Parasitism in Rattus rattus and sympatric Achatina fulica by Angiostrongylus cantonensis in an urban park in southeast Brazil.

In this study, rodents (Rattus rattus) and mollusks (Achatina fulica) were captured in a small forest located in a large metropolitan city in Brazil, and they were examined to investigate possible parasitism by Angiostrongylus cantonensis. The parasites were recovered as helminths from the pulmonary arteries of the synanthropic rodents and as third-stage larvae (with Metastrongylidae family characteristics) from the mollusks. To confirm the species, these larvae were used to experimentally infect Rattus norvegicus for the posterior recovery of adult helminths. To identify the adult helminths, morphological, morphometric, molecular, and phylogenetic techniques were employed. Furthermore, we also characterized the histological lesions associated with parasitism in naturally infected definitive hosts. Our results demonstrated the occurrence of a natural life cycle of A. cantonensis (with the presence of adult helminths) in definitive hosts, Rattus rattus, and third-stage larvae in an intermediate host, A. fulica. In free-living rodents, lesions of granulomatous pneumonia in the lungs and meningitis in the brain were also found. These results warn of the risk of accidental transmission of A. cantonensis to human residents around the park because of the extensive interaction among the fauna of the park, domestic animals, and the surrounding human population.

Stem rust on barberry species in Europe: Host specificities and genetic diversity.

The increased emergence of cereal stem rust in southern and western Europe, caused by the pathogen Puccinia graminis, and the prevalence of alternate (sexual) host, Berberis species, have regained attention as the sexual host may serve as source of novel pathogen variability that may pose a threat to cereal supply. The main objective of the present study was to investigate the functional role of Berberis species in the current epidemiological situation of cereal stem rust in Europe. Surveys in 11 European countries were carried out from 2018 to 2020, where aecial infections from five barberry species were collected. Phylogenetic analysis of 121 single aecial clusters of diverse origin using the elongation factor 1-α gene indicated the presence of different special forms (aka formae speciales) of P. graminis adapted to different cereal and grass species. Inoculation studies using aecial clusters from Spain, United Kingdom, and Switzerland resulted in 533 stem rust isolates sampled from wheat, barley, rye, and oat, which confirmed the presence of multiple special forms of P. graminis. Microsatellite marker analysis of a subset of 192 sexually-derived isolates recovered on wheat, barley and rye from the three populations confirmed the generation of novel genetic diversity revealed by the detection of 135 multilocus genotypes. Discriminant analysis of principal components resulted in four genetic clusters, which grouped at both local and country level. Here, we demonstrated that a variety of Berberis species may serve as functional alternate hosts for cereal stem rust fungi and highlights the increased risks that the sexual cycle may pose to cereal production in Europe, which calls for new initiatives within rust surveillance, epidemiological research and resistance breeding.

Nodular and sclerosing gastritis caused by Cylicospirura felineus in a puma (Puma concolor).

An adult male puma (Puma concolor), hit by a car in an urban area, died three days later despite the therapeutic support provided. At necropsy, multiple firm nodules were identified in the gastric mucosa. The nodules were coated by an intact mucosa with a central opening from which reddish and cylindrical nematodes protruded into the lumen. Twenty-seven nematodes were retrieved for morphological and morphometric evaluations. During histopathological examination of the gastric tissue, the adult nematodes appear in longitudinal and transverse sections, surrounded by thick bands of collagen, interspersed with mixed inflammatory infiltrates. The nematodes had an eosinophilic cuticle with caudal serrated projections (bulbar type), coelomyarian musculature, pseudocoelom, and females with uterus containing numerous larvated eggs, characteristics consistent with the Cylicospirura genus. Morphologically, female nematodes had six large tricuspid teeth in the oral cavity and the vulva had an opening anterior to the esophagus-intestinal junction. Male nematodes had five pairs of small papillae near the tip of the tail. These findings were consistent with Cylicospirura felineus. This parasite should be included in the differential diagnosis of nodular gastric wall lesions in wild felids.