顶复门原虫入侵相关因子的研究进展

顶复门原虫是一类专一性的细胞内寄生原虫,包括弓形虫(Toxoplasma gondii)、隐孢子虫(Cryptosporidium spp.)、疟原虫(Plasmodium spp.)、巴贝斯虫(Babesia spp.)及艾美耳球虫(Eimeria spp.)等,是人和动物的重要病原.这类原虫具有相似的亚细胞结构和保守的入侵机制.研究结果表明,入侵过程是由大量的入侵相关蛋白分子所介导的,包括微线、棒状体及致密颗粒所分泌的相关蛋白等.随着生物信息学及分子生物学的发展,顶复门原虫入侵相关蛋白分子的研究资料也日益增多.笔者结合最近几年本课题组的研究成果,综述了顶复门原虫入侵相关蛋白因子的最新进展.     

顶复门原虫3-磷酸甘油醛脱氢酶功能及其应用研究进展

糖酵解途径广泛存在于各类生物中,是顶复门原虫的主要供能方式。3-磷酸甘油醛脱氢酶是糖酵解途径的重要酶,与顶复门原虫的生存密切相关,可以作为抗寄生虫药物研发的重要靶标。文章主要从顶复门原虫糖酵解途径、3-磷酸甘油醛脱氢酶的基因分析、作用机理及应用等方面进行综述。     

顶复门原虫γ-氨基丁酸代谢旁路研究进展

顶复门原虫包括一大类单细胞寄生性原虫,是人和动物的重要病原,会对人类健康以及畜牧业生产造成严重危害。γ-氨基丁酸是一种四碳非蛋白质氨基酸,广泛存在于生物体内。顶复门原虫的γ-氨基丁酸代谢旁路主要参与能量代谢,为虫体生长提供短期的能量储备,在虫体适应不同寄生环境过程中起着关键性作用。寄生原虫的γ-氨基丁酸代谢明显区别于哺乳动物宿主,仅限于中枢神经系统中的代谢,可在虫体入侵宿主细胞及有性生殖阶段发挥重要的作用。本文对顶复门原虫γ-氨基丁酸代谢途径及其生物学作用进行综述。     

顶复门原虫多胺合成研究进展

多胺是一类聚阳离子脂肪族化合物,广泛存在于生物体内,其在顶复门原虫的生长、发育和繁殖等多个阶段发挥着重要作用。顶复门原虫的多胺合成途径存在多样性,其与宿主细胞的经典路径不同,且顶复门原虫多胺生物合成限速酶(鸟氨酸脱羧酶与S-腺苷甲硫氨酸脱羧酶)的半衰期与宿主细胞限速酶的半衰期存在显著差异。因此,顶复门原虫多胺合成限速酶及转运载体成为抗原虫药物研发的候选靶标,以顶复门原虫多胺合成限速酶及多胺转运载体为靶标的抗寄生原虫抑制剂研究取得一定进展。论文综述了顶复门原虫多胺的生物学功能、生物合成途径及其抑制剂研究进展,以期为抗原虫药物靶标研究及新型抑制剂研发提供参考。     

顶复门原虫糖酵解代谢及其关键酶:己糖激酶的研究进展

顶复门原虫是包括刚地弓形虫、疟原虫及球虫等在内的一大类寄生性原虫的总称,引起重要的人畜寄生虫病。由于药物的长期使用,对于原有的药物产生了明显的抗药性,急需新型抗寄生虫药物的出现。顶复门原虫不能利用脂肪和蛋白质作为能量来源,只能依赖己糖激酶(Hex-okinase,HK)参与的糖酵解途径提供ATP。顶复门原虫HK的基因序列、结构特征与植物等一些低等生物更为接近,而明显区别于脊椎动物和大多数的真核生物,成为研究开发药物的理想靶位。本文对顶复门原虫糖酵解途径及其关键酶进行了综述。     

顶复门原虫顶质体研究进展

顶复门寄生虫包括多种细胞内寄生的原虫,能够引起严重的人和动物疾病,其中包括疟疾(疟原虫)、弓形虫病(刚地弓形虫)、巴贝斯虫病(牛巴贝斯虫)、球虫病(艾美尔球虫)及孢子虫病(圆孢子虫)等。顶复门寄生虫含有一个特殊的、不可或缺的细胞器,具有与藻类和植物的叶绿体同源的残留质体,称为顶质体。来源于叶绿体的残留质体保仍保留着一个能够自主复制的35kb大小的环状DNA。虽然残留质体(顶质体)无法进行光合作用,但它却扮演了一个重要的角色,参与了寄生虫体内脂肪酸、类异戊二烯及血红素的生物学合成。论文从顶质体最初的发现、起源、基因组及生物学功能等方面介绍了顶复门寄生虫顶质体的一些研究进展。     

