas, posing a threat to native mollusk populations. Since 2008, Perkinsus spp. has been detected among bivalves from Brazil. Two species (P. olsenii and P. chesapeaki) were sporadically observed. In contrast, two others (P. marinus and P. beihaiensis) are frequently detected in oyster populations, reaching high infection intensities and prevalences depending on the populations and species (Crassostrea gasar, C. rhizophorae, and Magallana gigas). Diagnosis based on molecular techniques, such as qPCR, has been developed to detect protozoan parasites, including Perkinsus spp.. However, the qPCRs developed for the diagnosis of P. marinus and P. beihaiensis 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 Perkinsus spp. over the continents, prompted by several factors (environmental or anthropogenic), there is an urgent need to accurately detect Perkinsus 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 P. marinus and P. beihaiensis that are spreading worldwide.
{"title":"Development of two quantitative real-time PCRs for the detection of Perkinsus beihaiensis and P. marinus","authors":"Kamila dos Santos Bezerra, Natanael Dantas Farias, Sofia Lucena de Oliveira Coutinho, Darlânia Santos da Silva, 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":"2026-01-11","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}
Pub Date : 2026-01-02DOI: 10.1016/j.jip.2025.108529
Shabnum Mumtaz , Mudasir Gani , Gozde B. Eroglu , Tariq Rasool Rather , Arif Hussain Wani , Sajad Mohi-ud-Din , Akhtar Ali Khan , Kamlesh Bali , Rakesh Kumar Gupta
The mulberry silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), is an economically important insect domesticated for silk production in India and other countries, whereas the Bombyx mori nucleopolyhedrovirus (BmNPV) and Bombyx mori bidensovirus (BmBDV) are the two most serious viral pathogens infecting the domestic silkworms. In this study, the frequency of co-occurrence of BmNPV and BmBDV in silkworm larvae from sericulture practicing regions of North, Central, and South Kashmir was investigated. The prevalence of grasserie disease (%) and extent of cocoon crop loss varied significantly between the different regions. On the basis of PCR analyses, the mean co-occurrence (%) of BmNPV and BmBDV infection was 94%, 92.7% and 98% in the samples from North, Central and South Kashmir, respectively. The BmBDV isolates from Mysore, Andhra Pradesh, Tamil Nadu, Kashmir, Dehradun, Ghumarwin and Jammu grouped together and are most closely related to other BmBDV isolates on the basis of gene sequencing and phylogenetic analyses of the VD-1 gene fragments. The BmBDV-S1 isolate had the lowest LD50 and ST50 values revealing that it was more virulent to B. mori larvae as compared to BmBDV-N1 and BmBDV-C1 isolates. Overall, the results revealed that the BmNPV and BmBDV co-exist in the silkworm larvae and highlight the need for greater research into the interaction of these viruses in Bombyx mori.
家蚕（Bombyx mori L.）（鳞翅目：家蚕科）是印度和其他国家重要的经济昆虫，家蚕核多角体病毒（BmNPV）和家蚕bidensovirus （BmBDV）是感染家蚕的两种最严重的病毒病原体。本研究调查了北、中、南克什米尔蚕业区家蚕幼虫中BmNPV和BmBDV的共现频率。不同地区间草瘟流行率（%）和蚕茧作物损失程度差异显著。PCR分析结果显示，克什米尔北部、中部和南部地区BmNPV和BmBDV的平均共感染率分别为94%、92.7%和98%。根据基因测序和系统发育分析，来自迈索尔、安得拉邦、泰米尔纳德邦、克什米尔、德拉敦、古玛温和查谟的BmBDV分离株与其他BmBDV分离株亲缘关系最密切。分离物BmBDV-S1的LD50和ST50值最低，表明其对家蚕幼虫的毒力高于分离物BmBDV-N1和BmBDV-C1。总之，结果表明BmNPV和BmBDV在家蚕幼虫中共存，并强调需要对这些病毒在家蚕中的相互作用进行更深入的研究。
