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Potential effects of host competence and schooling behavior on parasite transmission in a host-pathogen system: a test of the dilution effect 宿主能力和学校行为对宿主-病原体系统中寄生虫传播的潜在影响:稀释效应测试。
IF 3.7 2区 医学 Q1 PARASITOLOGY Pub Date : 2024-11-01 DOI: 10.1016/j.ijpara.2024.08.002
Shun Zhou , Xiao Jin , Ming Duan , Hong Zou , Ming Li , David J. Marcogliese , Guitang Wang , Wenxiang Li
High species diversity in a community may reduce the risk of infectious disease, termed the dilution effect. However, the generality of the dilution effect in different disease systems remains controversial as both host competence and behaviors of hosts may play roles in dilution or amplification of disease. Using the goldfish (Carassius auratus)-monogenean ectoparasite (Gyrodactylus kobayashii) system, effects of host competence and schooling behavior on parasite transmission were investigated while holding focal host density constant. Following competency tests of 12 fish species as potential hosts for the parasite, infection by G. kobayashii was determined on fins of goldfish mixed with each of three different species based on their level of host competence, including Prussian carp, Carassius gibelio (low competence), grass carp, Ctenopharyngodon idellus (non-competent), swordtail, Xiphophorus helleri (non-competent), and the four species combined. Compared with mean abundance (85.8 ± 25.1) on goldfish in the control group, the mean abundance on goldfish decreased significantly when paired with 10 Prussian carp (30.0 ± 16.5), but did not differ significantly when paired with 10 swordtail (70.0 ± 22.2), 10 grass carp (116.1 ± 33.2), or the multi-species of three Prussian carp, four grass carp and three swordtail (75.9 ± 30.8) during the 11-day experiment. The parasite was also found on the Prussian carp in the Prussian carp group and the multi-species group at a mean abundance of 7.1 and 10.9, respectively. Video recording showed that the school of goldfish mixed well with the Prussian carp, while they maintained separation from the grass carp and swordtail when mixed together. The distance between goldfish increased, and swimming speed and contact time decreased with the additional of other fish species for all groups. The results suggested that the presence of a low-competence host in sufficient numbers was a necessary condition for a dilution effect due to encounter reduction, and the dilution effect may also be enhanced by changes in schooling behavior of goldfish in the presence of low competence hosts. However, the presence of non-competent hosts did not result in any dilution effect owing to the specialist nature of the parasites and the lack of mixing with schools of goldfish.
群落中物种的高度多样性可能会降低传染病的风险,这被称为稀释效应。然而,稀释效应在不同疾病系统中的普遍性仍然存在争议,因为宿主的能力和行为都可能在稀释或放大疾病方面发挥作用。研究人员利用金鱼(Carassius auratus)-单基因外寄生虫(Gyrodactylus kobayashii)系统,在保持焦点寄生虫密度不变的情况下,研究了寄生虫传播中宿主能力和游动行为的影响。在对作为寄生虫潜在宿主的 12 种鱼类进行能力测试之后,根据其宿主能力水平(包括普氏鲫(低能力)、草鱼(无能力)、剑尾鱼(无能力)以及四种鱼类的总和),分别测定了与三种不同鱼类混合的金鱼鳍上的小林天牛感染情况。在为期 11 天的实验中,与对照组金鱼身上的平均虫量(85.8 ± 25.1)相比,金鱼身上的平均虫量在与 10 条普氏鲤配对时显著下降(30.0 ± 16.5),但在与 10 条剑尾(70.0 ± 22.2)、10 条草鱼(116.1 ± 33.2)或 3 条普氏鲤、4 条草鱼和 3 条剑尾的多鱼种(75.9 ± 30.8)配对时没有显著差异。在普氏鲤组和多鱼种组的普氏鲤身上也发现了寄生虫,平均数量分别为 7.1 条和 10.9 条。视频记录显示,金鱼群与普氏鲤混养得很好,而与草鱼和剑尾鱼混养时则保持了一定的距离。各组金鱼之间的距离随着其他鱼种的增加而增加,游泳速度和接触时间则随着其他鱼种的增加而减少。结果表明,足够数量的低能力宿主的存在是因相遇减少而产生稀释效应的必要条件,稀释效应也可能因金鱼在低能力宿主存在时的游动行为变化而增强。然而,由于寄生虫的专一性和不与金鱼群混合,非能力寄主的存在不会导致任何稀释效应。
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引用次数: 0
Acanthamoeba castellanii trophozoites need oxygen for normal functioning and lipids are their preferred substrate, offering new possibilities for treatment. 卡斯特拉氏棘阿米巴滋养体需要氧气才能正常运作,而脂质是它们的首选底物,这为治疗提供了新的可能性。
IF 3.7 2区 医学 Q1 PARASITOLOGY Pub Date : 2024-10-26 DOI: 10.1016/j.ijpara.2024.10.004
Maarten J Sarink, Anna Z Mykytyn, Aïsha Jedidi, Martin Houweling, Jos F Brouwers, George Ruijter, Annelies Verbon, Jaap J van Hellemond, Aloysius G M Tielens

Acanthamoebae, pathogenic free-living amoebae, can cause Granulomatous Amoebic Encephalitis (GAE) and keratitis, and for both types of infection, no adequate treatment options are available. As the metabolism of pathogens is an attractive treatment target, we set out to examine the energy metabolism of Acanthamoeba castellanii and studied the aerobic and anaerobic capacities of the trophozoites. Under anaerobic conditions, or in the presence of inhibitors of the electron-transport chain, A. castellanii trophozoites became rounded, moved sluggishly and stopped multiplying. This demonstrates that oxygen and the respiratory chain are essential for movement and replication. Furthermore, the simultaneous activities of both terminal oxidases, cytochrome c oxidase and the plant-like alternative oxidase, are essential for normal functioning and replication. The inhibition of normal function caused by the inactivity of the respiratory chain was reversible. Once respiration was made possible again, the rounded, rather inactive amoebae formed acanthopodia within 4 h and resumed moving, feeding and multiplying. Experiments with radiolabelled nutrients revealed a preference for lipids over glucose and amino acids as food. Subsequent experiments showed that adding lipids to a standard culture medium of trophozoites strongly increased the growth rate. Acanthamoeba castellanii trophozoites have a strictly aerobic energy metabolism and β-oxidation of fatty acids, the Krebs cycle, and an aerobic electron-transport chain coupled to the ATP synthase, producing most of the used ATP. The preference for lipids can be exploited, as we show that three known inhibitors of lipid oxidation strongly inhibited the growth of A. castellanii. In particular, thioridazine and perhexiline showed potent effects in low micromolar concentrations. Therefore, this study revealed a new drug target with possibly new options to treat Acanthamoeba infections.

