Approaches to Integrated Parasite Management (IPM) for Theileria orientalis with an Emphasis on Immunity

Integrated parasite management (IPM) for pests, pathogens and parasites involves reducing or breaking transmission to reduce the impact of infection or infestation. For Theileria orientalis, the critical impact of infection is the first wave of parasitaemia from the virulent genotypes, Ikeda and Chitose, associated with the sequelae from the development of anaemia. Therefore, current control measures for T. orientalis advocate excluding the movement of naïve stock from non-endemic regions into infected areas and controlling the tick Haemaphysalislongicornis, the final host. In Australia, treatment of established infection is limited to supportive therapy. To update and expand these options, this review examines progress towards prevention and therapy for T. orientalis, which are key elements for inclusion in IPM measures to control this parasite.

Mechanism of the Passage of Angiostrongylus cantonensis Across the Final Host Blood-Brain Barrier Using the Next-Generation Sequencing

Background: Multicellular parasites Angiostrogylus cantonensis larvae develop in the final host rat brain at the fourth stage (L4) and migrate to the lungs by the adult stage. The potential mechanism of its blood-brain barrier (BBB) passage remains unclear. Methods: By using Illumina Hiseq/Miseq sequencing, we obtained the transcriptomes of 3 groups of adult males and 3 groups of female of A. cantonensis to generate similarly expressed genes (SEGs) between 2 genders at the adult stage. Next 2 groups of L4 expressed genes were used to compared with SEGs to create differentially expressed genes (DEGs) between 2 life stages to unlock potential mechanism of BBB passage. Results: In total, we obtained 381 581 802 clean reads and 56 990 699 010 clean bases. Of these, 331 803 unigenes and 482 056 transcripts were successfully annotated. A total of 3 166 DEGs between L4 and adults SEGs were detected. Annotation of these DEGs showed 167 were down-regulated and 181 were up-regulated. Pathway analysis exhibited that calcium signaling pathway, the ECM−receptor interaction, focal adhesion, and cysteine and methionine metabolism were highly associated with DEGs. The function of these pathways might be related to BBB traversal, as well as neuro-regulation, interactions between parasite and host, environmental adaption. Conclusion: This study expanded the regulatory characteristics of the two important life stages of A. cantonensis. This information may provide a better appreciation of the biological features of the stages of the parasitic A. cantonensis.

Pathogens Spillover from Honey Bees to Other Arthropods

Honey bees, and pollinators in general, play a major role in the health of ecosystems. There is a consensus about the steady decrease in pollinator populations, which raises global ecological concern. Several drivers are implicated in this threat. Among them, honey bee pathogens are transmitted to other arthropods populations, including wild and managed pollinators. The western honey bee, Apis mellifera, is quasi-globally spread. This successful species acted as and, in some cases, became a maintenance host for pathogens. This systematic review collects and summarizes spillover cases having in common Apis mellifera as the mainteinance host and some of its pathogens. The reports are grouped by final host species and condition, year, and geographic area of detection and the co-occurrence in the same host. A total of eighty-one articles in the time frame 1960–2021 were included. The reported spillover cases cover a wide range of hymenopteran host species, generally living in close contact with or sharing the same environmental resources as the honey bees. They also involve non-hymenopteran arthropods, like spiders and roaches, which are either likely or unlikely to live in close proximity to honey bees. Specific studies should consider host-dependent pathogen modifications and effects on involved host species. Both the plasticity of bee pathogens and the ecological consequences of spillover suggest a holistic approach to bee health and the implementation of a One Health approach.

A systematic review of flukes (Trematoda) of domestic goose (Anser anser dom.)

