驯鹿艾美虫属一新种：（球虫目：艾美科）

本文寄生于驯鹿Ｒａｎｇｉｆｅｒ ｔａｒａｎｄｕｓ艾美虫属一新种－－敖鲁古雅艾美虫Ｅｉｍｅｒｉａ ａｏｌｕｇｕｙａｅｎｓｉｓ ｓｐ．ｎｏｖ．,新种的特种是具有卵囊残体和最小的量度,可与文献中记载寄生于驯鹿的五种艾美虫相区别。     

毁灭泰泽球虫(Tyzzeria perniciosa)内生发育的超微结构研究——Ⅰ.裂殖生殖(Schizogony)

利用透射电镜对寄生于北京鸭小肠的毁灭泰泽球虫的裂殖生殖过程进行了观察。滋养体内未见多糖颗粒、脂肪体和致密体,在细胞质的被膜空泡内发现退化的微线和棒状体。在裂殖体核分裂过程中,出现典型的球虫型有丝分裂装置(如中心粒、中心锥、纺锤体)。裂殖子的发生是外瓣生方式,裂殖子在裂殖体的表面形成,并以母细胞的限制膜为外膜。     

Australian dingoes are definitive hosts of Neospora caninum

To provide objective data on the potential role of dingoes (Canis lupus dingo) in the life cycle of Neospora caninum in Australia, the production of N. caninum oocysts by experimentally infected canids was investigated. Three dingo pups raised in captivity and three domestic dogs were fed tissue from calves infected with an Australian isolate of N. caninum, Nc-Nowra. Oocysts of N. caninum, confirmed by species-specific PCR, were shed in low numbers by one dingo pup at 12-14 days p.i. The remaining animals did not shed oocysts. Furthermore, the blood from two out of three dingoes tested positive for DNA of N. caninum using PCR tests at 14 and 28 days p.i. Oocyst shedding from the intestinal tract of a dingo demonstrates that dingoes are definitive hosts of N. caninum and horizontal transmission of N. caninum from dingoes to farm animals and wildlife may occur in Australia.     

Eimeria melogale n. sp. (Apicomplexa: Eimeriidae) in the Javan ferret-badger (Melogale orientalis)

The Javan ferret-badger Melogale orientalis (Carnivora: Mustelidae: Helictidinae) is a small carnivore endemic to Indonesia. In the family Mustelidae, 10 Eimeria, 12 Cystoisopora, one Isospora, and one Hammondia species are known, but no eimeriid coccidia has been yet described in the subfamily Helictinidae (ferret badgers). Coproscopic examination of Javan ferret-badgers imported into the Czech Republic revealed the presence of coccidian oocysts. Sporulated oocysts differ from other Eimeria known in the family Mustelidae by their small size (12.4–16.1 × 10.4–13.4 μm) and ovoidal shape. Morphological data and phylogenetic analyses of 18S rRNA and COI genes indicated a new species of Eimeria found in faecal samples of Javan ferret badgers. The species is described as E. melogale n. sp.     

Caution on the assessment of intestinal parasitic load in studying parasite-mediated sexual selection: The case of Blackbirds coccidiosis

The parasite-mediated sexual selection (PMSS) theory has led to an increasing number of experimental studies essentially focussed on blood parasites. Currently, more research is being carried out on intestinal parasites in relationship to this theory. Before testing the theory with gastrointestinal parasites, it is important: (i) to determine an optimal research methodology to obtain an accurate assessment of parasite burden and (ii) to have information about life-history traits of the parasite to interpret data appropriately. In this study, we present data on oocyst output of Isosporaturdi in the faeces of blackbirds (Turdus merula) that illustrate the importance of developing methods that are relevant for a particular model system, instead of relying on existing methods that may work in other systems. Our results show that: (i) a single droplet of faeces will accurately indicate the parasitic load in blackbirds, (ii) oocyst shedding varies greatly within and between days, (iii) the course of infection is characterised with two successive peaks of oocyst shedding, (iv) infection lasts approximately 1 month and (iv) there is no effect of sex, size of infective dose or re-infection on the course of infection. We discuss the practical implications of these results in determining the reliability of, and in avoiding erroneous conclusions about, PMSS when using intestinal parasites as models. In particular, we emphasise that numerous measurements must be performed on different days. In addition, faeces must be collected at a particular time of day because there is a strong temporal variation in oocyst shedding. Finally, a standardised methodology that has been developed for a particular host-parasite assemblage does not necessarily work with other biological models. Together, our results should encourage future investigators to identify an accurate methodology for assessing parasitic load as a first step before testing hypotheses associated with the PMSS theory.     

