Journal of invertebrate pathology最新文献

{"title":"Multiple diptericins of the black soldier fly (Hermetia illucens) differentially respond to bacterial challenges","authors":"Yoo Bin Yoon ,&nbsp;Ji Won Woo ,&nbsp;Beom Jun Park ,&nbsp;Kihwan Park ,&nbsp;Sangwook Kang ,&nbsp;David Chung ,&nbsp;Dong Ho Lee ,&nbsp;Yuno Do ,&nbsp;Soon Cheol Park ,&nbsp;Sung-Jin Cho","doi":"10.1016/j.jip.2024.108234","DOIUrl":"10.1016/j.jip.2024.108234","url":null,"abstract":"<div><div>Due to its significant bioconversion potential, the black soldier fly (BSF), <em>Hermetia illucens</em>, shows great promise as a cost-effective alternative for recycling biological waste. BSF larvae (BSFL) are constantly exposed high levels of pathogenic microorganisms, including bacteria and fungi, which endows BSFL with a robust immune system. Diptericin, a type of glycine-rich antimicrobial peptide (AMP) that exhibits activity against gram-negative bacteria, contains proline-rich domains (P-domains) and glycine-rich domains (G-domains); these domains are separated by a furin cleavage site. Although the presence and expression patterns of BSFL diptericins have been documented, their basic molecular properties remain unclear. To the best of our knowledge, in the present study, we report, for the first time, the molecular characteristics of seven full-length cDNA sequences of <em>H. illucens</em> diptericins and their expression patterns following challenges with gram-positive or gram-negative bacteria. Seven diptericin paralogs are located in tandem on chromosome 2, spanning a total length of 38.6 kb, with an average intergenic distance of approximately 5.5 kb. Sequence analysis revealed that three diptericins (<em>HipDptA/B/C</em>) are pseudogenized due to premature stop codons. In contrast, the other diptericins (HiDpt1/2/3/4) possess mature-sized G-domains rich in glycine at the C-terminus, which are essential for AMP activity, along with proline-rich domain (P-domain) in the <em>N</em>-terminal and either two (<em>HiDpt1</em>/<em>2</em>/<em>3</em>) or one (<em>HiDpt4</em>) putative furin cleavage sites (R-X-R/K-R) between these domains. These furin cleavage sites possibly produce a glycine-rich AMP and one or two additional peptides with unknown functions. Similar to other diptericins, the expression of <em>HiDpt1</em>/<em>2</em>/<em>3</em>/<em>4</em> mRNAs is predominantly induced by gram-negative bacteria, increasing typically by ≥ 1,000-fold (up to 5,000-fold). Additionally, <em>HiDpt1</em>/<em>3</em>/<em>4</em> show significant responses to gram-positive bacteria such as <em>Micrococcus luteus</em>, though not as strongly as to gram-negative bacteria. These findings suggest that HiDpts function as a rapid, effective, and broad-spectrum first-line defense mechanism in the BSFL immune system.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108234"},"PeriodicalIF":3.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142622337","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":"Metacollinia emscheri n. sp., a novel sanguicolous apostome ciliate of freshwater amphipods (Gammarus spp.)","authors":"Sebastian Prati ,&nbsp;Sonja Rückert ,&nbsp;Daniel S. Grabner ,&nbsp;Bernd Sures ,&nbsp;Jamie Bojko","doi":"10.1016/j.jip.2024.108224","DOIUrl":"10.1016/j.jip.2024.108224","url":null,"abstract":"<div><div>We describe a novel sanguicolous parasitic ciliate, <em>Metacollinia emscheri</em> n. sp., found in the freshwater amphipods <em>Gammarus pulex</em> and <em>G. fossarum</em>. This ciliate infected 8.05 % of the amphipods collected in a German stream catchment, the Boye, a tributary of the river Emscher. The ciliate showed morphological characteristics fitting the genus <em>Metacollinia</em>. Different life stages of variable size occurred simultaneously in the hemocoel throughout the hosts’ body. The tomont had 40–47 slightly spiraled kineties, a non-ciliated cortical band, a large macronucleus, and contractile vacuoles arranged in rows or scattered throughout the cytoplasm. The protomites/tomites with nine somatic kineties presented evidence of the buccal kineties x, y, and z reminiscent of those of the order Foettingeriida. Phylogenetic analyses of the 18S rRNA and COI regions confirm the ciliate placement in the Collinidae and a close relatedness to the type species of the genus <em>Metacollinia</em>, <em>Metacollinia luciensis</em>.