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Extracellular Vesicle Jun 2024Extracellular vesicles (EVs) are membrane-bound vesicles released into the extracellular milieu from various cell types including host cells and pathogens that infect...
Extracellular vesicles (EVs) are membrane-bound vesicles released into the extracellular milieu from various cell types including host cells and pathogens that infect them. As carriers of nucleic acids, proteins, lipids, metabolites, and virulence factors, EVs act as delivery vehicles for intercellular communication and quorum sensing. Innate immune cells have the capacity to intercept, internalize, and interpret 'messages' contained within these EVs. This review categorizes the ability of EVs secreted by bacterial, parasitic, and fungal pathogens to trigger both pro- and anti-inflammatory innate immune responses in the host. Understanding molecular pathways and inflammatory responses activated in innate immune cells upon pathogen-derived EV stimulation is critical to gain insight into potential therapeutics and combat these infectious diseases.
PubMed: 38939756
DOI: 10.1016/j.vesic.2024.100043 -
Current Tropical Medicine Reports Dec 2023Human African Trypanosomiasis (HAT), also known as sleeping sickness, is a vector-borne parasitic neglected tropical disease (NTD) endemic in sub-Saharan Africa. This...
PURPOSE OF REVIEW
Human African Trypanosomiasis (HAT), also known as sleeping sickness, is a vector-borne parasitic neglected tropical disease (NTD) endemic in sub-Saharan Africa. This review aims to enhance our understanding of HAT and provide valuable insights to combat this significant public health issue by synthesizing the latest research and evidence.
RECENT FINDINGS
HAT has reached a historical < 1000 cases in 2018. In patients without neurologic symptoms and signs, the likelihood of a severe meningoencephalitic stage is deemed low, obviating the need for a lumbar puncture to guide treatment decisions using fexinidazole.
SUMMARY
Both forms of the disease, gambiense HAT (gHAT) and rhodesiense HAT (rHAT), have specific epidemiology, risk factors, diagnosis, and treatment. Disease management still requires a high index of suspicion, infectious disease expertise, and specialized medical care. Essential stakeholders in health policy are critical to accomplishing the elimination goals of the NTD roadmap for 2021-2030.
PubMed: 38939748
DOI: 10.1007/s40475-023-00304-w -
Frontiers in Immunology 2024
Topics: Biomarkers; Animals; Humans; Host-Parasite Interactions; Trypanosomiasis; Trypanosomatina; Trypanosoma
PubMed: 38938579
DOI: 10.3389/fimmu.2024.1422067 -
Journal of Extracellular Biology Sep 2023Extracellular vesicles (EVs) recently emerged as important players in the pathophysiology of parasitic infections. While the protist parasite can produce EVs, their...
Extracellular vesicles (EVs) recently emerged as important players in the pathophysiology of parasitic infections. While the protist parasite can produce EVs, their role in giardiasis remains obscure. can disrupt gut microbiota biofilms and transform commensal bacteria into invasive pathobionts at sites devoid of colonizing trophozoites via unknown mechanisms. We hypothesized that EVs could modify gut bacterial behaviour via a novel mode of trans-kingdom communication. Our findings indicate that EVs exert bacteriostatic effects on HB101 and TW1, increasing their swimming motility. EVs also decreased the biofilm-forming ability of HB101 but not by TW1, supporting the hypothesis that these effects are, at least in part, bacteria-selective. HB101 and TW1 exhibited increased adhesion/invasion onto small intestine epithelial cells when exposed to EVs. EVs labelled with PKH67 revealed colocalization with HB101 and TW1 bacterial cells. Small RNA sequencing revealed a high abundance of ribosomal RNA (rRNA)- and transfer RNA (tRNA)-derived small RNAs, short-interfering RNAs (siRNAs) and micro-RNAs (miRNAs) within EVs. Proteomic analysis of EVs uncovered the presence of RNA chaperones and heat shock proteins that can facilitate the thermal stability of EVs and its sRNA cargo, as well as protein-modifying enzymes. In vitro, RNase heat-treatment assays showed that total RNAs in EVs, but not proteins, are responsible for modulating bacterial swimming motility and biofilm formation. small RNAs of EVs, but not proteins, were responsible for the increased bacterial adhesion to intestinal epithelial cells induced upon exposure to EVs. Together, the findings indicate that EVs contain a heat-stable, RNase-sensitive cargo that can trigger the development of pathobiont characteristics in Enterobacteria, depicting a novel trans-kingdom cross-talk in the gut.
