Hematophagous Parasites Research Articles

Immunomodulatory effect of hemozoin from Opisthorchis felineus and its participation in reducing allergic inflammation through activation of the inflammasome

Molecules of the excretory-secretory product arising as a result of co-evolution of a host and a parasite are able to inhibit the type 2 immune response, while activating the type 1 and the type 17 responses. The ability to alter the immune response can be used to inhibit inflammation in allergic diseases. In this regard, a search for helminth-associated molecules both with an immunomodulatory effect and immunogenicity and low toxicity is represented as a topical task. Hemozoin being a dark brown insoluble biocrystal is an excretory product of a number of hematophagous parasites (Schistosoma mansoni, Plasmodium falciparum and Opisthorchis felineus). This substance as a compound of parasitic origin with explicit immunomodulatory properties has prospects for deep research. Lots of relevant literature has been studied carefully before developing a concept about Opisthorchis felineus hemozoin and its unique properties. Thus, the current review presents an analysis of the accumulated data regarding the effect of Opisthorchis felineus trematode on the host immune system. Also the data on the immunomodulatory effect of hemozoin of various origins is analyzed. The current knowledge on the immune mechanisms of inflammasome activation and the possible role of hemozoin in reducing allergic inflammation through this mechanism is represented in this article. According to the systemized research results the excretory-secretory molecule of the liver fluke is a product of parasitic origin with an explicit immunomodulatory effect which is promising for prospective scientific study. Opisthorchis felineus extract increases the expression of T-regulatory cells and inhibits the Th2-immune response. Hemozoin produced by Opisthorchis felineus, like one produced by Plasmodium falciparum, may be involved in reducing the activity of allergic inflammation through activation of the inflammasome. Comprehension of the mechanism of how hemozoin interacts with the host immune system can be applied for correction of conditions associated with Th2-polarization of the immune response, which primarily include atopic diseases. Studying the mechanism of inflammation will help by the search for a biological target to create a vaccine to prevent the spread of atopic diseases, including bronchial asthma.

Tick species diversity and potential distribution alternation of dominant ticks under different climate scenarios in Xinjiang, China.

Ticks are a hematophagous parasite and a vector of pathogens for numerous human and animal diseases of significant importance. The expansion of tick distribution and the increased risk of tick-borne diseases due to global climate change necessitates further study of the spatial distribution trend of ticks and their potential influencing factors. This study constructed a dataset of tick species distribution in Xinjiang for 60 years based on literature database retrieval and historical data collection (January 1963-January 2023). The distribution data were extracted, corrected, and deduplicated. The dominant tick species were selected for analysis using the MaxEnt model to assess their potential distribution in different periods under the current and BCC-CSM2.MR mode scenarios. The results indicated that there are eight genera and 48 species of ticks in 108 cities and counties of Xinjiang, with Hyalomma asiaticum, Rhipicephalus turanicus, Dermacentor marginatus, and Haemaphysalis punctatus being the top four dominant species. The MaxEnt model analysis revealed that the suitability areas of the four dominant ticks were mainly distributed in the north of Xinjiang, in areas such as Altay and Tacheng Prefecture. Over the next four periods, the medium and high suitable areas within the potential distribution range of the four tick species will expand towards the northwest. Additionally, new suitability areas will emerge in Altay, Changji Hui Autonomous Prefecture, and other local areas. The 60-year tick dataset in this study provides a map of preliminary tick distribution in Xinjiang, with a diverse array of tick species and distribution patterns throughout the area. In addition, the MaxEnt model revealed the spatial change characteristics and future distribution trend of ticks in Xinjiang, which can provide an instrumental data reference for tick monitoring and tick-borne disease risk prediction not only in the region but also in other countries participating in the Belt and Road Initiative.