</div><div>We formally describe this new parasite as <em>Metacollinia emscheri</em> n. sp. using pathological, morphological, and nuclear/mitochondrial genetic data. The systemic infections observed in histological preparations and the pathogenicity of <em>Metacollinia emscheri</em> n. sp. suggest that this parasite might influence host population dynamics. Given the ecological importance of amphipods as keystone species in freshwater ecosystems, an outbreak of this parasite might indirectly impact ecosystem functioning.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108224"},"PeriodicalIF":3.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142502200","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":"Ferroptotic cyanobacteria as biocontrol agent of the southern house mosquito Culex quinquefasciatus","authors":"Antonella Cuniolo ,&nbsp;María Victoria Martin ,&nbsp;Corina M Berón","doi":"10.1016/j.jip.2024.108225","DOIUrl":"10.1016/j.jip.2024.108225","url":null,"abstract":"<div><div><em>Culex quinquefasciatus</em> is a hematophagous mosquito, widely distributed around the world, that plays a crucial role in public and veterinary health. As an efficient vector of etiological agents, it exhibits a marked preference for urban environments and human blood. Despite advances in mosquito-borne disease control, managing mosquito populations remains an economically efficient and safe strategy to reduce the impact of epidemic outbreaks. However, achieving this goal requires ecologically acceptable tools that ensure sustainability and minimize adverse environmental impacts. In the present work, we investigated the effect of a non-toxigenic model cyanobacterium on <em>Cx. quinquefasciatus</em> larvae through regulated cell death. We observed that heat stress treatment of <em>Synechocystis</em> PCC 6803 inducing ferroptosis, results in larval lipid oxidation, leading to their death. This effect can be mitigated by rearing larvae in an environment containing canonical inhibitors of ferroptosis, such as ferrostatin 1, or antioxidants, like glutathione and ascorbic acid. Furthermore, larval cell death induced by ferroptotic cyanobacteria is closely linked to oxidative dysregulation and lipid peroxidation, both hallmarks of ferroptosis. Moreover, while ferroptotic <em>Synechocystis</em> significantly affects larval development, it does not influence oviposition site selection by gravid females.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108225"},"PeriodicalIF":3.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142502202","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":"Study on the role of RPL23 gene in active immunity of termite Reticulitermes chinensis against Metarhizium anisopliae","authors":"Shuxin Yu ,&nbsp;Ali Hassan ,&nbsp;Nasir Mehmood ,&nbsp;Wei Zhou ,&nbsp;Taqi Raza ,&nbsp;Qiuying Huang","doi":"10.1016/j.jip.2024.108226","DOIUrl":"10.1016/j.jip.2024.108226","url":null,"abstract":"<div><div>Ribosomal proteins are considered to be involved in the immunity of different animals against pathogens. The protein level of RPL23 increased after fungal infection in termites, but how it influence active immunity in termites is unknown. The role of <em>RPL23</em> gene was studied to evaluate its impact on active immunity of termite <em>Reticulitermes chinensis</em> against entomopathogenic fungus (EPF) <em>Metarhizium anisopliae</em>. The <em>RPL23</em> gene fragment (414 bp) was cloned and phylogenetic analysis revealed that it’s very close to termite <em>Coptotermes formosanus</em>. Expression of <em>RPL23</em> gene was significantly higher in abdomen as compared to thorax and head. Silencing <em>RPL23</em> gene had no significant impact on the frequency and time of allogrooming towards fungus exposed termites from nestmates, which showed that nestmates acquired spores from infected termites through allogrooming. Expression of immune genes (<em>GNBP1</em>, <em>GNBP2</em> and phenoloxidase) and apoptosis related genes (<em>TNF-α,</em> caspase 1, caspase 3 and caspase 8) decreased significantly in nestmates of fungus-treated termites after silencing of <em>RPL23</em> gene as compared to control. Antifungal activity and survival of <em>RPL23</em> silenced nestmates of fungus-treated termites also decreased. To sum up, this study found that silencing of <em>RPL23</em> gene broke the active immunity against <em>M. anisopliae</em> infection, reduced the antifungal activity of termites, weakened cell apoptosis, and led to increased mortality of termites, which may help to find a potential alternative for chemical insecticides to control termites.