HSP70 is part of the synaptonemal complex in Eimeria tenella

Glucantime and quercetin electrospun nanofiber membranes: Fabrication and their evaluation as dressing for cutaneous leishmaniasis

Cutaneous leishmaniasis is considered as one of the most concerns of the World Health Organization (WHO). The main objective of this study was to use polycaprolactone (PCL) nanofiber scaffolds in order to provide a topical drug delivery system capable of delivering glucantime (glu) and quercetin (qur) to cutaneous leishmaniasis wounds. First, PCL/glu/qur, PCL/glu, and PCL/qur nanofibers were prepared by an electrospinning method followed by characterization through scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). Subsequently, we investigated the release of the drugs from nano-scaffolds and anti-promastigote effects. Lastly, the effect of nanobandage was evaluated on 20 female inbred BALB/c mice infected with the parasite. The nanofibers were bead-free and uniform with an average diameter of 224 ± 25 nm and showed a sustained release. Results from in vivo experiments showed that the number of amastigotes and macrophages infected with the parasite and the infiltration of inflammatory cells in mice treated with PCL/qur and PCL/glu/qur nanofibers significantly decreased as compared with those treated with the PCL/glu and PCL nanofibers. Collectively, PCL/glu/qur and PCL/qur nanofibers have promising therapeutic effects in cutaneous leishmaniasis wound healing.

Quercetin as a Promising Antiprotozoan Phytochemical: Current Knowledge and Future Research Avenues

Despite tremendous advances in the prevention and treatment of infectious diseases, only few antiparasitic drugs have been developed to date. Protozoan infections such as malaria, leishmaniasis, and trypanosomiasis continue to exact an enormous toll on public health worldwide, underscoring the need to discover novel antiprotozoan drugs. Recently, there has been an explosion of research into the antiprotozoan properties of quercetin, one of the most abundant flavonoids in the human diet. In this review, we tried to consolidate the current knowledge on the antiprotozoal effects of quercetin and to provide the most fruitful avenues for future research. Quercetin exerts potent antiprotozoan activity against a broad spectrum of pathogens such as Leishmania spp., Trypanosoma spp., Plasmodium spp., Cryptosporidium spp., Trichomonas spp., and Toxoplasma gondii. In addition to its immunomodulatory roles, quercetin disrupts mitochondrial function, induces apoptotic/necrotic cell death, impairs iron uptake, inhibits multiple enzymes involved in fatty acid synthesis and the glycolytic pathways, suppresses the activity of DNA topoisomerases, and downregulates the expression of various heat shock proteins in these pathogens. In vivo studies also show that quercetin is effective in reducing parasitic loads, histopathological damage, and mortality in animals. Future research should focus on designing effective drug delivery systems to increase the oral bioavailability of quercetin. Incorporating quercetin into various nanocarrier systems would be a promising approach to manage localized cutaneous infections. Nevertheless, clinical trials are needed to validate the efficacy of quercetin in treating various protozoan infections.

Eimeria proteins: order amidst disorder

Apicomplexans are important pathogens that cause severe infections in humans and animals. The biology and pathogeneses of these parasites have shown that proteins are intrinsically modulated during developmental transitions, physiological processes and disease progression. Also, proteins are integral components of parasite structural elements and organelles. Among apicomplexan parasites, Eimeria species are an important disease aetiology for economically important animals wherein identification and characterisation of proteins have been long-winded. Nonetheless, this review seeks to give a comprehensive overview of constitutively expressed Eimeria proteins. These molecules are discussed across developmental stages, organelles and sub-cellular components vis-à-vis their biological functions. In addition, hindsight and suggestions are offered with intention to summarise the existing trend of eimerian protein characterisation and to provide a baseline for future studies.

