Journal of invertebrate pathology最新文献

{"title":"Parasite and virus dynamics in the honeybee Apis mellifera unicolor on a tropical island recently invaded by Varroa destructor","authors":"Benoit Jobart ,&nbsp;Hélène Delatte ,&nbsp;Gérard Lebreton ,&nbsp;Nicolas Cazanove ,&nbsp;Olivier Esnault ,&nbsp;Johanna Clémencet ,&nbsp;Nicolas Blot","doi":"10.1016/j.jip.2024.108125","DOIUrl":"10.1016/j.jip.2024.108125","url":null,"abstract":"<div><p>In La Réunion, the established honeybee subspecies <em>Apis mellifera unicolor,</em> an endemic subspecies of African lineage, is facing considerable challenges. Since the introduction of the <em>Varroa destructor</em> mite in 2017 high colony losses have been recorded. We investigated the dynamics of <em>V. destructor</em> and two viruses, the Deformed Wing Virus (DWV), known to be transmitted by the mite, and the Chronic Bee Paralysis Virus (CBPV), in <em>A. m. unicolor</em>. Colonies from two apiaries located at 300 and 900 m a.s.l were monitored twice for one year without any acaricide treatment. The brood area, <em>V. destructor</em> infestation rates, DWV and CBPV prevalence and load were recorded monthly. <em>A. m. unicolor</em> maintained brood rearing throughout the year. <em>Varroa destructor</em> infestation resulted in high colony mortality (up to 85 %) and high phoretic mite rates (up to 52 mites per hundred bees). The establishment of DWV in colonies occurred after that of <em>V. destructor</em> and the mite infestation rate had a significant effect on the virus prevalence and load. CBPV appeared only transiently throughout the surveys. The data showed that, in tropical colonies with permanent brood rearing, <em>V. destructor</em> and DWV can reach high levels, but are still subject to seasonal variations that appear to be influenced by environmental conditions. This suggests that beekeeping practices could be adapted by favouring sites and periods for transhumance or acaricide treatment.</p></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"204 ","pages":"Article 108125"},"PeriodicalIF":3.4,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140864985","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":"Pathogens of the oak processionary moth Thaumetopoea processionea: Developing a user-friendly bioassay system and metagenome analyses for microorganisms","authors":"Lea Schäfer,&nbsp;Johannes A. Jehle,&nbsp;Regina G. Kleespies,&nbsp;Jörg T. Wennmann","doi":"10.1016/j.jip.2024.108121","DOIUrl":"10.1016/j.jip.2024.108121","url":null,"abstract":"<div><p>The oak processionary moth (OPM) <em>Thaumetopoea processionea</em> is a pest of oak trees and poses health risks to humans due to the urticating setae of later instar larvae. For this reason, it is difficult to rear OPM under laboratory conditions, carry out bioassays or examine larvae for pathogens. Biological control targets the early larval instars and is based primarily on commercial preparations of <em>Bacillus thuringiensis</em> ssp. <em>kurstaki</em> (Btk). To test the entomopathogenic potential of other spore-forming bacteria, a user-friendly bioassay system was developed that (i) applies bacterial spore suspensions by oak bud dipping, (ii) targets first instar larvae through feeding exposure and (iii) takes into account their group-feeding behavior. A negligible mortality in the untreated control proved the functionality of the newly established bioassay system. Whereas the commercial Btk HD-1 strain was used as a bioassay standard and confirmed as being highly efficient, a <em>Bacillus wiedmannii</em> strain was ineffective in killing OPM larvae. Larvae, which died during the infection experiment, were further subjected to Nanopore sequencing for a metagenomic approach for entomopathogen detection. It further corroborated that <em>B.<!--> <!-->wiedmannii</em> was not able to infect and establish in OPM, but identified potential insect pathogenic species from the genera <em>Serratia</em> and <em>Pseudomonas.