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108226"},"PeriodicalIF":3.6,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142502201","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":"Damage to the host cadaver, simulating the effects of scavenging, differentially affects fitness of entomopathogenic nematode species","authors":"Maria D. Cassells ,&nbsp;Niamh Treanor ,&nbsp;Emigdio Jordán Muñoz-Adalia ,&nbsp;Christine T. Griffin","doi":"10.1016/j.jip.2024.108217","DOIUrl":"10.1016/j.jip.2024.108217","url":null,"abstract":"<div><div>Insect cadavers infected by entomopathogenic nematodes (EPN) are defended against scavengers by chemical mechanisms and other means. Despite these defences, the cadaver may be bitten before being rejected. In this study, we investigated the effect of damage to the cadaver cuticle on the fitness of nematodes (<em>Heterorhabditis downesi Stock, Griffin &amp; Burnell</em> or <em>Steinernema feltiae Filipjev</em>) developing inside. We first quantified the severity of scavenger damage to EPN-infected <em>Galleria mellonella</em> Linnaeus cadavers in the field, and separately, with crickets <em>(Gryllus bimaculatus</em> De Geer) in the laboratory. In both field and laboratory, EPN-infected cadavers suffered less damage than freeze-killed controls, and damage consisted mainly of small lesions to the cuticle. In further experiments, scavenging damage was simulated shortly after death of infected cadavers by piercing the cuticle 0, 1, 3 or 5 times and incubating in moist (100% relative humidity (RH)) or dry (60–70% RH) conditions. The greater the level of damage, the greater the loss of moisture from the cadaver (estimated by weight loss), and this was exacerbated in dry conditions. The number of infective juveniles (IJs) emerging from <em>H. downesi-</em>infected cadavers was significantly reduced by damage, especially in dry conditions. In addition, emerging IJs were progressively smaller with increasing damage. For this species, the number of IJs was negatively correlated with moisture loss, indicating that the reduction in fitness was mediated by desiccation. For <em>S. feltiae,</em> damage impacted IJ number to a lesser extent and size was not affected. The reduction in numbers was not explained by moisture loss, indicating that for <em>S. feltiae</em>, some factor other than desiccation (perhaps competition with opportunistic microbes) impacts the nematodes when the cuticle is damaged. The greater vulnerability of <em>H. downesi,</em> compared to <em>S. feltiae,</em> to scavenger damage to the host cadaver may be due to its longer developmental time in the host resulting in longer exposure to damaging conditions. In conclusion, damage simulating biting by scavengers impacts the fitness of EPN, with the effect depending on nematode species, environmental conditions and the extent of damage. These findings have implications for the success of field application of EPN in infected cadavers.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108217"},"PeriodicalIF":3.6,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142467749","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":"Chitinase and proteinase K treatments enhance the DNA yield of microsporidium Ecytonucleospora hepatopenaei spores","authors":"Xiao-Meng Guo ,&nbsp;Wen Gao ,&nbsp;Hai-Liang Wang ,&nbsp;Prapatsorn Wongkhaluang ,&nbsp;Suparat Taengchaiyaphum ,&nbsp;Guo-Si Xie ,&nbsp;Chen Li ,&nbsp;Ruo-Heng Zhao ,&nbsp;Kallaya Sritunyalucksana ,&nbsp;Jie Huang","doi":"10.1016/j.jip.2024.108222","DOIUrl":"10.1016/j.jip.2024.108222","url":null,"abstract":"<div><div>Microsporidium <em>Ecytonucleospora hepatopenaei</em> (EHP) spores were purified from the hepatopancreas of <em>Penaeus vannamei</em> infected with EHP by percoll density gradient centrifugation and differential centrifugation. The EHP spores contain a thick chitin wall and might not rupture using the routine DNA extraction protocol. In this study, three enzymes were used, including chitinase, proteinase K, and DNase I. Chitinase or proteinase K digestions caused weakened fluorescence of chitin showing by a blurred edge of EHP spores stained with calcofluor white under a fluorescence microscope. Different combinations of these enzymes followed by DNA extraction with phenol–chloroform from EHP spores showed significant increases in the copy number of the EHP SSU gene per spore. The combination of the chitinase and proteinase K treatments resulted 4.46 ± 1.07 copies/spore detected, which is 31.6 ± 20.7 folds of no treatment groups, accounting to (55.7 ± 13.4)% of the total copies of the gene in the spore. The additional treatment with chitinase to the conventional extraction protocol with a proteinase K digestion step for feces and hepatopancreas samples of <em>P. vannamei</em> resulted in a significant difference in EHP copies in the DNA of (83.8 ± 64.1)% and (55.3 ± 88.0)% increases. The study proved that chitinase and proteinase K treatment enhance the DNA extraction from microsporidian spores resulting in high yield.