Search Results (180)

The small freshwater lakes of Spitsbergen remain poorly studied compared to surrounding marine ecosystems despite their sensitivity to rapid environmental changes. During the short ablation season, these shallow lakes exhibit physicochemical variability influenced by the harsh Arctic climate, local geology, and hydrology. This study analyzed six lakes located on marine terraces, moraine areas, and outwash plains in the Bellsund region to assess how physicochemical variability in their waters affects phytoplankton development. The lakes exhibited local and temporal variations in temperature, conductivity, ion composition, and nutrient levels, with generally low nutrient availability limiting biological productivity. Phytoplankton communities were quantitatively and qualitatively poor, dominated by green algae, either flagellates or mixed communities, including cyanobacteria. Green algae clearly dominated in lakes closest to the fjord shoreline, while dinoflagellates and cryptophytes dominated in inland lakes. Phytoplankton abundance and biomass were extremely low in one of the lakes situated on the raised marine terraces within the tundra vegetation zone (3 × 10³ ind L⁻¹ and 0.004 mg L⁻¹, respectively). In contrast, the much larger lake situated within the tundra zone nearer the fjord shoreline had values that were comparable to fertile lakes in the temperate zone (~30 thousand × 10³ ind L⁻¹ and ~28 mg L⁻¹, respectively). It should be noted that Monoraphidium contortum and Rhodomonas minuta dominated some of the lakes almost entirely. Phytoplankton abundance was related to physicochemical conditions: green algae increased with increasing ion concentrations (Cl⁻, Na⁺, K⁺, SO₄²⁻), P_min, Fe, and Mn; flagellates preferred colder waters with higher N_min and low TOC; cyanobacteria occurred in waters with lower COND, TOC, Ca²⁺, Si, Cu, and Zn. Phytoplankton biomass increased in July with increasing water temperature. Bird activity likely facilitated phytoplankton dispersal, increasing taxonomic diversity in frequently visited lakes. Full article

Chrysastrella is a small genus of the Ochromonas-like chrysophytes, taxonomy and phylogenetic placement of which remained unclear. For a long time Chrysastrella was considered a cyst genus, i.e., a morphogenus based on the structure of stomatocysts, the resting stages of chrysophytes. We isolated several new strains of C. paradoxa from the peat bogs in Murmansk Region and the Republic of Komi (Russia) and studied them using light and scanning electron microscopy as well as molecular techniques. We showed that morphological differences between C. paradoxa, C. minor and C. breviappendiculata are within the range of variability of stomatocysts during development. So, we synonymized C. minor and C. breviappendiculata with C. paradoxa. Molecular phylogenetic analysis based on SSU rDNA and rbcL sequences revealed that Chrysastrella belongs to the order Chrysosaccales. A new monotypic family, Chrysastrellaceae fam. nov., was formally described to accommodate this genus. Full article

Flagellin is the main structural protein of the bacterial flagellum, responsible for the movement of flagellated bacteria. Flagellin activates Toll-like receptor 5, inducing both innate and adaptive immune reactions, which highlights its potential as a vaccine adjuvant, particularly efficient in case of administration via mucosal routes. Genetic fusion of an antigen to flagellin has been shown to enhance the immune responses against the antigen. The molecular architecture of flagellin provides versatile and robust adjuvant functionality, facilitating the development of diverse vaccination strategies against multiple diseases as recombinant protein-based vaccines demonstrate substantial advantages over conventional live-attenuated and inactivated vaccines in both developmental efficiency and safety profiles. We present a comprehensive overview of vaccine design strategies employing genetic fusion of antigens to flagellin for protection against various infectious diseases. The proven effectiveness of flagellin-based delivery has enabled several vaccine candidates to enter clinical trials. Full article