棘阿米巴虫是一种致病性自由生活阿米巴虫,可引起肉芽肿阿米巴脑炎(GAE)和角膜炎,对于这两种类型的感染,目前还没有适当的治疗方案。由于病原体的新陈代谢是一个有吸引力的治疗目标,我们开始研究卡斯特拉氏阿米巴原虫的能量代谢,并研究滋养体的需氧和厌氧能力。在厌氧条件下,或在存在电子传递链抑制剂的情况下,卡斯特拉氏棘阿米巴滋养体变得浑圆,运动迟缓并停止繁殖。这表明氧气和呼吸链对运动和复制至关重要。此外,细胞色素 c 氧化酶和植物样替代氧化酶这两种末端氧化酶的同时活动对正常功能和复制至关重要。呼吸链不活跃对正常功能的抑制是可逆的。一旦呼吸作用得以恢复,这些圆形的、相当不活跃的变形虫就会在 4 小时内形成棘足,并恢复运动、进食和繁殖。用放射性标记的营养物质进行的实验表明,阿米巴虫更喜欢脂类而不是葡萄糖和氨基酸作为食物。随后的实验表明,在滋养体的标准培养基中添加脂质可大大提高滋养体的生长速度。卡氏棘阿米巴滋养体具有严格的有氧能量代谢和脂肪酸的β-氧化、克雷布斯循环,以及与 ATP 合成酶耦合的有氧电子传递链,可产生大部分用过的 ATP。我们发现,三种已知的脂质氧化抑制剂都能强烈抑制卡斯特氏菌的生长。特别是,硫利达嗪和过氧苯胺在低微摩尔浓度下显示出了强效作用。因此,这项研究揭示了一个新的药物靶点,可能是治疗棘阿米巴感染的新选择。
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引用次数: 0
Different life strategies of closely related louse species in sympatry: specialist and "generalist" lineages of Polyplax serrata. 同域中近缘虱子物种的不同生活策略:血清多毛虱的专科和 "通科 "品系。
IF 3.7 2区 医学 Q1 PARASITOLOGY Pub Date : 2024-10-11 DOI: 10.1016/j.ijpara.2024.10.003
Jana Martinů, Jan Štefka, Kateřina Vránková, Václav Hypša

The origin and significance of host specificity are intriguing questions in parasitology. In the case of single-host versus multiple-host parasites, this topic integrates with the concept of the specialist/generalist trade-off. We use the model of sucking lice Polyplax serrata and rodent hosts Apodemus, to address these concepts. Polyplax serrata was shown to form a complex genetic structure, with a strictly specific S lineage living on Apodemus flavicollis, and a less specific N lineage on A. flavicollis and Apodemus sylvaticus. Moreover, the S lineage formed two mitochondrial clades with geographically exclusive distributions and a narrow hybrid zone, providing an opportunity to test the hypothesis that hybrids suffer a decrease in fitness. We sampled 451 individual lice from two host species at 103 localities. We used prevalences and intensities as proxies of fitness, which the parasites realize on their host. The S lineage, strictly specific to Apodemus flavicollis, reached significantly higher prevalences and intensities on its host compared with the N lineage. Conversely, the N lineage occurred with high prevalence and intensity on A. sylvaticus but tended to use also A. flavicollis when the louse populations became too dense. We discuss possible mechanisms behind this difference (particularly interspecific competition as a typical phenomenon in the specialist/generalist systems). We conclude that a parasite's "choice", not accessibility of the host or interspecific competition, is the main factor affecting the louse prevalences. We suggest that historical differences in geographic distribution of both lice and mice may provide a possible explanation for the observed life strategy differences. In contrast to the convincing picture in S and N lineage prevalences, we did not detect an expected drop in fitness in hybrids. We consider instability of the hybrid zone, or decline in abundance of the respective hosts, as possible explanations for this result.