</em></p></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"205 ","pages":"Article 108121"},"PeriodicalIF":3.4,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022201124000648/pdfft?md5=d4508220242ac62b6e1e68c89e6dbb9a&pid=1-s2.0-S0022201124000648-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140865382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term suppression of turfgrass insect pests with native persistent entomopathogenic nematodes","authors":"Albrecht M. Koppenhöfer,&nbsp;Ana Luiza Sousa","doi":"10.1016/j.jip.2024.108123","DOIUrl":"https://doi.org/10.1016/j.jip.2024.108123","url":null,"abstract":"<div><p>Entomopathogenic nematodes (EPNs) can control several important turfgrass insect pests including white grubs, weevils, cutworms, and sod webworms. But most of the research has focused on inundative releases in a biopesticide strategy using EPN strains that may have lost some of their ability to persist effectively over years of lab maintenance and / or selection for virulence and efficient mass-production. Our study examined the potential of fresh field isolate mixes of endemic EPNs to provide multi-year suppression of turfgrass insect pests. In early June 2020, we applied isolate mixes from golf courses of the EPNs <em>Steinernema carpocapsae</em>, <em>Heterorhabditis bacteriophora</em>, and their combination to plots straddling fairway and rough on two golf courses in central New Jersey, USA. Populations of EPNs and insect pests were sampled on the fairway and rough side of the plots from just before EPN application until October 2022. EPN populations increased initially in plots treated with the respective species. <em>Steinernema carpocapsae</em> densities stayed high for most of the experiment. <em>Heterorhabditis bacteriophora</em> densities decreased after 6 months and stabilized at lower levels. Several insect pests were reduced across the entire experimental period. In the fairway, the combination treatment reduced annual bluegrass weevil larvae (59 % reduction) and adults (74 %); <em>S. carpocapsae</em> reduced only adults (42 %). White grubs were reduced by <em>H. bacteriophora</em> (67 %) and the combination (63 %). Black turfgrass ataenius adults were reduced in all EPN treatments (43–62 %) in rough and fairway. Sod webworm larvae were reduced by <em>S. carpocapsae</em> in the fairway (75 %) and the rough (100 %) and by <em>H. bacteriophora</em> in the rough (75 %). Cutworm larvae were reduced in the fairway by <em>S. carpocapsae</em> (88 %) and the combination (75 %). Overall, our observations suggest that inoculative applications of fresh field isolate mixes of endemic EPNs may be a feasible approach to long-term suppression of insect pests in turfgrass but may require periodic reapplications.</p></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"204 ","pages":"Article 108123"},"PeriodicalIF":3.4,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022201124000661/pdfft?md5=5dd21af5ef8931c45659234bfdfcccaf&pid=1-s2.0-S0022201124000661-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140823714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rhodobacter sphaeroides supplementation improves defense ability of Chinese mitten crab Eriocheir sinensis against Shewanella putrefaciens infection via intestinal flora and metabolism regulation","authors":"Haipeng Cao ,&nbsp;Xurui Zheng ,&nbsp;Chenhao Teng ,&nbsp;La Xu ,&nbsp;Youhong Wang ,&nbsp;Chunlei Gai ,&nbsp;Haibin Ye","doi":"10.1016/j.jip.2024.108120","DOIUrl":"https://doi.org/10.1016/j.jip.2024.108120","url":null,"abstract":"<div><p><em>Shewanella putrefaciens</em> is a vital bacterial pathogen implicated in serious diseases in Chinese mitten crab <em>Eriocheir sinensis</em>. Yet the use of probiotics to improve the defense ability of <em>E. sinensis</em> against <em>S. putrefaciens</em> infection remains poorly understood. In the present study, the protective effect of dietary <em>R. sphaeroides</em> against <em>S. putrefaciens</em> infection in <em>E. sinensis</em> was evaluated through antioxidant capability, immune response, and survival under bacterial challenge assays, and its protective mechanism was further explored using a combination of intestinal flora and metabolome assays. Our results indicated that dietary <em>R. sphaeroides</em> could significantly improve immunity and antioxidant ability of Chinese mitten crabs, thereby strengthening their disease resistance with the relative percentage survival of 81.09% against <em>S. putrefaciens</em>. In addition, dietary <em>R. sphaeroides</em> could significantly alter the