PubMed: 38938375
DOI: 10.1002/jex2.109 -
Parasites & Vectors Jun 2024Digital imaging combined with deep-learning-based computational image analysis is a growing area in medical diagnostics, including parasitology, where a number of...
BACKGROUND
Digital imaging combined with deep-learning-based computational image analysis is a growing area in medical diagnostics, including parasitology, where a number of automated analytical devices have been developed and are available for use in clinical practice.
METHODS
The performance of Parasight All-in-One (AIO), a second-generation device, was evaluated by comparing it to a well-accepted research method (mini-FLOTAC) and to another commercially available test (Imagyst). Fifty-nine canine and feline infected fecal specimens were quantitatively analyzed by all three methods. Since some samples were positive for more than one parasite, the dataset consisted of 48 specimens positive for Ancylostoma spp., 13 for Toxocara spp. and 23 for Trichuris spp.
RESULTS
The magnitude of Parasight AIO counts correlated well with those of mini-FLOTAC but not with those of Imagyst. Parasight AIO counted approximately 3.5-fold more ova of Ancylostoma spp. and Trichuris spp. and 4.6-fold more ova of Toxocara spp. than the mini-FLOTAC, and counted 27.9-, 17.1- and 10.2-fold more of these same ova than Imagyst, respectively. These differences translated into differences between the test sensitivities at low egg count levels (< 50 eggs/g), with Parasight AIO > mini-FLOTAC > Imagyst. At higher egg counts Parasight AIO and mini-FLOTAC performed with comparable precision (which was significantly higher that than Imagyst), whereas at lower counts (> 30 eggs/g) Parasight was more precise than both mini-FLOTAC and Imagyst, while the latter two methods did not significantly differ from each other.
CONCLUSIONS
In general, Parasight AIO analyses were both more precise and sensitive than mini-FLOTAC and Imagyst and quantitatively correlated well with mini-FLOTAC. While Parasight AIO produced lower raw counts in eggs-per-gram than mini-FLOTAC, these could be corrected using the data generated from these correlations.
Topics: Animals; Cats; Dogs; Feces; Dog Diseases; Parasite Egg Count; Cat Diseases; Toxocara; Ancylostoma; Trichuris; Helminths; Helminthiasis, Animal; Ovum
PubMed: 38937854
DOI: 10.1186/s13071-024-06351-0 -
Parasites & Vectors Jun 2024Indoor residual spraying (IRS) has been implemented to prevent malaria in Zambia for several decades, but its effectiveness has not been evaluated long term and in Vubwi...
BACKGROUND
Indoor residual spraying (IRS) has been implemented to prevent malaria in Zambia for several decades, but its effectiveness has not been evaluated long term and in Vubwi District yet. This study aimed to assess the association between IRS and the malaria burden in Zambia and Vubwi District and to explore the factors associated with refusing IRS.
METHODS
A retrospective study was used to analyze the association between IRS and malaria incidence in Zambia in 2001-2020 and in Vubwi District in 2014-2020 by Spearman correlation analysis. A case-control study was used to explore the factors associated with IRS refusals by households in Vubwi District in 2021. A logistic regression model was performed to identify factors associated with IRS refusals.
RESULTS
The malaria incidence reached its peak (391/1000) in 2001 and dropped to the lowest (154/1000) in 2019. The annual percentage change in 2001-2003, 2003-2008, 2008-2014, 2014-2018 and 2018-2020 was - 6.54%, - 13.24%, 5.04%, - 10.28% and 18.61%, respectively. A significantly negative correlation between the percentage of population protected by the IRS against the total population in Zambia (coverage) and the average malaria incidence in the whole population was observed in 2005-2020 (r = - 0.685, P = 0.003) and 2005-2019 (r = - 0.818, P < 0.001). Among 264 participants (59 in the refuser group and 205 in the acceptor group), participants with specific occupations (self-employed: OR 0.089, 95% CI 0.022-0.364; gold panning: OR 0.113, 95% CI 0.022-0.574; housewives: OR 0.129, 95% CI 0.026-0.628 and farmers: OR 0.135, 95% CI 0.030-0.608 compared to employees) and no malaria case among household members (OR 0.167; 95% CI 0.071-0.394) had a lower risk of refusing IRS implementation, while those with a secondary education level (OR 3.690, 95% CI 1.245-10.989) had a higher risk of refusing IRS implementation compared to those who had never been to school.