Hematin anhydride (β-hematin): An analogue to malaria pigment hemozoin possesses nonlinearity

Hematin anhydride (β-hematin), the synthetic analogue of the malaria pigment, “hemozoin”, is a heme dimer produced by reciprocal covalent bonds among carboxylic acid groups on the protoporphyrin-IX ring and the iron atom present in the two adjacent heme molecules. Hemozoin is a disposal product formed from the digestion of hemoglobin present in the red blood cells infected with hematophagous malaria parasites. Besides, as the parasites invade red blood cells, hemozoin crystals are eventually released into the bloodstream, where they accumulate over time in tissues. Severe malaria infection leads to significant dysfunction in vital organs such as the liver, spleen, and brain in part due to the autoimmune response to the excessive accumulation of hemozoin in these tissues. Also, the amount of these crystals in the vasculature correlates with disease progression. Thus, hemozoin is a unique indicator of infection used as a malaria biomarker and hence, used as a target for the development of antimalarial drugs. Hence, exploring various properties of hemozoin is extremely useful in the direction of diagnosis and cure. The present study focuses on finding one of the unknown properties of β-hematin in physiological conditions by using the Z-scan technique, which is simple, sensitive, and economical. It is observed that hemozoin possesses one of the unique material properties, i.e., nonlinearity with a detection limit of ∼ 15 µM. The self-defocusing action causes β-hematin to exhibit negative refractive nonlinearity. The observed data is analyzed with a thermal lensing model. We strongly believe that our simple and reliable approach to probing the nonlinearity of β-hematin will provide fresh opportunities for malaria diagnostics & cure in the near future.

Pathogenicity associated with an infestation of the marine leech parasite Pterobdella arugamensis in farmed fish.

The marine leech Pterobdella arugamensis is a hematophagous parasite, and the extent of injury to the host largely depends on the number of attached leeches. This study aimed to assess the pathogenicity of marine leeches in Asian seabass (Lates calcarifer) and tiger grouper (Epinephelus fuscoguttatus) fingerlings under laboratory conditions. Five groups of healthy Asian seabass and tiger grouper were exposed to varying numbers of marine leeches (0, 1, 10, 30, or 70 per fish) for 7 d. Infested Asian seabass and tiger grouper both showed pathological changes even with only 1 leech, manifesting as clinical signs like haemorrhages. The cumulative mortality at 7 d post-exposure (dpe) was 11 or 33% for Asian seabass infested with 1 or 10 marine leeches, respectively. Fish with 30 or 70 marine leeches showed higher rates of mortality (56%). A similar trend was seen in tiger grouper, with mortality rates reaching 78% in fish with 30 or 70 marine leeches, and 56 or 33% in fish with 10 leeches or 1 leech, respectively. Factorial analysis of mortality after 7 dpe between both species showed significant differences (2-way ANOVA p = 0.001) when exposed to varying numbers of marine leeches. The haematocrit values differed significantly between Asian seabass or tiger grouper infested with either 0 or 1 marine leech and those infested with 10, 30, or 70 marine leeches (1-way ANOVA, p = 0.0001). This suggests that marine leech infestation has a measurable impact on both species. Consequently, fish farmers should promptly address leech infestation upon discovery in their cages.

Bedbug (Cimex lectularius) infestations in Colombia. Report of two cases

Abstract Introduction: Cimex lectularius (bed bug) is a hematophagous parasite that can be considered as an emergent and neglected concern in Colombia. Due to their increasing importance, the following two clinical cases secondary to a bed bug infestation are presented. Case presentation: Two patients, one male and one female (31 and 30 years old, respectively) went on their honeymoon trip to Costa Rica and Nicaragua in 2017. During those trips, both patients stayed in the same room in hotels of different categories. Upon their return to Bogotá (Colombia), erythematous lesions and pruritic papules appeared without any apparent explanation, which were associated with intense pruritus and had a clustered and linear (breakfast-lunch-dinner) pattern. During consultation with the Travel Medicine service, a diagnosis of dermatitis due to bed bug infestation was made. With the recommendations given by the medical staff (in which no chemical measures were suggested), the bugs and lesions disappeared. Conclusion: Bed bugs are a public health problem of increasing importance worldwide. This report of two cases presents one of the few published evidences of their presence in Colombia. As both cases are domestic, the relevance of an early diagnosis and a comprehensive approach based on the needs of the patients is demonstrated.

