Molecular detection ofMetastrongylus salmieggs from pigs in low-resource communities in the state of Piauí, northeastern Brazil

Abstract

Metastrongylosis is an infection of the respiratory tract of pigs caused by parasites of the genus Metastrongylus, whose eggs are similar to other Strongylida through light microscopy; species-specific identification can be performed with molecular tools. We explored the species composition and the genetic diversity of Metastrongylus infecting pigs in close contact with humans in impoverished rural communities in the state of Piauí, in northeastern Brazil. Fecal samples ( n = 78) were collected for parasitologic tests. Egg morphometry and molecular characterization, using the cytochrome c oxidase subunit 1 ( cox1) gene, were performed. For strongyliform eggs, 62 of 78 (80%) pigs were positive and 6 of 99 (6%) eggs had dimensions compatible with Metastrongylus. Of the 37 samples submitted to PCR, 10 were identified as M. salmi. We found 3 M. salmi haplotypes, including 2 new and 1 described previously in Europe. Overall, M. salmi demonstrated lower intraspecific genetic diversity: diversity index (H) ± SD = 0.318 ± 0.164, n = 12, compared with published M. pudendotectus sequences (1.000 ± 0.272, n = 3). To our knowledge, M. salmi DNA sequences have not been published previously from pigs in South America.

Integrative taxonomy of Metastrongylus spp. in wild boars from Brazil

“…Mitochondrial genes such as cox-1 have a faster evolutionary rate and, for this reason, should be suitable for discriminating closely related species when compared with nuclear ribosomal genes [ 56 ]. The partial gene cox-1 was able to properly distinguish M. salmi eggs recovered from pigs of Piaui state, northeastern Brazil [ 8 ].…”

“…All species are described in wild and domestic suids except M. madagascariensis , which is only found in domestic pigs from Madagascar [ 7 ]. In Brazil, M. salmi , M. pudendotectus , and M. apri are reported [ 8 ].…”

“…genetic sequences available in databases such as GenBank are still limited, compromising studies that aim to describe the genetic variability or make phylogenetic inferences. Studies focusing on helminth genetic variability are scarce worldwide and almost nonexistent in Brazil [ 8 ]. Thus, the present study aims to characterize Metastrongylus spp.…”

Morphologic Characterization of Strongylida Larvae from Human and Swine Coprocultures in Rural Communities in the State of Piauí, Northeastern Brazil

“…Necator suillus is a hookworm species described in pigs for almost a century [14], and investigations into its validity, occurrence, epidemiology, and zoonotic potential have not been forwarded. e present work is part of a broader project, in which we assessed, through molecular tools (mitochondrial DNA sequencing), the zoonotic circulation of Strongylida and Ascaris in the human-swine interface in low-resource rural communities in the state of Piauí [15][16][17][18]. In this report, we present the results of the morphological study of Strongylida larvae obtained through cultivation of human and swine feces.…”

“…The present work is part of a broader project, in which we assessed, through molecular tools (mitochondrial DNA sequencing), the zoonotic circulation of Strongylida and Ascaris in the human-swine interface in low-resource rural communities in the state of Piauí [ 15 – 18 ]. In this report, we present the results of the morphological study of Strongylida larvae obtained through cultivation of human and swine feces.…”