Host and geographic differences in prevalence and diversity of gastrointestinal helminths of foxes (Vulpes vulpes), coyotes (Canis latrans) and wolves (Canis lupus) in Québec, Canada

Wild canids are hosts to a wide range of parasites and can play a role in transmission of zoonoses. As many parasites are transmitted through food webs, and wild canids are at high trophic levels, parasite prevalence and diversity in wild canids can serve as excellent indicators of ecosystem health. Our main objectives were to update knowledge on the composition of gastrointestinal helminths in wild canids from Québec, Canada, and to describe differences in parasite prevalence and diversity among canid species and regions. Hunters and trappers provided whole carcasses of red foxes (Vulpes vulpes) (N = 176), and intestinal tracts of coyotes (Canis latrans) (N = 77) and gray wolves (Canis lupus) (N = 23) harvested for non-research purposes over the winter of 2016-2017. A modified Stoll's centrifugation sucrose flotation on feces of 250 wild canids was used, and eggs of one family and eight genera of parasitic helminths were recovered: diphyllobothriids, Taenia/Echinococcus spp., Capillaria spp., Toxascaris sp., Toxocara sp., Trichuris sp., Uncinaria sp., and Metorchis sp. Adult Taenia spp. cestodes were recovered from 61 of 276 (22%) canids. Six different species (T. hydatigena, T. twitchelli, T. crassiceps, T. polyacantha, T. krabbei, and T. pisiformis-"like") were differentiated based on DNA sequenced from 65 individual adult cestodes using primers for the nicotinamide adenosine dinucleotide dehydrogenase subunit 1 (ND1) and cytochrome c oxidase subunit 1 (CO1) mitochondrial DNA loci. Alaria sp. trematodes infected 89 of 276 canids (32%). A subset were identified as A. americana at the CO1 locus. The marine trematode Cryptocotyle lingua was reported for the first time in foxes in the province of Québec. These results help us understand more fully the predator-prey relationships within this group of canids. This baseline data in regional parasite prevalence and intensity is critical in order to detect future changes following ecological disturbances due to climate and landscape alterations.

Prevalence and risk factors associated with cat parasites in Italy: a multicenter study

Background

Parasites that infect cats include protozoa, helminths and arthropods, many of which are transmissible to humans. Effective control relies on a good knowledge of parasite distribution and the risk factors for infection. The present study was aimed at evaluating the prevalence of major feline parasites in Italy and the risk factors associated with their occurrence.

Methods

Over a 12-month study period, feces, hair and ectoparasites from naturally infected cats from feral colonies, shelters and private households were analyzed at 13 study centers across Italy. Samples from these cats (n = 987) were analyzed at all centers using the same diagnostic methods. Prevalence values and risk factors were evaluated statistically for the identification of predictors of risk.

Results

The overall prevalence of gastro-intestinal and broncho-pulmonary (BP) nematodes was 35.9% (354/987). Toxocara cati was the most prevalent species (253/987; 25.6%), followed by Ancylostomatidae (98/987; 9.9%). Among BP nematodes, Aelurostrongylus abstrusus was the most common (76/987; 7.7%). Approximately 35.7% (352/987) of the study population was infested by ectoparasites, of which the most common were fleas (29.4%, 290/987), followed by ear mites Otodectes cynotis (9.8%, 97/987). Predictors of risk for parasite infection included age, a predominantly or exclusively outdoor lifestyle, geographic area and lack of antiparasitic treatment.

Conclusions

Both ecto- and endoparasites are still common in cats throughout Italy, many of them being of zoonotic concern and vectors of pathogens to humans. Given the presence of parasites throughout the entire study period, year-round treatment should be considered. Furthermore, data confirm the need to protect the human–animal bond using proper endo- and ectoparasiticides to reduce the risk of human infection, in application of the One-Health concept.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04981-2.

Rebound of cyst number following discontinuation of guanabenz treatment for latent toxoplasmosis

Toxoplasma gondii is a protozoan parasite that causes opportunistic infection in immunocompromised individuals. The parasite forms latent tissue cysts that are refractory to current treatments and give rise to life-threatening reactivated infection following immune suppression. Previously, we showed that guanabenz sharply reduces brain cyst count in BALB/c mice harboring latent toxoplasmosis; however, whether cyst count would change once drug treatment stopped was not addressed. In the present study, we observed a rebound in brain cysts following the discontinuation of guanabenz or a guanabenz-pyrimethamine combination therapy. The re-expansion of brain cysts was not accompanied by symptoms of acute toxoplasmosis. We also tested whether the rebound in cyst counts could be ameliorated by administering pyrimethamine during or after guanabenz treatment.

Diet, parasites, and other pathogens of Sunda leopard cats (Prionailurus javanensis Desmarest 1816) in Aborlan, Palawan Island, Philippines

This study is the first investigation of parasites and other pathogens present in Sunda leopard cats (Prionailurus javanensis) in Aborlan, Palawan, Philippines. With the nature of wild carnivore sampling, four (4) wild Sunda leopard cats were captured in Aborlan, Palawan, Philippines for a period of nine (9) months. Of these, three (3) were considered for blood and fecal examination due to the poor condition of one animal. Rapid diagnostic kits were used to detect the presence of selected pathogens in blood samples while fecal samples were examined for parasite fauna and diet contents. Nine (9) parasite species were identified namely: Toxoplasma gondii, Ancylostoma sp., Capillaria hepatica, Echinostoma sp., Hymenolepis nana, Isospora felis, Physaloptera sp., Trichostrongylus sp., and a fasciolid. Chlamydophila felis, a bacterial pathogen was also detected in the blood. No individuals were found to be positive for feline immunodeficiency virus, feline infectious peritonitis virus, and feline leukemia virus antibodies. Six (6) small mammal prey species were identified from the feces of Sunda leopard cats namely: Palawan spiny rat (Maxomys panglima), Asian house rat (Rattus tanezumi), Polynesian rat (Rattus exulans), house mouse (Mus musculus), Southern Palawan tree squirrel (Sundasciurus steerii), and Palawan treeshrew (Tupaia palawanensis). Sunda leopard cats in Aborlan, Palawan, may be highly infected by parasites primarily due to their diet of small mammals such as rodents. Transmission is also possible through environmental contact with contaminated water or soil or direct physical contact with infected domestic animals. This paper contributes to the knowledge on host-parasite systems in wildlife ecosystem in the Philippines which is extremely poorly understood.