{"title":"Co-occurrence of the nucleopolyhedrovirus and bidensovirus in silkworm, Bombyx mori L.: Evidence from Kashmir and molecular comparison of Indian bidensovirus isolates","authors":"Shabnum Mumtaz , Mudasir Gani , Gozde B. Eroglu , Tariq Rasool Rather , Arif Hussain Wani , Sajad Mohi-ud-Din , Akhtar Ali Khan , Kamlesh Bali , Rakesh Kumar Gupta","doi":"10.1016/j.jip.2025.108529","DOIUrl":"10.1016/j.jip.2025.108529","url":null,"abstract":"<div><div>The mulberry silkworm, <em>Bombyx mori</em> L. (Lepidoptera: Bombycidae), is an economically important insect domesticated for silk production in India and other countries, whereas the Bombyx mori nucleopolyhedrovirus (BmNPV) and Bombyx mori bidensovirus (BmBDV) are the two most serious viral pathogens infecting the domestic silkworms. In this study, the frequency of co-occurrence of BmNPV and BmBDV in silkworm larvae from sericulture practicing regions of North, Central, and South Kashmir was investigated. The prevalence of grasserie disease (%) and extent of cocoon crop loss varied significantly between the different regions. On the basis of PCR analyses, the mean co-occurrence (%) of BmNPV and BmBDV infection was 94%, 92.7% and 98% in the samples from North, Central and South Kashmir, respectively. The BmBDV isolates from Mysore, Andhra Pradesh, Tamil Nadu, Kashmir, Dehradun, Ghumarwin and Jammu grouped together and are most closely related to other BmBDV isolates on the basis of gene sequencing and phylogenetic analyses of the <em>VD-1</em> gene fragments. The BmBDV-S1 isolate had the lowest LD<sub>50</sub> and ST<sub>50</sub> values revealing that it was more virulent to <em>B. mori</em> larvae as compared to BmBDV-N1 and BmBDV-C1 isolates. Overall, the results revealed that the BmNPV and BmBDV co-exist in the silkworm larvae and highlight the need for greater research into the interaction of these viruses in <em>Bombyx mori.</em></div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"215 ","pages":"Article 108529"},"PeriodicalIF":2.4,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145900609","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}
Pub Date : 2025-12-25DOI: 10.1016/j.jip.2025.108528
Ziyi Qin , Wei Liu , Yumeng Bian , Jingwen Tang , Kuo Bao , Ruisheng Yang , Liang Xu , Yong Wang , Yiren Jiang
Microsporidia represent a group of eukaryotic, obligate intracellular parasites that form environmentally resistant spores. Spore wall proteins (SWPs) can mediate pathogen-host interactions for specific parasitism among different species. However, limited research has been conducted on SWPs in Nosema pernyi that causes microsporidiosis in the economically-important Chinese oak silkworm, Antheraea pernyi. Here, we identified a total of 636 proteins from N. pernyi using LC-MS/MS, among which 8 SWPs were listed. A hydrophilic SWP13, which has identity with other homologous SWP13 among the Nosema genus, was identified both from nucleotide and peptide sequences. After the anti-NpSWP13 polyclonal antibody was produced, western blotting and immunohistochemical analysis showed that the protein exists in N. pernyi. Indirect immunofluorescence analysis (IFA) and immunoelectron microscopy (IEM) consistently demonstrated the enrichment of NpSWP13 located in the endospore. Immunoprecipitation-Mass Spectrometry (IP-MS) analysis indicates NpSWP13 may interact with proteins in the midgut of silkworm. In this study, our results demonstrate that NpSWP13 is a novel SWP subcellularly localized in N. pernyi. Our research enhances the understanding of different SWPs in microsporidia and reveals possible mechanisms in specific infection among different Nosema species.