intestinal microbial composition and intestinal metabolism of crabs, causing not only the reduction of potential threatening pathogen load but also the increase of differential metabolites in tryptophan metabolism, pyrimidine metabolism, and glycerophospholipid metabolism. Furthermore, the regulation of differential metabolites such as <em>N</em>-Acetylserotonin positively correlated with beneficial <em>Rhodobacter</em> could be a potential protection strategy for <em>Shewanella</em> infection. To the best of our knowledge, this is the first study to illustrate the protective effect and mechanism of <em>R. sphaeroides</em> supplementation to protect <em>E. sinensis</em> against <em>S. putrefaciens</em> infection.</p></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"204 ","pages":"Article 108120"},"PeriodicalIF":3.4,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140807560","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":"Virus discovery in cultured portunid crabs: Genomic, phylogenetic, histopathological and microscopic characterization of a reovirus and a new bunyavirus","authors":"Camila Prestes dos Santos Tavares ,&nbsp;Samuel Paulo Cibulski ,&nbsp;Gisela Geraldine Castilho-Westphal ,&nbsp;Mingli Zhao ,&nbsp;Ubiratan de Assis Teixeira Silva ,&nbsp;Eric J. Schott ,&nbsp;Antonio Ostrensky","doi":"10.1016/j.jip.2024.108118","DOIUrl":"10.1016/j.jip.2024.108118","url":null,"abstract":"<div><p>Portunid crabs are distributed worldwide and highly valued in aquaculture. Viral infections are the main limiting factor for the survival of these animals and, consequently, for the success of commercial-scale cultivation. However, there is still a lack of knowledge about the viruses that infect cultured portunid crabs worldwide. Herein, the genome sequence and phylogeny of Callinectes sapidus reovirus 2 (CsRV2) are described, and the discovery of a new bunyavirus in <em>Callinectes danae</em> cultured in southern Brazil is reported. The CsRV2 genome sequence consists of 12 dsRNA segments (20,909 nt) encode 13 proteins. The predicted RNA-dependent RNA polymerase (RdRp) shows a high level of similarity with that of <em>Eriocheir sinensis</em> reovirus 905, suggesting that CsRV2 belongs to the genus <em>Cardoreovirus</em>. The CsRV2 particles are icosahedral, measuring approximately 65 nm in diameter, and exhibit typical non-turreted reovirus morphology. High throughput sequencing data revealed the presence of an additional putative virus genome similar to bunyavirus, called Callinectes danae Portunibunyavirus 1 (CdPBV1). The CdPBV1 genome is tripartite, consisting of 6,654 nt, 3,120 nt and 1,656 nt single-stranded RNA segments that each encode a single protein. Each segment has a high identity with European shore crab virus 1, suggesting that CdPBV1 is a new representative of the family <em>Cruliviridae</em>. The putative spherical particles of CdPBV1 measure ∼120 nm in diameter and present a typical bunyavirus morphology. The results of the histopathological analysis suggest that these new viruses can affect the health and, consequently, the survival of <em>C. danae</em> in captivity. Therefore, the findings reported here should be used to improve prophylactic and pathogen control practices and contribute to the development and optimization of the production of soft-shell crabs on a commercial scale in Brazil.</p></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"204 ","pages":"Article 108118"},"PeriodicalIF":3.4,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140850939","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":"Characterisation of Nematoda and Digenea in selected Australian freshwater snails","authors":"Shokoofeh Shamsi ,&nbsp;Alice Banfield ,&nbsp;Nidhish Francis ,&nbsp;Diane P. Barton ,&nbsp;Matthew McLellan","doi":"10.1016/j.jip.2024.108116","DOIUrl":"https://doi.org/10.1016/j.jip.2024.108116","url":null,"abstract":"<div><p>Freshwater snails are integral to local ecosystems as a primary food source for various vertebrate species, thereby contributing significantly to ecological food webs. However, their role as intermediate hosts also makes them pivotal in the transmission of parasites. In Australia, research on freshwater snails has predominantly focused on their role as intermediate hosts