Dog care and parasitosis in a rural community of Patagonia: An integrative approach

Human interaction with dogs can potentially lead to zoonoses. The aim of this integrative approach is to describe the relationship between dog parasites, dog care, and the human population of a rural Patagonian village. Surveys were carried out to evaluate owners' attitudes towards dogs, and coproparasitological and coproELISA analyses were performed to determine parasitic infection values. Fur samples and vegetable garden soil were also analyzed. A multivariate regression was performed to identify factors determining infection. All households owned at least one dog, of which only 54.9% had been dewormed in the past three months, and almost half of which were allowed to roam freely. Dogs with protozoan and helminth infections represented 68.8% of the total, 50% being parasitized by helminths of 7 species, including the zoonotic Toxocara canis, Uncinaria sp. Ancylostoma sp. and Echinococcus sp. All hair samples were negative, but 42.8% of vegetable gardens harbored Ancylostomatidae larvae. Statistical analyses indicated that the predictor "time since last deworming" explained infections by Cryptosporidium sp. and helminths, while the predictors "number of dogs per household", "sex", and "freedom to roam" explained the infections by helminths. This shows that the longer the time interval since the last deworming treatment, the greater the probability of a dog being infected by some type of parasite, either Cryptosporidium sp. or a helminth. On the other hand, the probability of being infected by helminths increased when there was more than one dog in the household. Furthermore, male dogs and dogs allowed to roam freely were more likely to be infected. Considering the inadequate care and sanitary status of dogs infected with zoonotic species, it is necessary to raise awareness of the need for responsible care of dogs.

Dispersal-based versus niche-based processes as drivers of flea species composition on small mammalian hosts: inferences from species occurrences at large and small scales

Biological communities may be assembled by both niche-based and dispersal-based (= historic) processes with the relative importance of these processes in community assembly being scale- and context-dependent. To infer whether (a) niche-based or dispersal-based processes play the main role in the assembly of flea communities parasitic on small mammals and whether (b) the main processes of flea community assembly are scale-dependent, we applied a novel permutation-based algorithm (PER-SIMPER) and the dispersal-niche continuum index (DNCI), to data on the species incidence of fleas and their hosts at two spatial scales. At the larger (continental) scale, we analysed flea communities in four biogeographic realms across adjacent continental sections. At the smaller (local) scale, we considered flea communities across two main regions (lowlands and mountains) and seven habitat types within Slovakia. Our analyses demonstrated that species composition of fleas and their small mammalian hosts depended predominantly on historical processes (dispersal) at both scale. This was true for the majority of biogeographic realms at continental scale (except the Nearctic) and both regions at local scale. Nevertheless, strong niche-based assembly mechanism was found in the Nearctic assemblages. At local scale, the intensity of dispersal processes was weaker and niche-driven processes were stronger between habitats within a region than between mountain and lowland regions. We provide historical and ecological explanations for these patterns. We conclude that the assembly of compound flea communities is governed, to a great extent, by the dispersal processes acting on their hosts and, to a lesser extent, by the niche-based processes.

Impact of socio-demographic factors on knowledge, attitude and practices toward scabies among syrian refugees in Jordan: A prospective cross sectional study

Background

Scabies is one of the prevalent dermatological conditions, accounting for a substantial proportion of skin diseases in developing countries. It represents a significant health challenge when an outbreak appears in homecare and refugee camps as it may lead to enormous morbidity and high treatment costs. Because Scabies can be easily prevented through education, the purpose of this study was to assess the impact of socio-demographic factors on the level of knowledge, attitude, and practices among Syrian refugees in Jordan's northern region.

Methods

A prospective cross-sectional study was conducted among Syrian refugees attending primary health centers in northern Jordan, Ramtha, Mafraq, and Irbid, from February 2021 to May 2021. The targeted population was adult Syrian refugees above the age of 18. Two thousand participants were included in this study using simple random selection. The study questionnaire included socio-demographic characteristics and knowledge questions such as hearing about Scabies, causes of Scabies, signs and symptoms of Scabies, and its way of transmission. The data was analyzed using (SPSS) version 25.

Results

Females with a mean age of 37.9 years old comprised the majority of the participants. The majority of the participants were married and had intermediate levels of education. The knowledge about Scabies lacked among the majority of the respondents (N = 1259); 321 respondents had moderate knowledge, while only 650 had good knowledge. A statistically significant association was found between knowledge scores and all demographic characteristics, including gender, marital status, income, and educational level.

Conclusion

The general knowledge about Scabies among Syrian refugees is relatively low, with 1259 out of 2000 participants having a bad knowledge score. Moreover, the level of knowledge, attitude, and practices toward Scabies is highly affected by the demographic factors of the Syrian refugees' Health education for refugees is needed to improve their knowledge and help implement prevention programs.

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Scabies is quite a common medical problem among Syrian Refugees in Jordan.

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The socio-demographics of Syrian Refugees affect the level of knowledge and attitude toward scabies infestation.

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The level of knowledge regarding scabies infestation is poor among Syrian Refugees in Jordan.

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Health education for refugees is needed to improve their knowledge and help implement prevention programs.

Identification of anti-horn fly vaccine antigen candidates using a reverse vaccinology approach

Background

The horn fly, Haematobia irritans irritans, causes significant production losses to the cattle industry. Horn fly control relies on insecticides; however, alternative control methods such as vaccines are needed due to the fly's capacity to quickly develop resistance to insecticides, and the pressure for eco-friendly options.