Molecular detection of Borrelia sp. in Ornithodoros cavernicolous (Acari: Argasidae) in midwestern Brazil

Ticks are obligate hematophagous parasites that can transmit to vertebrate hosts several pathogens, including viruses, bacteria, protozoa and helminths. Among these agents, some Borrelia species some Borrelia species cause disease in humans and other vertebrate hosts; therefore, they have medical and veterinary health importance. To gather additional information on Borrelia species in Brazil, the current study aimed to detect the presence of these species in Ornithodoros cavernicolous ticks collected in September 2019 from cement pipes that are used by bats as shelter in a farm located in the midwestern region of Brazil. DNA samples obtained from 18 specimens of O. cavernicolous were subjected of two polymerase chain reactions, targeting a segment of the Borrelia fla B gene. Of the samples tested, only one (6 %, 1/18) showed amplification. The nucleotide sequence of the amplified DNA showed more than 97 % (293/300) identity with a sequence of a Borrelia sp. detected in blood collected from a bat from Macaregua Cave, Colombia, and more than 97 % (292/300) detected in lungs from vampire bats from northeastern Brazil. The deduced amino acid sequences were identical to each other. Phylogenetic analysis indicated that these sequences formed a group of Borrelia species (putatively associated with bats) that is closely related to sequences of Borrelia species of the Lyme borreliosis group. Further investigations should be carried out in order to determine whether the sequence of the Borrelia sp. we found belongs to a new taxon. It will also be of great importance to determine which vertebrate hosts, besides bats, O. cavernicolous ticks can parasitize in order to investigate whether the Borrelia sp. we found may be transmitted and cause disease to the other vertebrate hosts.

An insight into the functional genomics and species classification of Eudiplozoon nipponicum (Monogenea, Diplozoidae), a haematophagous parasite of the common carp Cyprinus carpio

BackgroundMonogenea (Platyhelminthes, Neodermata) are the most species-rich class within the Neodermata superclass of primarily fish parasites. Despite their economic and ecological importance, monogenean research tends to focus on their morphological, phylogenetic, and population characteristics, while comprehensive omics analyses aimed at describing functionally important molecules are few and far between. We present a molecular characterisation of monogenean representative Eudiplozoon nipponicum, an obligate haematophagous parasite infecting the gills of the common carp. We report its nuclear and mitochondrial genomes, present a functional annotation of protein molecules relevant to the molecular and biochemical aspect of physiological processes involved in interactions with the fish hosts, and re-examinate the taxonomic position of Eudiplozoon species within the Diplozoidae family.ResultsWe have generated 50.81 Gbp of raw sequencing data (Illumina and Oxford Nanopore reads), bioinformatically processed, and de novo assembled them into a genome draft 0.94 Gbp long, consisting of 21,044 contigs (N50 = 87 kbp). The final assembly represents 57% of the estimated total genome size (~ 1.64 Gbp), whereby repetitive and low-complexity regions account for ~ 64% of the assembled length. In total, 36,626 predicted genes encode 33,031 proteins and homology-based annotation of protein-coding genes (PCGs) and proteins characterises 14,785 (44.76%) molecules. We have detected significant representation of functional proteins and known molecular functions. The numbers of peptidases and inhibitors (579 proteins), characterised GO terms (16,016 unique assigned GO terms), and identified KEGG Orthology (4,315 proteins) acting in 378 KEGG pathways demonstrate the variety of mechanisms by which the parasite interacts with hosts on a macromolecular level (immunomodulation, feeding, and development). Comparison between the newly assembled E. nipponicum mitochondrial genome (length of 17,038 bp) and other diplozoid monogeneans confirms the existence of two distinct Eudiplozoon species infecting different fish hosts: Cyprinus carpio and Carassius spp.ConclusionsAlthough the amount of sequencing data and characterised molecules of monogenean parasites has recently increased, a better insight into their molecular biology is needed. The E. nipponicum nuclear genome presented here, currently the largest described genome of any monogenean parasite, represents a milestone in the study of monogeneans and their molecules but further omics research is needed to understand these parasites’ biological nature.

