Search Results (216)

Haematopota pluvialis is a widely distributed hematophagic insect occurring across Eurasia. This horse fly may be a highly efficient mechanical vector of pathogens, including viruses, bacteria, and protozoa. Furthermore, its painful bites can cause local skin lesions and systemic symptoms. The aim of this study was to determine human exposure to H. pluvialis attacks in various types of open space habitats in Eastern Poland and to perform molecular screening of these tabanids for the presence of hematopathogens: Bartonella spp. and Anaplasma phagocytophilum. Specimens of H. pluvialis were collected at three distinct sites in Eastern Poland. The presence of Bartonella spp. and A. phagocytophilum was investigated using PCR-based methods. In total, 141 H. pluvialis females were analyzed. The molecular analysis of the rpoB gene fragment yielded one new haplotype of Bartonella sp. in 0.7% (1) of all studied samples, which may hypothetically exhibit zoonotic potential. Anaplasma phagocytophilum was not detected in the studied material. Moreover, a high level of human and animals exposure to horse fly bites was noted in the studied areas of Eastern Poland. The present results highlight the need for further targeted research on H. pluvialis to quantify pathogen prevalence, transmission efficiencies, and conditions facilitating pathogen transmission in natural settings. Full article

The poultry red mite Dermanyssus gallinae (PRM) is a hematophagous ectoparasite of major veterinary and public health concern, recognized as a potential vector of zoonotic pathogens. Despite recent advances in characterizing its microbiota, the temporal dynamics of the microbial community remain poorly understood. Here, we conducted a longitudinal metabarcoding survey of engorged PRM collected from a commercial cage-free laying hen farm over the laying hen’s productive cycle (30–105 weeks). High-throughput sequencing of the 16S rRNA V3–V4 region generated 412,078 sequences, identifying 186 bacterial species across all samples. Microbial richness peaked at 30 weeks (164 species), but sharply declined thereafter, with only 28, 55, and 43 species detected at 60, 90, and 105 weeks, respectively. Ordination (NMDS) and PERMANOVA analyses revealed significant temporal restructuring of microbial communities (R² = 0.76, p < 0.01), with distinct clustering across sampling points. A small subset of taxa persisted throughout time, including the genera Bartonella and Rickettsiella, while many species exhibited transient or stage-specific occurrence. Notably, zoonotic pathogens such as Staphylococcus aureus, Kocuria massiliensis, and Bartonella vinsonii were detected, suggesting that PRM may harbor microorganisms of potential medical and veterinary relevance. Overall, our findings demonstrate that PRM harbors a highly diverse but temporally dynamic microbiota, which progressively contracts into a community dominated by stable symbionts. These results highlight critical windows for microbial succession and reinforce the relevance of microbiome-based surveillance and integrated control strategies within a One Health framework. Full article

The protozoan Trypanosoma cruzi is the etiological agent of Chagas disease, a neglected tropical disease that mostly affects the population of Latin American countries, with an estimated 7 million infected people and more than 10,000 deaths per year worldwide. T. cruzi is typically transmitted by hematophagous triatomine insects, with Rhodnius prolixus being a major insect vector in South America. While the microbiome of triatomine insects has been investigated to a certain extent, the ternary interaction between triatomes insects, T. cruzi, and viruses remains virtually unexplored. In this study, we show by transmission electron microscopy and by RT-PCR that Rhodnius prolixus viruses (RpVs) can infect the intestine of R. prolixus, which places them in close contact with the gut microbiota. These observations suggest that T. cruzi can be infected by the insect viruses while transiting through the gut. Here, we show that the RpVs are capable of infecting the epimastigote forms of T. cruzi in vitro and maintain the viral load stabilized for 3 to 7 days after infection. We also show that, at least in the case of the iFlavirus RpV1, viral genomes are detectable in the T. cruzi cytoplasm. Interestingly, R. prolixus ovarian extracts enriched with RpVs decrease epimastigote proliferation and their capacity for differentiation into the ineffective metacyclic trypomastigotes in vitro. Our results start to shed light on the interaction between RpVs and T. cruzi, suggesting possible routes of infection and unveiling a role for viral infections in the development of this important pathogen. Full article