The phylogeny of Goussia and Choleoeimeria (Apicomplexa; Eimeriorina) and the evolution of excystation structures in coccidia

The phylogenetic relationships of Goussia janae and Choleoeimeria sp. were analyzed using the small subunit ribosomal RNA gene (SSU rDNA). This is a first attempt to study the molecular phylogeny of coccidian genera parasitizing strictly poikilotherm hosts. The biliary Eimeria-like coccidia of reptiles classified into the genus Choleoeimeria form a sister clade to the family Eimeriidae, which confirms the separate generic status of the genus Choleoeimeria. The position of Goussia is less robustly resolved, since it forms a trichotomy with the Eimeriidae and Sarcocystidae, or alternatively constitutes the earliest branch of the coccidian lineage. Morphological similarities, namely the extracytoplasmic location of the endogenous stages, and the presence of sutures in the sporocyst wall are discussed in the context of the traditional classification of eimeriids. In contrast to the morphology-based systematics, the monophyly of Goussia and Choleoeimeria is not supported by the SSU rDNA data.     

A new species of plasmodiidae (Coccidia: Hemosporidia) from the blood of the skink Scincus hemprichii (Scincidae: Reptilia) in Saudi Arabia

Fallisia arabica n. sp. was described from peripheral blood smears of the Skink lizard, Scincus hemprichii from Jazan Province in the southwest of Saudi Arabia. Schizogony and gametogony take place within neutrophils in the peripheral blood of the host. Mature schizont is rosette shaped 17.5 ± 4.1 × 17.0 ± 3.9 μm, with a L/W ratio of 1.03(1.02–1.05) μm and produces 24(18–26) merozoites. Young gametocytes are ellipsoidal, 5.5 ± 0.8 × 3.6 ± 0.5 μm, with a L/W of 1.53(1.44–1.61) μm. Mature macrogametocytes are ellipsoidal, 9.7 ± 1.2 × 7.8 ± 1.0 μm, with a L/W of 1.24(1.21–1.34) μm and microgametocytes are ellipsoidal, 7.0 ± 1.1 × 6.8 ± 0.9 μm. with a L/W of 1.03(1.01–1.10) μm. In comparison to the described Fallisia species, this new taxon has rosette schizonts and is larger than F. dominicensis, in Hispaniola, F. bipocrati, F. poecilopi, in Panama, F. thecadactyli in Venezuela, and F. effusa, F. simplex, F. modesta, in Brazil. F. arabica has fewer merozoites than F. effusa, F. poecilopi, F. thecadactyli and F. siamense in Thailand. This new species has more merozoites than F. dominicensis and F. modesta. All of these species belong to diverse saurian families (Agamidae, Gekkonidae, Polychrotidae, Scincidae and Teiidae) parasitize only thrombocytes or lymphocytes and some species parasitize immature erythroid cells and leucocytes.     

Eimeria nieschulzi: glucose absorption in infected rats

Liquid scintillation spectrophotometry was employed to determine absorption of ³H-glucose by rats infected with the coccidium Eimeria nieschulzi. In vivo studies showed increased uptake of label into small intestinal tissue and hepatic portal plasma at 3 days postinoculation and decreased absorption at 8 days postinfection compared to uninfected control animals. Observations of tissues incubated in labeled glucose in vitro confirm in vivo findings of increased uptake early in infection and malabsorption coinciding with the observation of clinical disease symptoms.     

Eimeria tenella: Effect of narasin,a polyether antibiotic on the ultrastructure of intracellular sporozoites

Eimeria tenella sporozoites were inoculated into cultures of chick kidney cells in the presence of 0.01 or 0.1 μg/ml of narasin and incubated at either 40 or 30 C for 24 hr. Electron microscopic examination revealed that either concentration of this polyether ionophore caused extensive ultrastructural damage to the intracellular sporozoite at 40 but not at 30 C, indicating that the severity of the coccidiocidal effect is influenced by temperature. The effect of 0.01 μg/ml monensin on the intracellular parasite was similar to that of narasin, suggesting a common destructive mechanism. The host cells were unaffected by 0.01 μg/ml of narasin at either temperature and by 0.1 μg/ml at 30 C, indicating that the polyether ionophores can be selectively lethal for the parasite. However, when the host cells were treated with 0.1 μg/ml narasin and incubated at 40 C, ultrastructural abnormalities were evident. The results suggest that the coccidiocidal effect of the polyether ionophorous antibiotics may be a general osmotic phenomenon.