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Microbiology Spectrum Jun 2024Lipid droplets (LDs) are dynamic organelles that participate in the regulation of lipid metabolism and cellular homeostasis inside of cells. LD-associated proteins, also...
Lipid droplets (LDs) are dynamic organelles that participate in the regulation of lipid metabolism and cellular homeostasis inside of cells. LD-associated proteins, also known as perilipins (PLINs), are a family of proteins found on the surface of LDs that regulate lipid metabolism, immunity, and other functions. In silkworms, pébrine disease caused by infection by the microsporidian () is a severe threat to the sericultural industry. Although we found that relies on lipids from silkworms to facilitate its proliferation, the relationship between PLINs and proliferation remains unknown. Here, we found infection caused the accumulation of LDs in the fat bodies of silkworm larvae. The characterized perilipin1 gene () promotes the accumulation of intracellular LDs and is involved in proliferation. is similar to in humans and is conserved in all insects. The expression of was mostly enriched in the fat body rather than in other tissues. Knockdown of enhanced proliferation, whereas overexpression of inhibited its proliferation. Furthermore, we confirmed that increased the expression of the and in the JAK-STAT immune pathway and inhibited proliferation. Taken together, our current findings demonstrate that inhibits proliferation by promoting the JAK-STAT pathway through increased expression of and . This study provides new insights into the complicated connections among microsporidia pathogens, LD surface proteins, and insect immunity.IMPORTANCELipid droplets (LDs) are lipid storage sites in cells and are present in almost all animals. Many studies have found that LDs may play a role in host resistance to pathogens and are closely related to innate immunity. The present study found that a surface protein of insect lipid droplets could not only regulate the morphological changes of lipid droplets but also inhibit the proliferation of a microsporidian pathogen () by activating the JAK-STAT signaling pathway. This is the first discovery of the relationship between microsporidian pathogen and insect lipid surface protein perilipin and insect immunity.
Topics: Bombyx; Animals; Nosema; Insect Proteins; Lipid Droplets; Janus Kinases; Signal Transduction; Perilipin-1; STAT Transcription Factors; Fat Body; Larva; Lipid Metabolism
PubMed: 38690912
DOI: 10.1128/spectrum.03671-23 -
PLoS Pathogens Apr 2024The microsporidian Enterocytozoon hepatopenaei (EHP) is a fungi-related, spore-forming parasite. EHP infection causes growth retardation and size variation in shrimp,...
The microsporidian Enterocytozoon hepatopenaei (EHP) is a fungi-related, spore-forming parasite. EHP infection causes growth retardation and size variation in shrimp, resulting in severe economic losses. Studies on shrimp immune response have shown that several antimicrobial peptides (AMPs) were upregulated upon EHP infection. Among those highly upregulated AMPs is c-type lysozyme (LvLyz-c). However, the immune signaling pathway responsible for LvLyz-c production in shrimp as well as its function against the EHP infection are still poorly understood. Here, we characterized major shrimp immune signaling pathways and found that Toll and JAK/STAT pathways were up-regulated upon EHP infection. Knocking down of a Domeless (DOME) receptor in the JAK/STAT pathways resulted in a significant reduction of the LvLyz-c and the elevation of EHP copy number. We further elucidated the function of LvLyz-c by heterologously expressing a recombinant LvLyz-c (rLvLyz-c) in an Escherichia coli. rLvLyz-c exhibited antibacterial activity against several bacteria such as Bacillus subtilis and Vibrio parahaemolyticus. Interestingly, we found an antifungal activity of rLvLyz-c against Candida albican, which led us to further investigate the effects of rLvLyz-c on EHP spores. Incubation of the EHP spores with rLvLyz-c followed by a chitin staining showed that the signals were dramatically decreased in a dose-dependent manner, suggesting that rLvLyz-c possibly digest a chitin coat on the EHP spores. Transmission electron microscopy analysis revealed that an endospore layer, which is composed mainly of chitin, was digested by rLvLyz-c. Lastly, we observed that EHP spores that were treated with rLvLyz-c showed a significant reduction of the spore germination rate. We hypothesize that thinning of the endospore of EHP would result in altered permeability, hence affecting spore germination. This work provides insights into shrimp immune signaling pathways responsible for LvLyz-c production and its anti-EHP property. This knowledge will serve as important foundations for developing EHP control strategies.