Methods

We used a reverse vaccinology approach comprising three vaccine prediction and 11 annotation tools to evaluate and rank 79,542 translated open reading frames (ORFs) from the horn fly's transcriptome, and selected 10 transcript ORFs as vaccine candidates for expression in Pichia pastoris. The expression of the 10 selected transcripts and the proteins that they encoded were investigated in adult flies by reverse transcription polymerase chain reaction (RT-PCR) and mass spectrometry, respectively. Then, we evaluated the immunogenicity of a vaccine candidate in an immunization trial and the antigen’s effects on horn fly mortality and fecundity in an in vitro feeding assay.

Results

Six of the ten vaccine candidate antigens were successfully expressed in P. pastoris. RT-PCR confirmed the expression of all six ORFs in adult fly RNA. One of the vaccine candidate antigens, BI-HS009, was expressed in sufficient quantity for immunogenicity and efficacy trials. The IgG titers of animals vaccinated with BI-HS009 plus adjuvant were significantly higher than those of animals vaccinated with buffer plus adjuvant only from days 42 to 112, with a peak on day 56. Progeny of horn flies feeding upon blood from animals vaccinated with BI-HS009 plus adjuvant collected on day 56 had 63% lower pupariation rate and 57% lower adult emergence than the control group (ANOVA: F_{(1, 6)} = 8.221, P = 0.028 and F_{(1, 6)} = 8.299, P = 0.028, respectively).

Conclusions

The reverse vaccinology approach streamlined the discovery process by prioritizing possible vaccine antigen candidates. Through a thoughtful process of selection and in vivo and in vitro evaluations, we were able to identify a promising antigen for an anti-horn fly vaccine.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04938-5.

[Toxoplasma gondii-Current drugs and future vaccines against an underestimated protozoan infection]

Toxoplasma gondii is a unicellular organism of the Apicomplexa that occurs worldwide and is therefore a close relative of the malaria pathogen Plasmodium. As T. gondii infests every warm-blooded vertebrate species as an intermediate host and has a very high prevalence worldwide, toxoplasmosis is one of the most important international foodborne diseases. Potential vaccines (human as well as veterinary) play a crucial role in controlling this disease.

Synthesis and in vitro and in silico studies of 1H- and 2H-1,2,3-triazoles as antichagasic agents

1,2,3-triazole heterocycles stand out in medicinal chemistry for having great structural diversity and bioactivities. In this study, two series of triazoles were synthesized. One was obtained by the 1,3-dipolar cycloaddition reaction between ethyl cyanoacetate and several phenyl azides forming 1H-1,2,3-triazoles and the other by rearrangement of Dimroth forming and 2H-1,2,3-triazoles. Both series were shown to be active against the epimastigote form of Trypanosoma cruzi. The 1,2,3-triazoles 16d (S.I. between 100 and 200), 17d and 16f (S.I. > 200) were the most active compounds and capable of breaking the plasma membrane of trypomastigotes acting on CYP51 and inhibiting ergosterol synthesis. Candidate 16d exhibited the best and most favorable profile when interacting with CYP51.

[Enteroparasitosis in Peru and its relation to the Human Development Index]

BACKGROUND

Diseases related to enteroparasites are a serious public health problem.

OBJECTIVE

To assess the prevalence of enteroparasites in Peru and its relationship with the Human Development Index (HDI).

MATERIAL AND METHODS

A coproparasitological study using the direct method from children and adults from the communities of Pamplona Alta in Lima, the province of San Sebastián de Quera, Castillo Grande, Pillco Marca and Puelles in Huánuco, Llupa-Huaraz in Ancash, and Machaguay in Arequipa, Peru, was carried out from 2012 to 2016.

RESULTS

864 samples were analyzed, and a total prevalence of 23.03% (199 cases) was found. The non-pathogenic protozoan Entamoeba coli, with 10.42% (90 cases), and the nematode Ascaris lumbricoides, with 6.37% (55 cases), were the most prevalent. PERMANOVA analysis based on the prevalences of enteroparasites in urban and rural areas of Peru showed differences among communities. The overall prevalence of urban communities was similar to that of the rural ones.

CONCLUSIONS

Enteroparasitosis in Peru are not related to HDI. However, the levels of infestation by enteroparasites varied between the different communities, and they were related to the bioecological characteristics of parasites.

Spiroxys ankarafantsika Roca et Garcia, 2008 (Nematoda: Gnathostomatidae) and Other Nematodes Parasitising Pelusios spp. (Testudines: Pelomedusidae) from South Africa and Mozambique

INTRODUCTION

The nematode Spiroxys ankarafantsika was described parasitising freshwater turtles Pelusios castanoides and Pelomedusa subrufra from Madagascar. During parasitological surveys at different localities in Mozambique and South Africa the species was recovered from the digestive tract of Pelusios sinuatus, P. subniger and P. castanoides.

METHODS

The species were identified based on the morphology of the anterior extremity (absence of additional teeth on pseudolabia) and the male caudal end (number and arrangement of caudal papillae, size and shape of spicules). Molecular data included a 720 bp sequence fragment of 18S rDNA, the entire internal transcribed spacer 1 (ITS1), 5.8S rRNA, and internal transcribed spacer 2 (ITS), flanked by a 288 bp 18S rDNA sequence and about 1000 bp 28S rDNA sequence, and the mitochondrial cytochrome c oxidase subunit I (cox1) gene marker obtained in the present study.

RESULTS

All specimen recovered were identical, based on morphological and molecular data, with the exception of two specimens showing an intraspecific divergence of 9% based on a 694 bp sequence fragment of the cox1 gene. Additionally, a Contracaecum sp. third stage larva and an unidentified larva with mushroom-shaped anterior extremity were found. Descriptions of S. ankarafantsika and the two above-mentioned larval stages, supported by photomicrographs and molecular data 18S rDNA, ITS1-5.8S-ITS2-28S and cox1 gene fragments are presented herein.