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108222"},"PeriodicalIF":3.6,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142467751","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":"An alphabaculovirus from the zebra caterpillar, Melanchra picta Harris, is an isolate of species Alphabaculovirus maconfiguratae","authors":"Robert L. Harrison,&nbsp;Charlotte B. Francoeur,&nbsp;Daniel L. Rowley","doi":"10.1016/j.jip.2024.108220","DOIUrl":"10.1016/j.jip.2024.108220","url":null,"abstract":"<div><div>A baculovirus had been previously identified in larvae of the zebra caterpillar, <em>Melanchra</em> (formerly <em>Ceramica</em>) <em>picta</em> Harris. To further characterize this virus, two isolates, Melanchra picta nucleopolyhedrovirus-185 (MepiNPV-185) and MepiNPV-600, were fully sequenced. Analysis of the genome sequences revealed that both isolates are members of alphabaculovirus species <em>Alphabaculovirus maconfiguratae</em>, along with alphabaculoviruses of the bertha armyworm, <em>Mamestra configurata</em> Walker. MepiNPV-600 displayed relatively low virulence against larvae of <em>Trichoplusia ni</em> Hübner in bioassays compared to other <em>T. ni</em>-pathogenic alphabaculoviruses. MepiNPV likely arose from a cross-species transfer between <em>M. configurata</em> and <em>M. picta</em> larvae, which often occur together.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108220"},"PeriodicalIF":3.6,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441075","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":"Nosema ceranae infection reduces the fat body lipid reserves in the honeybee Apis mellifera","authors":"Juliette Gilbert ,&nbsp;Laurianne Paris ,&nbsp;Aurore Dubuffet,&nbsp;Catherine Texier,&nbsp;Frédéric Delbac,&nbsp;Marie Diogon","doi":"10.1016/j.jip.2024.108218","DOIUrl":"10.1016/j.jip.2024.108218","url":null,"abstract":"<div><div><em>Nosema ceranae</em> is an intestinal parasite frequently found in <em>Apis mellifera</em> colonies. This parasite belongs to Microsporidia, a group of obligate intracellular parasites known to be strongly dependent on their host for energy and resources. Previous studies have shown that <em>N. ceranae</em> could alter several metabolic pathways, including those involved in the nutrient storage. To explore the impact of <em>N. ceranae</em> on the fat body reserves, newly emerged summer bees were experimentally infected, and we measured (1) the lipid percentage of the abdominal fat body at 2-, 7- and 14-days post-inoculation (p.i.) using diethyl ether lipid extraction, (2) the triglyceride and protein concentrations by spectrophotometric assay methods, and (3) the amount of intracellular lipid droplets in trophocytes at 14- and 21-days p.i. using Nile Red staining. Comparing the three methods used to evaluate lipid stores, our data revealed that Nile Red staining seemed to be the simplest, fastest and reliable method. Our results first revealed that the percentage of fat body lipids significantly decreased in infected bees at D14 p.i. The protein stores did not seem to be affected by the infection, while triglyceride concentration was reduced by 30% and lipid droplet amount by 50% at D14 p.i. Finally, a similar decrease in lipid droplet reserves in response to <em>N. ceranae</em> infection was observed in bees collected in fall.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108218"},"PeriodicalIF":3.6,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142406503","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":"Suppression of a transcriptional regulator, HexA, is essential for triggering the bacterial virulence of the entomopathogen, Xenorhabdus hominickii","authors":"Gahyeon Jin ,&nbsp;Ji-Seon Jeong ,&nbsp;Il-Hwan Kim ,&nbsp;Yonggyun Kim","doi":"10.1016/j.jip.2024.108219","DOIUrl":"10.1016/j.jip.2024.108219","url":null,"abstract":"<div><div>A nematode-symbiotic bacterium, <em>Xenorhabdus hominickii</em>, exhibits two distinct lifestyles. Upon infection of its host nematode into a target insect, <em>X. hominickii</em> is released into the insect hemocoel and becomes pathogenic. This study examines the critical transformation in bacterial life forms concerning the activity of a