During the 84th cruise of the R/V Akademik Mstislav Keldysh in August 2021, patterns of phytoplankton composition transformation were revealed along a northward gradient. The study involved three transects in the Fram Strait and adjacent Arctic waters: a southern transect (from the Barents Sea shelf to the Greenland shelf), a middle transect across the Fram Strait, and a northern transect along the ice edge. Ten species of diatoms and eleven of dinoflagellates were identified, and their ecological preferences were characterized by determining the minimum, maximum, mean, and median values for abundance, biomass, depth of the biomass maximum, salinity, temperature, and the concentrations and ratios of nitrogen, phosphorus, and silicon. Significant gradients in temperature, salinity, silicon, and nitrogen concentrations were recorded along the south–north direction in the study area. The phytoplankton community responds to these changing factors through restructuring. Dinoflagellates predominantly dominate the southern and middle transects, whereas large diatoms make a substantial contribution to the phytoplankton biomass in the northern transect. Diatom biomass is determined by nitrogen concentration. The dependence of dinoflagellate biomass on that of small flagellates confirms the importance of mixotrophic nutrition. A hypothesis is proposed that the most probable criterion for the selective selection of diatoms northward is the half-saturation constant for nitrogen uptake, while for dinoflagellates, it is temperature. Full article

Tritrichomonas foetus is an anaerobic flagellated protozoan that infects multiple animal hosts, primarily cattle and cats, with occasional isolation from pigs. It causes bovine trichomonosis, a venereal disease associated with infertility, abortion, and economic losses in cattle herd. In cats, T. foetus infects the gastrointestinal tract, causing chronic diarrhea which can be difficult to treat. Despite its broad impact, the pathogen is difficult to control because it evades immune responses and persists in host tissues. Recent advances in omics technologies, including genomics, transcriptomics, and proteomics, have contributed to a better understanding of the parasite’s genetic structure, virulence, drug resistance mechanisms, and metabolic pathways. These findings have identified potential drug targets and paved the way for targeted therapies. However, the biology, pathogenicity, and host interactions with T. foetus are still not fully understood, and many aspects of its life cycle and molecular mechanisms remain to be elucidated. This review summarizes the latest omics research on T. foetus, highlighting its genetic diversity and host-specific adaptations, and outlines the gaps in our understanding. Full article

Obligate symbionts often exhibit some degree of co-speciation with their hosts. One prominent example is the symbiosis between termites and their wood-feeding hindgut protists. This symbiosis is mutually obligate, vertically inherited by anal feeding, and it predates the emergence of termites from their cockroach ancestors. Termites and their symbiotic protists might therefore be expected to have congruent phylogenies, but symbiont loss, transfer, and independent diversification can impact the coevolutionary history to varying degrees. Here, we have characterized the symbiotic protist communities of eight Neoisoptera species from three families in order to gauge the phylogenetic congruence between each lineage of protists and their hosts. Using microscopy and 18S rRNA gene sequencing of individually isolated protist cells, we identified protists belonging to the Parabasalia genera Pseudotrichonympha, Holomastigotoides, Cononympha, and Cthulhu. Pseudotrichonympha were present in all of the investigated termites, with a strong pattern of codiversification with hosts, consistent with previous studies. The phylogeny of Holomastigotoides indicates several instances of diversification that occurred independently of the hosts’ diversification, along with lineage-specific symbiont loss. Cononympha occurs only in Heterotermitidae and Psammotermes. Surprisingly, the small flagellate Cthulhu is widespread and exhibits cophylogeny with its hosts. This study demonstrates that different symbiont lineages can show different coevolutionary patterns, even within the same host. Full article