Dynamically expressed genes provide candidate viability biomarkers in a model coccidian

Eimeria parasites cause enteric disease in livestock and the closely related Cyclosporacayetanensis causes human disease. Oocysts of these coccidian parasites undergo maturation (sporulation) before becoming infectious. Here, we assessed transcription in maturing oocysts of Eimeria acervulina, a widespread chicken parasite, predicted gene functions, and determined which of these genes also occur in C. cayetanensis. RNA-Sequencing yielded ~2 billion paired-end reads, 92% of which mapped to the E. acervulina genome. The ~6,900 annotated genes underwent temporally-coordinated patterns of gene expression. Fifty-three genes each contributed >1,000 transcripts per million (TPM) throughout the study interval, including cation-transporting ATPases, an oocyst wall protein, a palmitoyltransferase, membrane proteins, and hypothetical proteins. These genes were enriched for 285 gene ontology (GO) terms and 13 genes were ascribed to 17 KEGG pathways, defining housekeeping processes and functions important throughout sporulation. Expression differed in mature and immature oocysts for 40% (2,928) of all genes; of these, nearly two-thirds (1,843) increased their expression over time. Eight genes expressed most in immature oocysts, encoding proteins promoting oocyst maturation and development, were assigned to 37 GO terms and 5 KEGG pathways. Fifty-six genes underwent significant upregulation in mature oocysts, each contributing at least 1,000 TPM. Of these, 40 were annotated by 215 GO assignments and 9 were associated with 18 KEGG pathways, encoding products involved in respiration, carbon fixation, energy utilization, invasion, motility, and stress and detoxification responses. Sporulation orchestrates coordinated changes in the expression of many genes, most especially those governing metabolic activity. Establishing the long-term fate of these transcripts in sporulated oocysts and in senescent and deceased oocysts will further elucidate the biology of coccidian development, and may provide tools to assay infectiousness of parasite cohorts. Moreover, because many of these genes have homologues in C. cayetanensis, they may prove useful as biomarkers for risk.

What's Genetic Variation Got to Do with It? Starvation-Induced Self-Fertilization Enhances Survival in Paramecium

The pervasiveness of sex despite its well-known costs is a long-standing puzzle in evolutionary biology. Current explanations for the success of sex in nature largely rely on the adaptive significance of the new or rare genotypes that sex may generate. Less explored is the possibility that sex-underlying molecular mechanisms can enhance fitness and convey benefits to the individuals that bear the immediate costs of sex. Here, we show that the molecular environment associated with self-fertilization can increase stress resistance in the ciliate Paramecium tetraurelia. This advantage is independent of new genetic variation, coupled with a reduced nutritional input, and offers fresh insights into the mechanistic origin of sex. In addition to providing evidence that the molecular underpinnings of sexual reproduction and the stress response are linked in P. tetraurelia, these findings supply an integrative explanation for the persistence of self-fertilization in this ciliate.

Single components of botanicals and nature-identical compounds as a non-antibiotic strategy to ameliorate health status and improve performance in poultry and pigs

In the current post-antibiotic era, botanicals represent one of the most employed nutritional strategies to sustain antibiotic-free and no-antibiotic-ever production. Botanicals can be classified either as plant extracts, meaning the direct products derived by extraction from the raw plant materials (essential oils (EO) and oleoresins (OR)), or as nature-identical compounds (NIC), such as the chemically synthesised counterparts of the pure bioactive compounds of EO/OR. In the literature, differences between the use of EO/OR or NIC are often unclear, so it is difficult to attribute certain effects to specific bioactive compounds. The aim of the present review was to provide an overview of the effects exerted by botanicals on the health status and growth performance of poultry and pigs, focusing attention on those studies where only NIC were employed or those where the composition of the EO/OR was defined. In particular, phenolic compounds (apigenin, quercetin, curcumin and resveratrol), organosulfur compounds (allicin), terpenes (eugenol, thymol, carvacrol, capsaicin and artemisinin) and aldehydes (cinnamaldehyde and vanillin) were considered. These molecules have different properties such as antimicrobial (including antibacterial, antifungal, antiviral and antiprotozoal), anti-inflammatory, antioxidant, immunomodulatory, as well as the improvement of intestinal morphology and integrity of the intestinal mucosa. The use of NIC allows us to properly combine pure compounds, according to the target to achieve. Thus, they represent a promising non-antibiotic tool to allow better intestinal health and a general health status, thereby leading to improved growth performance.