Topics: Animals; Penaeidae; Signal Transduction; Muramidase; Enterocytozoon; Microsporidiosis
PubMed: 38683868
DOI: 10.1371/journal.ppat.1012199 -
Mikrobiyoloji Bulteni Apr 2024Microsporidia are obligate intracellular pathogens that can infect many vertebrate and invertebrate hosts. While the Microsporidia phylum was defined as protozoa until...
Microsporidia are obligate intracellular pathogens that can infect many vertebrate and invertebrate hosts. While the Microsporidia phylum was defined as protozoa until the 1990s, it has been associated with fungi in line with the data obtained as a result of phylogenetic and molecular analyzes in recent years. Although approximately 200 genera and 1400 Microsporidia species related to these genera have been reported to date, only 14 species are known to cause infection in humans. Encephalitozoon intestinalis is one of the most frequently detected species in humans and causes serious clinical conditions in immunosuppressed individuals. Little information is available about the immunology of this infection. This study was aimed to investigate the changes in Toll-Like receptor (TLR) gene expressions in Madin-Darby canine kidney (MDCK) cells treated with E.intestinalis spores. Three groups were formed in the study. In the first group, only the medium prepared for E.intestinalis was added to the MDCK cells. In the second group, 108 live spores waiting at +4 °C were added. In the third group, 108 heat-inactivated spores were added. All three groups were incubated at 37ºC with 5% CO2 . RNA isolation and cDNA synthesis were performed from samples taken from these groups at the 1st, 3rd, 6th, 12th and 24th hours. Expression of TLR1-10 genes from the obtained cDNAs was evaluated by real-time polymerase chain reaction (Rt-PCR). GAPDH and ACTB genes were used as housekeeping genes in the study. Target genes were normalized by taking the average of these two genes and statistical analysis was performed by applying the 2-ΔΔCt formula. Genes detected above the threshold value (threshold 1) were considered to have increased expression. Genes detected below the threshold value were considered to have decreased expression. The growth of the live and inactive spores were followed simultaneously with the experimental groups. Approximately two weeks after the start of the culture, it was observed that E.intestinalis grew in the culture with live spore, but did not grow in the culture with inactivated spores. No statistically significant change was observed in gene expressions in the inactivated spore group. In the live spore group, a significant increase was seen in the expression of only two genes. These genes were TLR3 and TLR4. It was observed that there was a significant increase in TLR3 gene expression at the first hour (1.6-fold of control group) but the expression level started to decrease at the third hour (1.4-fold of control group) and returned to the control level at the sixth hour. It was observed that TLR4 gene expression continued parallel to the control until the 24th hour and increased significantly (2.1-fold of control group) at the 24th hour. In conclusion, this study is the f irst report in which the changes in ten different TLR gene expressions were evaluated at different times in MDCK cells stimulated with E.intestinalis and the change in TLR3 gene expression.
Topics: Dogs; Animals; Toll-Like Receptors; Encephalitozoon; Encephalitozoonosis; Madin Darby Canine Kidney Cells; Gene Expression; Spores, Fungal
PubMed: 38676584
DOI: 10.5578/mb.202498201 -
Beneficial Microbes Sep 2023Honey bee colonies form a complex superorganism, with individual and social immune defences that control overall colony health. Sometimes these defences are not enough...