寄主特异性的起源和意义是寄生虫学中引人入胜的问题。就单宿主寄生虫与多宿主寄生虫而言,这一课题与专一性/专一性权衡的概念结合在一起。我们利用吸虱多浆虱和啮齿类宿主 Apodemus 的模型来探讨这些概念。研究表明,血清多浆吸虱形成了复杂的遗传结构,其中一个严格特异的 S 系生活在黄腹角雉上,而一个特异性较低的 N 系则生活在黄腹角雉和啮齿目猿猴上。此外,S系形成了两个线粒体支系,它们在地理分布上具有排他性,而且杂交区很窄,这就为检验杂交后体质下降的假说提供了机会。我们在 103 个地点从两种宿主物种中采集了 451 个虱子个体样本。我们使用流行率和强度作为寄生虫在宿主身上实现的适应性的代用指标。与 N 系寄生虫相比,S 系寄生虫在寄主上的流行率和强度明显更高,而 N 系寄生虫在寄主上的流行率和强度明显更低。相反,N系在A. sylvaticus上的流行率和强度都很高,但当虱子种群过于密集时,N系也倾向于使用A. flavicollis。我们讨论了这种差异背后的可能机制(特别是种间竞争,这是专科/专科系统中的典型现象)。我们的结论是,影响虱子流行的主要因素是寄生虫的 "选择",而不是宿主的可及性或种间竞争。我们认为,虱子和老鼠在地理分布上的历史差异可以为观察到的生活策略差异提供可能的解释。与令人信服的 S 系和 N 系流行情况相反,我们并没有在杂交种中发现预期的适应性下降。我们认为杂交区的不稳定性或各自宿主丰度的下降是这一结果的可能解释。
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引用次数: 0
Northward migration past the nearctic biogeographical divide; neotropical Gyrodactylus spp. infecting Astyanax have crossed the Trans-Mexican Volcanic Belt. 越过近北极生物地理分界线向北迁移;感染 Astyanax 的新热带 Gyrodactylus spp.穿越了跨墨西哥火山带。
IF 3.7 2区 医学 Q1 PARASITOLOGY Pub Date : 2024-10-10 DOI: 10.1016/j.ijpara.2024.10.001
Daniel Augusto Pozos-Carré, Carlos Daniel Pinacho-Pinacho, Miguel Calixto-Rojas, Juan Manuel Caspeta-Mandujano, Juan Pablo Ramírez-Herrejón, Adriana García-Vásquez, Juan José Barrios-Gutiérrez, Ismael Guzmán-Valdivieso, Miguel Rubio-Godoy

The neotropical fish genus Astyanax (Characidae) and its associated helminths migrated northward from South America following the Great American Biotic Interchange (GABI): ca. 150 Astyanax spp. are found throughout South and Central America, up to the Mexico-USA border. Most characids are distributed south of the Trans-Mexican Volcanic Belt (TMVB), which bisects the country and represents a major transition zone between the neotropical and nearctic realms. Here, we characterize parasites of the monogenean genus Gyrodactylus infecting Astyanax spp. in Mexico: Astyanax aeneus south of the TMBV, Astyanax mexicanus north of it. Based on morphological, phylogenetic (internal transcribed spacer (ITS) and cytochrome oxidase subunit II (cox 2)) and statistical analyses of morphometric data, we confirmed the validity of Gyrodactylus pakan and Gyrodactylus teken, and erected two new species, Gyrodactylus aphaa n. sp. and Gyrodactylus ricardoi n. sp. These four gyrodactylids are part of a complex of morphologically cryptic species, which are phylogenetically closely related to each other, and sister species to Gyrodactylus carolinae and Gyrodactylus heteracanthus, parasites of characins in Brazil. Four gyrodactylid lineages (G. pakan, G. ricardoi n. sp., G. teken, Gyrodactylus sp. A) are distributed north of the TMVB; G. pakan is also widely distributed south of the TMVB, together with G. aphaa n. sp. Based on the ITS phylogeny, Brazilian parasites form a sister clade to all Mexican gyrodactylids, whose derived clades are distributed in progressively more northerly latitudes in Mexico - the three most-derived species north of the TMVB. This would suggest that gyrodactylid species diverged gradually, presumably as their characid fish hosts colonized and adapted to new environments north of the TMVB.

新热带鱼类蓑鲉属(蓑鲉科)及其相关的蠕虫随着美洲生物大交汇(GABI)从南美洲向北迁移:约 150 种蓑鲉属鱼类遍布南美洲和中美洲,直至墨西哥-美国边境。大多数蛛形纲动物分布在跨墨西哥火山带(TMVB)以南,该火山带将墨西哥一分为二,是新热带地区和近北极地区的主要过渡地带。在这里,我们描述了感染墨西哥Astyanax属的单基因Gyrodactylus属寄生虫的特征:在TMBV以南为Astyanax aeneus,在TMBV以北为Astyanax mexicanus。根据形态学、系统发生学(内部转录隔距(ITS)和细胞色素氧化酶亚单位 II(cox 2))和形态计量数据统计分析,我们确认了 Gyrodactylus pakan 和 Gyrodactylus teken 的有效性,并建立了两个新种 Gyrodactylus aphaa n. sp.这四种旋毛虫是形态上隐蔽物种复合体的一部分,它们在系统发育上彼此密切相关,是寄生于巴西颊蟾蜍的Gyrodactylus carolinae和Gyrodactylus heteracanthus的姊妹物种。四个天旋地转虫系(G. pakan、G. ricardoi n. sp、根据 ITS 系统发育,巴西的寄生虫与所有墨西哥旋毛虫形成姊妹支系,其衍生支系分布在墨西哥逐渐偏北的纬度地区--这是 TMVB 以北衍生最多的三个物种。这表明旋毛虫物种是逐渐分化的,可能是随着其腥臭鱼类宿主在TMVB以北地区定居并适应新环境而分化的。
{"title":"Northward migration past the nearctic biogeographical divide; neotropical Gyrodactylus spp. infecting Astyanax have crossed the Trans-Mexican Volcanic Belt.","authors":"Daniel Augusto Pozos-Carré, Carlos Daniel Pinacho-Pinacho, Miguel Calixto-Rojas, Juan Manuel Caspeta-Mandujano, Juan Pablo Ramírez-Herrejón, Adriana García-Vásquez, Juan José Barrios-Gutiérrez, Ismael Guzmán-Valdivieso, Miguel Rubio-Godoy","doi":"10.1016/j.ijpara.2024.10.001","DOIUrl":"10.1016/j.ijpara.2024.10.001","url":null,"abstract":"<p><p>The neotropical fish genus Astyanax (Characidae) and its associated helminths migrated northward from South America following the Great American Biotic Interchange (GABI): ca. 150 Astyanax spp. are found throughout South and Central America, up to the Mexico-USA border. Most characids are distributed south of the Trans-Mexican Volcanic Belt (TMVB), which bisects the country and represents a major transition zone between the neotropical and nearctic realms. Here, we characterize parasites of the monogenean genus Gyrodactylus infecting Astyanax spp. in Mexico: Astyanax aeneus south of the TMBV, Astyanax mexicanus north of it. Based on morphological, phylogenetic (internal transcribed spacer (ITS) and cytochrome oxidase subunit II (cox 2)) and statistical analyses of morphometric data, we confirmed the validity of Gyrodactylus pakan and Gyrodactylus teken, and erected two new species, Gyrodactylus aphaa n. sp. and Gyrodactylus ricardoi n. sp. These four gyrodactylids are part of a complex of morphologically cryptic species, which are phylogenetically closely related to each other, and sister species to Gyrodactylus carolinae and Gyrodactylus heteracanthus, parasites of characins in Brazil. Four gyrodactylid lineages (G. pakan, G. ricardoi n. sp., G. teken, Gyrodactylus sp. A) are distributed north of the TMVB; G. pakan is also widely distributed south of the TMVB, together with G. aphaa n. sp. Based on the ITS phylogeny, Brazilian parasites form a sister clade to all Mexican gyrodactylids, whose derived clades are distributed in progressively more northerly latitudes in Mexico - the three most-derived species north of the TMVB. This would suggest that gyrodactylid species diverged gradually, presumably as their characid fish hosts colonized and adapted to new environments north of the TMVB.</p>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142406394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Unravelling the patterns of exo-erythrocytic development of Haemoproteus parasites (Haemoproteidae, Haemosporida), with a case of abortive tissue stages in a naturally infected bird. 揭示血孢子虫寄生虫(血孢子虫科、血孢子虫属)的外红细胞发育模式,以及自然感染鸟类的组织阶段流产案例。