CONCLUSIONS
Increasing coverage with IRS was associated with decreasing incidence of malaria in Zambia, though this was not observed in Vubwi District, possibly because of the special geographical location of Vubwi District. Interpersonal communication and targeted health education should be implemented at full scale to ensure household awareness and gain community trust.
Topics: Zambia; Humans; Case-Control Studies; Malaria; Mosquito Control; Incidence; Retrospective Studies; Insecticides; Female; Male; Animals; Adult; Child, Preschool; Child; Adolescent
PubMed: 38937791
DOI: 10.1186/s13071-024-06328-z -
Parasites & Vectors Jun 2024Along the southern shoreline of Lake Malawi, the incidence of schistosomiasis is increasing with snails of the genera Bulinus and Biomphalaria transmitting urogenital...
BACKGROUND
Along the southern shoreline of Lake Malawi, the incidence of schistosomiasis is increasing with snails of the genera Bulinus and Biomphalaria transmitting urogenital and intestinal schistosomiasis, respectively. Since the underlying distribution of snails is partially known, often being focal, developing pragmatic spatial models that interpolate snail information across under-sampled regions is required to understand and assess current and future risk of schistosomiasis.
METHODS
A secondary geospatial analysis of recently collected malacological and environmental survey data was undertaken. Using a Bayesian Poisson latent Gaussian process model, abundance data were fitted for Bulinus and Biomphalaria. Interpolating the abundance of snails along the shoreline (given their relative distance along the shoreline) was achieved by smoothing, using extracted environmental rainfall, land surface temperature (LST), evapotranspiration, normalised difference vegetation index (NDVI) and soil type covariate data for all predicted locations. Our adopted model used a combination of two-dimensional (2D) and one dimensional (1D) mapping.
RESULTS
A significant association between normalised difference vegetation index (NDVI) and abundance of Bulinus spp. was detected (log risk ratio - 0.83, 95% CrI - 1.57, - 0.09). A qualitatively similar association was found between NDVI and Biomphalaria sp. but was not statistically significant (log risk ratio - 1.42, 95% CrI - 3.09, 0.10). Analyses of all other environmental data were considered non-significant.
CONCLUSIONS
The spatial range in which interpolation of snail distributions is possible appears < 10km owing to fine-scale biotic and abiotic heterogeneities. The forthcoming challenge is to refine geospatial sampling frameworks with future opportunities to map schistosomiasis within actual or predicted snail distributions. In so doing, this would better reveal local environmental transmission possibilities.
Topics: Animals; Malawi; Lakes; Biomphalaria; Bulinus; Schistosomiasis; Spatial Analysis; Humans; Bayes Theorem; Snails; Disease Vectors
PubMed: 38937778
DOI: 10.1186/s13071-024-06353-y -
BMC Veterinary Research Jun 2024Rickettsia occurs worldwide and rickettsiosis is recognized as an emerging infection in several parts of the world. Ticks are reservoir hosts for pathogenic Rickettsia...
Rickettsia occurs worldwide and rickettsiosis is recognized as an emerging infection in several parts of the world. Ticks are reservoir hosts for pathogenic Rickettsia species in humans and domestic animals. Most pathogenic Rickettsia species belong to the spotted Fever Group (SFG). This study aimed to identify and diagnose tick fauna and investigate the prevalence of Rickettsia spp. in ticks collected from domestic animals and dogs in the rural regions of Kerman Province, Southeast Iran. In this study, tick species (fauna) were identified and 2100 ticks (350 pooled samples) from two genera and species including Rhipicephalus linnaei (1128) and Hyalomma deteritum (972) were tested to detect Rickettsia genus using Real-time PCR. The presence of the Rickettsia genus was observed in 24.9% (95%CI 20.28-29.52) of the pooled samples. Sequencing and phylogenetic analyses revealed the presence of Rickettsia aeschlimannii (48.98%), Rickettsia conorii israelensis (28.57%), Rickettsia sibirica (20.41%), and Rickettsia helvetica (2.04%) in the positive samples. The results showed a significant association between county variables and the following variables: tick spp. (p < 0.001), Rickettsia genus infection in ticks (p < 0.001) and Rickettsia spp. (p < 0.001). In addition, there was a significant association between tick species and host animals (dogs and domestic animals) (p < 0.001), Rickettsia spp infection in ticks (p < 0.001), and Rickettsia spp. (p < 0.001). This study indicates a high prevalence of Rickettsia spp. (SFG) in ticks of domestic animals and dogs in rural areas of Kerman Province. The health system should be informed of the possibility of rickettsiosis and the circulating species of Rickettsia in these areas.
