Molecular-phylogenetic investigation of trichomonads in dogs and cats reveals a novel Tritrichomonas species.

BACKGROUND: Trichomonosis is a common infection in small animals, mostly manifesting in gastrointestinal symptoms such as diarrhea. Although oral trichomonads are also known, the species found colonizing the large intestine are more frequently detected protozoa. METHODS: In the present study, four wildcats, 94 domestic cats, and 25 dogs, originating from 18 different locations in Hungary, were investigated for the presence of oral and large intestinal trichomonads based on the 18S rRNA gene and ITS2. RESULTS: All oral swabs were negative by polymerase chain reaction (PCR). However, Tritrichomonas foetus was detected in a high proportion among tested domestic cats (13.8%) and dogs (16%), and Pentatrichomonas hominis only in two domestic cats. In addition, a novel Tritrichomonas genotype was identified in one cat, probably representing a new species that was shown to be phylogenetically most closely related to Tritrichomonas casperi described recently from mice. All positive dogs and half of the positive cats showed symptoms, and among cats, the most frequent breed was the Ragdoll. CONCLUSIONS: With molecular methods, this study evaluated the prevalence of oral and intestinal trichomonads in clinical samples of dogs and cats from Hungary, providing the first evidence of T. foetus in dogs of this region. In contrast to literature data, P. hominis was more prevalent in cats than in dogs. Finally, a hitherto unknown large intestinal Tritrichomonas species (closely related to T. casperi) was shown to be present in a cat, raising two possibilities. First, this novel genotype might have been a rodent-associated pseudoparasite in the relevant cat. Otherwise, the cat was actually infected, thus suggesting the role of a predator-prey link in the evolution of this trichomonad.

Bit by bit toward the diversity of metopids: Description of the genus Pidimetopus n. gen. (Ciliophora: Armophorea).

While metopids (Armophorea: Metopida) represent the most species-rich group of free-living anaerobic ciliates thriving in hypoxic environments, our understanding of their true diversity remains incomplete. Most metopid species are still characterized only morphologically. Particularly, the so-called IAC clade (named in the past after some of the taxa included, Idiometopus, Atopospira, and Clevelandellida), comprising free-living members as well as the endosymbiotic ones (order Clevelandellida), is in serious need of revision. In our study, we establish a new free-living genus in the IAC clade, Pidimetopus n. gen., with descriptions of two new species, P. nanus n. sp., and P. permonicus n. sp., using up-to-date molecular and morphologic methods. The genus is characterized by small cells (up to 75 µm long), not more than 10 adoral membranelles and eight somatic kineties, and usually, four long caudal cilia that can stiffen. In addition to morphologic and molecular characterizations, we also conducted a statistical morphotype analysis of the polymorphic species P. nanus n. sp. We discuss the relevance of the earlier morphologically described species Metopus minor as a putative collective taxon for several small metopids less than 50 µm long.

Reductitherus cryptostomus n. gen., n. sp. (Ciliophora: Armophorea: Clevelandellida), a remarkable new nyctotherid from an Australian cockroach, Parapanesthia gigantea (Blaberidae: Panesthiinae).

Ciliates of the family Nyctotheridae (Armophorea: Clevelandellida) are frequent intestinal symbionts of various invertebrates and some poikilotherm vertebrates. Depending on the classification scheme, there are between 15 and 18 recognized genera of Nyctotheridae, the majority of which exhibit a rather uniform morphology. They have round to ellipsoidal cells with an adoral zone of membranelles that begins anteriorly in an adoral groove and continues posteriorly into the buccal cavity where it extends deep into the cell in the peristomial funnel. The taxonomy of the Nyctotheridae is primarily based on the number and location of kinetal sutures. The only known divergence from the relatively conservative nyctortherid body plan are the bizarre symbionts of Panesthiinae cockroaches, ciliates of the family Clevelandellidae, which forms a clade nested within the Nyctotheridae genus Nyctotherus. In this study we report another ciliate that diverges morphologically from the canonical Nyctotheridae body plan, and which is also found in Panesthiinae hosts. The novel ciliate Reductitherus cryptostomus n. gen., n. sp. differs from the rest of Nyctotheridae by absence of the anterior adoral groove, a shortened adoral zone completely enclosed in a notably small buccal cavity, and two strongly reduced kinetal sutures, one left anterodorsal and the other right posterodorsal.