IF 3.7 2区 医学 Q1 PARASITOLOGY Pub Date : 2024-10-10 DOI: 10.1016/j.ijpara.2024.10.002
Mélanie Tchoumbou, Tatjana Iezhova, Carolina Hernández-Lara, Mélanie Duc, Gediminas Valkiūnas

Haemoproteus species (Haemosporida, Haemoproteidae) are cosmopolitan blood parasites that affect bird fitness and health. Recent discoveries based on the application of molecular markers showed that exo-erythrocytic or tissue stages of haemoproteids damage various internal organs including the brain. However, the patterns of exo-erythrocytic development remain unclear for most of the described species. This study aimed to understand the exo-erythrocytic development of Haemoproteus parasites in naturally infected Thrush nightingales Luscinia luscinia (Muscicapidae). Infections were confirmed in eight bird individuals by microscopic examination and PCR-based methods. Organs were examined using histology and in situ hybridization, which applied genus-specific and lineage-specific oligonucleotide probes targeting the 18S rRNA of the parasites. Exo-erythrocytic meronts of Haemoproteus attenuatus (lineage hROBIN1) were found and described for the first known time in this avian host. Most meronts were seen in the lungs, with a few also present in the liver, heart, and pectoral muscle. The available data suggest that this parasite produces only meronts, and not megalomeronts. However, numerous megalomeronts at different stages of development were observed in the gizzard and the heart of one individual. Based on the morphology, location in organs, and diagnostics using the lineage-specific probes, the megalomeronts were attributed to Haemoproteus majoris (lineage hWW2). Two cases of empty capsular-like walls of megalomeronts were seen in the gizzard, indicating that the megalomeronts had already ruptured and degenerated. The extensive microscopic examination did not reveal gametocytes of H. majoris, obviously indicating an abortive development. Abortive haemosporidian infections were often speculated to occur in wildlife but have not been documented in naturally infected birds. This study recognised patterns in the exo-erythrocytic development of H. attenuatus, and is to our knowledge the first documentation of abortive Haemoproteus infection in a naturally infected bird during exo-erythrocytic development.

血蛋白虫(Haemosporida,Haemoproteidae)是一种影响鸟类健康的世界性血液寄生虫。基于分子标记应用的最新发现表明,血包虫的外红细胞阶段或组织阶段会损害包括大脑在内的各种内脏器官。然而,大多数已描述物种的外红细胞发育模式仍不清楚。本研究旨在了解血蛋白寄生虫在自然感染的鸫夜莺(鹟科)中的外红细胞发育过程。通过显微镜检查和基于 PCR 的方法确认了 8 只鸟类的感染情况。使用组织学和原位杂交法对器官进行了检查,原位杂交法使用了针对寄生虫 18S rRNA 的属特异性和系特异性寡核苷酸探针。首次在这一禽类宿主体内发现并描述了减毒血单胞菌(血系 hROBIN1)的外红细胞经虫。大多数子囊虫出现在肺部,少数出现在肝脏、心脏和胸肌。现有数据表明,这种寄生虫只产生美拉隆子,而不产生巨型美拉隆子。不过,在一个个体的胗和心脏中观察到了大量处于不同发育阶段的巨核细胞。根据巨核细胞的形态、在器官中的位置以及使用血系特异性探针进行的诊断,这些巨核细胞被认为是 Haemoproteu smajoris(血系 hWW2)。在胗中发现两例巨核细胞的空囊壁,表明巨核细胞已经破裂和退化。大量的显微镜检查没有发现大肠杆菌的配子细胞,这显然表明大肠杆菌的发育已经中止。人们经常推测野生动物中会出现血孢子虫感染,但在自然感染的鸟类中还没有记录。这项研究确认了 H. attenuatus 的外红细胞发育模式,据我们所知,这是首次记录自然感染的鸟类在外红外发育过程中出现血孢子虫感染流产的情况。
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引用次数: 0
Optimized plasmid loading of human erythrocytes for Plasmodium falciparum DNA transfections 用于恶性疟原虫 DNA 转染的人红细胞质粒装载优化。
IF 3.7 2区 医学 Q1 PARASITOLOGY Pub Date : 2024-10-01 DOI: 10.1016/j.ijpara.2024.04.011
In vitro modification of Plasmodium falciparum genes is the cornerstone of basic and translational malaria research. Achieved through DNA transfection, these modifications may entail altering protein sequence or abundance. Such experiments are critical for defining the molecular mechanisms of key parasite phenotypes and for validation of drug and vaccine targets. Despite its importance, successful transfection remains difficult and is a resource-intensive, rate-limiting step in P. falciparum research. Here, we report that inefficient loading of plasmid into erythrocytes limits transfection efficacy with commonly used electroporation methods. As these methods also require expensive instrumentation and consumables that are not broadly available, we explored a simpler method based on plasmid loading through hypotonic lysis and resealing of erythrocytes. We used parasite expression of a sensitive NanoLuc reporter for rapid evaluation and optimization of each step. Hypotonic buffer composition, resealing buffer volume and composition, and subsequent incubation affected plasmid retention and successful transfection. While ATP was critical for erythrocyte resealing, addition of Ca++ or glutathione did not improve transfection efficiency, with increasing Ca++ concentrations proving detrimental to outcomes. Compared with either the standard electroporation method or a previously reported hypotonic loading protocol, the optimized method yields greater plasmid loading and higher expression of the NanoLuc reporter 48 h after transfection. It also produced significantly faster outgrowth of parasites in transfections utilizing either episomal expression or CRISPR-Cas9 mediated integration. This new method produces higher P. falciparum transfection efficiency, reduces resource requirements and should accelerate molecular studies of malaria drug and vaccine targets.