进化的自噬系统

顶复门原虫是一大类寄生性囊泡虫。多种顶复门原虫能够造成人和动物的严重疾病,例如引起弓形虫病原的刚地弓形虫,以及引起疟疾的疟原虫等。绝大多数顶复门原虫顶端都有独特的细胞器,包括顶质体、微腺体、棒状体以及顶端复合结构等。顶质体对于虫体有着极其重要的作用。抑制顶质体的功能会导致虫体死亡。近年来的研究表明,顶质体的生物发生依赖于一系列自噬相关蛋白(ATGs)的作用。     

顶复门原虫钙依赖蛋白激酶的研究进展

钙依赖蛋白激酶(Calcium-dependent protein kinases,CDPKs)是一类大的蛋白激酶家族,属于丝氨酸/苏氨酸类蛋白激酶,广泛存在于各种植物和原生动物中,参与多种生命活动的调控.随着生物信息学、分子生物学及基因工程的迅速发展,对顶复门原虫CDPKs的研究日益增多.研究结果表明,这类蛋白家族成员参与调控寄生虫入侵、外出宿主细胞、配子形成、宿主体内移行等顶复门原虫生活史的多个重要时期,其特殊的分子结构或可成为研究抗寄生虫疫苗或药物的候选靶标.本文以疟原虫、弓形虫和艾美耳球虫CDPKs为重点,综述了顶复门原虫CDPKs的结构、功能及生物学意义,展望了顶复门原虫CDPKs的研究和应用前景,以期为研究顶复门原虫的致病机理及研发抗原虫生物制剂提供参考.     

顶复门原虫电子转移链代谢及Ⅱ型NADH脱氢酶研究进展

顶复门原虫是包括刚地弓形虫、疟原虫及球虫等在内的一大类寄生性原虫的总称,可引起重要的人畜寄生虫病.抗顶复门原虫药物的长期使用,甚至是滥用,使得这类寄生虫对现有药物产生了明显的抗药性,急需开发新型药物.Ⅱ型NAD(P)H脱氢酶是电子转移链途径中的关键酶,由于其仅存在于某些植物、细菌、真菌和寄生原虫等一些低等生物体内,而在高等动物体内缺失,是研发新型抗感染性药物的重要靶标.笔者主要针对顶复门原虫线粒体电子转移链代谢途径以及Ⅱ型NAD(P)H脱氢酶的研究概况进行综述.     

顶复门原虫醛缩酶的生物学功能与应用进展

顶复门原虫是一类专一性细胞内寄生原虫,不仅危害畜禽的健康,有些种类还是人兽共患病原,威胁人类的健康。醛缩酶是一类可逆醇醛裂合酶,根据作用机理可分为Ⅰ型与Ⅱ型醛缩酶。研究发现,顶复门原虫存在Ⅰ型醛缩酶,它们主要参与顶复门原虫的能量代谢、虫体黏附及入侵宿主细胞等过程,或可成为抗原虫药物研发的候选靶标。论文主要对顶复门原虫醛缩酶的生物学功能与应用研究现状进行综述,以期为顶复门原虫感染的防控提供参考。     

顶复门原虫棒状体蛋白疫苗候选分子的研究进展

顶复门原虫是一类专一性的胞内寄生性原虫,其种类丰富、分布广泛,包括艾美耳球虫、巴贝斯虫、隐孢子虫、疟原虫和弓形虫等。此类原虫具有保守的棒状体、致密颗粒以及微线等顶端复合器结构,这些细胞器可分泌大量的入侵相关蛋白分子介导虫体入侵宿主细胞。而棒状体蛋白是这类原虫在入侵过程中由棒状体分泌的一类蛋白,其在虫体入侵宿主细胞、纳虫空泡形成及胞内虫体的增殖调控等方面发挥着至关重要作用,是最具潜力的疫苗候选抗原。本文对棒状体蛋白的发现、组成、功能及定位进行概述,以目前研究最深入的弓形虫棒状体蛋白为主,归纳总结近年来关于棒状体蛋白作为顶复门原虫疫苗候选分子的研究进展,以期为新型抗原虫分子疫苗的研制提供理论依据。     

Detection of antibodies against Brucella abortus, Leptospira spp., and Apicomplexa protozoa in water buffaloes in the Northeast of Argentina

Water buffalo industry has become a profitable activity worldwide, including the Northeast of Argentina (NEA). However, research on diseases affecting this species is scarce. The aim of the present study was to detect antibodies against Brucella abortus, Leptospira spp., Neospora caninum, Toxoplasma gondii, and Sarcocystis spp. in 500 water buffalo cows from five ranches (100 animals each) in the NEA. Serum samples were tested for B. abortus by fluorescence polarization assay, Leptospira spp. by microagglutination test, and N. caninum, T. gondii, and Sarcocystis spp. by indirect fluorescent antibody tests. Overall, the proportion of seropositive animals was 6.4, 22.2, 42.2, 25.4, and 50.8 % for brucellosis, leptospirosis, neosporosis, toxoplasmosis, and sarcocystosis, respectively. The proportion of seropositive animals for all diseases was statistically different among herds (p?<?0.05). Statistical differences were also detected among age groups for brucellosis and neosporosis (p?<?0.05). The detection of specific antibodies to B. abortus, Leptospira spp., and several Apicomplexa protozoans in water buffaloes in the NEA is reported in this study.     