Honey bee colonies form a complex superorganism, with individual and social immune defences that control overall colony health. Sometimes these defences are not enough to overcome infections by parasites and pathogens. For that reason, several studies have been conducted to evaluate different strategies to improve honey bee health. A novel alternative that is being studied is the use of beneficial microbes. In a previous study, we isolated and characterised bacterial strains from the native gut microbiota of honey bees. Four Apilactobacillus kunkeei strains were mixed and administered in laboratory models to evaluate their potential beneficial effect on larvae and adult bees. This beneficial microbe mixture was safe; it did not affect the expression of immune-related genes, and it was able to decrease the mortality caused by Paenibacillus larvae infection in larvae and reduced the Nosema ceranae spore number in infected adult honey bees. In the present study, we aimed to delve into the impact of the administration of this beneficial microbe mixture on honey bee colonies, under field conditions. The mixture was administered in sugar syrup using lyophilised bacterial cells or fresh cultures, by aspersion or sprayed and feeder, once a week for three consecutive weeks, in autumn or spring 2015, 2017 and 2019. Colony strength parameters were estimated before the administration, and one and three months later. Simultaneously different samples were collected to evaluate the infection levels of parasites and pathogens. The results showed that administering the beneficial microbe mixture decreased or stabilised the infection by N. ceranae or Varroa destructor in some trials but not in others. However, it failed to improve the colony's strength parameters or honey production. Therefore, field studies can be a game-changer when beneficial microbes for honey bees are tested, and meticulous studies should be performed to test their effectiveness.
Topics: Bees; Animals; Nosema; Larva; Gastrointestinal Microbiome; Probiotics; Honey; Paenibacillus larvae
PubMed: 38661390
DOI: 10.1163/18762891-20220099 -
Journal of Hazardous Materials Jun 2024Health of honey bees is threatened by a variety of stressors, including pesticides and parasites. Here, we investigated effects of acetamiprid, Varroa destructor, and...
Health of honey bees is threatened by a variety of stressors, including pesticides and parasites. Here, we investigated effects of acetamiprid, Varroa destructor, and Nosema ceranae, which act either alone or in combination. Our results suggested that interaction between the three factors was additive, with survival risk increasing as the number of stressors increased. Although exposure to 150 μg/L acetamiprid alone did not negatively impact honey bee survival, it caused severe damage to midgut tissue. Among the three stressors, V. destructor posed the greatest threat to honey bee survival, and N. ceranae exacerbated intestinal damage and increased thickness of the midgut wall. Transcriptomic analysis indicated that different combinations of stressors elicited specific gene expression responses in honey bees, and genes involved in energy metabolism, immunity, and detoxification were altered in response to multiple stressor combinations. Additionally, genes associated with Toll and Imd signalling, tyrosine metabolism, and phototransduction pathway were significantly suppressed in response to different combinations of multiple stressors. This study enhances our understanding of the adaptation mechanisms to multiple stressors and aids in development of suitable protective measures for honey bees. ENVIRONMENTAL IMPLICATION: We believe our study is environmentally relevant for the following reasons: This study investigates combined effects of pesticide, Varroa destructor, and Nosema ceranae. These stressors are known to pose a threat to long-term survival of honey bees (Apis mellifera) and stability of the ecosystems. The research provides valuable insights into the adaptive mechanisms of honey bees in response to multiple stressors and developing effective conservation strategies. Further research can identify traits that promote honey bee survival in the face of future challenges from multiple stressors to maintain the overall stability of environment.
Topics: Animals; Bees; Nosema; Neonicotinoids; Varroidae; Insecticides
PubMed: 38657514
DOI: 10.1016/j.jhazmat.2024.134380 -
MBio Jun 2024The impacts of microsporidia on host individuals are frequently subtle and can be context dependent. A key example of the latter comes from a recently discovered...
