Molecular circumscription of the blackfly Simulium oyapockense from South America.

Problems related to the identity of Simuliidae species are impediments to effective disease control in Amazonia. Some of these species, such as Simulium oyapockense Floch & Abonnenc, 1946 (Diptera: Simuliidae), are vectors of the organisms that cause onchocerciasis and mansonellosis diseases. This blackfly species has a wide distribution in South America, and it is suspected of being a complex of cryptic species. The aim of this study is to characterize the nominal species S. oyapockense using partial COI gene sequences. Seven populations of S. oyapockense (morphologically identified) were analysed, including one from its type-locality. The other six populations were collected in Brazil and in Argentina. A taxon collected in Amazonas state, Brazil, with adults similar to S. oyapockense but with distinct pupae, was also included in the analysis (Simulium 'S'). The nominal species S. oyapockense is circumscribed, and its geographical distribution is restricted to areas north of the Amazon River. Populations of S. oyapockense s.l. collected south of the Amazon River comprise a species complex that needs to be evaluated using integrative taxonomy. Simulium 'S' represents a species with unique morphological and molecular characteristics. Distinguishing cryptic species is a prerequisite for reducing the taxonomic impediment, especially in medically important taxa.

Litomosoides silvai (Nematoda: Onchocercidae) parasitizing Akodon montensis (Rodentia: Cricetidae) in the southern region of Brazil / Litomosoides silvai (Nematoda: Onchocercidae) parasitando Akodon montensis (Rodentia: Cricetidae) na região Sul do Brasil

Abstract In the present study, Litomosoides silvai parasitizing Akodon montensis in the southern region of Brazil is reported for the first time. New morphological information is provided for some structures of this nematode species, such as a flattened cephalic extremity, presence of two dorsal cephalic papillae, female tail with a constriction at its tip, "s" shaped vagina, spicules characteristic of the carinii species group and microfilaria tail constricted at the tip. This nematode was found parasitizing the thoracic cavity with a prevalence of 10% (2/20), mean intensity of 4 (6/2), mean abundance of 0.4 (8/20) and range of infection of 2-6 specimens per host, in southern Brazil. This occurrence of L. silvai in A. montensis is a new geographical record for southern Brazil, in the Upper Paraná Atlantic Forest ecoregion of the northwestern region of Rio Grande do Sul, which is part of the Atlantic Forest biome.

Resumo No presente estudo é relatado pela primeira vez Litomosoides silvai parasitando Akodon montensis coletados na região Sul do Brasil. Foram fornecidas novas informações morfológicas para algumas estruturas desta espécie de nematódeo, tais como extremidade cefálica achatada, a presença de duas papilas cefálicas dorsais, cauda das fêmeas com uma constrição na ponta da cauda, vagina em forma de "s", espículas de característica do grupo de espécies de carinii e cauda da microfilária com constrição na ponta. Este nematódeo parasitava a cavidade torácica com uma prevalência de 10% (2/20), intensidade média de 4 (8/2) e abundância média de 0,4 (8/20), e intervalo de infecção de 2-6 espécimes por hospedeiro no Sul do Brasil. A ocorrência de L. silvai em A. montensis é um novo registro geográfico, no sul do Brasil, a noroeste do estado do Rio Grande do Sul, na ecorregião da Mata Atlântica do Alto Paraná, parte do bioma da Mata Atlântica.

Litomosoides silvai (Nematoda: Onchocercidae) parasitizing Akodon montensis (Rodentia: Cricetidae) in the southern region of Brazil.

In the present study, Litomosoides silvai parasitizing Akodon montensis in the southern region of Brazil is reported for the first time. New morphological information is provided for some structures of this nematode species, such as a flattened cephalic extremity, presence of two dorsal cephalic papillae, female tail with a constriction at its tip, "s" shaped vagina, spicules characteristic of the carinii species group and microfilaria tail constricted at the tip. This nematode was found parasitizing the thoracic cavity with a prevalence of 10% (2/20), mean intensity of 4 (6/2), mean abundance of 0.4 (8/20) and range of infection of 2-6 specimens per host, in southern Brazil. This occurrence of L. silvai in A. montensis is a new geographical record for southern Brazil, in the Upper Paraná Atlantic Forest ecoregion of the northwestern region of Rio Grande do Sul, which is part of the Atlantic Forest biome.

