Description of the parasitic fauna of a specimen of Didelphis albiventris at Rio Grande do Sul.

Didelphis albiventris is considered the most common marsupial in Rio Grande do Sul. With omnivorous and synanthropic habits, it can serve as a host to various parasites, playing an important role in maintaining their biological cycle. Despite being a widespread and abundant species, it has a relatively little-known parasitic fauna. Therefore, the aim of this study was to report the diversity of parasites in a fecal sample from D. albiventris in Rio Grande do Sul, Southern Brazil. Modified Centrifugal-flotation and Spontaneous sedimentation techniques were used, revealing a high taxonomic diversity of parasites. Eggs of Ancylostoma spp., Toxocara spp., and Anoplocephalidae were reported for the first time in the host in the southern region of the country, along with the first report of pseudoparasitism by Syphacia spp. and Monocystis spp. in this animal species. The presence of different parasites in the feces of D. albiventris is of utmost importance, primarily for public health, but also for understanding the biodiversity of parasites present in wildlife, which has been poorly studied until now. This allows the implementation of effective strategies for controlling, preventing and treating these diseases.

Didelphis albiventris é considerado o marsupial mais comum no Rio Grande do Sul. Com hábitos onívoros e sinantrópicos, pode servir de hospedeiro para diversos parasitas, desempenhando importante papel na manutenção do seu ciclo biológico. Apesar de ser uma espécie difundida e abundante, possui uma fauna parasitária relativamente pouco conhecida. Portanto, o objetivo deste estudo foi relatar a diversidade de parasitas em uma amostra fecal de D. albiventris no Rio Grande do Sul, Sul do Brasil. Foram utilizadas técnicas modificadas de flutuação centrífuga e sedimentação espontânea, revelando uma alta diversidade taxonômica de parasitas. Ovos de Ancylostoma spp., Toxocara spp. e Anoplocephalidae foram relatados pela primeira vez no hospedeiro na região sul do país, juntamente com o primeiro relato de pseudoparasitismo por Syphacia spp. e Monocystis spp. nesta espécie animal. A presença de diferentes parasitas nas fezes de D. albiventris é de extrema importância, principalmente para a saúde pública, mas também para a compreensão da biodiversidade de parasitas presentes na vida selvagem, que tem sido pouco estudada até agora. Isto permite a implementação de estratégias eficazes para controlar, prevenir e tratar estas doenças.

Ctenocephalides felis (Siphonaptera, Pulicidae) parasitizing White-eared opossum (Didelphis albiventris) at Southern Brazil - Case report.

Didelphis albiventris is a marsupial with synanthropic habits, whose contact with domestic animals and humans is increasing. They are considered potential disseminators of diseases, present as definitive hosts or reservoirs of various pathogenic agents. The present study aim to report, for the first time, the parasitism by Ctenocephalides felis in D. albiventris in Rio Grande, Southern Rio Grande do Sul state, Brazil. An adult female White-eared Opossum (D. albiventris), killed by being run over, was collected on the roads of the city of Rio Grande, Rio Grande do Sul, Brazil and sent to the laboratory for necropsy. During external inspection, a flea was found, which was stored in 70o alcohol until taxonomic identification, being classified as C. felis. This study reports the occurrence of parasitism by C. felis in D. albiventris for the first time in the location studied, demonstrating that these arthropods circulate between the wild and urban environments, and play an important role in the cycle of zoonotic pathogens among wild fauna, companion animals and humans.