Advances in diagnostic techniques, along with environmental changes driven by human activity, have intensified the surveillance and monitoring of virus and arbovirus circulation on the Amazon. These efforts have increased the detection of insect-specific viruses in field-collected hematophagous arthropods. This study reports the first isolation of the Aguas Brancas virus from mosquitoes collected in the Brazilian Amazon and in a rural area of Brasília, Federal District, Brazil. Arthropods of the family Culicidae, genus Limatus durhamii, were collected at ground level in forest fragments. Sample BEAR812610 originated from Ananindeua, Pará, within the Evandro Chagas Institute’s grounds, and sample BEAR839941 from a forest fragment in Brasília (Ceilândia—Núcleo Rural Boa Esperança, Site B4). Specimens were identified to the species/genus level, macerated, and the supernatant inoculated into C6/36 and Vero cell cultures for viral isolation. The presence of arboviruses was determined by indirect immunofluorescence using antibodies against major arbovirus groups. Positive samples were sequenced for nucleotide and amino acid identification, and phylogenetic analysis confirmed the virus as belonging to the genus Orthoflavivirus. This represents the first report of the isolation and characterization of the insect-specific Aguas Brancas virus. Full article

Heme released during blood digestion represents a major oxidative challenge for hematophagous insects, promoting the generation of reactive oxygen species (ROS) and redox imbalance. Although Aedes aegypti has evolved specialized mechanisms to mitigate heme toxicity, how these responses vary across developmental stages remains poorly understood. Here, we applied quantitative proteomics to compare the effects of heme exposure in larvae and adult females. In larvae, heme treatment predominantly led to downregulation of metabolic and antioxidant proteins, consistent with a shift toward energy conservation and growth regulation. Nonetheless, selective upregulation of proteins associated with mitochondrial MnSOD activity, lipid remodeling, and cytoskeletal organization indicates the engagement of complementary protective mechanisms. In contrast, adults exhibited a coordinated bioenergetic response, characterized by enrichment of mitochondrial pathways, redox-related proteins, and molecular chaperones, reflecting enhanced resilience to oxidative stress. Enrichment of cuticle-associated proteins in both stages further suggests heme-induced structural remodeling. Together, these findings demonstrate that A. aegypti employs divergent, stage-specific proteomic strategies to cope with heme toxicity: larvae suppress metabolic activity while maintaining structural and redox homeostasis, whereas adults reinforce mitochondrial function and proteostatic defenses. These insights advance our understanding of mosquito redox biology and highlight stage-specific vulnerabilities that may be exploited for innovative vector control strategies. Full article

Avian haemosporidians are globally distributed protozoan parasites transmitted by hematophagous vectors, yet information on their occurrence in the Stone-curlew (Burhinus oedicnemus), particularly from the Canary Islands, is scarce. Between 2020 and 2024, 47 Stone-curlews were examined for Haemoproteus, Plasmodium, and Leucocytozoon spp. using nested PCR targeting the cytochrome b gene, followed by sequencing and phylogenetic analysis. Histopathological examination was performed on formalin-fixed tissues. Leucocytozoon sp. DNA was detected in one individual (case FS415/23), with identical sequences amplified from multiple organs. Phylogenetic analysis placed this isolate within lineage CIAE02, previously reported in raptors and other avian taxa. Microscopic evaluation revealed megalomeronts in the liver, kidney, and skin, consistent with Leucocytozoon infection. Despite concurrent infection with Avipoxvirus and Aspergillus fumigatus, no prominent inflammatory reaction surrounded the haemosporidian tissue states. The only prior haemosporidian reported in Burhinus is Haemoproteus burhinus, described from B. oedicnemus saharae in Iraq, and no Leucocytozoon infections have previously been recorded in this genus. Therefore, this represents the first evidence of Leucocytozoon infection in the Stone-curlew, extending the known host range of lineage CIAE02. These findings highlight the relevance of integrative diagnostic approaches for detecting latent or cryptic haemosporidian infections in non-passerine avian hosts. Full article