{"title":"Proteomic analysis of total spore proteins from Nosema pernyi and characterization of a novel spore wall protein, NpSWP13","authors":"Ziyi Qin , Wei Liu , Yumeng Bian , Jingwen Tang , Kuo Bao , Ruisheng Yang , Liang Xu , Yong Wang , Yiren Jiang","doi":"10.1016/j.jip.2025.108528","DOIUrl":"10.1016/j.jip.2025.108528","url":null,"abstract":"<div><div>Microsporidia represent a group of eukaryotic, obligate intracellular parasites that form environmentally resistant spores. Spore wall proteins (SWPs) can mediate pathogen-host interactions for specific parasitism among different species. However, limited research has been conducted on SWPs in<!--> <em>Nosema pernyi</em> that causes microsporidiosis in the economically-important Chinese oak silkworm, <em>Antheraea pernyi</em>. Here, we identified a total of 636 proteins from<!--> <em>N. pernyi</em> <!-->using LC-MS/MS, among which 8 SWPs were listed. A hydrophilic SWP13, which<!--> <!-->has identity with other homologous SWP13 among the <em>Nosema</em> genus, was identified both from nucleotide and peptide sequences. After the anti-NpSWP13 polyclonal antibody was produced, western blotting and immunohistochemical<!--> <!-->analysis<!--> <!-->showed<!--> <!-->that the protein exists in<!--> <em>N. pernyi</em>. Indirect immunofluorescence analysis (IFA) and immunoelectron microscopy (IEM) consistently demonstrated<!--> <!-->the<!--> <!-->enrichment of NpSWP13 located in the endospore. Immunoprecipitation-Mass Spectrometry (IP-MS) analysis indicates NpSWP13 may interact with proteins in the midgut of silkworm<em>.</em> In this study, our results demonstrate that<!--> <!-->NpSWP13 is<!--> <!-->a novel SWP subcellularly localized in<!--> <em>N. pernyi</em>.<!--> <!-->Our research<!--> <!-->enhances<!--> <!-->the understanding of different SWPs in microsporidia and reveals possible mechanisms in specific infection among different <em>Nosema</em> species.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"215 ","pages":"Article 108528"},"PeriodicalIF":2.4,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837204","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}
Holotrichia consanguinea is a destructive pest of sugarcane in India. Out of urgent need to control the grubs, indiscriminate application of Bacillus cereus followed by Heterorhabditis indica is practiced. Based on the compatibility studies between the two bioagents, we found that B. cereus-treated grubs succumbed faster to H. indica infection suggesting synergism. Infection with H. indica even at the minimum dose of 250 IJ/grub decreased the survival to 3.7 ± 1.33 days, compared to 9.2 ± 1.93 days in untreated grubs. The Kaplan-Meier estimates depicted reduced survival time gap between treated and untreated grubs for all probability levels with an increase in nematode dose. Following mortality, the cadavers supported 65.2 % higher multiplication of Photorhabdus luminescens over B. cereus till day three, which gradually reversed to 67.5 % in favour of B. cereus by day eight. The suppression of P. luminescens by B. cereus had negative implication on the growth and development of H. indica as it coincided with significant decline in the production of hermaphrodites, females and the final recovery of the infective juveniles after 3, 6 and 8 days of insect death, respectively. Recommending combined application of the two bioagents can have a negative implication on the long-term persistence of H. indica.
{"title":"Two-fold application of Bacillus cereus followed by Heterorhabditis indica to manage Holotrichia consanguinea adversely effects nematode reproduction","authors":"Sharad Mohan , Akanksha Upadhyay , Prakash Banaker , Ritu Gupta","doi":"10.1016/j.jip.2025.108527","DOIUrl":"10.1016/j.jip.2025.108527","url":null,"abstract":"<div><div><em>Holotrichia consanguinea</em> is a destructive pest of sugarcane in India. Out of urgent need to control the grubs, indiscriminate application of <em>Bacillus cereus</em> followed by <em>Heterorhabditis indica</em> is practiced. Based on the compatibility studies between the two bioagents, we found that <em>B. cereus</em>-treated grubs succumbed faster to <em>H. indica</em> infection suggesting synergism. Infection with <em>H. indica</em> even at the minimum dose of 250 IJ/grub decreased the survival to 3.7 ± 1.33 days, compared to 9.2 ± 1.93 days in untreated grubs. The Kaplan-Meier estimates depicted reduced survival time gap between treated and untreated grubs for all probability levels with an increase in nematode dose. Following mortality, the cadavers supported 65.2 % higher multiplication of <em>Photorhabdus luminescens</em> over <em>B. cereus</em> till day three<em>,</em> which gradually reversed to 67.5 % in favour of <em>B. cereus</em> by day eight. The suppression of <em>P. luminescens</em> by <em>B. cereus</em> had negative implication on the growth and development of <em>H. indica</em> as it coincided with significant decline in the production of hermaphrodites, females and the final recovery of the infective juveniles after 3, 6 and 8 days of insect death, respectively. Recommending combined application of the two bioagents can have a negative implication on the long-term persistence of <em>H. indica</em>.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"215 ","pages":"Article 108527"},"PeriodicalIF":2.4,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145834112","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}
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