恶性疟原虫基因的体外改造是疟疾基础研究和转化研究的基石。通过 DNA 转染,这些修饰可能会改变蛋白质序列或丰度。此类实验对于确定关键寄生虫表型的分子机制以及验证药物和疫苗靶点至关重要。尽管转染很重要,但成功转染仍然很困难,是恶性疟原虫研究中一个资源密集型的限制性步骤。在此,我们报告了质粒在红细胞中的低效负载限制了常用电穿孔方法的转染效果。由于这些方法还需要昂贵的仪器和耗材,而这些仪器和耗材并不能广泛使用,因此我们探索了一种更简单的方法,即通过低渗裂解红细胞并重新封口来装载质粒。我们利用寄生虫表达敏感的 NanoLuc 报告器来快速评估和优化每个步骤。低渗缓冲液的成分、再封闭缓冲液的容量和成分以及随后的培养都会影响质粒的保留和成功转染。虽然 ATP 对红细胞再封闭至关重要,但添加 Ca++ 或谷胱甘肽并不能提高转染效率,Ca++ 浓度的增加对转染结果不利。与标准电穿孔方法或之前报道的低渗装载方案相比,优化方法能在转染 48 小时后产生更多的质粒装载和更高的 NanoLuc 报告基因表达。在利用外显子表达或 CRISPR-Cas9 介导的整合进行转染时,它还能明显加快寄生虫的生长速度。这种新方法可提高恶性疟原虫的转染效率,减少资源需求,并可加速疟疾药物和疫苗靶标的分子研究。
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引用次数: 0
Tick salivary proteome and lipidome with low glycan content correlate with allergic type reactions in the zebrafish model 低糖含量的蜱唾液蛋白质组和脂质组与斑马鱼模型中的过敏型反应相关。
IF 3.7 2区 医学 Q1 PARASITOLOGY Pub Date : 2024-10-01 DOI: 10.1016/j.ijpara.2024.07.002
Rita Vaz-Rodrigues , Lorena Mazuecos , Margarita Villar , Marinela Contreras , Almudena González-García , Paolo Bonini , Ruth C Scimeca , Albert Mulenga , José de la Fuente
Ticks, as hematophagous ectoparasites, can manipulate host immune and metabolic processes, causing tick-borne allergies such as α-Gal syndrome (AGS). Glycolipids with bound galactose-alpha-1–3-galactose (α-Gal) are potential allergenic molecules associated with AGS. Nevertheless, proteins and lipids lacking α-Gal modifications may contribute to tick salivary allergies and be linked to AGS. In this study, we characterized the effect of deglycosylated tick salivary proteins without lipids on treated zebrafish fed with dog food formulated with mammalian (beef, lamb, pork) meat by quantitative proteomics analysis of intestinal samples. The characterization and functional annotations of tick salivary lipids with low representation of glycolipids was conducted using a lipidomics approach. Results showed a significant effect of treatment with saliva and saliva deglycosylated protein fraction on zebrafish abnormal or no feeding (p < 0.005). Treatment with this fraction affected multiple metabolic pathways, defense responses to pathogens and protein metabolism, which correlated with abnormal or no feeding. Lipidomics analysis identified 23 lipid classes with low representation of glycolipids (0.70% of identified lipids). The lipid class with highest representation was phosphatidylcholine (PC; 26.66%) and for glycolipids it corresponded to diacylglycerol (DG; 0.48%). Qualitative analysis of PC antibodies revealed that individuals bitten by ticks were more likely to produce PC-IgG antibodies (p < 0.001). DG levels were significantly higher in tick salivary glands (p < 0.05) compared with tick saliva and salivary fractions. The α-Gal content was higher in tick saliva than in deglycosylated saliva and lipid fractions. These results support a possible role for tick salivary proteins and lipids without α-Gal modifications in AGS.