Hematophagous leeches rely on a broad diversity of bioactive factors that interfere with the host’s defense systems to secure a successful blood meal. The most prominent examples of such factors are the antithrombotics that address either the primary hemostasis (the platelet aggregation) or the secondary hemostasis (the blood coagulation). Whereas the inhibitors of platelet aggregation mainly cause continuous blood flow, coagulation inhibitors mainly keep the blood fluid within the stomach of the leech. The critical dependency of hematophagous leeches on the accurate action of all antithrombotic factors may explain the presence of multiple genes for each type of these factors that is regularly observed in leech genomes. The genome of Hirudinaria manillensis Lesson, 1842, the Asian buffalo leech, contains five individual genes that encode variants of the coagulation inhibitor hirudin. However, no genes that encode putative decorsins, the archetype of leech-derived inhibitors of platelet aggregation, have been described to date. Here, we report the identification of one monomeric and four multimeric decorsin encoding genes in the genome of H. manillensis. A selection of the putative decorsins was expressed as recombinant proteins, purified and functionally characterized. All but one of these putative decorsins displayed platelet aggregation-inhibitory potencies. Furthermore, we provide a mathematical calculation based on the mechanism of alternative pre-mRNA splicing that illustrates the potential to generate an enormous variety of different factors from one single multimeric ornatin gene. Full article

Background/Objectives: Leeches constitute a pharmacologically significant animal group in traditional medicine due to their antithrombotic peptides, which include numerous members of the hirustasin gene superfamily. However, a comparative expression profile of this pharmaceutically important family across different leech species is lacking. Methods: This study conducted a comparative transcriptomic analysis of hirustasin gene superfamily expression in the hematophagous leech Hirudinaria manillensis and the non-hematophagous leech Whitmania pigra. Results: The total expression of the hirustasin gene superfamily, quantified as transcripts per million (TPM), showed no significant difference (p = 0.237) between H. manillensis (11,802.60 ± 1596.59) and W. pigra (8623.12 ± 965.96). However, both species exhibited pronounced intergenic expression heterogeneity. Five dominantly expressed genes (TPM > 1000) in H. manillensis and three in W. pigra were identified, collectively comprising 81% and 62% of the total hirustasin gene superfamily expression per species, respectively. Critically, the dominantly expressed genes exhibited no phylogenetic correspondence between species. Integrating expression profiles with phylogenetic reconstruction identified five high-potential candidate genes: poecistasin_Hman2, hirustasin_like_Hman01, hirustasin_like_Hman11, guamerin_Wpig, and bdellastasin_Wpig. Population-level analysis revealed marked population-specific expression patterns in H. manillensis, contrasting with minimal inter-population divergence in W. pigra. Nevertheless, geographically distinct populations of both species showed significant variation in the expression of their respective dominantly expressed genes. Conclusions: These findings provide a set of high-priority candidate genes and insights into their expression characteristics, serving as a starting point for subsequent functional validation and, when integrated with other screening methods, for future antithrombotic drug discovery. Full article

Adult black flies were collected from diverse habitats in five provinces of Laos. In total, 4659 adults (4570 females and 89 males) were collected. Morphological identification, supplemented with the mitochondrial cytochrome c oxidase I gene, revealed 12 species. The most abundant taxa were Simulium khelangense/S. chumpornense and S. asakoae/S. myanmarense with 58% (2628 of 4476) and 38% (1720 of 4476) of the total specimens, respectively. Simulium asakoae/S. myanmarense was the most geographically widespread taxon (65% of sites) from 174 to 1219 m above sea level. The remaining species were far less abundant (<2%) and found in only one or a few locations. Molecular identifications of vertebrate blood meals indicated that most hosts (57 of 66) were chickens. Five taxa, S. asakoae, S. khelangense, S. myanmarense, S. aureohirtum, and S. striatum group, fed on chickens, representing the first hosts records for the latter three taxa. Simulium daoense fed on water buffalo, marking the first record of this species in Laos and the first report of its blood hosts. The abundance and frequent use of domestic chickens as hosts suggests that S. khelangense and S. asakoae could be significant pests and might serve as vectors of avian blood parasites in Laos. Full article