Topics: Animals; Rickettsia; Iran; Dogs; Dog Diseases; Phylogeny; Ixodidae; Cattle; Sheep; Horses; Cats; Female; Goats; Male; Cattle Diseases; Tick Infestations; Rickettsia Infections; Animals, Domestic; Sheep Diseases; Sheep, Domestic
PubMed: 38937767
DOI: 10.1186/s12917-024-04142-4 -
Scientific Reports Jun 2024Poor birth outcomes in low- and middle income countries are associated with maternal vitamin D deficiency and chronic helminth infections. Here, we investigated whether...
Poor birth outcomes in low- and middle income countries are associated with maternal vitamin D deficiency and chronic helminth infections. Here, we investigated whether maternal Schistosoma haematobium affects maternal or cord vitamin D status as well as birth outcomes. In a prospective cross-sectional study of pregnant women conducted in Lambaréné, Gabon, we diagnosed maternal parasitic infections in blood, urine and stool. At delivery we measured vitamin D in maternal and cord blood. S. haematobium, soil-transmitted helminths, and microfilariae were found at prevalences of 30.2%, 13.0%, and 8.8%, respectively. Insufficient vitamin D and calcium levels were found in 28% and 15% of mothers, and in 11.5% and 1.5% of newborns. Mothers with adequate vitamin D had lower risk of low birthweight babies (aOR = 0.11, 95% CI 0.02-0.52, p = 0.01), whilst offspring of primipars had low cord vitamin D levels, and low vitamin D levels increased the risk of maternal inflammation. Maternal filariasis was associated with low calcium levels, but other helminth infections affected neither vitamin D nor calcium levels in either mothers or newborns. Healthy birth outcomes require maintenance of adequate vitamin D and calcium levels. Chronic maternal helminth infections do not disrupt those levels in a semi-rural setting in sub-Saharan Africa.
Topics: Humans; Pregnancy; Female; Infant, Newborn; Adult; Pregnancy Complications, Parasitic; Vitamin D; Helminthiasis; Vitamin D Deficiency; Cross-Sectional Studies; Pregnancy Outcome; Young Adult; Prospective Studies; Prevalence
PubMed: 38937587
DOI: 10.1038/s41598-024-65232-9 -
International Journal For Parasitology Jun 2024Establishing an intact intracellular parasitophorous vacuole (PV) that enables efficient nutrient uptake and protein trafficking is essential for the survival and...
Establishing an intact intracellular parasitophorous vacuole (PV) that enables efficient nutrient uptake and protein trafficking is essential for the survival and proliferation of Toxoplasma gondii. Although the PV membrane (PVM)-localized dense granule protein 17 (GRA17) and GRA23 mediate the permeability of the PVM to small molecules, including nutrient uptake and excretion of metabolic by-products, the molecular mechanism by which T. gondii acquires nutrients remains unclear. In this study, we showed that the secreted protein GRA47 contributed to normal PV morphology, PVM permeability to small molecules, growth, and virulence in T. gondii. Co-immunoprecipitation analysis demonstrated potential interaction of GRA47 with GRA72, and the loss of GRA72 affected PV morphology, parasite growth and infectivity. To investigate the biological relationship among GRA47, GRA72, GRA17 and GRA23, attempts were made to construct strains with double gene deletion and overexpressing strains. Only Δgra23Δgra72 was successfully constructed. This strain exhibited a significant increase in the proportion of aberrant PVs compared with the Δgra23 strain. Overexpressing one of the three related GRAs partially rescued PVs with aberrant morphology in Δgra47, Δgra72 and Δgra17, while the expression of the Plasmodium falciparum PVM protein PfExp2, an ortholog of GRA17 and GRA23, fully rescued the PV morphological defect in all three Δgra strains. These results suggest that these three GRA proteins may not be functionally redundant but rather work in different ways to regulate nutrient acquisition. These findings highlight the versatility of the nutrient uptake mechanisms in T. gondii, which may contribute to the parasite's remarkable ability to grow in different cellular niches in a very broad range of hosts.
PubMed: 38936501
DOI: 10.1016/j.ijpara.2024.06.003