Metabarcoding of pathogenic parasites based on copro-DNA analysis of wild animals in South Korea.

Four species of dominant wild animals, namely, Prionailurus bengalensis euptilurus, Nyctereutes procyonoides koreensis, Hydropotes inermis argyropus, and Sus scrofa coreanus, are hosts of potential infectious agents, including helminths and protozoa. Therefore, it is necessary to analyze the infectious agents present in these wild animals to monitor and control the spread of pathogens. In the present study, fecal samples from 51 wild animals were collected from the mountains of Yangpyeong, Hoengseong, and Cheongyang in South Korea and metabarcoding of the V9 region of the 18S rRNA gene was performed to identify various parasite species that infect these wild animals. Genes from nematodes, such as Metastrongylus sp., Strongyloides spp., Ancylostoma sp., and Toxocara sp., were detected in the fecal samples from wild animals. In addition, platyhelminthes, including Spirometra sp., Echinostomatidae gen. sp., Alaria sp., Neodiplostomum sp., and Clonorchis sp., and protozoa, including Entamoeba sp., Blastocystis sp., Isospora sp., Tritrichomonas sp., Pentatrichomonas sp., and Cryptosporidium sp., were detected. In the present study, various parasites infecting wild animals were successfully identified using metabarcoding. Our technique may play a crucial role in monitoring parasites within wild animals, especially those causing zoonoses.

The effect of the 13C abundance of soil microbial DNA on identifying labelled fractions after ultracentrifugation.

DNA-based stable isotope probing (DNA-SIP) technology has been widely employed to trace microbes assimilating target substrates. However, the fractions with labelled universal genes are sometimes difficult to distinguish when detected by quantitative real-time PCR. In this experiment, three paddy soils (AQ, CZ, and NB) were amended with 0.1% glucose containing 13C at six levels, and DNA was then extracted after a 7-day incubation and subjected to isopycnic gradient centrifugation. The results showed that the amount of labelled DNA was notably related to the 13C-glucose percentage, while the separation spans of 18S rRNA and 16S rRNA genes between labelled and unlabelled treatments became notably clearer when the δ13C values of the total DNA were 90.9, 61.6, and 38.9‰ and 256.2, 104.5 and 126.1‰ in the AQ, CZ, and NB soils, respectively. Moreover, fractionated DNA was also labelled by determining the δ13C values while adding only 5 atom% 13C-glucose to the soil. The results suggest that the optimal labelling fractions were not always those fractions with the maximal gene abundance, and detecting the δ13C values of the total and fractionated DNA was beneficial in estimating the results of DNA-SIP. KEY POINTS: • Appropriate 13C-DNA amount was needed for DNA-SIP. • Detecting the 13C ratio of fractionated DNA directly was an assistant method for identifying the labelled fractions. • Fractions with the maximal 18S or 16S rRNA gene abundance always were not labelled.

Assessing the potential of nematode metabarcoding for benthic monitoring of offshore oil platforms.

Environmental DNA metabarcoding is gaining momentum as a time and cost-effective tool for biomonitoring and environmental impact assessment. Yet, its use as a replacement for the conventional marine benthic monitoring based on morphological analysis of macrofauna is still challenging. Here we propose to study the meiofauna, which is much better represented in sediment DNA samples. We focus on nematodes, which are the most numerous and diverse group of meiofauna. Our aim is to assess the potential of nematode metabarcoding to monitor impacts associated with offshore oil platform activities. To achieve this goal, we used nematode-optimized marker (18S V1V2-Nema) and universal eukaryotic marker (18S V9) region to analyse 252 sediment DNA samples collected near three offshore oil platforms in the North Sea. For both markers, we analysed changes in alpha and beta diversity in relation to distance from the platforms and environmental variables. We also defined three impact classes based on selected environmental variables that are associated with oil extraction activities and used random forest classifiers to compare the predictive performance of both datasets. Our results show that alpha- and beta-diversity of nematodes varies with the increasing distance from the platforms. The variables directly related to platform activity, such as Ba and THC, strongly influence the nematode community. The nematode metabarcoding data provide more robust predictive models than eukaryotic data. Furthermore, the nematode community appears more stable in time and space, as illustrated by the overlap of nematode datasets obtained from the same platform three years apart. A significative negative correlation between distance and Shannon diversity also advocates for higher performance of the V1V2-Nema over the V9. Overall, these results suggest that the sensitivity of nematodes is higher compared to the eukaryotic community. Hence, nematode metabarcoding has the potential to become an effective tool for benthic monitoring in marine environment.

