Integrative taxonomy of Metastrongylus spp. in wild boars from Brazil

Abstract

Background Wild boars (Sus scrofa) may cause substantial damage to crops and can spread zoonotic parasites to domestic animals, posing a risk to health and animal production. Metastrongylus spp. can negatively affect the wild boar population, increasing piglet mortality. In addition to that, studies with Metastrongylus genetic characterization are still scarce in Brazil. The present study aims to characterize Metastrongylus spp. from wild boars hunted in the states of São Paulo, Paraná, and Rio Grande do Sul, Brazil, using traditional morphological description and DNA sequences in an integrative taxonomic approach. Methods After nematode collection from 58 wild boars, the parasites were morphologically identified and genetically characterized by the amplification of 18S ribosomal DNA (rDNA), 28S rDNA, internal transcribed spacer (ITS) region, and cox-1 mitochondrial DNA (mtDNA). Descriptors of infection were determined and Pearson's Chi-square test was applied to compare the prevalence of infections among the identified parasite species, host age group (juveniles and adults), and sex. The Mann–Whitney U test was performed to compare the mean intensity between the age groups and sex. Results Metastrongylus salmi, Metastrongylus apri, and Metastrongylus pudendotectus were identified in 77.6% (45/58) of the necropsied wild boars. Metastrongylus salmi was the most prevalent and abundant species (70.7%, 11.1), followed by M. pudendotectus (18.9%, 4.3) and M. apri (17.2%, 2.2). Metastrongylus pudendotectus showed the highest mean intensity and range (25.2, 1–93), followed by M. salmi (15.7, 1–58) and M. apri (12.6, 3–27). We found a significantly higher prevalence of Metastrongylus spp. and M. salmi in adult wild boars, probably associated with a more prolonged time of exposure to intermediate host species. The phylogenetic analysis revealed that ITS2 region and cox-1 mtDNA are the most suitable genetic markers for Metastrongylus species characterization. Genetic variability between M. apri and M. salmi isolates was verified. Conclusions We expand the knowledge about the Metastrongylus community in the non-captive wild boar population from Brazil as well as the importance of this exotic species in the maintenance of Metastrongylus spp. in its areas of occurrence. The novel genetic sequences obtained may help further studies to understand the genetic diversity in other nematode populations from Brazil and other countries. Graphical Abstract

Subclinical Ovine Gammaherpesvirus 2-Related Infections in Free-Ranging Wild Boars (Sus scrofa) from Southern Brazil

“…The cross-section of the nematodes observed within the pulmonary bronchi of three wild boars are characteristic of infestation by the lungworm Metastrongylus spp. [ 53 , 54 ]; similar findings were described in wild boars from Brazil [ 68 ] and several European countries [ 69 , 70 ]. Infestations by Metastrongylus spp.…”

Toxoplasma gondii and Neospora caninum in invasive wild boars (Sus scrofa) and hunting dogs from Brazil

“…The samples from hunting dogs were collected in eight municipalities from Two Brazilian states: Paraíso, Colina, Araraquara, Bonfim Paulista, Birigui, Braúna and Clementina (São Paulo), and Ipiranga (Paraná). Details on the vegetation, climate, and major economic activities of the study areas were described by Oliveira et al (2023) . The number of wild boar and dog samples collected by location can be found in Fig.…”

“…Information about estimated weight, sex, pregnancy status, date of sampling, and place of capture was registered. Regarding the age group, the animals were categorized as juveniles (less than 6 months old), or adults (more than 6 months old) ( Oliveira et al, 2023 ). The sampling strategy carried out without biostatistical criteria due to the lack of data on the wild boar population, depended on the hunting success of our partner hunters, resulting in a convenience sampling approach.…”