Giardia lamblia is a flagellated protozoan and the etiological agent of giardiasis, a leading cause of epidemic and sporadic diarrhoea globally. The clinical and public health relevance of giardiasis underscores the need for robust methodologies to investigate and manage this pathogen. This study reviews the main methodologies described in the literature for studying the life cycle of G. lamblia, focusing on isolation, purification, axenization, excystation, and encystation. A systematic literature review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) statement. Searches were performed in MEDLINE, ScienceDirect, and Web of Science Core Collection databases. A total of 43 studies were included, revealing 58 methods for isolation and purification, 7 for excystation, 2 for axenization, and 5 for encystation. Isolation and purification methods exhibited significant variability, often involving two phases: an initial separation (e.g., filtration and centrifugation) followed by purification using a density gradient for faecal samples or immunomagnetic separation for water samples. Method effectiveness differed depending on the sample source and type, limiting comparability across studies. In contrast, methods used for other life cycle stages were more consistent. These findings underscore the need for standardised methodologies to enhance the reproducibility and reliability of research outcomes in this field. Full article

Climate change can have a direct impact on the decomposition of organic matter, as well as indirect effects on peatland vegetation (including carnivorous plants) and the microbial communities associated with this environment. The activity of microbes varies depending on the type of peatland they inhabit. Because some microorganisms are highly sensitive, they can be used as indicators of climate change. However, there is still little knowledge of how changes in the temperature of the environment can affect the microbiome of carnivorous plants. The study was conducted to test the following hypotheses: (1) The effect of rising water temperature on the qualitative and quantitative structure of the microbiome of carnivorous peatland plants depends on the type of peatland; (2) habitats with a higher trophic status stimulate the development of microbial communities in the water, but are an unfavourable habitat for the development of the microbiome of plant traps. Irrespective of the type of peatland, the species richness of microorganisms was much higher in the water than in the traps. As the temperature increased, there was an increase in the abundance of bacteria, heterotrophic flagellates, and testate amoebae, which was much more pronounced in the peat bog than in the carbonate fen. Full article

This review presents information obtained over the past 10 years on the methods to control the widespread worldwide phytopathogen Pectobacterium carotovorum subsp. carotovorum (Pcc). This bacterium is among the ten most dangerous phytopathogens; it affects a wide range of cultivated plants: vegetables, ornamental and medicinal crops, both during vegetation and during the storage of fruits. Symptoms of Pcc damage include the wilting of plants, blackening of vessels on leaves, stems and petioles. At the flowering stage, the stem core gradually wilts and, starting from the root, the stem breaks and the plant dies. Pcc is a rod-shaped, non-capsule and endospore-forming facultative anaerobic Gram-negative bacterium with peritrichous flagellation. Pcc synthesizes bacteriocins—carocins. The main virulence factors of Pcc are the synthesis of N-acyl-homoserine lactone (AHL) and plant cell wall-degrading enzymes (PCWDEs) (pectinases, polygalacturonases, cellulases, and proteases). Diagnostic methods for this phytopathogen include polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), multilocus genotyping of strain-specific genes and detection of unique volatile organic compounds (VOCs). The main methods to control this microorganism include the use of various chemicals (acids, phenols, esters, salts, gases), plant extracts (from grasses, shrubs, trees, and algae), antagonistic bacteria (Bacillus, Pseudomonas, Streptomyces, and lactic acid bacteria), viruses (including a mixture of bacteriophages), and nanomaterials based on metals and chitosan. Full article

Trichomonas tenax is an anaerobic flagellate usually found in the oral cavity of humans and domestic animals. It is very likely to be transmitted through kissing, sharing saliva, contaminated utensils, and water. However, research on its transmission dynamics is scarce. Hence, there is a need to identify potential knowledge gaps in T. tenax transmission for future research and emphasize the importance of the One Health approach in controlling the spread of this flagellar protozoan. Trichomonas tenax has been found in humans, dogs, cats, horses, and birds at various body sites, including the lungs and the urogenital tract, in addition to the oral cavity. Its transmission is influenced by environmental factors such as temperature and socioeconomic factors such as age, income, smoking, and public awareness, along with poor oral hygiene and systemic diseases. Direct host-to-host transmission also plays an important role; however, transmission through fomites or contaminated water still needs to be scientifically proven to gain a better understanding of these mechanisms. More studies on this flagellate are warranted, especially using animal models and epidemiological studies, to better understand its transmission dynamics. Prioritizing research in these areas could result in a more comprehensive understanding of T. tenax transmission dynamics and the factors that influence it, ultimately aiding in the development of effective control and prevention strategies. It is also recommended to encourage collaboration between medical and veterinary professionals in addressing this zoonotic protozoan, recognizing that it aligns with the One Health approach. Full article