Didelphis albiventris é um marsupial de hábitos sinantrópicos, cujo contato com animais domésticos e humanos está aumentando. São considerados potenciais disseminadores de doenças, apresentando-se como hospedeiros definitivos ou reservatórios de vários agentes patogênicos. O presente estudo tem como objetivo relatar, pela primeira vez, o parasitismo por Ctenocephalides felis em D. albiventris em Rio Grande, Sul do Rio Grande do Sul, Brasil. Uma fêmea adulta de gambá-de-orelha-branca (D. albiventris), morta por atropelamento, foi recolhida nas estradas da cidade de Rio Grande, Rio Grande do Sul, Brasil e encaminhado ao laboratório para necropsia. Durante inspeção externa foi encontrada uma pulga que foi armazenada em álcool 70º até a identificação taxonômica sendo classificado como C. felis. Este estudo relata a ocorrência de parasitismo por C. felis em D. albiventris para o primeira vez no local estudado, demonstrando que esses artrópodes circulam entre a natureza e ambientes urbanos e desempenham um papel importante no ciclo de patógenos zoonóticos entre a fauna selvagem, animais de companhia e humanos.

Gastrointestinal Parasites in Sheep from the Brazilian Pampa Biome: Prevalence and Associated Factors.

Parasitic infections are common in sheep farming worldwide. A cross-sectional study was carried out to determine the prevalence and associated risk factors among gastrointestinal parasites and sheep herds from the Brazilian Pampa biome, Rio Grande do Sul state, Brazil. Twenty-one farms were visited, where rectal faecal samples were individually collected from 309 animals. The sheep industry on the studied farms was characterised by small farms with a low level of technification, an extensive grazing system and meat production. Of all samples analysed, strongyle nematodes had the highest prevalence (77.02%), followed by Eimeria spp. (70.55%), Moniezia expansa (20.39%) and Strongyloides papillosus (17.48%). Mixed infection, between helminths and protozoans, was detected in 68.61% of samples. All herds were positive for strongyle and Eimeria spp. A predominance of Haemonchus spp. and Trichostrongylus spp. nematodes was observed in the herds. Younger animals were significantly more affected by Eimeria and M. expansa. In the semi-intensive and intensive systems, a higher frequency of Eimeria and strongyle infections was observed. Parasite infection was significantly reduced at low animal densities. The Brazilian Pampa region presents a high prevalence of gastrointestinal parasites among sheep; age, breeding system and stocking density were factors associated with parasite infection.

As infecções parasitárias são comuns na criação de ovinos em todo o mundo. Um estudo transversal foi realizado para determinar a prevalência e fatores de risco associados entre parasitoses gastrintestinais e rebanhos ovinos do bioma Pampa brasileiro, estado do Rio Grande do Sul, Brasil. Vinte e uma fazendas foram visitadas, onde foram coletadas amostras de fezes individuais da ampola retal de 309 animais. A produção ovina era caracterizada por pequenas propriedades com baixo nível de tecnificação, os animais eram criados em sistema extensivo e para produção de carne. De todas as amostras analisadas, os estrongilídeos (Nematoda: Strongylida) foram mais prevalentes (77,02%), seguido por Eimeria spp. (70,55%), Moniezia expansa (20,39%) e Strongyloides papillosus (17,48%). Infecção mista, entre helmintos e protozoários, foi detectada em 68,61% das amostras. Todos os rebanhos foram positivos para estrongilídeos e Eimeria spp. Foi observada predominância dos nematódeos Haemonchus spp. e Trichostrongylus nos rebanhos. Animais mais jovens foram significativamente mais afetados por Eimeria e M. expansa. Nos sistemas semi-intensivo e intensivo, observou-se maior frequência de infecções por Eimeria e estrongilídeos. A infecção parasitária foi significativamente menor em fazendas com baixa densidade animal. A região do Pampa brasileiro apresenta alta prevalência de parasitos gastrintestinais em ovinos; idade, sistema reprodutivo e densidade animal foram fatores associados à infecção parasitária.

Cryptosporidium spp. in Columba livia Gmelin, 1789 (Columbiformes: Columbidae) free-living pigeons from urban areas in Pelotas, Rio Grande do Sul, Brazil.