This study investigates the species composition and distribution of blackflies (Diptera: Simuliidae) in Kazakhstan, with a focus on two species newly recorded for the country: Simulium murmanum (Enderlein, 1935) and Simulium reptans (Linnaeus, 1758). The presence of S. murmanum in Kazakhstan is reported for the first time, supported by morphological and molecular genetic analyses. Diagnostic features of the larva, pupa, and adult stages are described in detail, including the structure and coloration of the larval head capsule, pupal cocoon, and genitalia of both sexes. Habitat preferences and pupal substrate attachment patterns are illustrated, with observations on variations in cocoon branching across different flow regimes. Species identification was conducted using the morphological keys of Rubtsov and Yankovsky, and taxonomic classification was confirmed using the framework proposed by Adler. Molecular confirmation of S. murmanum was performed via DNA analysis. The species was found to be restricted to the foothill regions of East Kazakhstan, suggesting a distribution closely associated with the Altai mountain systems and adjacent regions in Mongolia and China. Unlike its status as a dominant hematophagous species in parts of Russia, S. murmanum has not demonstrated biting activity in Kazakhstan, Mongolia, or China. Additionally, the study provides the first records of S. reptans within the fauna of Kazakhstan, initially identified in the Irtysh River (Pavlodar Region). Subsequent sampling conducted in June 2024 revealed a continuous distribution of S. reptans along the Irtysh River through to the mountain streams of East Kazakhstan. The species was found in mountainous, foothill, and lowland environments, highlighting its wide ecological plasticity. Full article

Stomoxys calcitrans (Linnaeus, 1758) is a hematophagous fly species of veterinary importance, known for its negative effects on animal health and productivity. The stress caused by their painful bites results in losses in milk and meat production. Despite its impact, data on its ecology and activity in Algeria are lacking. Such knowledge is needed to evaluate its potential effects on livestock production and rural health, and to support surveillance, outbreak prediction, and control strategies. This study aimed to investigate the monthly and daily dynamics of S. calcitrans in livestock farms in the Batna region and evaluate the influence of climatic factors on its abundance. From July 2022 to July 2023, Vavoua traps were placed monthly from 7 a.m. to 6 p.m. on four farms in the Batna region, representing different livestock types. Captured flies were identified, sexed, and counted every two hours. Climatic data were collected both in situ and from NASA POWER datasets. Fly abundance was analyzed using non-parametric statistics, Spearman’s correlation, and multiple regression analysis. A total of 1244 S. calcitrans were captured, mainly from cattle farms. Activity occurred from August to December, with a peak in September. Males were more abundant and exhibited a bimodal activity in September. Fly abundance was positively correlated with temperature and precipitation and negatively correlated with wind speed and humidity. This study presents the first ecological data on S. calcitrans in northeastern Algeria, highlighting its seasonal dynamics and the climatic drivers that influence it. The results highlight the species’ preference for cattle and indicate that temperature and rainfall are key factors influencing its abundance. These findings lay the groundwork for targeted control strategies against this neglected pest in Algeria. Full article

Background: Argas persicus is a hematophagous ectoparasite of poultry and is the vector of several agents infectious to poultry. This study aims to explore the key genes affecting the ovarian development of A. persicus. Methods: RNA-seq was performed on the ovaries of A. persicus before blood-feeding, on the day of engorgement, and 6 days post-engorgement. Utilizing the threshold padj < 0.05 and|log₂(foldchange)| > 1, differentially expressed genes were identified, and hub genes were determined by constructing protein–protein interaction (PPI) networks. Results: A total of 1008 differentially expressed genes were obtained during the feeding period, including 448 up-regulated and 560 down-regulated genes. Further, 2179 differentially expressed genes were screened in the preoviposition stage, including 1957 up-regulated and 222 down-regulated genes. These genes are mainly annotated in functions such as peptidase activity (especially serine protease activity), protein folding, protein assembly, and cell component assembly, and enriched in pathways such as protein processing in endoplasmic reticulum, lysosome, glutathione metabolism, and sphingolipid metabolism. In addition, some proteins that are closely related to ovarian development, including heat shock protein 70, protein disulfide isomerase, paramyosin, troponin I, hexosaminidase, serine protease, Kunitz serine protease inhibitors, and vitellogenin, were obtained. Conclusions: These findings fill the gap in the biological data for the ovarian development of soft ticks, provide a reference database for subsequent proteomics research, and offer fundamental support for the screening and development of candidate antigens for anti-tick vaccines. Full article