Trematodes are one of the most numerous and widespread groups of parasitic invertebrates among helminths, characterized by a complex life cycle. As the final host, digenetic flukes parasitize vertebrates, including domestic waterfowl. Infection of hosts with parasitic digenetic worms causes huge economic damage to poultry. But trematode fauna of domestic geese are presented mainly only for individual regions. Despite the fact that there is already a systematic review of tapeworms and acanthocephala of domestic birds – geese and ducks, there are, unfortunately, no review articles on the taxonomy of digenetic flukes for geese (Anser anser dom.). Taking into account the relevance of the topic, based on our own and extensive literature data, we set the task to determine the general species composition of digenetic flukes (Trematoda), parasitizing in domestic geese which have been recorded in the world until 2020. Each Trematoda species is provided with the following data: scientific name, authority and year, first, second intermediate, auxiliary and final hosts, site in the host body, collecting localities and geographic distribution, and literature sources. Currently it is established that there are 149 species of helminths parasitising domestic geese. The taxonomic composition of the class Trematoda registered in domestic geese consists of 2 classes, 14 families, 30 genera and 65 species. Of all the species of trematodes parasitizing in domestic geese, 44 species have been recorded in Europe, 26 species in Asia, 6 species in North America, 1 species in South America, 1 species in Africa and 2 species in Oceania. Three species are registered in domestic geese (Echinoparyphium recurvatum, Echinostoma revolutum, Prosthogonimus ovatus) are cosmopolitan parasites. The biggest species diversity is characterized by the families Echinostomatidae (17 species) and Notocotylidae (12 species). There are 11 species of digenetic flukes recorded in domestic geese Cyclocoelum mutabile, Echinostoma grande, E. paraulum, E. revolutum, E. robustum, Hypoderaeum conoideum, Paryphostomum novum, P. pentalobum, Catatropis verrucosa, Notocotylus attenuatus, N. parviovatus) on the territory of Azerbaijan. Four of them (Echinostoma revolutum, Hypoderaeum conoideum, Paryphostomum novum, Notocotylus attenuatus) were also noted in the course of our helminthological studies. The trematode Cyclocoelum mutabile was recorded in domestic ducks only in Azerbaijan. Most species of trematodes were found in the north-eastern part (total 9 species) and southern part (total 5 species) of Azerbaijan. This is due to the widespread distribution of molluscs – intermediate hosts of digenetic flukes, in these regions. Eighteen species of digenetic flukes parasitize both birds and mammals (Rodentia, Carnivora, Lagomorpha, Artiodactyla). And eleven species of trematodes are of medical importance, registered in humans.

Parasite immune evasion and manipulation of host phenotype

All parasites manipulate their hosts by interference with immune defences and host behaviour. Passive evasion, for example, is by molecular mimicry or by changing surfaces. Active interference involves production of molecules that block or modify host immune defence regulation or affect metabolism and neuronal systems. All steps of the immune defence cascades are attacked by parasites, including the microbiota. Manipulation can increase the duration of infection or transmission success. The latter is particularly prominent in intermediate hosts that need to be consumed by a final host. Host fecundity reduction and gigantism provide extra resources for the parasite. Theory can predict what manipulation should be best; conflicts arise among co-infecting parasites.

Dogs are final hosts of Sarcocystis morae (Apicomplexa: Sarcocystidae): First report of this species in Hungary and its region – Short communication

In this study, faecal samples of four American Staffordshire terrier dogs (used for illegal fighting) were analysed by DNA extraction, molecular-phylogenetic and parasitological methods, in order to examine the occurrence of protozoan, apicomplexan parasites. In one sample, the DNA of Sarcocystis morae was shown to be present. This species was identified based on 100% identity with already reported sequences of S. morae from cervids in Lithuania and Spain. The result was also confirmed by phylogenetic analysis. The sporocysts of the canine S. morae isolate measured 14.95 × 9.75 μm on average. This is the first molecular evidence in support of the final host role of domestic dogs in the life cycle of S. morae. The most likely source of the infection was raw meat given to the examined dog to increase its physical achievement. In conclusion, under similar circumstances dogs may participate in the life cycle of S. morae in a ‘natural way’, shedding sporocysts/oocysts when used for hunting or taken to walks in forested areas.