for livestock parasites, while there has been limited exploration of the impact of these parasites on snail health and population dynamics. The aim of this study was to determine parasitic infection in freshwater snails. This study was conducted in the south-eastern region of Australia, in 2022. A total of 163 freshwater snails from four different species were collected and examined in the Murrumbidgee catchment area in the southeastern part of Australia during the Southern Hemisphere summer and autumn months (February to May). The species included <em>Isidorella hainesii, Glyptophysa novaehollandica, Bullastra lessoni</em> (endemic species), and <em>Physella acuta</em> (an introduced species). Through the analysis of sequence data from the various regions of the nuclear ribosomal DNA, we determined that the Digenea species in this study belonged to three distinct species, including <em>Choanocotyle hobbsi, Petasiger</em> sp. and an unidentified species belonging to Plagiorchioidea. Additionally, analysis of the sequences from Nematoda found in this study, revealed they could be categorized into two separate taxa, including <em>Krefftascaris</em> sp. and an unidentified nematode closely associated with plant and soil nematodes. This research holds significant implications for the future understanding and conservation of Australian freshwater ecosystems. Most parasites found in the present study complete their life cycle in snails and turtles. As many of freshwater snail and turtle species in Australia are endemic and face population threats, exploring the potential adverse impacts of parasitic infections on snail and turtle health, is crucial for advancing our understanding of these ecosystems and also paving the way for future research and conservation efforts. While none of the native snail species in the present study have been listed as endangered or threatened, this may simply be attributed to the absence of regular population surveys.</p></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"204 ","pages":"Article 108116"},"PeriodicalIF":3.4,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022201124000594/pdfft?md5=779a508c83479216c199aa3064fa811d&pid=1-s2.0-S0022201124000594-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140816561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First report of Perkinsus marinus occurrence associated with wild Pacific oysters Crassostrea gigas from the west coast of Korea","authors":"Seung-Hyeon Kim ,&nbsp;S.D.N.K. Bathige ,&nbsp;Hyung-Bae Jeon ,&nbsp;Donghyun Lee ,&nbsp;Kwang-Sik Choi ,&nbsp;Hyoun Joong Kim ,&nbsp;Kyung-Il Park","doi":"10.1016/j.jip.2024.108119","DOIUrl":"https://doi.org/10.1016/j.jip.2024.108119","url":null,"abstract":"<div><p>This study reports the occurrence of <em>Perkinsus marinus</em> associated with wild Pacific oyster (<em>Crassostrea gigas</em>) specimens collected along the west coast of Korea. Confirmation of <em>P. marinus</em> presence was achieved by conventional PCR using World Organization of Animal Health (WOAH)-recommended primers that specifically targeted regions of the rDNA locus (ITS1, 5.8S, and ITS2). Sequencing of 10 samples revealed two distinct sequences differing by a single base pair, indicating potential haplotype variability. One sequence closely resembled the <em>P. marinus</em> strain found in Maryland, USA, whereas the other exhibited divergence, indicative of species diversity in the Korean strain, as was evident from the haplotype network analysis. Further validation involved the Ray’s Fluid Thioglycollate Medium (RFTM) assay, which initially yielded inconclusive results, possibly due to low infection intensity. Subsequently, RFTM and 2 M NaOH assays conducted on the isolates in the present study, cultured <em>P. marinus</em> cells in standard DMEM/F12 medium, and a positive <em>P. marinus</em> strain (ATCC 50509), revealed characteristic hypnospores of <em>P. marinus</em> upon Lugol’s iodine staining. These comprehensive investigations underscore the conclusive confirmation of <em>P. marinus</em> in Korean waters and mark a significant milestone in our understanding of the distribution and characteristics of this parasite in previously unreported regions.