Phytochemical profile and nematicidal activity of a hydroalcoholic extract from Cazahuate flowers (Ipomoea pauciflora M. Martens & Galeotti) against Haemonchus contortus infective larvae.

Haemonchus contortus (Hc) is a hematophagous parasite affecting the health and productivity of flocks. The administration of chemical anthelmintic drugs (AH) is the common method of deworming; however, generates resistance in the parasites to AH and it is a public health risk due to drug residues in milk, meat and sub-products. Natural compounds from plants are explored to diminish this parasitosis, improving their health and productivity, without the negative effects of AH. Ipomoea genus is a group of climbing plants belonging to the Convulvulaceae family possessing perennial leaves and tuberous roots. Medicinal properties has been attributed to this plant including nutritional agents, emetics, diuretics, diaphoretics, purgatives and pesticides. The objective of this study was assessing the in vitro nematocidal activity of a hydroalcoholic extract (HA-E) obtained from Ipomoea pauciflora (Cazahuate) flowers against Hc infective larvae (L3) and to identify its phytochemical profile (PhC-P). The assay was carried out using microtiter plates (MTP). Four HA-E concentrations were assessed and Ivermectin and distilled water were used as positive and negative control groups, respectively. Approximately 100 Hc L3 were deposited in each well (n=12) and incubated at 25-35°C for 7 days. Data were analyzed using ANOVA and a General Linear Model (GLM) followed by Tukey test (P<0.05). The treatments showing a concentration-dependent effect (CDE) were analyzed to identify their 50% and 90% lethal concentrations (CL50, 90) via a Probit Analysis. The highest mortality was observed at 50 mg/mL (82.64 ± 0.71%) and the lowest at 6.25 mg/mL (56.46 ± 2.49%), showing a CDE with increasing mortality from 6.25 to 50 mg/mL. The PhC-P revealed the presence of alkaloids, coumarins, flavonoids, tannins and triterpenes/ sterols. A HA-E from flowers of I. pauciflora will be considered to assess its potential use in the control of haemonchosis in small ruminants.

Larvicidal activity of the black pepper, Piper nigrum (Fam: Piperaceae) extracts on the cattle tick, Rhipicephalus australis (Acari: Ixodidae)

BackgroundThe cattle farming parasite Rhipicephalus australis is the main tick and one of the most important in the world from an economic point of view. Various studies have been developed in order to find plant extracts with effective acaricidal properties and environmentally friendly. Studies involving plant extracts for parasite control on commercial animal herds is a developing area in New Caledonia. Bioactive natural products play an important role as lead compounds in the development of new pesticides.ResultsThe ethanolic extract of Piper nigrum L. dried fruits as well as the ethyl acetate extract and the methanolic extract of stems exhibited 100% larvicidal activity (50 mg/mL) against Rh. australis larvae, the cattle tick, an hematophagous parasite. Bioguided fractionation of the ethanolic extract of dried mature fruits using the same assay led to the isolation of five compounds belonging to piperamide family. The structures of isolated compounds were elucidated using spectroscopic methods: ESI-HRMS, 1H- and 13C-NMR spectral data, including DEPT and 2D-NMR experiments (COSY, HSQC, HMBC, and NOESY). These include 1 compound described for the first time in P. nigrum, homopellitorine (2) and 4 known compounds, namely pellitorine (1), pipyaqubine (3), 2-methylpropylamide (4), and N-isobutyl-2,4-eicosadienamide (5).ConclusionThis first report on the larvicidal activity of P. nigrum extract and pure compounds on this tick species suggests that P. nigrum could be a natural biosourced alternative for the control of the larval stage of Rh. australis.Graphical

A Diverse Flea (Siphonaptera) Assemblage from the Small Mammals of Central New Mexico

