Phylogeny of the anaerobic ciliate genus Sonderia (Protista: Ciliophora: Plagiopylea), including the description of three novel species and a brief revision of the genus

Molecular characterization and zoonotic potential of Entamoeba spp., Enterocytozoon bieneusi and Blastocystis from captive wild animals in northwest China

BACKGROUND

Parasites Entamoeba spp., Enterocytozoon bieneusi and Blastocystis are prevalent pathogens causing gastrointestinal illnesses in animals and humans. Consequently, researches on their occurrence, distribution and hosts are crucial for the well-being of both animals and humans. Due to the confined spaces and frequent interaction between animals and humans, animal sanctuaries have emerged as potential reservoirs for these parasites. In this study, the wildlife sanctuary near the Huang Gorge of the Qinling Mountains in northwest China is chosen as an ideal site for parasite distribution research, considering its expansive stocking area and high biodiversity.

RESULTS

We collected 191 fecal specimens from 37 distinct wildlife species and extracted genomic DNA. We identified these three parasites by amplifying specific gene regions and analyzed their characteristics and evolutionary relationships. All the parasites exhibited a high overall infection rate, reaching 90.05%. Among them, seven Entamoeba species were identified, accounting for a prevalence of 54.97%, with the highest infection observed in Entamoeba bovis. In total, 11 Enterocytozoon bieneusi genotypes were discovered, representing a prevalence of 35.08%, including three genotypes of human-pathogenic Group 1 and two novel genotypes (SXWZ and SXLG). Additionally, 13 Blastocystis subtypes were detected, showing a prevalence of 74.87% and encompassing eight zoonotic subtypes. All of the above suggests significant possibilities of parasite transmission between animals and humans.

CONCLUSIONS

This study investigated the occurrence and prevalence of three intestinal parasites, enhancing our understanding of their genetic diversity and host ranges in northwest China. Furthermore, the distribution of these parasites implies significant potential of zoonotic transmission, underscoring the imperative for ongoing surveillance and implementation of control measures. These efforts are essential to mitigate the risk of zoonotic disease outbreaks originating from wildlife sanctuary.

Morphology and molecular phylogeny of three Parasonderia species including a new species (Ciliophora, Plagiopylea)

Ciliates of the class Plagiopylea play a vital role in various anaerobic environments as consumers of prokaryotes. Yet, the diversity and phylogeny of this group of ciliates, especially marine representatives, remain poorly known. In this study, three Parasonderia species, viz., Parasonderia elongata spec. nov., and the already known P. cyclostoma and P. vestita, discovered in anaerobic sediments from various intertidal zones in China, were investigated based on their living morphology, infraciliature, and small subunit ribosomal rRNA gene sequences. Parasonderia elongata can be recognized by its larger body size, elongated body shape, oval oral opening, number of oral kineties, and significantly shortened leftmost postbuccal polykineties on the cell surface. Improved diagnosis and redescription of P. cyclostoma is provided for the first time, including data on infraciliature and molecular sequence. Phylogenetic analyses revealed that the three species cluster together and with the sequence of a Chinese population of P. vestita already present in the GenBank database, forming a robust clade.

Morphogenesis of an anaerobic ciliate Heterometopus palaeformis (Kahl, 1927) Foissner, 2016 (Ciliophora, Armophorea) with notes on its morphological and molecular characterization

The morphology, morphogenesis, and molecular phylogeny of Heterometopus palaeformis (Kahl, 1927) Foissner, 2016 were studied using microscopical observations on live and protargol-stained specimens as well SSU rRNA gene sequencing. The morphogenetic data for the genus are presented for the first time. Compared to other metopids, the morphogenesis of H. palaeformis is distinct since its (1) perizonal stripe rows 4 and 5 are involved in the formation of the opisthe's adoral polykinetids; (2) perizonal stripe rows 3-5 and two adjacent preoral dome kineties contribute to most of the opisthe's paroral membrane while perizonal stripe rows 1 and 2 contribute very little; (3) four kinety rows are formed to the left of the opisthe's adoral zone of polykinetids. The Chinese population resembles the original and neotype populations well in terms of general morphology - characterized by a life size of 55-120 × 10-20 μm, an elongate ellipsoidal body with a hardly spiralized flat preoral dome, about 18 somatic kineties and 20 adoral polykinetids. The SSU rDNA sequence of the present population exhibits a disparity of 1.33%-2.22% divergence from sequences of other populations. Nevertheless, phylogenetic analysis reveals that populations of H. palaeformis form a separate, stable cluster within the paraphyletic Metopidae clade.

Integrative data of a novel ciliate (Alveolata, Ciliophora) propose the establishment of Heterodeviata nantongensis nov. sp

BACKGROUND

As unicellular eukaryotes, ciliates are an indispensable component of micro-ecosystems that play the role of intermediate nutrition link between bacteria or algae and meiofauna. Recent faunistic studies have revealed many new taxa of hypotrich ciliates, indicating their diversity is greater than previously thought. Here we document an undescribed form isolated from an artificial brackish water pond in East China. Examination of its morphology, ontogenesis and molecular phylogeny suggests that it represents a new species.