</p></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"204 ","pages":"Article 108119"},"PeriodicalIF":3.4,"publicationDate":"2024-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140816560","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":"RNA virus diversity and prevalence in field and laboratory populations of melon fly throughout its distribution","authors":"Sanjay Kumar Pradhan ,&nbsp;Jennifer L. Morrow ,&nbsp;Stephen R. Sharpe ,&nbsp;Ashok Karuppannasamy ,&nbsp;Ellango Ramasamy ,&nbsp;Shivanna Bynakal ,&nbsp;Manamohan Maligeppagol ,&nbsp;Asokan Ramasamy ,&nbsp;Markus Riegler","doi":"10.1016/j.jip.2024.108117","DOIUrl":"10.1016/j.jip.2024.108117","url":null,"abstract":"<div><p>Insects have a rich diversity of RNA viruses that can either cause acute infections or persist in host populations without visible symptoms. The melon fly, <em>Zeugodacus cucurbitae</em> (Tephritidae) causes substantial economic losses through infestation of diverse cucurbit and other crops. Of Indomalayan origin, it is now established in many tropical regions of the world. The virome diversity of <em>Z. cucurbitae</em> is largely unknown across large parts of its distribution, including the Indian subcontinent. We have analysed three transcriptomes each of one field–collected and one laboratory-reared <em>Z. cucurbitae</em> population from Bangalore (India) and discovered genomes of ten putative RNA viruses: two sigmaviruses, one chimbavirus, one cripavirus, one noda-like virus, one nora virus, one orbivirus, one partiti-like virus, one sobemovirus and one toti-like virus. Analysis of the only available host genome of a Hawaiian <em>Z. cucurbitae</em> population did not detect host genome integration of the detected viruses. While all ten viruses were found in the Bangalore field population only seven were detected in the laboratory population, indicating that these seven may cause persistent covert infections. Using virus-specific RNA-dependent RNA polymerase gene primers, we detected nine of the RNA viruses with an overall low variant diversity in some but not all individual flies from four out of five Indian regions. We then screened 39 transcriptomes of <em>Z. cucurbitae</em> laboratory populations from eastern Asia (Guangdong, Hainan, Taiwan) and the Pacific region (Hawaii), and detected seven of the ten virus genomes. We found additional genomes of a picorna-like virus and a negev-like virus. Hawaii as the only tested population from the fly’s invasive range only had one virus. Our study provides evidence of new and high RNA virus diversity in Indian populations within the original range of <em>Z. cucurbitae</em>, as well as the presence of persistent covert infections in laboratory populations. It builds the basis for future research of tephritid-associated RNA viruses, including their host effects, epidemiology and application potential in biological control.</p></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"204 ","pages":"Article 108117"},"PeriodicalIF":3.4,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0022201124000600/pdfft?md5=b408a0e1c01722af1dc1fe36e2cc75cb&pid=1-s2.0-S0022201124000600-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140860317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular characterization, expression and antibacterial function of a macin, HdMac, from Haliotis discus hannai","authors":"Chunli Jiao ,&nbsp;Jian Ruan ,&nbsp;Wei Sun ,&nbsp;Xinze Zhang ,&nbsp;Xiaobo Liu ,&nbsp;Guodong Sun ,&nbsp;Caili Liu ,&nbsp;Chunxiao Sun ,&nbsp;Xiuhui Tian ,&nbsp;Dinglong Yang ,&nbsp;Lizhu Chen ,&nbsp;Zhongquan Wang","doi":"10.1016/j.jip.2024.108113","DOIUrl":"https://doi.org/10.1016/j.jip.2024.108113","url":null,"abstract":"<div><p>Macins are a family of antimicrobial peptides, which play multiple roles in the elimination of invading pathogens. In the present study, a macin was cloned and characterized from Pacific abalone <em>Haliotis discus hannai</em> (Designated as HdMac). Analysis of the conserved domain suggested that HdMac was a new member of the macin family. In non-stimulated abalones, HdMac transcripts were constitutively expressed in all five tested tissues, especially in hemocytes. After <em>Vibrio harveyi</em> stimulation, the expression of HdMac mRNA in hemocytes was significantly up-regulated at 12 hr (<em>P &lt;</em> 0.01). RNAi-mediated