UNLABELLED
The impacts of microsporidia on host individuals are frequently subtle and can be context dependent. A key example of the latter comes from a recently discovered microsporidian symbiont of , the net impact of which was found to shift from negative to positive based on environmental context. Given this, we hypothesized low baseline virulence of the microsporidian; here, we investigated the impact of infection on hosts in controlled conditions and the absence of other stressors. We also investigated its phylogenetic position, ecology, and host range. The genetic data indicate that the symbiont is , a newly described microsporidian parasite of . We show that infection damages the gut, causing infected epithelial cells to lose microvilli and then rupture. The prevalence of this microsporidian could be high (up to 100% in the lab and 77% of adults in the field). Its overall virulence was low in most cases, but some genotypes suffered reduced survival and/or reproduction. Susceptibility and virulence were strongly host-genotype dependent. We found that North American were able to infect multiple species, including the European species , as well as spp. Given the low, often undetectable virulence of this microsporidian and potentially far-reaching consequences of infections for the host when interacting with other pathogens or food, this symbiosis emerges as a valuable system for studying the mechanisms of context-dependent shifts between mutualism and parasitism, as well as for understanding how symbionts might alter host interactions with resources.
IMPORTANCE
The net outcome of symbiosis depends on the costs and benefits to each partner. Those can be context dependent, driving the potential for an interaction to change between parasitism and mutualism. Understanding the baseline fitness impact in an interaction can help us understand those shifts; for an organism that is generally parasitic, it should be easier for it to become a mutualist if its baseline virulence is relatively low. Recently, a microsporidian was found to become beneficial to its hosts in certain ecological contexts, but little was known about the symbiont (including its species identity). Here, we identify it as the microsporidium . Despite the parasitic nature of microsporidia, we found to be, at most, mildly virulent; this helps explain why it can shift toward mutualism in certain ecological contexts and helps establish is a valuable model for investigating shifts along the mutualism-parasitism continuum.
Topics: Animals; Daphnia; Symbiosis; Host Specificity; Phylogeny; Virulence; Microsporidia; Microsporidia, Unclassified
PubMed: 38651867
DOI: 10.1128/mbio.00582-24 -
Journal of Fish Diseases Apr 2024
PubMed: 38648249
DOI: 10.1111/jfd.13956 -
Malaria Journal Apr 2024Microsporidia MB, an endosymbiont naturally found in Anopheles mosquitoes inhibits transmission of Plasmodium and is a promising candidate for a transmission-blocking...
BACKGROUND
Microsporidia MB, an endosymbiont naturally found in Anopheles mosquitoes inhibits transmission of Plasmodium and is a promising candidate for a transmission-blocking strategy that may involve mosquito release. A rapid assessment was carried out to develop insight into sociodemographic factors, public health concerns, and malaria awareness, management, and prevention practices with the willingness to accept and participate in Microsporidia MB-based transmission-blocking strategy to develop an informed stakeholder engagement process.
METHODS
The assessment consisted of a survey conducted in two communities in western Kenya that involved administering a questionnaire consisting of structured, semi-structured, and open questions to 8108 household heads.
RESULTS
There was an overall high level of willingness to accept (81%) and participate in the implementation of the strategy (96%). Although the willingness to accept was similar in both communities, Ombeyi community was more willing to participate (OR 22, 95% CI 13-36). Women were less willing to accept (OR 0.8, 95% CI 0.7-0.9) compared to men due to fear of increased mosquito bites near homes. Household heads with incomplete primary education were more willing to accept (OR 1.6, 95% CI 01.2-2.2) compared to those educated to primary level or higher. Perceiving malaria as a moderate or low public health issue was also associated with a lower willingness to accept and participate. Experience of > 3 malaria cases in the family over the last six months and knowledge that malaria is transmitted by only mosquito bites, increased the willingness to accept but reduced the willingness to participate. Awareness of malaria control methods based on mosquitoes that cannot transmit malaria increases the willingness to participate.