CERCARIAL FAUNA OF TREMATODES OF MOLLUSCS (GASTROPODA, PULMONATA) IN RESERVOIRS OF NORTH-WESTERN AND CENTRAL UZBEKISTAN

Some features of the fauna of cercariae of trematodes of mollusks in reservoirs of Northwestern and Central Uzbekistan produced by gastropods Lymnaeidae Rafinesque, 1815, Planorbidae Rafinesque, 1815, Physidae Fitziger, 1833 and Thiaridae Gill, 1871 have been studied. In the reservoirs of the Amu Darya (within Uzbekistan) and Zarafshan rivers, natural infection with fluke larvae was observed in 14 species of mollusks, Lymnaea (8 species), Planorbis (1 species), Gyraulus (1 species), Anisus (2 species), Physa (1 species) and Melanoides (1 species). In total, 24 species of cercariae belonging to trematodes of 11 families Fassiolidae, Echinostomidae, Philophthalmidae, Paramphistomidae, Gastrothylacidae, Notocotylidae, Plagiorchidae, Sanguinicolidae, Strigeidae, Diplostomidae, Schistosomatidae and Bilharziellidae were found. The cercariae identified by us, according to the nature of the search and infection (second intermediate and definitive) hosts, are divided into the following three groups: the first group cercariae encyst in the environment, their final hosts are infected by ingestion of adolescariae settled in aquatic substrates. The second group cercariae penetrate into the body (of the second intermediate hosts) of insects, fish, amphibians, etc. and turn into metacercaria. The final hosts are infected by eating the second intermediate hosts. The third is the cercariae released from the host mollusk, they attack and actively penetrate the blood vessels of the final host through its integument.

Seasonal variation of Hedruris dratini (Nematoda) parasitizing Hydromedusa tectifera (Chelidae), with focus on host’s torpor state

Background The aim of this study was to analyze the seasonal distribution of the nematode Hedruris dratini parasitizing the South American Snake-necked turtle Hydromedusa tectifera and the amphipod Hyalella spp. in an urban stream. We focused on understand which strategies parasite population displays to get through the host’s hibernation period. Results The highest prevalence and abundance of H. dratini were found in summer. The parasitic load was lower in winter, however there were no significant differences when it was compared with autumn and spring. Generalized linear model identified the temperature as a determining factor for the presence of parasites in turtles. Conclusions Our results indicate that, beside turtles enter in a diapause state, the life cycle of H. dratini never stop throughout the year, being a continuous transmission between both the intermediate and final host throughout the year. Turtles feed and become infected with parasite larvae even in winter although with a lower ingestion rate.

Molecular Cage Promoted Aerobic Oxidation or Photo-Induced Rearrangement of Spiroepoxy Naphthalenone

Herein, we report a Pd4L2-type molecular cage (1) and catalyzed reactions of spiroepoxy naphthalenone (2) in water, where selective formation of 2-(hydroxymethyl)naphthalene-1,4-dione (3) via aerobic oxidation, or 1-hydroxy-2-naphthaldehyde (4) via photo-induced rearrangement under N2 have been accomplished. Encapsulation of four molecules of guest 2 within cage 1, i.e., (2)4⊂1, has been confirmed by NMR, and a final host-guest complex of 3⊂1 has also been determined by single crystal X-Ray diffraction study. While the photo-induced ring-opening isomerization from 2 to 4 are known, appearance of charge-transfer absorption on the host-guest complex of (2)4⊂1 allows low-power blue LEDs irradiation to promote this process.

Avian schistosome species in Danish freshwater lakes: relation to biotic and abiotic factors

Due to the increased prevalence of human infections with bird schistosome larvae (cercarial dermatitis) associated with bathing in Danish lakes, a nationwide survey of infected intermediate host snails was conducted in 2018–2020. Pulmonate snails (10,225 specimens) were collected from 39 freshwater lakes (in the four major geographic regions in Denmark) and subjected to shedding. Released schistosome cercariae were isolated and identified by polymerase chain reaction and sequencing whereby Trichobilharzia regenti, Trichobilharzia franki, Trichobilharzia szidati and Trichobilharzia anseri were recorded. Infections were primarily determined by biotic factors such as the presence of final host birds and intermediate host snails and water temperature was noted as an important abiotic parameter associated with the infection. No clear connection with other abiotic factors (conductivity, alkalinity, pH, nitrogen, phosphorous) was seen. The widespread occurrence of infected snails, when compared to previous investigations, suggests that climate changes at northern latitudes could be responsible for the increased risk of contracting cercarial dermatitis.