Advancing age in men significantly contributes to declining sperm fertility. Information on age-related proteomic changes in spermatozoa is limited. This study involved normal fertile Arab men in three age groups: young adult (21–30 years; n = 6), late adult (31–40 years; n = 7), and advanced age (40–51 years; n = 5). Gradient-purified spermatozoa were analyzed using LC-MS/MS and proteomic data were processed using Progenesis QI (QIfp) v3.0 and UniProt/SwissProt. Significantly enriched annotations and clustering of proteins in the proteomic datasets were identified (2-fold change; p < 0.05). A total of 588 proteins were identified, with 93% shared across the three groups. Unique proteins were MYLK4 for the young adult group, PRSS57 for the late adult group, and HMGB4, KRT4, LPGAT1, OXCT2, and MGRN1 for the advanced age group. Furthermore, 261 (44%) proteins were differentially expressed (p < 0.05) across the three groups. Functional enrichment analysis suggested an aging-related significant increase in pathways associated with neurodegenerative diseases and protein folding, alongside decreases in glycolysis/gluconeogenesis, flagellated sperm motility, acetylation, phosphoprotein modifications, oxidation processes, and Ubl conjugation. Cluster analysis highlighted significantly upregulated proteins in young adults (e.g., H2BC1, LAP3, SQLE, LTF, PDIA4, DYNLT2) and late adults (e.g., ATP5F1B, ODF2, TUBA3C, ENO1, SPO11, TEX45, TEKT3), whereas most proteins in the advanced age group exhibited downregulation (e.g., SPESP1, RAB10, SEPTIN4, RAB15, PTPN7, USP5, ANXA1, PRDX1). In conclusion, this study revealed aging-associated proteomic changes in spermatozoa that impact critical processes, including spermatogenesis, motility, metabolism, and fertilization, potentially contributing to fertility decline. These changes provide a molecular framework for developing therapies to preserve sperm proteostasis and enhance fertility in older men. Full article

Trichomitus batrachorum is a species of trichomonad that has gained attention due to its ecological importance and potential interactions with various hosts, such as amphibians (anurans) and reptiles (lizards and chelonians), where it has been recorded in the gastrointestinal tract of these vertebrates, specifically in their feces. Molecular studies have placed this flagellated protist within the Metamonada clade. Unlike parabasalids that inhabit endothermic mammals in relatively stable temperature conditions, protists associated with ectothermic reptiles are subject to significant temperature fluctuations. The ability of T. batrachorum to thrive in the variable temperatures encountered by reptiles suggests that its parasitism may remain largely unaffected by climate change. In our study, we detected and characterized T. batrachorum from the liver tissue of the lizard species Ameiva ameiva, collected in Presidente Figueiredo Municipality, Amazonas State, Brazil. The identification of T. batrachorum was confirmed by cultivation technique, light microscopy, scanning electron microscopy and transmission electron microscopy for ultrastructural analyses, and sequencing the 5.8S rDNA (region ITS1- ITS2) and 18S rRNA (ribosomal RNA) genes. One potential interpretation for this finding is that the flagellates may have migrated from the intestine to the bile duct, ultimately reaching the liver. This is the first successful characterization of T. batrachorum in the liver of a lizard, and provides a solid foundation for further research to elucidate the potential pathogenicity of this flagellate and the role of A. ameiva in the epidemiology of parabasalids in other animal species. Full article