transcriptional regulator, HexA. When <em>X. hominickii</em> was cultured in tryptic soy broth, <em>HexA</em> was expressed during the stationary phase of bacterial growth. Conversely, <em>HexA</em> was expressed in the early growth stage within the insect host, <em>Spodoptera exigua</em>, when infected with <em>X. hominickii</em>. The transient expression of <em>HexA</em> was succeeded by the expression of another transcriptional regulator, <em>Lrp</em>, which led to the production of bacterial virulent factors. Expression of <em>HexA</em> was manipulated by replacing its promoter with an inducible promoter controlled by the inducer, <span>l</span>-arabinose. In the absence of the inducer, the mutant bacteria expressed <em>HexA</em> at a low level, resulting in a bacterial culture broth that was more effective at suppressing insect immune responses than the wild type. When the inducer was added, <em>HexA</em> was expressed at high levels, rendering the culture broth ineffective in immunosuppression. Interestingly, expression of <em>HexA</em> inhibited the expression of another transcriptional regulator, <em>Lrp</em>, which in turn induced the expression of a non-ribosomal peptide synthetase, <em>gxpS</em>, leading to the production of an immunosuppressive metabolite, GXP. Suppression of <em>HexA</em> expression in mutant bacteria augmented GXP levels in secondary metabolites. This indicates that infection of <em>X. hominickii</em> into the insect host represses <em>HexA</em> expression and upregulates <em>Lrp</em> expression, leading to GXP production. The GXP metabolites inhibit insect immunity, thus protecting the bacteria-nematode complex. Therefore, the suppression of <em>HexA</em> expression in the insect hemocoel is crucial for the bacteria’s transition from a symbiotic to a pathogenic life form.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108219"},"PeriodicalIF":3.6,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142406504","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":"Differences in phagosome acidification of Manila clam hemocytes in response to two Perkinsus species with contrasting proliferation dynamics in the host: P. olseni and P. mediterraneus","authors":"Vince Neil B. Fuertes,&nbsp;Yuho Watanabe,&nbsp;Naoki Itoh","doi":"10.1016/j.jip.2024.108216","DOIUrl":"10.1016/j.jip.2024.108216","url":null,"abstract":"<div><div>Understanding the factors determining the host ranges of <em>Perkinsus</em> spp., a significant group of pathogenic protozoans affecting shellfish, is essential for preventing their spread and designing effective control measures. Considering that differences in the ability to proliferate within the host may influence the determination of host range, we first injected six <em>Perkinsus</em> spp. into Manila clams <em>Ruditapes philippinarum</em> and monitored the variations of trophozoite numbers. Although all six species were detected in the challenged clams 28 days post infection, the infection intensities varied among species, and particularly two species showed contrasting infection trends: <em>P. mediterraneus</em> showed a decreasing trend of infection, declining to the lowest intensity, whereas that of <em>P. olseni</em> continuously increased, reaching the highest intensity. <em>In vitro</em> exposure to Manila clam hemocytes revealed that the survival of <em>P. mediterraneus</em> trophozoites was suppressed, in contrast to <em>P. olseni</em>, which maintained their viability. Despite similar phagocytic indices for both species, the rate of phagosome acidification was significantly higher for hemocytes phagocytizing <em>P. mediterraneus</em> than those targeting <em>P. olseni</em>. Notably, phagosome acidification was significantly suppressed in hemocytes phagocytizing live <em>P. olseni</em> trophozoites, suggesting that <em>P. olseni</em> may secrete a substance that modulates phagosome acidification, and thereby evades intracellular digestion by the host’s hemocytes. Conversely, <em>P. mediterraneus</em>, with a lower affinity for infecting Manila clams, did not exhibit such modulation. Based on these results, we consider that the ability to modulate phagosome acidification in host hemocytes might be at least one factor in determining the host range of <em>Perkinsus</em> species.</div></div>","PeriodicalId":16296,"journal":{"name":"Journal of invertebrate pathology","volume":"207 ","pages":"Article 108216"},"PeriodicalIF":3.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142400509","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}