蜱虫作为食血的体外寄生虫,可以操纵宿主的免疫和代谢过程,导致蜱传过敏症,如α-Gal综合征(AGS)。与半乳糖-α-1-3-半乳糖(α-Gal)结合的糖脂是与 AGS 相关的潜在过敏原分子。然而,缺乏α-Gal修饰的蛋白质和脂质也可能导致蜱唾液过敏,并与AGS有关。在这项研究中,我们通过对肠道样本进行定量蛋白质组学分析,确定了不含脂质的脱糖蜱唾液蛋白对用哺乳动物(牛肉、羊肉、猪肉)肉配制的狗粮喂养的斑马鱼的影响。利用脂质组学方法对糖脂含量较低的蜱唾液脂质进行了表征和功能注释。结果表明,用唾液和唾液脱糖蛋白部分处理斑马鱼异常或不摄食有明显影响(p < 0.005)。用唾液和唾液脱糖蛋白处理斑马鱼会影响多种代谢途径、对病原体的防御反应和蛋白质代谢,这与斑马鱼摄食异常或不摄食有关。脂质组学分析确定了 23 类脂质,其中糖脂的代表性较低(占所确定脂质的 0.70%)。代表性最高的脂类是磷脂酰胆碱(PC;26.66%),糖脂类则是二酰甘油(DG;0.48%)。PC 抗体的定性分析显示,被蜱虫叮咬的个体更容易产生 PC-IgG 抗体(p < 0.001)。与蜱唾液和唾液组分相比,蜱唾液腺中的 DG 含量明显更高(p < 0.05)。蜱唾液中的α-Gal含量高于脱糖唾液和脂质部分。这些结果支持了蜱唾液蛋白质和脂质在 AGS 中可能起的作用。
{"title":"Tick salivary proteome and lipidome with low glycan content correlate with allergic type reactions in the zebrafish model","authors":"Rita Vaz-Rodrigues ,&nbsp;Lorena Mazuecos ,&nbsp;Margarita Villar ,&nbsp;Marinela Contreras ,&nbsp;Almudena González-García ,&nbsp;Paolo Bonini ,&nbsp;Ruth C Scimeca ,&nbsp;Albert Mulenga ,&nbsp;José de la Fuente","doi":"10.1016/j.ijpara.2024.07.002","DOIUrl":"10.1016/j.ijpara.2024.07.002","url":null,"abstract":"<div><div>Ticks, as hematophagous ectoparasites, can manipulate host immune and metabolic processes, causing tick-borne allergies such as α-Gal syndrome (AGS). Glycolipids with bound galactose-alpha-1–3-galactose (α-Gal) are potential allergenic molecules associated with AGS. Nevertheless, proteins and lipids lacking α-Gal modifications may contribute to tick salivary allergies and be linked to AGS. In this study, we characterized the effect of deglycosylated tick salivary proteins without lipids on treated zebrafish fed with dog food formulated with mammalian (beef, lamb, pork) meat by quantitative proteomics analysis of intestinal samples. The characterization and functional annotations of tick salivary lipids with low representation of glycolipids was conducted using a lipidomics approach. Results showed a significant effect of treatment with saliva and saliva deglycosylated protein fraction on zebrafish abnormal or no feeding (<em>p</em> &lt; 0.005). Treatment with this fraction affected multiple metabolic pathways, defense responses to pathogens and protein metabolism, which correlated with abnormal or no feeding. Lipidomics analysis identified 23 lipid classes with low representation of glycolipids (0.70% of identified lipids). The lipid class with highest representation was phosphatidylcholine (PC; 26.66%) and for glycolipids it corresponded to diacylglycerol (DG; 0.48%). Qualitative analysis of PC antibodies revealed that individuals bitten by ticks were more likely to produce PC-IgG antibodies (<em>p</em> &lt; 0.001). DG levels were significantly higher in tick salivary glands (<em>p</em> &lt; 0.05) compared with tick saliva and salivary fractions. The α-Gal content was higher in tick saliva than in deglycosylated saliva and lipid fractions. These results support a possible role for tick salivary proteins and lipids without α-Gal modifications in AGS.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 12","pages":"Pages 649-659"},"PeriodicalIF":3.7,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141792396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Detection of Toxoplasma gondii in wild bivalves from the Kerguelen and Galapagos archipelagos: influence of proximity to cat populations, exposure to marine currents and kelp density 在凯尔盖朗群岛和加拉帕戈斯群岛的野生双壳贝中检测到弓形虫:与猫群的距离、暴露于海流和海藻密度的影响
IF 3.7 2区 医学 Q1 PARASITOLOGY Pub Date : 2024-10-01 DOI: 10.1016/j.ijpara.2024.06.001
Oocysts of the protozoan Toxoplasma gondii are found in felid feces and can be washed into coastal waters, where they persist for months, attaching to algae and accumulating in invertebrates. We used wild bivalves to assess contamination of coastal waters of the Kerguelen and Galapagos archipelagos by this zoonotic parasite. Additionally, we leveraged the contrasting situations of these archipelagos to identify some potential drivers of contamination. In the Galapagos, with a cat density reaching 142 per km2, 15.38% of the sampled oysters (Saccostrea palmula) tested positive for T. gondii by quantitative real-time PCR (qPCR) (n = 260), and positive samples were found in all eight sampling sites. In Kerguelen, with 1-3 cats per km2, 40.83% of 120 tested mussels (Mytilus edulis platensis) were positive, and positive samples were found in four out of the five sampling sites. These findings provide evidence of T. gondii contamination in the coastal waters of these archipelagos. Furthermore, T. gondii-positive bivalves were found on islands located 20 km away (Galapagos) and 5 km away (Kerguelen) from the nearest cat population, indicating that T. gondii oocysts can disperse through waterborne mechanisms over several kilometers from their initial deposition site. In the Galapagos, where runoff is infrequent and all sites are exposed to currents, the prevalence of qPCR-positive bivalves did not show significant variations between sites (p = 0.107). In Kerguelen where runoff is frequent and site exposure variable, the prevalence varied significantly (p < 0.001). The detection of T. gondii in Kerguelen mussels was significantly correlated with the site exposure to currents (odds ratio (OR) 60.2, p < 0.001) and the on-site density of giant kelp forests (OR 2.624, p < 0.001). This suggests that bivalves can be contaminated not only by oocysts transported by currents but also by consuming marine aggregates containing oocysts that tend to form in kelp forests.