Prevalence and Preferred Niche of Small Eukaryotes with Mixotrophic Potentials in the Global Ocean.

Unicellular eukaryotes that are capable of phago-mixotrophy in the ocean compete for inorganic nutrients and light with autotrophs, and for bacterial prey with heterotrophs. In this study, we ask what the overall prevalence of eukaryotic mixotrophs in the vast open ocean is, and how the availability of inorganic nutrients, light, and prey affects their relative success. We utilized the Tara Oceans eukaryotic 18S rRNA gene and environmental context variables dataset to conduct a large-scale field analysis. We also performed isolate-based culture experiments to verify growth and nutritional resource relationships for representative mixotrophic taxa. The field analysis suggested that the overall prevalence of mixotrophs were negatively correlated with nutrient concentrations and positively associated with light availability. Concentrations of heterotrophic bacteria as a single variable also presented a positive correlation with mixotrophic prevalence, but to a lesser extent. On the other hand, the culture experiments demonstrated a taxa-specific relationship between mixotrophic growth and nutrition resources, i.e., the growth of one group was significantly dependent on light availability, while the other group was less affected by light when they received sufficient prey. Both groups were capable of growing efficiently with low inorganic nutrients when receiving sufficient prey and light. Therefore, our field analysis and culture experiments both suggest that phago-mixotrophy for ocean eukaryotes is seemingly an efficient strategy to compensate for nutrient deficiency but unnecessary to compensate for light scarcity. This study collectively revealed a close relationship between abiotic and biotic nutritional resources and the prevalence of trophic strategies, shedding light on the importance of light and nutrients for determining the competitive success of mixotrophs versus autotrophic and heterotrophic eukaryotes in the ocean.

Redescription and molecular characterization of Loxocephalus luridus Eberhard, 1862 based on Czech populations: Implications for order Loxocephalida Jankowski, 1980.

The phylogenetic and taxonomic affinities of lineages currently assigned to the non-monophyletic ciliate order Loxocephalida Jankowski (1980) within subclass Scuticociliatia Small (1967) remain unresolved. In the current study, we redescribe the morphology of the type species, Loxocephalus luridus Eberhard (1862) based on two Czech populations and include the first scanning and transmission electron microscopy images of the species. We provide the first 18S rRNA gene sequences for L. luridus and consider its phylogenetic position. Our results support the separation of Dexiotricha from Loxocephalus; however, the former genus is recovered as non-monophyletic. The monophyly of genus Dexiotricha and that of Loxocephalus + Dexiotricha is rejected. Loxocephalus luridus, together with Dexiotricha species, nests within a fully supported clade with Conchophthirus species, long presumed to belong to the Pleuronematida. Haptophrya is recovered as sister to this clade. The monophyly of the Astomatia Schewiakoff (1896) including Haptophrya is rejected. No clear morphologic synapomorphy is identified for the fully supported clade consisting of Haptophrya, Dexiotricha, Loxocephalus, and Conchophthirus.

Redescription and molecular phylogeny of the freshwater metopid, Castula strelkowi (Jankowski, 1964) from the Czech Republic and synonymization of Pileometopus with Castula.

The relationships of the mainly free living, obligately anaerobic ciliated protists belonging to order Metopida continue to be clarified and now comprise three families: Metopidae, Tropidoatractidae, and Apometopidae. The most species-rich genus of the Metopidae, Metopus has undergone considerable subdivision into new genera in recent years as more taxa are characterized by modern morphologic and molecular methods. The genus, Castula, was established to accommodate setae-bearing species previously assigned to Metopus: C. setosa and C. fusca, and one new species, C. flexibilis. Another new species, C. specialis, has been added since. Here we redescribe another species previously included in Metopus, using morphologic and molecular methods, and transfer it to Castula as C. strelkowi n. comb. (original combination Metopus strelkowi). We also reassess the monotypic genus, Pileometopus, which nests within the strongly supported Castula clade in 18S rRNA gene trees and conclude that it represents a morphologically divergent species of Castula.

