Morphological and genetic description of Moniliformis necromysi sp. n. (Archiacanthocephala) from the wild rodent Necromys lasiurus (Cricetidae: Sigmondontinae) in Brazil

A morphological and molecular study of adults and cystacanths of Oncicola luehei Travassos, 1917 (Acanthocephala: Archiacanthocephala), from the Neotropical region of Mexico

Members of the genus Oncicola Travassos, 1916 are generalist parasites able to infect a broad spectrum of carnivorous hosts, such as marsupials, procyonids, felids, and canids, and are distributed globally. Adult specimens were collected from the intestines of three white-nosed coatis (N. narica), whereas cystacanths (larval form) were found in the body cavities of two amphibian species (paratenic hosts) in localities from northern and southeastern Mexico. Morphologically, both stages were identified as O. luehei (Travassos, 1917) on the basis of the following features: trunk cylindrical, narrow anteriorly, enlarging midbody, tapering gradually to narrow posteriorly; proboscis globular with six circular rows of hooks with six hooks each, decreasing in size posteriorly; neck short with sensory papilla; tubular lemnisci long, extending to the posterior region; protonephridia dendritic type; and eight cement glands, compact with a single giant nuclei. Sequences from cytochrome c oxidase subunit 1 from mtDNA were aligned and compared with sequences available in GenBank. Phylogenetic analyses revealed that adults and cystacanths formed a clade with two other isolates identified as Oncicola sp. and O. luehei from Mexico. The intraspecific genetic divergence among the isolates was low, ranging from 0.0% to 3.0%, indicating that the two stages of the life cycle belong to the same species. The haplotype network was inferred with 11 sequences and revealed a lack of shared haplotypes between populations, suggesting a reduced recombination rate and a high pattern of genetic variation among individuals. Finally, these new records of O. luehei increase the distribution range of O. luehei on both coasts of Mexico.

Morphology, genetic characterization and phylogeny of Moniliformis tupaia n. sp. (Acanthocephala: Moniliformidae) from the northern tree shrew Tupaia belangeri chinensis Anderson (Mammalia: Scandentia)

A new species of Moniliformis, M. tupaia n. sp. is described using integrated morphological methods (light and scanning electron microscopy) and molecular techniques (sequencing and analysing the nuclear 18S, ITS, 28S regions and mitochondrial cox1 and cox2 genes), based on specimens collected from the intestine of the northern tree shrew Tupaia belangeri chinensis Anderson (Scandentia: Tupaiidae) in China. Phylogenetic analyses show that M. tupaia n. sp. is a sister to M. moniliformis in the genus Moniliformis, and also challenge the systematic status of Nephridiacanthus major. Moniliformis tupaia n. sp. represents the third Moniliformis species reported from China.

The discovery of Moniliformis saudi (Acanthocephala: Moniliformidae) in the Algerian hedgehog Atelerix algirus in Malta: morphological, molecular, and metal analyses

The acanthocephalan Moniliformis saudi Amin, Heckmann, Mohammed, Evans, 2016 was originally described from the desert hedgehog, Paraechinus aethiopicus (Ehrenberg) in central Saudi Arabia. The distribution of P. aethiopicus extends to North Africa and west to Mauritania. Moniliformis saudi was recently found in the Algerian hedgehog Atelerix algirus (Lereboullet) in Malta. The distribution of A. algirus is restricted to the North African and east Iberian Mediterranean coast and associated islands. Both host species cohabit and share the same feeding grounds in northern Algeria where common infections appear to take place. The morphology of specimens from both acanthocephalan populations was similar, with minor variations mostly related to the relatively larger Maltese specimens especially the trunk and the male reproductive system. Taxonomic features like the cone-shaped anterior trunk, size and formula of proboscis and hooks, the receptacle, size and shape of eggs, anatomy of the apical proboscis sensory pores, and the stellate body wall giant nuclei were, however, practically identical. SEM and microscope images of specimens of the Maltese population emphasize their qualitative characteristics such as the degree of the extreme spiral muscle development and the development of the posterior nucleated pouches of the proboscis receptacle. Proboscis hooks of specimens from both the Maltese and the Saudi populations had similarly high levels (percent weights) of calcium, moderate levels of phosphorus, and minimal levels of sulfur, magnesium and sodium marking the diagnostic value of the Energy Dispersive x-ray analysis in species recognition. Newly generated partial sequences of the 18S ribosomal RNA and cytochrome C oxidase subunit 1 (Cox1) of the mitochondrial gene were generated from M. saudi from Malta. Moniliformis saudi from Malta, when compared with other available sequences of the same species isolates available in the GenBank database, formed a strongly supported clade with other congeners. The comparison of the molecular profiles of specimens from populations in Malta, Spain, and Saudi Arabia shows no or low genetic variation between them. Ultimately, we provide a morphological and molecular description of a new population of M. saudi from a new host species in a new geographical location, vastly exceeding the originally described ones from Saudi Arabia. A Cox 1 haplotype network inferred with 10 sequences revealed the presence of eight haplotypes, one of which was shared between the populations of Malta and Spain of M. saudi.