原生动物弓形虫的卵囊存在于猫科动物的粪便中,会被冲入沿岸水域,并在那里存留数月,附着在藻类上,并在无脊椎动物体内积累。我们利用野生双壳贝类来评估这种人畜共患病寄生虫对凯尔盖朗群岛和加拉帕戈斯群岛沿岸水域的污染情况。此外,我们还利用这两个群岛截然不同的情况,确定了一些潜在的污染驱动因素。在加拉帕戈斯群岛,猫的密度达到每平方公里 142 只,通过实时定量 PCR(qPCR)检测,15.38% 的采样牡蛎(Saccostrea palmula)的淋病双球菌检测呈阳性(n = 260),在所有八个采样点都发现了阳性样本。在凯尔盖朗(Kerguelen),每平方公里有 1-3 只猫,在 120 个检测的贻贝(Mytilus edulis platensis)中,有 40.83% 呈阳性,在五个采样点中的四个采样点都发现了阳性样本。这些发现提供了这些群岛沿海水域受到淋病双球菌污染的证据。此外,在距离最近的猫群 20 千米(加拉帕戈斯群岛)和 5 千米(凯尔盖朗岛)以外的岛屿上也发现了 T. gondii 阳性双壳贝,这表明 T. gondii 卵囊可以通过水传播机制从最初的沉积地点扩散到几千米以外的地方。在加拉帕戈斯群岛,径流并不频繁,而且所有地点都暴露在水流中,qPCR 阳性双壳贝的流行率在不同地点之间并无显著差异(p = 0.107)。在凯尔盖朗岛,由于径流频繁,各地点的水流情况各不相同,因此双壳类动物的发病率差异很大(p = 0.001)。在凯尔盖朗贻贝中检测到的淋病双球菌与现场暴露于水流的情况(几率比(OR)60.2,p <0.001)和现场巨型海藻林的密度(OR 2.624,p <0.001)有明显的相关性。这表明,双壳类动物不仅会受到由水流传播的卵囊的污染,也会因食用海藻林中往往会形成的含有卵囊的海洋聚集体而受到污染。
{"title":"Detection of Toxoplasma gondii in wild bivalves from the Kerguelen and Galapagos archipelagos: influence of proximity to cat populations, exposure to marine currents and kelp density","authors":"","doi":"10.1016/j.ijpara.2024.06.001","DOIUrl":"10.1016/j.ijpara.2024.06.001","url":null,"abstract":"<div><div>Oocysts of the protozoan <em>Toxoplasma gondii</em> are found in felid feces and can be washed into coastal waters, where they persist for months, attaching to algae and accumulating in invertebrates. We used wild bivalves to assess contamination of coastal waters of the Kerguelen and Galapagos archipelagos by this zoonotic parasite. Additionally, we leveraged the contrasting situations of these archipelagos to identify some potential drivers of contamination. In the Galapagos, with a cat density reaching 142 per km<sup>2</sup>, 15.38% of the sampled oysters (<em>Saccostrea palmula</em>) tested positive for <em>T. gondii</em> by quantitative real-time PCR (qPCR) (<em>n</em> = 260), and positive samples were found in all eight sampling sites. In Kerguelen, with 1-3 cats per km<sup>2</sup>, 40.83% of 120 tested mussels (<em>Mytilus edulis platensis</em>) were positive, and positive samples were found in four out of the five sampling sites. These findings provide evidence of <em>T. gondii</em> contamination in the coastal waters of these archipelagos. Furthermore, <em>T. gondii</em>-positive bivalves were found on islands located 20 km away (Galapagos) and 5 km away (Kerguelen) from the nearest cat population, indicating that <em>T. gondii</em> oocysts can disperse through waterborne mechanisms over several kilometers from their initial deposition site. In the Galapagos, where runoff is infrequent and all sites are exposed to currents, the prevalence of qPCR-positive bivalves did not show significant variations between sites (<em>p</em> = 0.107). In Kerguelen where runoff is frequent and site exposure variable, the prevalence varied significantly (<em>p</em> &lt; 0.001). The detection of <em>T. gondii</em> in Kerguelen mussels was significantly correlated with the site exposure to currents (odds ratio (OR) 60.2, <em>p</em> &lt; 0.001) and the on-site density of giant kelp forests (OR 2.624, <em>p</em> &lt; 0.001). This suggests that bivalves can be contaminated not only by oocysts transported by currents but also by consuming marine aggregates containing oocysts that tend to form in kelp forests.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 12","pages":"Pages 607-615"},"PeriodicalIF":3.7,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141410628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Unraveling new players in helminth pathology: extracellular vesicles from Fasciola hepatica and Dicrocoelium dendriticum exert different effects on hepatic stellate cells and hepatocytes 揭示蠕虫病理学中的新角色:来自肝脏法氏囊和树枝状微囊藻的细胞外囊泡对肝星状细胞和肝细胞产生不同影响。
IF 3.7 2区 医学 Q1 PARASITOLOGY Pub Date : 2024-10-01 DOI: 10.1016/j.ijpara.2024.06.002
Fasciola hepatica and Dicrocoelium dendriticum are parasitic trematodes residing in the bile ducts of mammalian hosts, causing, in some cases, impairment of liver function and hepatic fibrosis. Previous studies have shown that extracellular vesicles released by F. hepatica (FhEVs) and D. dendriticum (DdEVs) induce a distinct phenotype in human macrophages, but there is limited information on the effect of parasitic EVs on liver cells, which interact directly with the worms in natural infections. In this study, we isolated FhEVs and DdEVs by size exclusion chromatography and labeled them with a lipophilic fluorescent dye to analyze their uptake by human hepatic stellate cells (HSC) and hepatocytes, important cell types in liver pathology, using synthetic liposomes as internal labeling and uptake control. We analyzed EV uptake and the proteome profiles after the treatment with EVs for both cell types. Our results reveal that EVs establish unique and specific interactions with stellate cells and hepatocytes, suggesting a different role of EVs derived from each parasite, depending on the migration route to reach their final niche. FhEVs have a cytostatic effect on HSCs, but induce the extracellular matrix secretion and elicit anti-inflammatory responses in hepatocytes. DdEVs have a more potent anti-proliferative effect than FhEVs and trigger a global inflammatory response, increasing the levels of NF-κB and other inflammatory mediators in both cell types. These interactions may have a major influence on the progression of the disease, serving to generate conditions that may favor the establishment of the helminths in the host.