A new centrohelid heliozoan, Pterocystis polycristalepis sp. nov., and taxonomic and phylogenetic concerns within Pterista (Haptista: Centroplasthelida).

A new species of centrohelid heliozoans, Pterocystis polycristalepis sp. nov. (Pterocystidae), was examined using light and electron microscopy. The novel centrohelid is characterized by the presence of leaf-like spine-scales with a broad pedicel-like structure on the proximal part and many subparallel ribs on the lateral wing surface. The plate-scales are ovoid with medial tubular thickening and many subparallel ribs on the very extensive marginal rim. The closely related species Pterocystis striata has also been studied in detail using light and electron microscopy. Phylogenetic analysis of 18S rRNA gene sequences placed both species into a separate clade within Pterista. The closest morphologically characterized species to the new clade is Triangulopteris lacunata. The 18S rRNA sequence of Pseudoraphidiophrys veliformis was grouped within Pterista and found to be closely related to Pterocystis polycristalepis, Pterocystis striata, and Triangulopteris lacunata. Cyst-scales of various shapes, cell and cyst aggregations, syncytia, and a cell with a stalk were revealed in a clonal culture of P. veliformis. Analysis of the morphology and phylogenetic position of the studied species and other centrohelids revealed a large number of taxonomic and phylogenetic problems in Pterista.

Acanthamoeba Sequence Types and Allelic Variations in Isolates from Clinical and Different Environmental Sources in Italy.

The genus Acanthamoeba comprises free-living amoebae distributed in a wide variety of environments. These amoebae are clinically significant, causing opportunistic infections in humans and other animals. Despite this, limited data on Acanthamoeba sequence types and alleles are available in Italy. In the present study, we analyzed all Acanthamoeba sequences deposited from Italy with new positive Acanthamoeba clinical samples from symptomatic AK cases, to provide an overview of the genetic variants' spatial patterns from different sources within the Italian context. A total of 137 Acanthamoeba sequences were obtained. Six sequence types were identified: T2/6, T3, T4, T11, T13, and T15. Only T4 and T15 were found in both sources. The Acanthamoeba T4 sequence type was found to be the most prevalent in all regions, accounting for 73% (100/137) of the Italian samples analyzed. The T4 sequence type demonstrated significant allelic diversity, with 30 distinct alleles from clinical and/or environmental samples. These outcomes enabled a better understanding of the distribution of Acanthamoeba isolates throughout Italy, reaffirming its well-recognized ubiquity. Acanthamoeba isolates analysis from keratitis, together with the environmental strains monitoring, might provide important information on different genotypes spreading. This might be useful to define the transmission pathways of human keratitis across different epidemiological scales.

Redescription and molecular phylogeny of Trochilia sigmoides Dujardin, 1841 (Ciliophora, Cyrtophoria) collected from South Korea.

During a survey of Korean marine ciliates, Trochilia sigmoides, the type species of the genus Trochilia, was collected and examined using in vivo observation and protargol impregnation. Moreover, scanning electron microscopy and 18S rRNA gene sequencing have been applied for the first time to study this species. Morphologically, T. sigmoides is characterized by the small body size, the oval body outline, and the spiral dorsal ridges. The Korean population of T. sigmoides shows only minute differences to other populations reported in the literature, mainly in body size and the number of dorsal ridges. Phylogenetic analyses based on 18S rRNA gene sequences show that T. sigmoides and T. petrani are placed together with two members of the family Kyaroikeidae, causing the family Dysteriidae to be non-monophyletic. The present new data increase the knowledge about the morphology and phylogeny of the genus Trochilia and would assist in understanding the phylogenetic relationship between the free-living Dysteriidae and the parasitic Kyaroikeidae.

How host species and body part determine the microbial communities of five ambrosia beetle species.