Looks can deceive: Molecular identity of an intraerythrocytic apicomplexan parasite in Australian gliders

Two yellow-bellied gliders (Petaurus australis) had an intraerythrocytic parasite closely related to the cyst-forming coccidia (Apicomplexa: Sarcocystidae). The parasitaemia persisted for 3 months or more but was observed to clear within 3 years in captivity. The parasite appears not to significantly debilitate its infected host. Traditionally, using morphological identification, the intraerythrocytic parasite would have been classified within the Hepatozoon species typically found in red blood cells. However, molecular diagnostic techniques targeting the parasite's SSU rDNA and LSU rDNA demonstrated the unusual identity of this blood parasite and disputed its identity as a haemogregarine parasite of the genus Hepatozoon. The sequence was compared with available sequences from diverse mammalian and non-mammalian blood parasites (malaria, piroplasms, hemosporidia and sarcosporidia). The intraerythrocytic blood parasite was found to be most closely related to the cyst-forming coccidia including Besnoitia spp., Cystoisospora spp., Hammondia spp., Hyaloklossia lieberkuehni, Neospora caninum, Sarcocystis spp. and Toxoplasma gondii. The life cycle of this intraerythrocytic parasite remains unknown. The presented DNA identification demonstrates its suitability for an improved identification of blood parasites.     

禾本科牧草与草坪草转基因研究进展

禾本科牧草和草坪草在饲料作物、城市绿化、生态环境保护方面发挥着积极作用.笔者总结了近10年来国内外对此类植物资源的转基因技术研究工作,从转化方法、受体系统、筛选体系等方面探讨了包括黑麦草、高羊茅、鸭茅、早熟禾、剪股颖、结缕草、狗牙根、雀稗等属的一些常用牧草和草坪草的遗传转化体系的建立和完善,所取得的研究成果包括改善营养品质,增加禾本科草对各种逆境的适应能力,提高对各种虫害、病害和除草剂的抗性等.     

Vector-borne infections in cats: molecular study in Barcelona area (Spain)

Previous serological surveys have reported the presence of different organisms in cats from Spain but little reports exist about the exact identity of these organisms. The purpose of the study reported here was to assess the presence of DNA of several vector-borne infections in a population of cats from Barcelona area. One hundred blood samples obtained from cats admitted to the UAB-VTH were entered into the study and classified as healthy (n=48) or unhealthy (n=52). EDTA-blood samples were assayed for Leishmania infantum, Ehrlichia spp., Anaplasma spp., Rickettsia spp., Bartonella spp., Hepatozoon spp., Babesia spp. and Theileria spp. DNA by means of PCR amplification and amplicons obtained were sequenced. Prevalence of infectious agents found were Leishmania infantum (3%), Ehrlichia/Anaplasma sp. (1%), Hepatozoon felis (4%) and Bartonella clarridgeiae (1%). Cats being less than 5 years old had more probability of having at less one PCR positive result (P=0.028). The results of this study show a low prevalence of several vector-borne pathogens among cats from Barcelona area. Although higher feline seroprevalences are previously reported, they evidenced exposure and probably overestimate the real or active degree of infection. However, it is important to maintain a high index of suspicion on these infectious diseases, both in sick and asymptomatic cats, and molecular techniques could aid in the identification of these pathogens.     

鸡球虫入侵相关分子的研究进展

鸡球虫病是由艾美耳球虫寄生于肠道所引起的一种危害极其严重的寄生虫病,给养鸡业造成巨大的经济损失.艾美耳球虫属于顶复器门原虫,在入侵宿主细胞过程中需要通过入侵虫体顶端的顶复器分泌蛋白发挥作用.目前已报道与鸡球虫入侵相关的重要蛋白,包括微线蛋白、蛋白激酶、热激蛋白以及糖酵解酶等.这些蛋白主要参与了鸡球虫入侵宿主细胞以及在宿主细胞内的生长发育、参与了虫体的细胞周期活动以及参与了糖酵解提供虫体入侵需要的能量等,进一步对这些分子进行研究,对了解鸡球虫入侵宿主细胞的相关机理及发展抗球虫病疫苗和治疗药物将有积极的意义.     

Isolates of fungi from symptomatic carthorses in Awassa, Ethiopia.

Samples were collected from clinically infected carthorses in Awassa. Fungus species affecting the carthorses were identified. Eight genera of fungal groups were isolated from swabs and skin scrapes taken from symptomatic horses. These included Aspergillus spp., Histoplasma spp., Penicillium spp., Microsporum spp., Trichophyton spp., yeast cells of Candida spp., Cryptococcus spp. and Geotrichum spp. The most frequent isolates were from the genera Aspergillus (48%), Penicillium (39.2%) and Trichophyton (31.6%). Clinical findings are reported, the economic, zoonotic and pathogenetic importance of fungi causing dermatomycoses is discussed, and further studies are recommended.