Molecular Characterization of a New Moniliformis sp. From a Plateau Zokor (Eospalax fontanierii baileyi) in China

In the present study, a new species of the genus Moniliformis species is described taxonomically in the mitochondrial genomic context. The parasite was found in a plateau zokor captured in a high-altitude area of Xiahe County of Gansu Province, China. The mitochondrial (mt) genome length of this new species was 14,066 bp comprising 36 genes and 2 additional non-coding regions (SNR and LNR), without atp8. The molecular phylogeny inferred by the cytochrome c oxidase subunit I gene (cox1) and the18S ribosomal RNA gene (18S rDNA) sequences showed that the parasite as a sister species to other Moniliformis spp. and was named Moniliformis sp. XH-2020. The phylogeny of the concatenated amino acid sequences of the 12 protein-coding genes (PCGs) showed Moniliformis sp. XH-2020 in the same cluster as Macracanthorhynchus hirudinaceus and Oncicola luehei confirming the cox1 and 18S rDNA phylogenetic inference. In addition, the entire mt genome sequenced in this study represents the first in the order Moniliformida, providing molecular material for further study of the phylogeny of the class Archiacanthocephala. Moreover, the species of this class, use arthropods as intermediate hosts and mammals as definitive hosts and are agents of acanthocephaliasis, a zoonosis in humans. Therefore, this study not only expands the host range among potential wild animal hosts for Archiacanthocephalans which is of great ecological and evolutionary significance but also has important significance for the research of zoonotic parasitic diseases.

Composition and structure of the helminth community of rodents in matrix habitat areas of the Atlantic forest of southeastern Brazil

The predominant landscape of the Atlantic Forest of the Brazilian state of Rio de Janeiro is made up of forest fragments surrounded by a matrix of modified habitat, which may influence the occurrence and distribution of host species and their parasites in comparison with the original continuous forest. The present study describes the structure, composition, and diversity of the helminth community found in rodents in two areas of an open matrix of different status of conservation. The abundance, intensity, and prevalence were calculated for each helminth species in rodent species. The influence of biotic and abiotic factors on the abundance and prevalence of the helminth species was also investigated. Community structure was analyzed based on the beta diversity and a bipartite network. Nine helminth species were recovered from Akodon cursor, Necromys lasiurus and Mus musculus, with the greatest helminth species richness being recorded in A. cursor (S = 8), followed by N. lasiurus (S = 6), and M. musculus (S = 3). Only three of the helminths recorded in A. cursor had been recorded previously in this rodent in the Atlantic Forest, where 12 different helminths have been recorded, so that the other five are new occurrences for this rodent. All the helminth species of N. lasiurus had been reported previously in this rodent in the Cerrado and Caatinga regions. Mus musculus was infected with the same helminths as the local fauna. Host species and locality were the most important factors influencing helminth abundance and prevalence. Beta-diversity was high for infracommunities indicating more substitutions of helminth species than losses among individuals. Three helminths species were shared by the three host species. The reduced beta-diversity observed in the component communities was consistent with the overlap observed in the helminth fauna of the host species.

Description of a new species of Moniliformis (Acanthocephala: Moniliformidae) from Peromyscus hylocetes (Rodentia: Cricetidae) in Mexico

Moniliformis ibunami n. sp., is described from the intestine of the transvolcanic deermouse Peromyscus hylocetes Merriam 1898 (Cricetidae) from Parque Nacional Nevado de Colima "El Floripondio", Jalisco, Mexico. The new species can be distinguished morphologically from the other 18 congeneric species of Moniliformis by a combination of morphological and molecular characters including the number of hooks on the proboscis (12 longitudinal rows, each one with six to eight transversally arranged unrooted hooks), the proboscis length (230-270 μm), the female trunk length (159-186 mm) and egg size (40-70 × 20-40). For molecular distinction, nearly complete sequences of the small subunit (SSU) and large subunit (LSU) of the nuclear ribosomal DNA and cytochrome oxidase subunit 1 (cox 1) of the mitochondrial DNA of the new species were obtained and compared with available sequences downloaded from GenBank. Phylogenetic analyses inferred with the three molecular markers consistently showed that Moniliformis ibunami n. sp. is sister to other congeneric species of Moniliformis. The genetic distance with cox 1 gene among Moniliformis ibunami n. sp., M. saudi, M. cryptosaudi, M. kalahariensis, M. necromysi and M. moniliformis ranged from 20 to 27%. Morphological evidence and high genetic distance, plus the phylogenetic analyses, indicate that acanthocephalans collected from the intestines of transvolcanic deer mice represent a new species which constitutes the seventh species of the genus Moniliformis in the Americas.