knockdown of HdMac transcripts affected the survival rates of abalone against <em>V. harveyi</em>. Moreover, recombinant protein of HdMac (rHdMac) exhibited high antibacterial activities against invading bacteria, especially for <em>Vibrio anguillarum</em>. In addition, rHdMac possessed binding activities towards glucan, lipopolysaccharides (LPS), and peptidoglycan (PGN), but not chitin <em>in vitro</em>. Membrane integrity analysis revealed that rHdMac could increase the membrane permeability of bacteria. Meanwhile, both the phagocytosis and chemotaxis ability of hemocytes could be significantly enhanced by rHdMac. Overall, the results showed that HdMac could function as a versatile molecule involved in immune responses of <em>H. discus hannai</em>.</p></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"204 ","pages":"Article 108113"},"PeriodicalIF":3.4,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140618762","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":"Harnessing nature's arsenal: Ochrobactrum bacteria metabolites in the battle against root- knot nematode – Insights from in vitro and molecular docking studies","authors":"V.P Krithika ,&nbsp;Ganeshan Shandeep ,&nbsp;Anita Bellie ,&nbsp;J. Gulsar Banu ,&nbsp;Jayakanthan Mannu ,&nbsp;M. Suganthy ,&nbsp;V. Gomathi ,&nbsp;D. Uma ,&nbsp;Prasanthrajan Mohan","doi":"10.1016/j.jip.2024.108114","DOIUrl":"https://doi.org/10.1016/j.jip.2024.108114","url":null,"abstract":"<div><p>Agricultural Productivity and plant health are threatened by the root-knot nematode. The use of biocontrol agents reduces the need for chemical nematicides and improves the general health of agricultural ecosystems by offering a more environmentally friendly and sustainable method of managing nematode infestations. Plant-parasitic nematodes can be efficiently managed with the use of entomopathogenic nematodes (EPNs), which are widely used biocontrol agents. This study focused on the nematicidal activity of the secondary metabolites present in the bacteria <em>Ochrobactrum</em> sp. identified in the EPN, <em>Heterorhabditis</em> <em>indica</em> against Root-Knot Nematode (<em>Meloidogyne incognita</em>). Its effect on egg hatching and survival of juveniles of root- knot nematode (RKN) was examined. The ethyl acetate component of the cell-free culture (CFC) filtrate of the <em>Ochrobactrum</em> sp. bacteria was tested at four different concentrations (25 %, 50 %, 75 % and 100 %) along with broth and distilled water as control. The bioactive compounds of <em>Ochrobactrum</em> sp. bacteria showed the highest suppression of <em>M. incognita</em> egg hatching (100 %) and juvenile mortality (100 %) at 100 % concentration within 24 h of incubation. In this study, unique metabolite compounds were identified through the Gas Chromatography- Mass Spectrometry (GC–MS) analysis, which were found to have anti- nematicidal activity. In light of this, molecular docking studies were conducted to determine the impact of biomolecules from <em>Ochrobactrum</em> sp. using significant proteins of <em>M. incognita</em>, such as calreticulin, sterol carrier protein 2, flavin-containing monooxygenase, pectate lyase, candidate secreted effector, oesophageal gland cell secretory protein and venom allergen-like protein. The results also showed that the biomolecules from <em>Ochrobactrum</em> sp. had a significant inhibitory effect on the different protein targets of <em>M. incognita</em>. 3-Epimacronine and Heraclenin were found to inhibit most of the chosen target protein. Among the targets, the docking analysis revealed that Heraclenin exhibited the highest binding affinity of −8.6 Kcal/mol with the target flavin- containing monooxygenase. Further, the <em>in vitro</em> evaluation of 3- Epimacronine confirmed their nematicidal activity against <em>M. incognita</em> at different concentrations. In light of this, the present study has raised awareness of the unique biomolecules of the bacterial symbiont <em>Ochrobactrum</em> sp. isolated from <em>H. indica</em> that have nematicidal properties.</p></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"204 ","pages":"Article 108114"},"PeriodicalIF":3.4,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140607057","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}