The geographical ranges of many mammals and their associated parasites are dynamic. Comprehensive documentation of these communities over time provides a foundation for interpreting how changing environmental conditions, driven by accelerating climate change, other anthropogenic disturbances, and natural events, may influence host-parasite interactions. Fleas (Order Siphonaptera) are obligate, hematophagous parasites of birds and mammals with medical interest because of their role in transmitting pathogens. From 2016 to 2019, we sampled the small mammal and associated flea communities in El Malpais National Conservation Area (El Malpais) in Cibola County, New Mexico. Among 898 mammalian specimens, 925 fleas representing 29 species were collected from 18 host species. Pleochaetis exilis was the most abundant flea species, composing 27% of the total fleas collected, whereas Aetheca wagneri was the most prevalent flea species, parasitizing 8% of the community sampled. Across a total of 284 hosts recorded with fleas, A. wagneri, Malaraeus eremicus, and Peromyscopsylla hesperomys adelpha parasitized the most host species (n = 6 each). Onychomys leucogaster (Wied-Neuwied, 1841), the northern grasshopper mouse, a rodent highly implicated in plague dynamics, was host for the highest number of flea species (n = 15), followed by Peromyscus truei (Shufeldt, 1885) (n = 10). Our aims are to (a) describe the flea-mammal assemblage of a central New Mexico site, creating a baseline for diversity against which changing patterns of association can be assessed over time; (b) identify previously unrecognized host associations; and (c) examine infestation parameters, including the relationships of flea prevalence and mean abundance to host sex, host abundance, and seasonality. As such, our study exemplifies the Documentation and Assessment phases of the DAMA protocol (Document, Assess, Monitor, Act), a central component of exploring distribution and diversity of complex pathogen-host communities across space and time that are essential to a proactive understanding of emerging disease.

Immunization of guinea pigs with cement extract induces resistance against Ixodes scapularis ticks

As hematophagous parasites, many tick species are important vectors of medical and veterinary disease agents. Proteins found in tick saliva and midgut have been used with some success in immunizations of animal hosts against feeding ticks, and whole saliva has been used effectively in this capacity against Ixodes scapularis, the primary vector of tickborne pathogens in the United States. Tick saliva is a complex substance containing hundreds of proteins, and the identification of specific protective antigens is ongoing. We performed a series of experiments immunizing guinea pigs with extracts prepared from midgut or attachment cement collected from adult female I. scapularis followed by challenge with nymphs of the same species. Midgut extract did not induce protective immunity, while immunization with cement extract resulted in partial protection of hosts as evidenced by premature tick detachment and 34-41% reduction in tick engorgement weights. Proteomic characterization of I. scapularis cement was performed, demonstrating that the cement extract was compositionally different from tick saliva, and vitellogenin-like lipoproteins were the most abundant proteins in cement extract (>40%). Cement was also heavily enriched with lysozymes and defensins, including those originating from both the mammalian host as well as ticks. These results demonstrate that I. scapularis cement contains immunogenic components capable of stimulating host resistance against tick feeding. Because the cement is present at the tick-host interface for an extended period of time during the feeding process, these antigens present auspicious candidates for further evaluation and potential inclusion in an anti-tick vaccine.

FORMATION MONITORING OF PARASITE FAUNA IN STABLED ANIMALS OR ANIMALS IN ENCLOSED GRAZING AREAS

Monitoring studies were performed on biological diversity of parasite fauna in domesticated animals at the territory of the Joint Russian-Armenian Scientific Experimental Centre, within the piedmont zone of Armenia with moderate continental climate at 900-1200 m above the sea level. The study species were large and small ruminants, rabbits and hens. All the animals except sheep were kept indoors (stalls). We found 3 trematode species, 4 cestode species and 5 nematode species based on seasonal coproovoscopic and larvoscopic examinations, as well as an incomplete helminthological dissections of 5 sheep. The infection of sheep and cattle with hematophagous parasites was also detected and the infection of hens and rabbits with helminths and protozoa was found. Oribatid mites Scheloribates sp. were isolated from the studied soil samples. We also found and studied land and freshwater molluscs, intermediate hosts of a number of important parasite species for the infection. The land molluscs were found to have naturally-acquired invasions with larval forms of Protostrongylidae and Dicrocoeliidae. In total, we found 20 helminth species, 5 ixodid ticks, 1 oribatid mite and 7 protozoa, and vectors: 2 species of freshwater molluscs and 1 species of land molluscs.