A novel protist parasite, Salmoxcellia vastator n. gen., n. sp. (Xcelliidae, Perkinsozoa), infecting farmed salmonids in Norway

Background

In Norway, x-cell parasites associated with disease in farmed salmonids have been known as a rare phenomenon for two decades. These parasites cause systemic infections in farmed rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar), but have so far not been characterized and described.

Methods

The x-cells from several cases of diseased fish were studied using light and electron microscopy, and by phylogenetic analysis based on small subunit ribosomal RNA (SSU rRNA) gene sequences.

Results

We describe here the x-cell parasite as a new species in a new genus, Salmoxcellia vastator n. gen., n. sp. Phylogenetic analyses placed Salmoxcellia n. gen. together with Gadixcellia among the xcelliids, a group of perkinsozoan alveolates. The new genus and species were found to have vacuolate plasmodial x-cells filled with lipid droplets, and an electron-dense alveolar pellicle. Electron-dense cytoplasmic inclusions, which are characteristic of the other xcelliid genera Xcellia and Gadixcellia, are lacking in Salmoxcellia n. gen. These x-cell plasmodia divide by plasmotomy and occur as aggregates in the host tissues, particularly in blood-rich tissues such as those of the kidney, red musculature, heart and liver. Host reaction and the refractive lipid droplets in the x-cells result in S. vastator n. gen., n. sp. aggregates appearing as white patches in the tissues.

Conclusions

We describe a new genus and species of xcelliid protist parasites from two very important farmed fish species and provide molecular methods for detection. The new parasite is associated with disease, but more importantly it has a spoiling effect on farmed salmonid fillets, rendering them unsuitable for sale. Consequently, this parasite represents a threat to the aquaculture industry.

Graphical abstract

Furuncular myiasis in a traveller to West Africa

Cutaneous myiasis with swarming and oscillatory movement inside the wounds.

Pathological conditions of the sentinel bivalve, the little mussel Brachidontes rodriguezii, from contaminated intertidal sites in the Southwestern Atlantic coast

A survey of pathological conditions affecting the natural beds of the dominant bivalve species of the intertidal rocky coasts of the Southern Atlantic Ocean, was performed. Samples of the little mussel (n = 992), Brachidontes rodriguezii, which is considered a sentinel species, were collected from seven sites that present different anthropogenic activity (low anthropogenic activity, harbor, and sewage waste) along the Argentinean coast, and processed by standard histological techniques. Our results showed for the first time in a B. rodriguezii population from Mar del Plata harbor a bacterium causing cellular lysis of the spermatogenic cells (6.5% of prevalence) and in a population from Villa Gesell, a site with low anthropogenic activity, one little mussel presented cytoplasmic vacuoles in the oocytes's cytoplasm similar to a microsporidian (0.2% of prevalence). A ciliated protozoan parasitizing the cytoplasm of the epithelial digestive tubules and larval stages of two different digenean parasites, was found infecting the little mussel from both contaminated and uncontaminated sites. Sporocysts of the family Bucephalidae invaded the gonad, causing severe gonadal damage including castration, and gymnophallid metacercariae located between the mantle and shell or embedded in the mantle tissues, occupied the gonadal space. In Punta Carballido, a site located next to a sewage outfall, the highest prevalence of infection was found, for the ciliated protozoan in the digestive tubules (5.1%) and for the digenean parasites (bucephalid sporocyst 24.4%, and gymnophallid metacercariae 50%). Moreover, we found a positive correlation between shell length and overall prevalence of parasites.

Higher temperatures reduce the number of Trypanosoma cruzi parasites in the vector Triatoma pallidipennis

Background

Relatively little is known about how pathogens transmitted by vector insects are affected by changing temperatures analogous to those occurring in the present global warming scenario. One expectation is that, like their ectothermic vectors, an increase in temperature could reduce their fitness. Here, we have investigated the effect of high temperatures on the abundance of Trypanosoma cruzi parasites during infection in the vector Triatoma pallidipennis.

Methods

We exposed T. pallidipennis nymphs to two strains (Morelos and Chilpancingo) of T. cruzi. Once infected, the fifth-instar bugs were distributed among three different temperature groups, i.e. 20, 30, and 34 °C, and the resulting parasites were counted when the bugs reached adulthood.

Results

The number of parasites increased linearly with time at 20 °C and, to a lesser extent, at 30 °C, especially in the Chilpancingo compared to the Morelos strain. Conversely, at 34 °C, the number of parasites of both strains decreased significantly compared to the other two temperatures.

Conclusions

These results suggest negative effects on the abundance of T. cruzi in T. pallidipennis at high temperatures. This is the first evidence of the effect of high temperatures on a pathogenic agent transmitted by an insect vector in the context of global warming. Further tests should be done to determine whether this pattern occurs with other triatomine species and T. cruzi strains.

Graphical abstract

Identifying Potential Hosts of Short-Branch Microsporidia

Microsporidia are obligate parasites that are closely related to Fungi. While the widely known "long-branch" Microsporidia infect mostly metazoans, the hosts of "short-branch" Microsporidia are only partially characterized or not known at all. Here, we used network analyses from Neotropical rainforest soil metabarcoding data, to infer co-occurrences between environmental lineages of short-branch microsporidians and their potential hosts. We found significant co-occurrences with several taxa, especially with Apicomplexa, Cercozoa, and Fungi, as well as some Metazoa. Our results are the first step to identify potential hosts of the environmental lineages of short-branch microsporidians, which can be targeted in future molecular and microscopic studies.

