Marta D’Agosto

Antimalarial Activity of the Novel Quinoline/6‐Thiopurine Conjugate in Gallus gallus Linnaeus, Infected Experimentally by Plasmodium (Novyella) juxtanucleare

This study aimed to evaluate the 4‐(6′‐thiopurine)‐7‐chloroquinoline, a novel quinoline/6‐thiopurine conjugate, for the treatment of Gallus gallus experimentally infected with Plasmodium juxtanucleare, an avian malaria agent. The avian group treated with 4‐(6′‐thiopurine)‐7‐chloroquinoline showed a significative parasite clearance and maintained a low level of parasitaemia, when compared with the untreated control group and to the chloroquine treated avian group.

Prevalência e variação dos estádios eritrocíticos do Plasmodium (Novyella) juxtanucleare em Gallus gallus sob condições naturais, no período de um ano

The avian malaria caused by Plasmodium juxtanucleare in Gallus gallus, is a tipical plasmodiose from Brazilian gallinaceous. This disease can causes morbidy and mortality in its vertebrate hosts. This work was conducted at Boa Vista farm, Municipality of Santa Barbara do Tugurio, Minas Gerais, Brazil and the ours objectives were to evaluate the hight prevalence found in previous studies and to accompany the variation of the erytrocytic forms during one year. The bloods smears, dyed with Giemsa were examined in microscopy immersion. Twenty five half-breed fowls were accompany duting one year, monthly (from November/00 to May/01) and biweekly (from June/01 to October/01). The erytrocytic forms were registered and quantified by the observation of 100 microscopic fields. Was verified a prevalence of 100% by P. juxtanuclerare, but there wasn’t statistics correlation between the increase of the erytrocytic forms during the year. The trophozoites were the more abundant form found in this studie.

Spatial and temporal occurrence of Rhabdostyla cf. chironomi Kahl, 1933 (Ciliophora, Peritrichia) as an epibiont on chironomid larvae in a lotic system in the neotropics

In order to show how environmental factors could influence the spatial and temporal distribution of epibiosis, we investigated the occurrence of the ciliate Rhabdostyla cf. chironomi (Ciliophora, Peritrichia) attached to Chironomidae larvae in an urban stream in southeast Brazil. Samples were collected monthly for 1-year period at five sampling stations along the stream. Among the 24 genera analyzed, the genus Chironomus was the most abundant, with 16.84% carrying R. cf. chironomi. This epibiotic relationship was only recorded in sample stations located in a heavily populated urban area of the stream. Statistical analyses demonstrated significant correlations between infestation prevalence and environmental parameters such as rainfall, bacterial density, and host abundance. The occurrence of epibionts on the larvae was spatially and temporally heterogeneous. The results are discussed in terms of possible factors related to the heterogeneous spatial and temporal occurrence. Greater understanding of the ecological factors governing the occurrence of the epibiont–host relationship is essential to establish future use of this relationship as water quality indicator in lotic systems.

Rumen ciliates in Brazilian sheep ( Ovis aries ), with new records and redescription of Entodinium contractum (Entodiniomorphida: Ophryoscolecidae)

The species composition, prevalence, and average relative abundance of rumen ciliates were analyzed in 16 Brazilian sheep. 28 species of ciliates were identified belonging to 3 families: Isotrichidae, Ophryoscolecidae, and Parentodiniidae. Among these ciliates, Entodinium alces, Metadinium esalqum, and M. rotundatum were found for the first time in sheep, and other 12 species for the first time in Brazilian sheep. Different morphotypes of parentodiniid ciliates were identified in 7 of the 16 sheep analyzed and this is the second report of this family in ruminants. The species Entodinium contractum was redescribed based on the new data on the general morphological features; for the first time, we described the oral infraciliature, which in this species is of the Entodinium-type. In this species, it is noteworthy that the prominent vestibular polybrachykinety can be used as an important identifying characteristic.

Morphology and description of infraciliary bands pattern in four Metadinium Awerinzew & Mutafowa, 1914 species (Ciliophora, Entodiniomorphida, Ophryoscolecidae) with taxonomic notes on the genus

The genus Metadinium includes ophryoscolecid ciliates, with two retractile ciliary zones in the anterior body portion, two broad skeletal plates, a lobed macronucleus and two contractile vacuoles. Species belonging to this genus were recorded in several geographical locations and in different host species. However, they were mostly described based on a single ciliatological technique, and until now, there is only one description of the infraciliary pattern in Metadinium ciliates (Metadinium medium). The present study performs the morphological and infraciliature characterization of four species belonging to Metadinium: M. esalqum, M. minorum, M. rotundatum and M. ypsilon; and presents taxonomic notes on the genus. The oral infraciliature in these four Metadinium species corresponds to the Diplodinium-type, pattern shared with genera Diplodinium, Diploplastron, Eudiplodinium, Eremoplastron and Polyplastron. A brief review conducted highlights the difficulty of delimiting Metadinium species due to the morphological similarity among them.

Description of Diploplastron dehorityi sp. nov. (Entodiniomorphida, Ophryoscolecidae), a new rumen ciliate from Brazilian sheep ( Ovis aries )

To date the genus Diploplastron comprised only one species of ophryoscolecid ciliate, Diploplastron affine, which is characterized by having two retractable ciliary zones in the anterior end of the body, two slender and juxtaposed skeletal plates on the right side, a rod shape macronucleus, and two contractile vacuoles. During study on the characterization of rumen ciliate community composition in Brazilian domestic sheep, we observed ciliates with atypical morphology but with diagnostic features of genus Diploplastron. This study describes Diploplastron dehorityi, a new species of ophryoscolecid ciliate, that differs from D. affine, primarily, in the morphology of skeletal plates, morphology of nuclear apparatus and body shape. In addition to the similarities between the new species and congener species, D. dehorityi has some morphological similarities to species of genus Eremoplastron.