Leeches are aquatic annelids of significant medicinal value, known to produce a variety of antithrombotic proteins. However, the extent of interspecies variation in these bioactive components remains poorly understood. In this study, next-generation sequencing and the Pichia pastoris eukaryotic expression system were employed to systematically analyze the diversity of leech-derived tryptase inhibitor (LDTI) genes and their functional activities across four dominant medicinal leech species: Hirudinaria manillensis, Hirudo nipponia, Whitmania pigra, and Whitmania laevis. Our results revealed a slightly higher genetic variation in LDTI genes and their protein among non-hematophagous leeches (W. pigra and W. laevis) compared to hematophagous species (H. manillensis and H. nipponia). Selection analysis indicated purifying selection in H. manillensis (ω = 0.47), while the other species exhibited either neutral or weak positive selection (ω ≥ 1). LDTI expression levels were significantly higher in hematophagous leeches, with peak expression observed in H. manillensis (transcripts per million = 2942.07 ± 1593.12). In vitro chromogenic substrate-based anticoagulant assays of recombinant proteins confirmed anticoagulation activity across all species, with H. manillensis displaying the most potent inhibition. These findings demonstrate the antithrombotic potential of all four species, regardless of their feeding ecology. Moreover, H. manillensis emerges as the optimal candidate for therapeutic development, owing to its superior LDTI sequence conservation, expression levels, and specific anticoagulant activity per unit concentration. Full article

This study continues earlier work aimed at identifying potential natural reservoirs of camelpox virus (CMLV) during interepizootic periods. In 2023–2024, field expeditions in western Kazakhstan led to the collection and analysis of biological samples from camels, rodents and hematophagous insects. Despite the absence of clinical symptoms, PCR-positive results were obtained from camel blood samples. These samples underwent molecular genetic analysis, including viral DNA detection and whole-genome sequencing. Using next-generation sequencing, the complete genome of the Camelpox virus/Beineu/2023 isolate (202.273 bp) was obtained and deposited in the NCBI database (accession number PV920573.1). The isolate showed >98% genetic similarity to the previously described Kazakhstan strain M-96, indicating long-term local circulation of a genetically stable variant. Phylogenetic analysis confirmed the isolate’s evolutionary conservatism and close relationship with other CMLV strains. The findings suggest that camels serve as a natural reservoir, enabling viral persistence and potential reactivation under stress-related conditions. The observed geographic clustering underscores the need for region-specific molecular surveillance to ensure timely detection of new variants and prevent cross-border spread. Full article

Ticks are hematophagous ectoparasites capable of transmitting a wide array of pathogens. The recent proliferation and geographic expansion of tick populations have intensified concerns regarding the escalating risk of tick-borne pathogen transmission. Among these, Anaplasma phagocytophilum poses a notable threat to both public and veterinary health due to its zoonotic potential. In this study, a total of 4316 ticks were collected from 16 pasture sites near livestock farms in Gyeonggi and Gangwon Provinces, Republic of Korea, between April and October 2024. Molecular epidemiological analysis was subsequently performed. Of the 400 tick pools tested, Ixodes nipponensis accounted for two Anaplasma-positive pools, Haemaphysalis spp. larvae for two pools, and Haemaphysalis longicornis for one pool. This study is the first to examine the infection rate of A. phagocytophilum in ticks collected from pasture sites near livestock farms in Gyeonggi and Gangwon Provinces. Although the observed infection rate was low, the presence of A. phagocytophilum in regions with potential human exposure emphasizes the risk of transmission. Importantly, the detection of A. phagocytophilum in larval-stage ticks suggests the possibility of transovarial transmission, meriting further investigation. These findings underscore the need for conducting surveillance and targeted preventive strategies to reduce the burden of tick-borne diseases in livestock-associated settings. Full article