Molecular detection of a novel Ancylostoma sp. by whole mtDNA sequence from pangolin Manis javanica

BackgroundAncylostoma species are hematophagous parasites that cause chronic hemorrhage in various animals and humans. Pangolins, also known as scaly anteaters, are mammals that live in soil environments where they are readily exposed to soil-borne parasitic nematodes. However, only a limited number of helminth species have been identified in this animal host so far.MethodsAncylostoma sp. was isolated from a wild pangolin, and the complete mitochondrial (mt) genome of Ancylostoma sp. was obtained by Illumina sequencing of total genomic DNA.ResultsThe circular complete mt genome that was assembled had a total length of 13,757 bp and comprised 12 protein-coding genes (PCGs), 22 transfer ribosomal RNAs, two ribosomal RNAs (rRNAs), two non-coding regions and one AT-rich region, but lacked the gene coding for ATPase subunit 8 (atp8). The overall AT content of the mt genome of Ancylostoma sp. was 76%, which is similar to that of other nematodes. The PCGs used two start codons (ATT and TTG) and three stop codons (TAA, TAG, and T). The nucleotide identity of the 12 PCGs ranged from 83.1% to 89.7% and had the highest sequence identity with Ancylostoma caninum among species in the Ancylostomatidae family. Also, the pangolin-derived Ancylostoma sp. lacked repeat sequences in the non-coding regions and in the unique sequence of the short non-coding regions, which differentiated it from other Ancylostoma species. In addition, phylogenetic analyses of 18S rRNA and mtDNA sequences revealed that the Ancylostoma sp. was positioned in a separate branch in the subfamily Ancylostomatinae along with other Ancylostoma species.ConclusionsThe Ancylostoma sp. isolated from a pangolin in this study was identified as a possible new Ancylostoma species. The identification of this Ancylostoma sp. from pangolin enriches our knowledge of the species in the Ancylostomatidae family and provides information that will lead to a better understanding of the taxonomy, diagnostics, and biology of hookworms.Graphical

The First Data on Parasitic Arthropods of the European Bison in the Summer Season with a World Checklist

The European bison (wisent) Bison bonasus is not only the largest terrestrial mammal in Europe, but also an example of the successful restitution and reintroduction of a species that became extinct in nature at the beginning of the 20th century. Even so, it remains a rare, protected species, and one susceptible to varied threats, including diseases. It has a specific parasitofauna, comprising only a few specific species retained with the last hosts in the restitution process, and some others acquired from other ungulates, or via environmental interactions. The current data on parasitic arthropods originated from the winter season, and less frequently, from autumn and early spring. The present study contains the first information on the occurrence of arthropods in the European bison (n = 6) in the summer season, which is the period of their increased activity. Data on the seasonal and populational dynamics of ectoparasites have been verified; specific parasite species (Demodex bisonianus, Bisonicola sedecimdecembrii, and recently described Demodex bialoviensis) and typical parasite species (Chorioptes bovis, Ixodes ricinus) have been recorded. The data refer to the information from other study periods, summarizing and valorizing data on parasitic arthropods in the form of a global checklist. These arthropods occur in European bison frequently (prevalence reaches up to 100%), but they are present in small numbers, and do not present a burden for the host; only sometimes, with high intensity of infection, they cause parasitoses (chorioptosis, mallohagosis). However, as an effect of regular activity, by penetrating the skin of the host, they create gateways for secondary infections, and hematophagous parasites (e.g., ticks) can be vectors of pathogens that can be hazardous, even at low infection levels. The identification of the parasitological threats faced by European bison is not only important from the standpoint of the study object, i.e., the Białowieża Forest European bison population, from which the existing bison population of Europe has been derived, but also the fact that their transfer to different parts of Europe can entail the additional transfer of their parasites.