RESULTS

The morphology and morphogenesis of the new brackish-water deviatid ciliate, Heterodeviata nantongensis nov. sp., isolated from Nantong, China, were investigated using live observations and protargol staining. The diagnostic traits of the new species include three frontal cirri, one buccal cirrus, one or two parabuccal cirri, an inconspicuous frontoventral cirral row of four to six frontoventral cirri derived from two anlagen, three left and two right marginal rows, two dorsal kineties, dorsal kinety 1 with 9-14 dikinetids and dorsal kinety 2 with only two dikinetids, and one to three caudal cirri at the rear end of dorsal kinety 1. Its main morphogenetic features are: (i) the old oral apparatus is completely inherited by the proter except undulating membranes, which are reorganized in situ; (ii) anlagen for marginal rows and the left dorsal kinety develop intrakinetally in both proter and opisthe; (iii) dorsal kinety 2 is generated dorsomarginally; (iv) five cirral anlagen are formed in both proter and opisthe; (v) in the proter, anlagen I and II very likely originate from the parental undulating membranes and the buccal cirrus, respectively, anlage III from anterior parabuccal cirrus, anlage IV originates from the parental frontoventral cirri and anlage V from the innermost parental right marginal row; and (vi) anlagen I-IV of the opisthe are all generated from oral primordium, anlage V from the innermost parental right marginal row. Phylogenetic analyses based on SSU rRNA gene sequence data were performed to determine the systematic position of the new taxon.

CONCLUSIONS

The study on the morphology, and ontogenesis of a new brackish-water taxon increases the overall knowledge about the biodiversity of this ciliate group. It also adds to the genetic data available and further provides a reliable reference for environmental monitoring and resource investigations.

First redescription and molecular phylogeny of Trimyema claviforme Kahl, 1933 with the description of a Chinese population of Plagiopyla nasuta Stein, 1860 (Ciliophora, Plagiopylea)

Ciliates belonging to the class Plagiopylea are obligate anaerobes that are often neglected due to their cryptic lifestyles, difficulty of observation, and overall under-sampling. Here, we investigate two species, namely Trimyema claviforme Kahl, 1933 and Plagiopyla nasuta Stein, 1860, collected in China from marine and freshwater anaerobic sediments, respectively. A complete morphological dataset, together with SSU rRNA gene sequence data were obtained and used to diagnose the species. No molecular sequencing had ever been performed on Trimyema claviforme, with its ciliature also previously unknown. Based on these novel data presented here, the ciliate is characterized by a claviform cell shape, with a size of 35-45 × 10-20 μm in vivo, 28-39 longitudinal somatic ciliary rows forming five ciliary girdles (four complete girdles and a shorter one), two dikinetids left to anterior end of oral kinety 1, and an epaulet. A Chinese population of the well-known ciliate P. nasuta was investigated, and morphological comparisons revealed phenotypic stability of the species. The phylogenetic analyses supported previous findings about the monophyly of the families Trimyemidae and Plagiopylidae, with Trimyema claviforme branching off early in the genus Trimyema. The Chinese population of P. nasuta clusters together with two other populations with full support corroborating their conspecificity.

Morphological and molecular examination of the ciliate family Lagynusidae (Protista, Ciliophora, Prostomatea) with descriptions of two new genera and two new species from China

Ciliates in the class Prostomatea play an important role in the global microbial loop due to their significant abundances and broad feeding strategies at the foundation of food webs. Despite their importance in ecosystems, the taxonomy and systematics of this group of ciliates has long been poorly understood, with this being especially true for members of the family Lagynusidae. Here we examine four lagynusids collected from sandy beaches in China, using silver-staining and 18S rRNA gene sequencing techniques. These investigations revealed two new genera and two new species and provided details for two little known forms: Penardella marina gen. nov., sp. nov., Apolagynus cucumis (as reported by Penard. Études sur les infusoires d'eau douce. Georg and Cie, Genève, 1922) gen. nov., comb. nov., Lagynus minutus sp. nov., and Lagynus elegans (Engelmann in Z Wiss Zool 11:347-393, 1862) Quennerstedt (Acta Univ Lund 4:1-48, 1867). Penardella gen. nov. can be morphologically distinguished by having more than three dikinetidal perioral kineties. Apolagynus gen. nov. differs from the closely related genus Lagynus in the absence of a conspicuous neck-like region. The ciliature of Apolagynus cucumis is revealed here for the first time, which demonstrates the classification of this species within Lagynusidae. Furthermore, Apolagynus binucleatus (Jiang et al., 2021) comb. nov. is established according to the new finding. The results of our phylogenetic analyses based on the 18S rRNA gene support the establishment of two new genera and indicate that Lagynusidae is monophyletic, which further strengthens its valid taxonomic status.