Fasciola hepatica 和 Dicrocoelium dendriticum 是寄生在哺乳动物宿主胆管中的吸虫,在某些情况下会导致肝功能受损和肝纤维化。以前的研究表明,肝吸虫(FhEVs)和树枝状吸虫(DdEVs)释放的胞外囊泡会诱导人类巨噬细胞出现不同的表型,但关于寄生EVs对肝细胞影响的信息却很有限,因为在自然感染中,肝细胞会直接与虫体发生相互作用。在这项研究中,我们通过尺寸排阻色谱法分离了FhEVs和DdEVs,并用亲脂性荧光染料对其进行标记,以合成脂质体作为内部标记和摄取对照,分析肝脏病理学中重要的细胞类型--人肝星状细胞(HSC)和肝细胞对它们的摄取情况。我们分析了这两种细胞对EVs的吸收情况以及EVs处理后的蛋白质组图谱。我们的研究结果表明,EVs 与星状细胞和肝细胞建立了独特的特异性相互作用,这表明每种寄生虫产生的 EVs 都有不同的作用,这取决于它们到达最终龛位的迁移路线。FhEVs对造血干细胞有细胞抑制作用,但能诱导细胞外基质分泌并引起肝细胞的抗炎反应。与 FhEVs 相比,DdEVs 具有更强的抗增殖作用,并引发整体炎症反应,提高两种细胞中 NF-κB 和其他炎症介质的水平。这些相互作用可能会对疾病的进展产生重大影响,从而产生有利于蠕虫在宿主体内繁殖的条件。
{"title":"Unraveling new players in helminth pathology: extracellular vesicles from Fasciola hepatica and Dicrocoelium dendriticum exert different effects on hepatic stellate cells and hepatocytes","authors":"","doi":"10.1016/j.ijpara.2024.06.002","DOIUrl":"10.1016/j.ijpara.2024.06.002","url":null,"abstract":"<div><div><em>Fasciola hepatica</em> and <em>Dicrocoelium dendriticum</em> are parasitic trematodes residing in the bile ducts of mammalian hosts, causing, in some cases, impairment of liver function and hepatic fibrosis. Previous studies have shown that extracellular vesicles released by <em>F. hepatica</em> (<em>Fh</em>EVs) and <em>D. dendriticum</em> (<em>Dd</em>EVs) induce a distinct phenotype in human macrophages, but there is limited information on the effect of parasitic EVs on liver cells, which interact directly with the worms in natural infections. In this study, we isolated <em>Fh</em>EVs and <em>Dd</em>EVs by size exclusion chromatography and labeled them with a lipophilic fluorescent dye to analyze their uptake by human hepatic stellate cells (HSC) and hepatocytes, important cell types in liver pathology, using synthetic liposomes as internal labeling and uptake control. We analyzed EV uptake and the proteome profiles after the treatment with EVs for both cell types. Our results reveal that EVs establish unique and specific interactions with stellate cells and hepatocytes, suggesting a different role of EVs derived from each parasite, depending on the migration route to reach their final niche. <em>Fh</em>EVs have a cytostatic effect on HSCs, but induce the extracellular matrix secretion and elicit anti-inflammatory responses in hepatocytes. <em>Dd</em>EVs have a more potent anti-proliferative effect than <em>Fh</em>EVs and trigger a global inflammatory response, increasing the levels of NF-κB and other inflammatory mediators in both cell types. These interactions may have a major influence on the progression of the disease, serving to generate conditions that may favor the establishment of the helminths in the host.</div></div>","PeriodicalId":13725,"journal":{"name":"International journal for parasitology","volume":"54 12","pages":"Pages 617-634"},"PeriodicalIF":3.7,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141456592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Parasite airlines: mapping the distribution and transmission of avian blood parasites in migratory birds 寄生虫航线:绘制候鸟血液寄生虫的分布和传播图。
IF 3.7 2区 医学 Q1 PARASITOLOGY Pub Date : 2024-10-01 DOI: 10.1016/j.ijpara.2024.06.004
During their journeys, migratory birds encounter a wider range of parasites than residents, transporting them over vast distances. While some parasites are widely distributed, transmission is not inevitable and depends on the presence of competent arthropod vectors as well as parasite compatibility with native bird species. Distinguishing between parasite distribution and transmission areas is crucial for monitoring and assessing risks to native bird species, as distribution areas, with the appropriate conditions, could become potential transmission areas. In this study, blood samples from 455 reed-living birds of the genera Acrocephalus, Locustella, and Emberiza, collected in the nature reserve “Die Reit” in Hamburg, Germany were screened, targeting haemosporidian parasites, trypanosomes, and filarioid nematodes. Determination of migratory bird age was employed to ascertain the transmission area of the detected parasites. Transmission areas were determined, based on information provided by resident and juvenile birds as well as findings in competent vectors. Long-distance migratory birds of the genus Acrocephalus showed a higher prevalence and diversity of blood parasites compared with partially migratory birds such as Emberiza schoeniclus. Notably, an age-dependent difference in parasite prevalence was observed in Acrocephalus spp., but not in E. schoeniclus. Nematodes were absent in all examined bird species. Proposed transmission areas were identified for nine haemosporidian lineages, showing three different types of transmission area, either with limited transmission in Europe or Africa, or active transmission in both regions.
候鸟在旅途中会遇到比本地鸟类更多的寄生虫,并将它们带到很远的地方。虽然有些寄生虫分布广泛,但传播并非不可避免,这取决于是否存在有能力的节肢动物媒介以及寄生虫与本地鸟类物种的兼容性。区分寄生虫分布区和传播区对于监测和评估本地鸟类面临的风险至关重要,因为分布区在适当的条件下可能成为潜在的传播区。本研究对在德国汉堡 "Die Reit "自然保护区采集的 455 只芦苇属鸟类的血液样本进行了筛查,目标是血孢子虫寄生虫、锥虫和丝状线虫。通过确定候鸟年龄来确定检测到的寄生虫的传播区域。根据留鸟和幼鸟提供的信息以及合格病媒的调查结果确定传播区域。与Emberiza schoeniclus等部分候鸟相比,Acrocephalus属的长途迁徙鸟类血液寄生虫的流行率和多样性更高。值得注意的是,在 Acrocephalus 属鸟类中,寄生虫的流行率与年龄有关,而在 E. schoeniclus 中则没有。所有检查过的鸟类都没有线虫。为九个血孢子虫品系确定了拟议的传播区域,显示出三种不同类型的传播区域,要么在欧洲或非洲传播有限,要么在这两个地区传播活跃。
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引用次数: 0
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International journal for parasitology
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