The ambrosia beetles are farming insects that feed mainly on their cultivated fungi, which in some occasions are pathogens from forest and fruit trees. We used a culture-independent approach based on 16S and 18S rRNA gene metabarcoding analysis to investigate the diversity and composition of the bacterial and fungal communities associated with five ambrosia beetle species: four species native to America (Monarthrum dimidiatum, Dryocoetoides capucinus, Euwallacea discretus, Corthylus consimilis) and an introduced species (Xylosandrus morigerus). For the bacterial community, the beetle species hosted a broad diversity with 1,579 amplicon sequence variants (ASVs) and 66 genera, while for the fungal community they hosted 288 ASVs and 39 genera. Some microbial groups dominated the community within a host species or a body part (Wolbachia in the head-thorax of E. discretus; Ambrosiella in the head-thorax and abdomen of X. morigerus). The taxonomic composition and structure of the microbial communities appeared to differ between beetle species; this was supported by beta-diversity analysis, which indicated that bacterial and fungal communities were clustered mainly by host species. This study characterizes for the first time the microbial communities associated with unexplored ambrosia beetle species, as well as the factors that affect the composition and taxonomic diversity per se, contributing to the knowledge of the ambrosia beetle system.

Water stratification alters phytoplankton assemblages in scallop farming waters of the North Yellow Sea in China.

As evaluation indicators of the primary productivity, the phytoplankton biomass and community structure are of great significance to the fishery industry, which can be driven by ocean currents, nutrients and water stratification. In the present study, the characteristics of phytoplankton assemblages in different water layers of a typical Yesso scallop farming area in Zhangzi Island, the North Yellow Sea were investigated from March 2021 to January 2022. According to the vertical distribution of temperature, water stratification was observed from June to August (stratification period), and disappeared in March, October and the following January with vertical homogeneity (mixing period). 18S rRNA gene sequencing results revealed that Pyrrophyta was the most dominant phylum during the sampling period, with high gene proportions in the stratification (63.36%) and mixing periods (77.35%). The gene proportion of Bacillariophyta in the stratification period was 5.44%, which was significantly lower than that in the mixing period of 8.93% (p < 0.05). Moreover, Pseudo-nitzschia, a toxin-producing taxon affiliated with Bacillariophyta, exhibited a significantly higher proportion in the stratification period than in the mixing period. During the stratification period, a number of toxin-producing taxa such as Pseudo-nitzschia and Karlodinium were enriched in the bottom layer, which was 1.29-fold and 1.37-fold of that in the surface layer, respectively. Redundancy analysis showed that phosphate and water temperature were major environmental factors driving the vertical distribution of phytoplankton assemblages. The phosphate (0.11 µM) and silicate (2.09 µM) concentrations in the surface layer approached the minimum threshold for phytoplankton growth, and the stoichiometric limitation of phosphate was detected in the surface and middle layers. Collectively, these results indicated that the decreased proportion ratio of Bacillariophyta to Pyrrophyta and unfavorable community composition of Bacillariophyta for scallops were observed during summer, which might result from the phosphate limitation driven by water stratification. The results will further our understanding of the dynamics of phytoplankton communities under the background of intensifying ocean stratification and provide ecological guidance for mollusc mariculture.

Turtle species and ecology drive carapace microbiome diversity in three seasonally interconnected wetland habitats.

Different species of freshwater turtles exhibit primary behaviours ranging from aerial basking to benthic bottom-walking, cycle between wet and dry conditions at different time intervals, and undertake short-distance overland movements between aquatic habitats. These behaviours in turn may impact the accumulation of microbes on external shell surfaces of turtles and provide novel niches for differentiation of microbial communities. We assessed microbial diversity using 16S and 18S rRNA metabarcoding on carapace surfaces of six species of freshwater turtles residing in three adjacent and seasonally interconnected wetland habitats in southeast Oklahoma (United States). Communities were highly diverse, with nearly 4200 prokaryotic and 500 micro-eukaryotic amplicon sequence variants recovered, and included taxa previously reported as common or differentially abundant on turtle shells. The 16S rRNA alpha diversity tended to be highest for two species of benthic turtles, while 18S rRNA alpha diversity was highest for two basking and one shallow-water benthic species. Beta diversity of communities was more strongly differentiated by turtle species than by collection site, and ordination patterns were largely reflective of turtle species' primary habits (i.e. benthic, basking, or benthic-basking). Our data support that freshwater turtles could play a role in microbial ecology and evolution in freshwater habitats and warrant additional exploration including in areas with high native turtle diversity and inter-habitat turtle movements.

Morphological and molecular characterization of a new member of the phylum Rhodelphidia.