Nematicidal effect of a lectin preparation from Artocarpus heterophyllus (Moraceae) on larvae and adults of Haemonchus contortus

Haemonchus contortus is a hematophagous parasite that causes damage to ruminant production worldwide. This study reported the in vitro nematicidal effect of a lectin preparation (LP) isolated from Artocarpus heterophyllus seeds on larvae and adults of H. contortus. The protein extraction was in phosphate-buffered saline followed by protein precipitation with ammonium sulfate 70% and dialysis. The dialyzed protein fraction was chromatographed to obtain isolated LP. The LP was characterized by hemagglutinating activity (HA) assays, protein dosage and polyacrylamide gel electrophoresis. The motility index of H. contortus in the third larval stage (unsheathed L3 larvae) and adult stage was evaluated. The HA inhibition of LP by mannose and galactose as well as the electrophoretic profile indicated the presence of the lectins ArtinM and Jacalin. The motility index of H. contortus was significantly reduced (p < 0.001) during the first 8 h of LP exposure, both in larvae (lowest index 8.3% with LP at 1 mg mL−1) and female adults (lowest index 20% with LP at 500 μg mL−1; index 40% with LP at 1 mg mL−1). This research revealed that the LP has potential for being utilized in the development of natural nematicides.

Serology for Borrelia spp. in Northwest Italy: A Climate-Matched 10-Year Trend

Ticks are hematophagous parasites that can transmit a variety of human pathogens, and their life cycle is dependent on several climatic factors for development and survival. We conducted a study in Piedmont and Aosta Valley, Italy, between 2009 and 2018. The study matched human sample serologies for Borrelia spp. with publicly available climatic and meteorological data. A total of 12,928 serological immunofluorescence assays (IFA) and Western blot (WB) tests were analysed. The median number of IFA and WB tests per year was 1236 (range 700–1997), with the highest demand in autumn 2018 (N = 289). In the study period, positive WB showed an increasing trend, peaking in 2018 for both IgM (N = 97) and IgG (N = 61). These results were consistent with a regional climatic variation trending towards an increase in both temperature and humidity. Our results suggest that coupling data from epidemiology and the environment, and the use of a “one health” approach, may provide a powerful tool in understanding disease transmission and strengthen collaboration between specialists in the era of climate instability.

Haematophagous parasites of some fish species in the Lower Irtysh

The purpose of the research is study of four fish species infected with haematophagous parasites in the rivers of the Lower Irtysh basin. Materials and methods. The work was performed in the rivers of the Lower Irtysh basin in 2017–2020. A total of 390 fish of different sex and age were examined including 47 roach (Rutilus rutilus lacustris, (Pallas)), 41 ide (Leuciscus idus, (Linnaeus, 1758)), 47 pike (Esox lucius, (Linnaeus, 1758)) and 255 Siberian sterlet (Acipenser ruthenus marsiglii (Brandt, 1833)). We took blood from the tail artery, and examined its fresh drop under a microscope, and prepared a thin smear, then dried it in the air and fixed in a mixture of 70% ethyl alcohol and diethyl ether (1 : 1) for 30 minutes. The fixed smears were dried in the air at room temperature and stained with azure and eosin at a dilution of 1 : 10 for 40 minutes. We identified species of the found parasites and calculated the prevalence of infection with standard error of the mean.Results and discussion. We found representatives of the Coccidea and Kinetoplastea classes parasitizing in fish blood. Trypanoplasma acipenseris and Haemogregarina acipenseris were recorded in the Siberian sterlet. The pike was infected with T. schulmani and H. esoci. T. schulmani was found in the blood of the ide and roach. Piscicola geometra is the main host of flagellates and sporozoans that parasitize in fish blood in the basin of the Lower Irtysh. The roach and the Siberian sterlet become infected with parasitic flagellates from the age of 1+. All examined fish were infected in age groups 2+ – 4+. Haemogregarina parasitize in the pike aged 4+ and 5+, and in the Siberian sterlet aged 1+ – 4+ and 6+ – 7+.

Associations between Afrotropical bats, eukaryotic parasites, and microbial symbionts.