Evaluation of haemoparasite and Sarcocystis infections in Australian wild deer

Wild animals are natural reservoir hosts for a variety of pathogens that can be transmitted to other wildlife, livestock, other domestic animals, and humans. Wild deer (family Cervidae) in Europe, Asia, and North and South America have been reported to be infected with gastrointestinal and vector-borne parasites. In Australia, wild deer populations have expanded considerably in recent years, yet there is little information regarding which pathogens are present and whether these pathogens pose biosecurity threats to humans, wildlife, livestock, or other domestic animals. To address this knowledge gap, PCR-based screening for five parasitic genera was conducted in blood samples (n = 243) sourced from chital deer (Axis axis), fallow deer (Dama dama), rusa deer (Rusa timorensis) and sambar deer (Rusa unicolor) sampled in eastern Australia. These blood samples were tested for the presence of DNA from Plasmodium spp., Trypanosoma spp., Babesia spp., Theileria spp. and Sarcocystis spp. Further, the presence of antibodies against Babesia bovis was investigated in serum samples (n = 105) by immunofluorescence. In this study, neither parasite DNA nor antibodies were detected for any of the five genera investigated. These results indicate that wild deer are not currently host reservoirs for Plasmodium, Trypanosoma, Babesia, Theileria or Sarcocystis parasites in eastern Australia. We conclude that in eastern Australia, wild deer do not currently play a significant role in the transmission of these parasites. This survey represents the first large-scale molecular study of its type in Australian wild deer and provides important baseline information about the parasitic infection status of these animals. The expanding populations of wild deer throughout Australia warrant similar surveys in other parts of the country and surveillance efforts to continually assess the level of threat wild deer could pose to humans, wildlife, livestock and other domestic animals.

Comorbid early esophageal cancer and Gongylonema pulchrum infection: a case report

Background

Gongylonema pulchrum is a zoonotic parasite rarely found in humans. To date, there have been no reports on the carcinogenic properties of G. pulchrum, and there are few reports overall on the relationship between esophageal cancer and parasites.

Case presentation

This report describes the first case of esophageal gongylonemiasis coexisting with early esophageal cancer. The patient had no high-risk factors for esophageal cancer, such as smoking, flushing after drinking, or tumor history. We speculate the existence of unknown links between esophageal cancer and parasitic infection in this patient.

Discussion and conclusions

We report the first case of a human presenting both esophageal G. pulchrum infection and esophageal squamous cell carcinoma with the hope that it may provide evidence for a new hypothesis of tumorigenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01873-8.

An Illumina MiSeq-Based Amplicon Sequencing Method for the Detection of Mixed Parasite Infections Using the Blastocystis SSU rRNA Gene as an Example

Parasite mixed infections remain a relatively unexplored field in part due to the difficulties of unraveling complex mixtures of parasite DNA using classical methods of sequencing. Next-generation amplicon sequencing (NGS) is a powerful tool for exploring mixed infections of multiple genetic variants of the same parasite in clinical, environmental (water or soil), or food samples. Here, we provide a method for NGS-based detection of mixed parasite infections which uses the Blastocystis SSU rRNA gene as an example and includes steps for parasite concentration, DNA extraction, sequencing library preparation, and bioinformatic analysis.

Correlated evolution of fish host length and parasite spore size: a tale from myxosporeans inhabiting elasmobranchs

Myxozoa represent a diverse group of microscopic cnidarian endoparasites alternating between invertebrate and vertebrate hosts. Of the approximately 2,600 species described predominantly from teleost fish, only 1.8% have been reported from cartilaginous fishes (Elasmobranchii). As ancestral vertebrate hosts of myxozoans, elasmobranchs may have played an important role in myxozoan evolution, however, they are also some of the largest vertebrate hosts known for this group of parasites. We screened 50 elasmobranchs belonging to nine species and seven families, from various geographical areas, for myxozoan infection. We found a 22% overall prevalence of myxozoans in elasmobranchs and describe five species new to science. We investigated, for the first known time, the evolution of spore size within three phylogenetic clades, Ceratomyxa, Sphaerospora sensu stricto and Parvicapsula. We found that spores from elasmobranch-infecting myxozoans were on average 4.8× (Ceratomyxa), 2.2× (Parvicapsula clade) and 1.8× (Sphaerospora sensu stricto except polysporoplasmic Sphaerospora spp.) larger than those from teleosts. In all analysed clades, spore size was correlated with phylogenetic position. In ceratomyxids, it was further strongly positively correlated with fish body size and habitat depth, independent of cellular composition of the spores and phylogenetic position in the tree. While in macroparasites a host size-correlated increase in parasite size occurs on a large scale and is often related to improved exploitation of host resources, in microscopic parasites size ranges vary at the scale of a few micrometres, disproportionate to the available additional space in a large host. We discuss the ecological role of these changes with regard to transmission under high pressure and an invertebrate fauna that is adapted to deeper marine habitats.

Molecular and morphological phylogeny of host-specific Dactylogyrus parasites (Monogenea) sheds new light on the puzzling Middle Eastern origin of European and African lineages

Background

Freshwater fauna of the Middle East encompass elements shared with three continents—Africa, Asia, and Europe—and the Middle East is, therefore, considered a historical geographic crossroad between these three regions. Even though various dispersion scenarios have been proposed to explain the current distribution of cyprinids in the peri-Mediterranean, all of them congruently suggest an Asian origin for this group. Herein, we investigated the proposed scenarios using monogenean parasites of the genus Dactylogyrus, which is host-specific to cyprinoid fishes.

Methods

A total of 48 Dactylogyrus species parasitizing cyprinids belonging to seven genera were used for molecular phylogenetic reconstruction. Taxonomically important morphological features, i.e., sclerotized elements of the attachment organ, were further evaluated to resolve ambiguous relationships between individual phylogenetic lineages. For 37 species, sequences of partial genes coding 18S and 28S rRNA, and the ITS1 region were retrieved from GenBank. Ten Dactylogyrus species collected from Middle Eastern cyprinoids and D. falciformis were de novo sequenced for the aforementioned molecular markers.