Cryptosporidium spp. are parasites with zoonotic potential that cause intestinal diseases, generally intense diarrheal, on their hosts, which tend to be immunocompromised. Large populations of pigeons in urban environments can lead to greater human exposure to Cryptosporidium spp., as this bird is considered a potential reservoir and is able to transmit several pathogens. This study aimed in determining the occurrence of Cryptosporidium spp. oocysts in feces of free-living pigeons (Columba livia) found in urban areas in the city of Pelotas, Rio Grande do Sul, south of Brazil. Fecal samples (n = 50) were collected from young and adult pigeons captured in different locations in the urban area and the parasitological diagnosis was performed through Ritchie's modified technique and Kinyoun's technique. Among the 50 samples, 18% (IC95% 9.7-30.8) were positive for Cryptosporidium spp. with a low number of oocysts being detected on fecal smears. Our results confirmed the occurrence of Cryptosporidium spp. oocysts in feces of free-living pigeons from the urban area of the city of Pelotas. This is the first report of Cryptosporidium spp. oocysts in feces of pigeons in south Brazil. This data has epidemiological significance because the oocysts could be from zoonotic species, which consequently shows that humans might be exposed to infection.

Production of low molecular weight chitosan by acid and oxidative pathways: Effect on physicochemical properties.

Chitosan-based biomaterials with a low molecular weight (LMW) have been drawn attention due to the promising applications in the pharmaceutical and food fields. For this reason, the aim of this work was to study the effect of two distinct depolymerization pathways on the chitosan physicochemical properties. Chitosan was submitted to depolymerization reaction to obtain chitosan with low molecular weight (LMW), using the oxidative pathway (H2O2) and the acid pathway (HCl). The molecular weight reduction was investigated by kinetic study and chain scission mechanism. Chitosan characterization was performed according to its viscosimetric average molecular weight and deacetylation degree, respectively, through the viscosimetric method and proton nuclear magnetic resonance spectroscopy (1H NMR). The structural integrity was evaluated by Fourier transform infrared (FTIR) and energy dispersive spectroscopy (EDS). The crystalline and thermal properties were investigated, respectively, by X-ray diffraction (XRD) spectroscopy and thermogravimetric (TGA)/ differential thermal (DTA)/ differential scanning calorimetry (DSC) analysis. The water-chitosan interaction study was used to estimate the chitosan solubility. The results pointed out that both pathways resulted in chitosan with low molecular weight (<50 kDa). Moreover, the structural integrity of chitosan polymeric chains was preserved after depolymerization by oxidative pathway, while the acid pathway modified the polymer chain arrangement. Therefore, the chemical pathways resulted in two distinct low molecular weight chitosans, which allows different applications in food science.

Amblyomma aureolatum (Pallas, 1772) (Acari: Ixodidae) parasitizing margay cat (Leopardus wiedii) (Schinz, 1821), in Uruguaiana, Rio Grande do Sul, Brazil / Amblyomma aureolatum (Pallas, 1772) (Acari: Ixodidae) parasitando gato-maracajá (Leopardus wiedii) (Schinz, 1821), em Uruguaiana, Rio Grande do Sul, Brasil

Ticks are parasites of wild animals, affecting diverse and several species. The present study reveals the presence of Amblyomma aureolatum parasitizing the margay cat (Leopardus wiedii) in the city of Uruguaiana. This is the first report of the presence of this tick specie in this city, situated in west (29° 45' 18" S 57° 05' 16" W) of the state of Rio Grande do Sul, Brazil, indicating a wide host diversity.

Carrapatos podem ser parasitos de animais selvagens, afetando diversas espécies. O presente trabalho relata a presença de Amblyomma aureolatum parasitando o gato-maracajá (Leopardus wiedii) na região de Uruguaiana, esse é o primeiro relato da presença desta espécie de ixodídeo nesta cidade (29° 45' 18" S 57° 05' 16" W), situada na região oeste do estado do Rio Grande do Sul, Brasil, indicando que diversos hospedeiros silvestres podem ser acometidos pelo parasito.