Anatomopatologia de bursite cervical (oncocercose) encontrada em bovinos abatidos sob inspeção estadual no estado do Rio de Janeiro / Anatomopathology of onchocerciases (cervical bursitis) in slaughtered bovine in the north of Rio de Janeiro state

A patologia descritiva das lesões em animais domésticos de açougue permite enriquecer a literatura médica veterinária especializada em inspeção sanitária de carnes, assim como subsidiar tecnicamente os profissionais inspetores. A oncocercose é uma parasitose causada pelo nematódeo Onchocerca sp,, sendo que a espécie O. gutturosa é a que mais acomete bovinos na América do Sul. Foram avaliados, pelo exame anatomopatológico, dois casos de lesões localizadas no ligamento nucal de bovinos abatidos para o consumo. A macroscopia de um caso revelou bursite crônica, representada por grande quantidade de líquido citrino e viscoso e, ainda, muitos corpúsculos livres, elípticos e achatados desprovidos de raiz (arrizo). A microscopia dessas estruturas evidenciou moldes de fibrinas amorfos e eosinofílicos. O segundo caso foi caracterizado por bursite aguda, e a microscopia das lesões ligamentar e periligamentar revelou granulomas epitelioides com reação gigantocitária, centralizados por formações semelhantes ao Onchocerca sp...

The descriptive pathology of lesions in butcher's domestic animals contribute to enrich literature specialized in veterinary sanitary inspection of meat as well as to guide professional meat inspectors. Oncorcecose is a parasitic disease caused by the nematode Onchocerca sp, and the O. gutturosa species affects cattle in South America. Two cases of lesions located in the nuchal ligament of cattle slaughtered for consumption were evaluated by pathological examination. Macroscopic analysis revealed a case of chronic bursitis represented by a large amount of clear and viscous liquid, and also many free, elliptical and flat corpuscles. Microscopy showed arrizoides molds fibrin, amorphous, and eosinophilic structures. The second case was characterized by acute bursitis and microscopic lesions and ligament periligamentous revealed multiple epithelioid granulomas and giant cells centered on formations similar to Onchocerca sp...

Anatomopatologia de bursite cervical (oncocercose) encontrada em bovinos abatidos sob inspeção estadual no estado do Rio de Janeiro / Anatomopathology of onchocerciases (cervical bursitis) in slaughtered bovine in the north of Rio de Janeiro state

A patologia descritiva das lesões em animais domésticos de açougue permite enriquecer a literatura médica veterinária especializada em inspeção sanitária de carnes, assim como subsidiar tecnicamente os profissionais inspetores. A oncocercose é uma parasitose causada pelo nematódeo Onchocerca sp,, sendo que a espécie O. gutturosa é a que mais acomete bovinos na América do Sul. Foram avaliados, pelo exame anatomopatológico, dois casos de lesões localizadas no ligamento nucal de bovinos abatidos para o consumo. A macroscopia de um caso revelou bursite crônica, representada por grande quantidade de líquido citrino e viscoso e, ainda, muitos corpúsculos livres, elípticos e achatados desprovidos de raiz (arrizo). A microscopia dessas estruturas evidenciou moldes de fibrinas amorfos e eosinofílicos. O segundo caso foi caracterizado por bursite aguda, e a microscopia das lesões ligamentar e periligamentar revelou granulomas epitelioides com reação gigantocitária, centralizados por formações semelhantes ao Onchocerca sp.(AU)

The descriptive pathology of lesions in butcher's domestic animals contribute to enrich literature specialized in veterinary sanitary inspection of meat as well as to guide professional meat inspectors. Oncorcecose is a parasitic disease caused by the nematode Onchocerca sp, and the O. gutturosa species affects cattle in South America. Two cases of lesions located in the nuchal ligament of cattle slaughtered for consumption were evaluated by pathological examination. Macroscopic analysis revealed a case of chronic bursitis represented by a large amount of clear and viscous liquid, and also many free, elliptical and flat corpuscles. Microscopy showed arrizoides molds fibrin, amorphous, and eosinophilic structures. The second case was characterized by acute bursitis and microscopic lesions and ligament periligamentous revealed multiple epithelioid granulomas and giant cells centered on formations similar to Onchocerca sp.(AU)

Oswaldofiaria chabaudi n. sp. (Nematoda: Onchocercidae) from a South American tropidurid lizard (Squamata: Iguania) with an update on Oswaldofilariinae.