Results

The phylogenetic reconstruction divided all investigated Dactylogyrus species into four phylogenetic clades. The first one encompassed species with the “varicorhini” type of haptoral ventral bar with a putative origin linked to the historical dispersion of cyprinids via the North African coastline. The second clade included the majority of the investigated species parasitizing various phylogenetically divergent cyprinid hosts. The morphological and molecular data suggest the ancestral diversification of the species of this clade into two groups: (1) the group possessing the haptoral ventral bar of the “cornu” type, and (2) the group possessing the “wunderi” type. Dactylogyrus diversification apparently occurred in the Middle East, which is indicated by the presence of species with all morphotypes in the region. The last two clades included species parasitizing cyprinids with an East Asian origin, and species possessing the “magnihamatus” type of ventral bar.

Conclusions

The molecular data suggest that some morphological characters of host-specific parasites may undergo convergent evolution in the divergent lineages, and therefore, to fully resolve the phylogenetic relationships among host-specific parasites, an integrative approach combining morphological and molecular data is still needed. In addition, our study indicates that parasite diversity in many regions is still under-explored, and thus we highlight the importance of studies of host-associated parasites, especially in the context of freshwater fish biogeography.

Graphical Abstract

Management of cell death in parasitic infections

For a long time, host cell death during parasitic infection has been considered a reflection of tissue damage, and often associated with disease pathogenesis. However, during their evolution, protozoan and helminth parasites have developed strategies to interfere with cell death so as to spread and survive in the infected host, thereby ascribing a more intriguing role to infection-associated cell death. In this review, we examine the mechanisms used by intracellular and extracellular parasites to respectively inhibit or trigger programmed cell death. We further dissect the role of the prototypical “eat-me signal” phosphatidylserine (PtdSer) which, by being exposed on the cell surface of damaged host cells as well as on some viable parasites via a process of apoptotic mimicry, leads to their recognition and up-take by the neighboring phagocytes. Although barely dissected so far, the engagement of different PtdSer receptors on macrophages, by shaping the host immune response, affects the overall infection outcome in models of both protozoan and helminth infections. In this scenario, further understanding of the molecular and cellular regulation of the PtdSer exposing cell-macrophage interaction might allow the identification of new therapeutic targets for the management of parasitic infection.

A global checklist of the parasites of the harbor porpoise Phocoena phocoena, a critically-endangered species, including new findings from the Baltic Sea

The common harbor porpoise is a widely-distributed marine mammal with three known subspecies, including P. phocoena phocoena, with a clearly distinct and critically endangered (CR) subpopulation from the Baltic Sea (Baltic Proper). As part of an assessment of the condition and health threats of these mammals, it is important to conduct parasitological monitoring. The aim of the study was therefore to compare the data on porpoise parasitofauna from this subpopulation with those on porpoises from other areas. The study included 37 individuals from 1995 to 2019; eight species of parasites were found (prevalence 83.8%, mean intensity 724.2, range 2-3940), with a predominance of lung nematodes - Stenurus minor (94.7%), Torynurus convolutus (69.4%), Pseudalius inflexus (63.8%), Halocercus invaginatus (22.2%); the highest intensity was recorded for S. minor (989, 53-2928). Two species of Anisakidae (Anisakis simplex - 33.3%, Contracaecum sp. - 20.0%) were found in the digestive tracts, which were a new record for this population. The fluke Campula oblonga was found in the livers of 31.3% of porpoises. The tapeworm Diphylobothrium stemmacephalum was also recorded in the intestine of one individual; this is typical for these hosts, but previously undetected in the Baltic subpopulation. Parasites coexisted in numerous hosts, constituting a heavy burden for them. The obtained data were compared with those from the P. phocoena parasitofauna from other regions, based on a compiled checklist (1809-2021) including all species of porpoise parasites (55 taxa). Compared to the worldwide porpoise parasitofauna checklist, the number of parasites found in the nominative subspecies (Baltic Proper subpopulation) is small: including only 10 taxa (eight in the current study). These species are typical of porpoises and usually the most common; however, the level of infection of Baltic porpoises (intensity and total parasite load) is very high, which can undoubtedly have a negative impact on their condition and overall health.

Preventive Health Care for Working Dogs

The goal of preventive care is to maintain and optimize health by averting preventable problems. Effective preventive care programs for working dogs must incorporate standard procedures applicable to dogs in general with additional elements pertinent to the more specific characteristics of breed, geographic location, living and working conditions, and physical and mental tasks required of the working dog. This article covers the basic essential preventive health guidelines for all working dogs as well as the specific breed, occupational, and regional considerations to be taken into account.

ENTPDases from Pathogenic Trypanosomatids and Purinergic Signaling: Shedding Light towards Biotechnological Applications

ENTPDases are enzymes known for hydrolyzing extracellular nucleotides and playing an essential role in controlling the nucleotide signaling via nucleotide/purinergic receptors P2. Moreover, ENTPDases, together with Ecto-5´-nucleotidase activity, affect the adenosine signaling via P1 receptors. These signals control many biological processes, including the immune system. In this context, ATP is considered as a trigger to inflammatory signaling, while adenosine (Ado) induces anti-inflammatory response. The trypanosomatids Leishmania and Trypanosoma cruzi, pathogenic agents of Leishmaniasis and Chagas Disease, respectively, have their own ENTPDases named "TpENTPDases," which can affect the nucleotide signaling, adhesion and infection, in order to favor the parasite. Besides, TpENTPDases are essential for the parasite nutrition, since the Purine De Novo synthesis pathway is absent in them, which makes these pathogens dependent on the intake of purines and nucleopurines for the Salvage Pathway, in which TpENTPDases also take place. Here, we review information regarding TpNTPDases, including their known biological roles and their effect on the purinergic signaling. We also highlight the roles of these enzymes in parasite infection and their biotechnological applications, while pointing to future developments.