Characterization and expression analysis of a new small heat shock protein Hsp20.4 from Eimeria tenella

Small heat shock proteins (sHsps) are ubiquitous and diverse molecular chaperones. Found in almost all organisms, they regulate protein refolding and protect cells from stress. Until now, no sHsp has been characterized in Eimeria tenella. In this study, the novel EtsHsp20.4 gene was cloned from E. tenella by rapid amplification of cDNA ends based on a previously identified expressed sequence tag. The full-length cDNA was 1019bp in length and contained an open reading frame of 558bp that encoded a 185-amino acid polypeptide with a calculated molecular weight of 20.4 kDa. The EtsHsp20.4 protein contained a distinct HSP20/alpha-crystallin domain that is the key determinant of their function as molecular chaperones and belongs to the HSP20 protein family. EtsHsp20.4 mRNA levels were higher in sporulated oocysts than in sporozoites or second-generation merozoites by real-time quantitative PCR, the transcription of EtsHsp20.4 was barely detectable in unsporulated oocysts. Immunolocalization with EtsHsp20.4 antibody showed that EtsHsp20.4 was mainly located on the surface of sporozoites, first-generation merozoites and second-generation merozoites. Following the development of parasites in DF-1 cells, EtsHsp20.4 protein was uniformly dispersed in trophozoites, immature schizonts, and mature schizonts. Malate dehydrogenase thermal aggregation assays indicated that recombinant EtsHsp20.4 had molecular chaperone activity in vitro. These results suggested that EtsHsp20.4 might be involved in sporulation in external environments and intracellular growth of the parasite in the host.

Inhibitory effect of S-nitroso-glutathione on Eimeria tenella oocysts was mainly limited to the early stages of sporogony

The objective of this study was to evaluate the action of S-nitroso-glutathione (GSNO) on the sporogony and the mRNA expression for EtCRK2 (a cyclin-dependent kinase related protein-2 in Eimeria tenella) during oocyst sporulation. Meanwhile, the effects of GSNO on the sporozoite excystability and infectivity to chickens were also investigated. The results showed that within 10 h after the initial sporulation, the sporulation process could be interrupted by GSNO treatment, and most of the oocysts failed to continue to sporulate. However, if the sporulation lasted more than 12 h, the sporogony process could not be blocked by GSNO. RT-PCR assay suggested that in the early stage of sporulation, the mRNA expression of EtCRK2 was completely inhibited by GSNO. For the infective oocysts or sporocysts treated by GSNO, the proportion of sporozoite excystation decreased significantly by about 20% and 40%, respectively. However, clinical coccidiosis could be observed in all experimental broilers inoculated with the oocysts or sporocysts treated by GSNO or not. The animal test showed that GSNO treatment reduced the infectivity of sporocysts, whereas it did not alleviate that of oocysts to broilers. Taken together, the data indicated that the viability of sporulated E. tenella oocysts could not be inactivated in vitro by GSNO. The inhibiting action of GSNO on oocysts was mainly limited to the early stages of sporulation, and this may partially associate with the inhibition of EtCRK2 mRNA expression.

Meiotic chromosome pairing and bouquet formation during Eimeria tenella sporulation

In Eimeria tenella, meiotic division occurs exclusively in oocysts within the first 8h of sporulation. Difficulties with the wall-oocyst breakage in gaining access to chromosomes during meiosis have resulted in a scarcity of morphological data on Eimeria chromosomes. This study tracks the general behaviour of telomeres, attachment plaques and synaptonemal complexes in the nucleus of the meiotic oocyst of E. tenella. Fluorescence microscopy methods, in combination with immunoelectron microscopy techniques, were applied to obtain a series of time-lapse images during oocyst sporulation. Antibodies to Structural Maintenance of Chromosome proteins SMC1 and SMC3, and lamin were labelled with either fluorescence or colloidal gold to visualise the telomeres, central elements of the synaptonemal complex (SC) and nuclear periphery, respectively, at both the structural and ultrastructural levels. Using oocyst spreads and ultrathin sections of fixed oocysts it was possible to study telomere dynamics at stages during meiosis. The stages of the meiotic prophase I are delineated on the basis of the telomere position and the SC synapsis and desynapsis. During the leptotene stage, at 4h following the start of sporulation, meiotic chromosomes attached to the nuclear envelope. At that stage, chromosome synapsis was initiated in the telomeric regions but no interstitial synapsis pairing was observed. In the zygotene stage, telomere signals were clustered in a limited area of the nuclear envelope. Bouquet formation occurred at 5h after the start of sporulation, whereas chromosomes did not appear completely synapsed until the pachytene stage at 6h of sporulation. Desynapsis was observed at 8h of sporulation during the diplotene stage. This study provides the first morphological description of both the behaviour of the chromosomes and the timing of the prophase I stages in the meiotic nucleus of E. tenella.