CONCLUSION
The study showed a high level of willingness to accept and participate in a Microsporidia MB-based strategy in the community, which is influenced by several factors such as community, disease risk perception, gender, education level, knowledge, and experience of malaria. Further research will need to focus on understanding the concerns of women, educated, and employed community members, and factors that contribute to the lower disease risk perception. This improved understanding will lead to the development of an effective communication strategy.
Topics: Male; Animals; Humans; Female; Kenya; Microsporidia; Insect Bites and Stings; Malaria; Public Health; Mosquito Control; Mosquito Vectors
PubMed: 38643165
DOI: 10.1186/s12936-024-04941-y -
Environmental Microbiology Reports Apr 2024Fungi are present in a wide variety of natural environments, and in the last years, various studies have shown that they are quite abundant in aquatic ecosystems. In...
Fungi are present in a wide variety of natural environments, and in the last years, various studies have shown that they are quite abundant in aquatic ecosystems. In addition, a whole new highly diverse phylum, the Cryptomycota, was discovered. Nevertheless, research on aquatic fungi and a detailed evaluation of their functions and distribution are still sparse. One of the main reasons is a limitation in reliable identification and quantification methods. To bridge part of the research gap, this study aims to implement a quantitative PCR method to detect and quantify the newly discovered phylum. We developed and validated a Cryptomycota-specific qPCR primer pair targeting the 5.8S region that detects the majority of Cryptomycota, but Microsporidia. The resulting amplicon is 102 bp long. We used different environmental samples to evaluate the primer pair, various fungal sequences as negative control and positive control sequences. Obtained amplicons were sequenced using Illumina, and the obtained ASVs were all classified as Cryptomycota. The qPCR method works reliably and specifically for the quantification of Cryptomycota in environmental samples.
Topics: Ecosystem; Fungi; Microsporidia; Environment
PubMed: 38615691
DOI: 10.1111/1758-2229.13257 -
Parasites & Vectors Apr 2024In the context of climate change, a growing concern is that vector-pathogen or host-parasite interactions may be correlated with climatic factors, especially increasing...
BACKGROUND
In the context of climate change, a growing concern is that vector-pathogen or host-parasite interactions may be correlated with climatic factors, especially increasing temperatures. In the present study, we used a mosquito-microsporidian model to determine the impact of environmental factors such as temperature, humidity, wind and rainfall on the occurrence rates of opportunistic obligate microparasites (Microsporidia) in hosts from a family that includes important disease vectors (Culicidae).
METHODS
In our study, 3000 adult mosquitoes collected from the field over 3 years were analysed. Mosquitoes and microsporidia were identified using PCR and sequencing of the hypervariable V5 region of the small subunit ribosomal RNA gene and a shortened fragment of the cytochrome c oxidase subunit I gene, respectively.
RESULTS
DNA metabarcoding was used to identify nine mosquito species, all of which were hosts of 12 microsporidian species. The prevalence of microsporidian DNA across all mosquito samples was 34.6%. Microsporidian prevalence in mosquitoes was more frequent during warm months (> 19 °C; humidity < 65%), as was the co-occurrence of two or three microsporidian species in a single host individual. During warm months, microsporidian occurrence was noted 1.6-fold more often than during the cold periods. Among the microsporidians found in the mosquitoes, five (representing the genera Enterocytospora, Vairimorpha and Microsporidium) were positively correlated with an increase in temperature, whereas one (Hazardia sp.) was significantly correlated with a decrease in temperature. Threefold more microsporidian co-occurrences were recorded in the warm months than in the cold months.
CONCLUSIONS
These results suggest that the susceptibility of mosquitoes to parasite occurrence is primarily determined by environmental conditions, such as, for example, temperatures > 19 °C and humidity not exceeding 62%. Collectively, our data provide a better understanding of the effects of the environment on microsporidian-mosquito interactions.
Topics: Animals; Culicidae; Temperature; Humidity; Mosquito Vectors; Microsporidia; DNA
PubMed: 38605410
DOI: 10.1186/s13071-024-06254-0