Rhodelphidia is a recently discovered phylum within the supergroup Archaeplastida, comprising only two known representatives (Rhodelphis marinus and Rhodelphis limneticus). Despite its close phylogenetic relatedness to red algae, Rhodelphidia differ markedly by being nonphotosynthetic eukaryotrophic flagellates with gene- and intron-rich genomes. Here, we describe a new freshwater Rhodelphidia species, Rhodelphis mylnikovi sp. n., strain Rhod-M. It shows clear morphological differences with the two other Rhodelphis species, including larger cell body size, presence of two contractile vacuoles, short and blunt pseudopodia, absence of cysts, and tendency to cannibalism. 18S rRNA-based phylogenetic analysis placed it sister to the freshwater species R. limneticus.

Effect of two shampoo formulations on the prokaryotic and eukaryotic microbiota composition of the human scalp.

OBJECTIVE: The human scalp is characterized by a moderately diverse microbial community, comprising prokaryotic (bacteria) and eukaryotic (fungi) members. Although the details are far from being fully understood, the human scalp microbiota is implicated in several scalp disorders, in particular dandruff formation. Hence, the protection of an intact and diverse scalp microbiota can be regarded as a quality criterion for hair and scalp care formulations. In this study, we investigated the influence of two commercially available, non-antimicrobial shampoo formulations on the structure of the scalp microbiota. METHODS: Scalp microbiota samples, obtained by swab sampling from two cohorts of probands (n = 25, each), were analysed before and after daily use of two different shampoo formulations for 2 weeks, respectively. A polyphasic approach was used, comprising quantitative cultivation of bacteria and fungi on selective media as well as sequencing of PCR-amplified 16S rRNA and 18S rRNA genes, respectively. RESULTS: All analyses revealed a microbiota composition typical for the human scalp. While in particular fungal germ numbers increased significantly during the treatments, overall bacterial and fungal community composition was not affected, based on alpha- and beta-diversity measures. However, we observed an increase in structural bacterial diversity with the age of the probands. CONCLUSIONS: Over an application period of 2 weeks, the investigated shampoo induced quantitative but no qualitative changes in the scalp microbial community structure of the investigated probands, suggesting no adverse but rather preserving or even stimulating effects of the underlying formulations on the scalp microbiota. Further investigation will have to clarify if this is also true for longer application periods and if the formulations might affect community functionality, for example microbial gene expression, rather than community composition.

OBJECTIF: Le cuir chevelu humain se caractérise par une communauté microbienne modérément diversifiée, comprenant des membres procaryotes (bactéries) et eucaryotes (champignons). Bien que l'on soit loin de comprendre totalement les détails, le microbiote du cuir chevelu humain est impliqué dans différents troubles du cuir chevelu, en particulier la formation de pellicules. La protection du microbiote du cuir chevelu intact et diversifié peut être considérée comme un critère de qualité pour les formulations de soins pour les cheveux et le cuir chevelu. Dans cette étude, nous avons examiné l'influence de deux formulations de shampooing non antimicrobien disponibles dans le commerce sur la structure du microbiote du cuir chevelu. MÉTHODES: Des échantillons de microbiote du cuir chevelu, obtenus par écouvillonnage dans deux cohortes de proposants (n = 25 dans chaque cohorte), ont été analysés respectivement avant et après l'utilisation quotidienne de deux formulations de shampooing pendant deux semaines. Une approche en plusieurs phases a été utilisée, dont une culture quantitative de bactéries et de champignons sur des milieux sélectifs et un séquençage respectivement des gènes de l'ARN ribosomique 16S et de l'ARN ribosomique 18S amplifiés par PCR. RÉSULTATS: Toutes les analyses ont révélé une composition du microbiote typique pour le cuir chevelu humain. Bien que le nombre de germes fongiques en particulier ait augmenté significativement pendant les traitements, la composition globale des communautés bactériennes et fongiques n'a pas été affectée, d'après les mesures de diversité alpha et bêta. Cependant, nous avons observé une augmentation de la diversité bactérienne structurelle avec l'âge des proposants. CONCLUSIONS: Sur une période d'utilisation de deux semaines, le shampooing étudié a induit des modifications quantitatives, mais pas qualitatives, de la structure des communautés microbiennes du cuir chevelu des proposants étudiés, ce qui suggère qu'il n'y a pas d'effets indésirables, mais qu'il y a des effets de préservation, voire de stimulation, des formulations sous-jacentes sur le microbiote du cuir chevelu. Des recherches supplémentaires devront clarifier si cela s'avère également pour des périodes d'utilisation plus longues et si les formulations peuvent affecter la fonctionnalité des communautés, par exemple, l'expression des gènes microbiens, plutôt que la composition des communautés.