Skin is the largest mammalian organ and the first defensive barrier against the external environment. The skin and fur of mammals can host a wide variety of ectoparasites, many of which are phylogenetically diverse, specialized, and specifically adapted to their hosts. Among hematophagous dipteran parasites, volatile organic compounds (VOCs) are known to serve as important attractants, leading parasites to compatible sources of blood meals. VOCs have been hypothesized to be mediated by host‐associated bacteria, which may thereby indirectly influence parasitism. Host‐associated bacteria may also influence parasitism directly, as has been observed in interactions between animal gut microbiota and malarial parasites. Hypotheses relating bacterial symbionts and eukaryotic parasitism have rarely been tested among humans and domestic animals, and to our knowledge have not been tested in wild vertebrates. In this study, we used Afrotropical bats, hematophagous ectoparasitic bat flies, and haemosporidian (malarial) parasites vectored by bat flies as a model to test the hypothesis that the vertebrate host microbiome is linked to parasitism in a wild system. We identified significant correlations between bacterial community composition of the skin and dipteran ectoparasite prevalence across four major bat lineages, as well as striking differences in skin microbial network characteristics between ectoparasitized and nonectoparasitized bats. We also identified links between the oral microbiome and presence of malarial parasites among miniopterid bats. Our results support the hypothesis that microbial symbionts may serve as indirect mediators of parasitism among eukaryotic hosts and parasites.

Unusual Localization of Pennella Sp. in Swordfish (Xiphias gladius) Hearts.

Simple SummaryCopepods of the genus Pennella are parasites of marine aquatic organisms (e.g., cephalopods, pelagic fish, cetaceans). They can infest fish of economic interest, including tuna and swordfish. The infestation of Pennella sp. in fish creates problems of food safety and fish marketing. Generally, these copepods penetrate the host’s muscle, without damaging internal organs. Here, we report on Pennella sp. infestation in swordfish heart muscle. The severity of the cardiac lesions we observed suggests that parasites of the genus Pennella pose a concern for food safety as well as animal health.The genus Pennella comprises hematophagous parasites of marine aquatic species, including cephalopods, marine mammals, and pelagic fish. Nine species have been officially included in the genus Pennella plus another six species inquirendae. They are most often found in the host’s musculature, without penetrating internal organs. For the present study, 83 hearts from swordfish (Xiphias gladius) caught in the Mediterranean Sea were sampled and immediately fixed in formalin for histopathological analysis. In total, 10 (12.05%) hearts were found to be parasitized by copepods of the genus Pennella. Macroscopically, there was mild-to-severe fibrinous pericarditis with atrial wall thickening and multiple parasitic nodules. Histologically, the parasitic nodules were surrounded by an inflammatory-necrotizing reaction. Parasitic infestation by Pennella spp. is common in pelagic fish and in swordfish, in particular. Here, however, we report atypical cardiac localization. A future area of focus is the evaluation of cardiac Pennella spp. infestation by histopathology and genetic identification of the parasites.

Exogenous Integrin αIIbβ3 Inhibitors Revisited: Past, Present and Future Applications.

The integrin αIIbβ3 is the most abundant integrin on platelets. Upon platelet activation, the integrin changes its conformation (inside-out signalling) and outside-in signalling takes place leading to platelet spreading, platelet aggregation and thrombus formation. Bloodsucking parasites such as mosquitoes, leeches and ticks express anticoagulant and antiplatelet proteins, which represent major sources of lead compounds for the development of useful therapeutic agents for the treatment of haemostatic disorders or cardiovascular diseases. In addition to hematophagous parasites, snakes also possess anticoagulant and antiplatelet proteins in their salivary glands. Two snake venom proteins have been developed into two antiplatelet drugs that are currently used in the clinic. The group of proteins discussed in this review are disintegrins, low molecular weight integrin-binding cysteine-rich proteins, found in snakes, ticks, leeches, worms and horseflies. Finally, we highlight various oral antagonists, which have been tested in clinical trials but were discontinued due to an increase in mortality. No new αIIbβ3 inhibitors are developed since the approval of current platelet antagonists, and structure-function analysis of exogenous disintegrins could help find platelet antagonists with fewer adverse side effects.