Sheep scab spatial distribution: the roles of transmission pathways

BACKGROUND

Ovine psoroptic mange (sheep scab) is a highly pathogenic contagious infection caused by the mite Psoroptes ovis. Following 21 years in which scab was eradicated in the UK, it was inadvertently reintroduced in 1972 and, despite the implementation of a range of control methods, its prevalence increased steadily thereafter. Recent reports of resistance to macrocyclic lactone treatments may further exacerbate control problems. A better understanding of the factors that facilitate its transmission are required to allow improved management of this disease. Transmission of infection occurs within and between contiguous sheep farms via infected sheep-to-sheep or sheep-environment contact and through long-distance movements of infected sheep, such as through markets.

METHODS

A stochastic metapopulation model was used to investigate the impact of different transmission routes on the spatial pattern of outbreaks. A range of model scenarios were considered following the initial infection of a cluster of highly connected contiguous farms.

RESULTS

Scab spreads between clusters of neighbouring contiguous farms after introduction but when long-distance movements are excluded, infection then self-limits spatially at boundaries where farm connectivity is low. Inclusion of long-distance movements is required to generate the national patterns of disease spread observed.

CONCLUSIONS

Preventing the movement of scab infested sheep through sales and markets is essential for any national management programme. If effective movement control can be implemented, regional control in geographic areas where farm densities are high would allow more focussed cost-effective scab management.

Account and Utilization of Blood Lipid Profiles: Lipid Levels Predicted Hemosporidian Infection in Migrating Northern Saw-Whet Owls of Eastern North America

Noting lipidomic changes following the parasitism of migrating birds, the metabolic needs of which are primarily fueled by lipids, can deepen our understanding of host-parasite interactions. We identified lipids of migrating Northern saw-whet owls (Aegolius acadicus) using collision-induced dissociation mass spectrometry, compared the lipidomic signatures of hemoparasite-infected and noninfected individuals, and performed cross-validation analyses to reveal associations between parasite infection and lipid levels. We found significantly lower levels of lipid classes phosphatidic acid (PA), phosphatidylglycerol (PG), phosphatidylinositol (PI), phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylcholine (PC), and sphingomyelin (SM) in infected Northern saw-whet owls than in the noninfected individuals. Conversely, we found higher levels for certain lysoPS and lysoPE species, and variable lipid level changes for free fatty acid (FFA) species. Reporting lipidomic changes observed between hemosporidian-infected and noninfected Northern saw-whet owls can strengthen our understanding of the mechanisms governing parasite proliferation in this species. Furthermore, our analysis indicated that lipidomic signatures are better predictors of parasite infection than the log-adjusted mass/wing chord body index, a metric commonly used to assess the influence of hemosporidia infection on the health of birds. Establishing a lipidomic profile for Northern saw-whet owls that provides baseline lipid levels during fall migration may assist future studies assessing causes of reductions in breeding brought about from subtle differences in behaviors such as delayed migration.

REVIEW OF PARASITES FOUND IN EXTINCT ANIMALS: WHAT CAN BE REVEALED

Parasitism is inherent to life and observed in all species. Extinct animals have been studied to understand what they looked like, where and how they lived, what they fed on, and the reasons they became extinct. Paleoparasitology helps to clarify these questions based on the study of the parasites and microorganisms that infected those animals, using as a source material coprolites, fossils in rock, tissue, bone, mummy, and amber, analyses of ancient DNA, immunodiagnosis, and microscopy.

A review on application of next-generation sequencing methods for profiling of protozoan parasites in water: Current methodologies, challenges, and perspectives

The advancement in metagenomic techniques has provided novel tools for profiling human parasites in environmental matrices, such as water and wastewater. However, application of metagenomic techniques for the profiling of protozoan parasites in environmental matrices is not commonly reported in the literature. The key factors leading to the less common use of metagenomics are the complexity and large eukaryotic genome, the prevalence of small parasite populations in environmental samples compared to bacteria, difficulties in extracting DNA from (oo)cysts, and limited reference databases for parasites. This calls for further research to develop optimized methods specifically looking at protozoan parasites in the environment. This study reviews the current workflow, methods and provide recommendations for the standardization of techniques. The article identifies and summarizes the key methods, advantages, and limitations associated with metagenomic analysis, like sample pre-processing, DNA extraction, sequencing approaches, and analysis methods. The study enhances the understanding and application of standardized protocols for profiling of protozoan parasite community from highly complexe samples and further creates a resourceful comparison among datasets without any biases.

A novel duplex ddPCR assay for detection and differential diagnosis of Ascaridia galli and Heterakis gallinarum eggs from chickens feces

Since the EU ban on battery cages, many studies have listed Ascaridia galli and Heterakis gallinarum as the most common roundworms in the European laying hen population. A complicating factor is that the eggs of these parasites are almost identical. Thus, lack of molecular diagnostic approaches has driven epidemiological studies to take on necropsy for species discrimination, which is labor and cost intensive. Here, we describe a novel diagnostic tool based on droplet digital PCR for simultaneous identification and absolute quantification of the eggs of both of these ascarids in chickens' droppings using two different genus-specific primer-probe sets targeting the second internal transcribed spacer region (ITS-2) in the nuclear ribosomal (rRNA) gene array. No cross-reaction was observed when different combinations of DNA and species-specific primers and probes were tested. The lowest obtained frequency threshold for the detection of H. gallinarum in the presence of a constant A. galli DNA concentration was determined to be 0.8 %. After validation, we used the assay to analyze field samples collected from several Swedish laying hen farms. Out of 134 samples, 86 (64 %) were positive for A. galli while 11 (8.3 %) samples were positive for H. gallinarum. These samples were initially analyzed with flotation technique for detection of ascarid eggs. The results of the Cohen's kappa indicated substantial agreement (85.8 %) between the two tests. In conclusion, we have validated a novel molecular-based diagnostic tool for quantification and differentiation between intestinal parasites of major importance in chickens with high precision. Although this study focuses on identification of parasites of laying hens, the findings may well have a bearing on all types of chicken production systems. The present study lays the groundwork for future research into epidemiology of these two important chicken parasite species.