A new species of Oswaldofilaria is described from Tropidurus torquatus (Tropiduridae: Iguania); its prevalence at the rocky study area at Juiz de Fora, Minas Gerais, Brazil, was approximately 30% and its mean intensity 3.13 +/- 2.51. Oswaldofilaria chaboudi n. sp. is distinct from the thirteen Oswaldofilaria species known in Australia, Africa and South-America in having the following characteristics: oesophagus medium-sized, left spicule 1 mm long and high spicular ratio (about 5), tail extremity ornated in both sexes with a bifurcated projection, and tooth-like structures near phasmids in the female. A long left spicule and high spicular ratio are convergent derived characters also found in a parasite of Australian crocodilians, O. kanbaya, and in several species of the closely related genus Befilaria, such as the Central American B. puertoricensis from polychrotids. Oswaldofilaria in South America is represented by eight species. Within these, a primitive group that is parasitic in Iguanidae, Polychrotidae (Iguania) and Crocodylidae and that possesses a long oesophagus is recognised, together with two distinct derived lines: three species with numerous, aligned precloacal papillae, parasitic in Teiidae (Laterato) and Scincidae (Scincomorpha), and O. chabaudi n. sp., in which this character is absent. Tropidurids (Tropiduris and Plica) had previously been reported in the host range of two oswaldofilarine genera, Oswaldofilaria and Piratuba, and their parasites assigned to known species described from other groups of lizards.

Onchocerca cervicalis in horses from southern Brazil.

The objective of this study was to determine the occurrence of Onchocerca cervicalis in 1200 adult horses from rural areas of Rio Grande do Sul, Brazil. Umbilical skin specimens measuring 2 x 2 cm were minced, suspended in 10 ml of distilled water and incubated at room temperature overnight. The liquid volume was centrifuged and the sediment was screened for microfilariae. The ligamentum nuchae were totally removed, preserved in ice and dissected for the detection of adult forms of Onchocerca cervicalis. Microfilariae of Onchocerca cervicalis were detected in midventral skin biopsy samples in 215 (17.9%) of 1200 horses examined and the adult worms were recovered from 200 (16.6%) ligamentum nuchae from the same animals. These findings provide a basis for further studies to determine infection rates in horses from other regions of the state and to identify the intermediate host that transmits the disease.

Comparative efficacy of moxidectin 2% equine oral gel and ivermectin 2% equine oral paste against Onchocerca cervicalis (Railliet and Henry, 1910) microfilariae in horses with naturally acquired infections in Formosa (Argentina).

On the basis of positive skin snips for Onchocerca cervicalis microfilariae (MF), 45 horses were chosen from 48 in a total of 257 screened on 12 locations in the northeast Province of Formosa (Argentina), and randomly assigned to two treatment groups of 20 horses each, and a nontreated control group of five horses. On Day 14 post-treatment (PT), skin snip samples in the ivermectin-treated (0.2 mg/kg) group were negative for normal viable microfilariae (MF), while horses in the control group maintained their pretreatment level of infection. On the same Day in the moxidectin-treated (0.4 mg/kg) group, 18 horses were negative for MF, but the remaining two had a total of 1 and 2 MF, respectively (equivalent to 10 and 20 MF/g of skin), but all three parasites showed marked cuticular and structural damage. Both horses were negative in a repeat biopsy on Day 21. From Day 3 PT, one ivermectin-treated horse (5%) evidenced an approximate 15 x 2 x 3 cm-sized, apparently nonpainful, oedematous swelling on the ventral midline, 20 cm in front of the navel, which remained unchanged on Day 14 PT. Adverse reactions were not observed in the moxidectin-treated group. Parasitaemia was found in 18.7% of sampled horses (48 of 257), and the number of MF varied between 10-1820/g of skin snip (mean 172). Similar prevalence and total counts had been described previously in 1985 and 1986 in cattle-farm horses in the same area of Argentina; in surveys in Texas (1974) and Louisiana (1995) in the USA, infection rates were also similar, but total counts much higher. It is concluded that moxidectin 2% equine oral gel and ivermectin 2% equine oral paste, were equally 100% effective in the control of O. cervicalis MF. Contrary to ivermectin, moxidectin did not cause post-treatment dermal reactions.

Morphological characteristics and isoenzyme patterns of an Onchocerca sp. found in cattle in Southern Mexico.

An Onchocerca sp. was isolated from the nuchal ligaments of 78 out of 79 naturally infected cattle in Southern Mexico. Infections were moderate to heavy, averaging 20-30 parasites per nuchal ligament. Microfilariae were concentrated in the skin of the head and neck, although small numbers were found in the skin of the withers, brisket and medial abdomen. High numbers of microfilariae were found in the skin around the eye, but not in the ocular tissues themselves a situation dissimilar to that found in human onchocerciasis. Morphologically, adult females, males and microfilariae were identified as being O. gutturosa. Analysis of the isoenzyme patterns of LDH, MDH, PGM, GPI, PGD and ES of adult female worms, showed the Mexican parasite to be the same as O. gutturosa from England and Australia.