Morphology and molecular phylogeny of two hypotrichous ciliates (Ciliophora, Spirotrichea) from South Korea, including Hemiurosomoida koreana n. sp.

The living morphology, infraciliature, and molecular phylogeny of a new soil ciliate, Hemiurosomoida koreana n. sp., discovered in a sample collected from a mountain in the northeast of South Korea, were investigated. The new species possesses the characteristics of the genus Hemiurosomoida, i.e., a reduced number of frontal-ventral-transverse cirri, three dorsal kineties of which kineties 1 and 2 each bears a caudal cirrus, and a single dorsomarginal kinety. It is distinguishable from congeners and other similar species by at least one distinct qualitative or quantitative character including the body size, the presence and arrangement of cortical granules, the number of adoral membranelles, marginal cirri, and dorsal dikinetids, or by the arrangement of transverse cirri. Phylogenetic analyses based on 18S rRNA gene sequences also support the assignment of the new species to the non-monophyletic genus Hemiurosomoida. In addition, the living morphology, infraciliature, and the 18S rRNA gene sequence of a Korean population of Nothoholosticha flava were studied.

The Mite Steatonyssus periblepharus Is a Novel Potential Vector of the Bat Parasite Trypanosoma dionisii.

Trypanosoma dionisii, for which only bat bugs (Cimicidae) had previously been demonstrated as vectors, was, for the first time, detected in the gamasine mite Steatonyssus periblepharus in Russia. The molecular phylogenetic analysis indicated that trypanosomes found in these mites belong to the "clade A" of T. dionisii, which, based on genetic distances, can be considered as a species separate from the sister clade B, and according to available data also has a distinct geographic distribution. The presence of developmental forms of T. dionisii resembling those previously described during the development of this trypanosome in cimicids suggests that S. periblepharus is a novel vector of the studied trypanosome.

Rapid detection of Cryptosporidium spp. in diarrheic cattle feces by isothermal recombinase polymerase amplification assays.

As a zoonotic parasite, Cryptosporidium spp. could cause severe diarrhea mainly in calves and children globally. Monitoring and prevention of Cryptosporidium spp.'s prevalence is of great significance in both economy and public health aspects. In this study, specific primers and probes were designed within the conserved region of 18S rRNA gene for Cryptosporidium spp. and recombinase polymerase amplification assays based on the fluorescence monitoring (real-time RPA) as well as combined with a lateral flow strip (LFS RPA) were developed. Both of the two RPA assays allowed the exponential amplification of the target fragment within 20 min. After incubation on a metal bath at 42 °C, the LFS RPA results were displayed on the lateral flow strip within 5 min while real-time RPA allowed the real-time observation of the results in Genie III at 39 °C. The RPA assays showed high specificity for Cryptosporidium spp. without any cross-reaction with other tested pathogens causing diarrhea in cattle. With the recombinant plasmid DNA containing the 18S rRNA gene of Cryptosporidium spp. serving as a template, the limit of detection for real-time RPA and LFS RPA assays were 14.6 and 12.7 copies/reaction, respectively. Moreover, the RPA assays were validated by testing diarrheic cattle fecal samples and compared with a real-time PCR. The positive ratio of Cryptosporidium spp. was 24.04 % (44/183) and 26.23 % (48/183) in both RPA assays and real-time PCR assay, respectively, and the kappa coefficient value was 0.942. The diagnostic specificity and diagnostic sensitivity of both RPA assays were 100 % and 91.67 %, respectively. Forty-one of 48 positive samples were successfully sequenced and four Cryptosporidium species were detected, including C. parvum (n = 20), C. andersoni (n = 17), C. bovis (n = 3) and C. ryanae (n = 1). The developed RPA assays are easy to operate and faster to obtain the detection results, and they are suiting for the point-of-care detection and facilitating the prevention and control of Cryptosporidium spp. infections.