Flagellates of the genus Giardia are intestinal parasites with a broad host range. Several Giardia duodenalis variants (assemblages) recently elevated to species rank—G. duodenalis (assemblage A1), G. intestinalis (A2) and Giardia enterica (B) are human pathogens. Giardia enterica has been reported in some hystricomorph rodents such as wild crested porcupines (Hystrix cristata), but no data were previously available from Brazilian porcupines (Coendou prehensilis) and naked mole rats (Heterocephalus glaber). The aim of this study is to genetically identify the Giardia isolates from these three rodent species, all housed in a zoological institution. Fecal samples were processed using the Bailenger concentration method, and DNA was extracted from the sediments using commercial kits. Partial PCR amplification and sequencing of the glutamate dehydrogenase, beta-giardin, and triose-phosphate isomerase genes revealed that all isolates belonged to G. enterica, showing 99–100% identity with sequences available in GenBank. Prevalences could not be reliably estimated due to small group sizes and the resulting proportions may be biased. To our knowledge, this is the first report identifying Giardia (G. enterica) in C. prehensilis and H. glaber, thus expanding the known host range of this parasite species and reinforcing the importance of surveillance in captive wild hosts. Full article

Infections with zoonotic pathogens have received increasing attention in recent years, as reflected in the literature of both veterinary and human medicine. Cryptosporidium and Giardia are recognised as the principal causes of waterborne outbreaks worldwide, but there is still limited data on the role of wild carnivores, such as red foxes and wolves, as reservoir hosts and in disseminating these pathogens in the environment. The aim of the current project was to analyse the prevalence and abundance of Cryptosporidium and Giardia infections in foxes from seven voivodeships and in wolves from the Warmia-Masuria Voivodeship in Poland and to conduct a phylogenetic analysis of the detected parasites. For the detection of both parasites, we used the commercial immunofluorescent assay MeriFluor Cryptosporidium/Giardia. For Cryptosporidium detection we also applied modified Ziehl–Neelsen (ZN) staining of faecal smears and, following PCR amplification, sequenced the 18S rDNA locus. For Giardia detection, we sequenced the glutamate dehydrogenase (gdh) gene. In total, 117 and 69 faecal samples obtained from red foxes and wolves, respectively, were screened for the presence of Cryptoporidium/Giardia. In red foxes, prevalence was 38.5% and 15.4% for Cryptosporidium spp. and G. intestinalis, respectively. In wolves, the prevalence of Cryptosporidium spp. was 14.5%, and only one sample was Giardia-positive. Cryptosporidium canis, Cryptosporidium sp. vole genotype, C. baileyi and Cryptosporidium sp. were identified in red foxes, while C. canis and Cryptosporidium sp. were detected in wolves. Our results indicate that red foxes and grey wolves act as reservoir hosts of Cryptosporidium spp. and G. intestinalis in natural areas in Poland. Full article

Giardia duodenalis is a flagellated protozoan pathogen causing parasitic enteric disease outbreaks worldwide. Among detection methods, loop-mediated isothermal amplification (LAMP) has high selectivity and sensitivity, and the detection time is lower than that of conventional molecular methods. In this study, three published Giardia LAMP primer sets were tested and adapted to touchdown LAMP conditions. The measurement time, the volume of reagents, the effect of the denaturation step, different kinds of polymerases, and the presence or absence of betaine on the reaction were tested and evaluated. Based on the results of this study, the 66–60 °C range touchdown LAMP with the use of betaine, 90 °C denaturation step, Bst 2.0 WarmStart^® DNA Polymerase, and the primer set of Momoda et al. were the optimal conditions. We increased the analytical sensitivity of the LAMP reaction to 7.8- and 8-fold higher than the previously published methods for G. duodenalis assemblages A and B, with detection limits of 20 and 19.5 fg/assay, respectively, instead of 156 fg/assay. The detection time was less than 49 min for G. duodenalis assemblage A and less than 35 min for assemblage B, compared to the previously published 60 min. Our optimized LAMP protocol can be directly applied to improve Giardia LAMP tests in routine testing laboratories, could be implemented in standard diagnostic or environmental monitoring workflows, and can be used for the development of Giardia LAMP point-of-care devices or high-throughput systems. Full article