Dietary intake, intestinal infection, and safe drinking water among children with anemia in Peru: a cross-sectional analysis

BACKGROUND

Anemia is a major public health concern that is present in 41.7% of children under 5 worldwide. The prevalence of anemia in Peru was 43.6% in 2017, a decrease by only 6.8% in 8 years. Despite great efforts made by the government to reduce anemia by distributing free multi-micronutrient supplements and promote the consumption of iron rich foods, progress has been slow. The current study sought to better understand why the prevalence remains high by analyzing the dietary intake, incidence of intestinal infectious disease, and access to safe drinking water by children with anemia in Peru.

METHODS

A cross-sectional analysis was conducted using data from two national surveys that were combined by child ID. Descriptive statistics was analyzed to understand the experience of children with anemia in comparison to child without anemia. Logistic multivariate regression analyses were conducted to test the associations between anemia and dietary intake, intestinal infection, and access to safe drinking water.

RESULTS

The sample included 586 children between 6 and 35 months. The prevalence of anemia in this population was 53%. The portion of children that consumed sufficient iron to meet the recommendation for their age was 62%. Of the children with anemia, 52% consumed sufficient iron to meet their recommendation, vs. 72% of children without anemia (p < 0.001). The children with anemia were more likely to have an intestinal infection during the previous year (35% vs. 26%, p = 0.057) and less likely to have access to safe drinking water (77% vs. 86%, p = 0.002) than those without anemia. The logistic analysis revealed that having an intestinal infection increased the odds of having anemia (OR = 1.64, CI 95% [1.041-2.584]), and having access to safe drinking waters decreased the odds of having anemia (OR = 0.578, [0.334-0.998]).

CONCLUSIONS

More than half of the children with anemia in Peru already consume sufficient iron to meet their daily requirement. However, they continue to have anemia, likely due to intestinal infection, such as diarrhea and parasites, from a lack of access to safe drinking water and hygienic practices.

Encephalitozoon intestinalis Infection Impacts the Expression of Apoptosis-Related Genes in U937 Macrophage Cells

PURPOSE

Encephalitozoon intestinalis affects many physiological processes of host cells to survive, proliferate, and spread to different regions within the body. In this study, the effects of the parasite on host cell apoptosis and proliferation were investigated.

METHODS

To determine the impact of the parasite on the host cell apoptosis, changes in the expression profile of genes were investigated with the qPCR array using the Human Apoptosis Panel in infected and non-infected macrophage cells. Also, the rate of apoptosis in the cells was determined by Giemsa staining method. Cell proliferation was determined by measuring the DNA concentration in infected and non-infected cells.

RESULTS

The thirty-six of apoptosis-related genes were down-regulated, while 20 of apoptosis-related genes were up-regulated in infected cells compared to uninfected cells. However, there were no significant changes detected in 32 analyzed genes between infected and control groups. E. intestinalis was determined to decrease cell proliferation in U937 macrophage cells. Unexpectedly, Giemsa staining showed an increase in the rate of apoptosis in infected cells.

CONCLUSION

Regulated genes after infection are involved in many different biological pathways and various components of the cell. This suggests that the parasite uses highly sophisticated ways to maintain the viability of the cell.

Evaluating the effects of finishing diet and feeding location on sheep performance, carcass characteristics, and internal parasites

A 3 yr experiment was conducted to evaluate the influence of diet and feeding location on animal performance, carcass characteristics, whole blood counts, and internal parasite burden of lambs assigned to 1 of 4 treatments: 1) confinement fed 71% alfalfa, 18% barley pellet, 5% molasses, 0.013% Bovatec, 6.1% vitamin/mineral package diet (CALF), 2) confinement fed 60% barley, 26% alfalfa pellet, 4% molasses, 2.5% soybean-hi pro, 0.016% Bovatec, 7.4% vitamin/mineral package diet (CBAR), 3) field fed 71% alfalfa, 18% barley pellet, 5% molasses, 0.013% Bovatec, 6.1% vitamin/mineral package diet (FALF), and 4) field fed 60% barley, 26% alfalfa pellet, 4% molasses, 2.5% soybean-hi pro, 0.016% Bovatec, 7.4% vitamin/mineral package diet (FBAR). A year × location interaction was detected for ending body weight (BW), average daily gain (ADG), and dry matter intake (DMI); therefore results are presented by year. In all years, cost of gain and DMI were greater for CALF and FALF than for CBAR and FBAR feed treatments (p ≤ 0.03). In yr 2 and 3 field treatments had greater ending BW and ADG than confinement treatments. For all years, diet did not affect ending BW or ADG. In yr 1 dressing percent and rib eye area were greater for field finished lambs than confinement finished (p ≤ 0.02) and Warner-Bratzler shear force was greater for CALF and FALF (p = 0.03). In yr 2 lambs in FALF and FBAR treatments had greater leg scores and conformation than CALF and CBAR (p = 0.09). In yr 1, FALF had a greater small intestine total worm count than all other treatments. In yr 1, ending Trichostrongyle type egg counts were greater for FALF (p = 0.05). In yr 2, ending Nematodirus spp. egg counts were greater for FALF and lowest for CBAR (p < 0.01). Abomasum Teladorsagia circumcinta worm burden was greater in CALF than all other treatments (p = 0.07) in yr 2. While field finishing lambs with a grain- or forage-based diet we conclude that it is possible to produce a quality lamb product without adverse effects to animal performance, carcass quality or increasing parasite burdens.

Cross-sectional study on intestinal parasite infections in different ecological zones of the Department of La Paz, Bolivia

We performed a cross-sectional parasitological survey to assess the prevalence of protozoa and helminth infection among 275 school-age children (SAC) living in rural and peri-urban areas located in different ecological zones of the Department of La Paz, Bolivia. Public health activities for the control of STH, based on the biannual administration of mebendazole to preschool and school children are implemented at national level since 1986.

We found an overall prevalence of 82.2% for intestinal parasites, including protozoa (80%) and helminths (23.3%). Blastocystis and Entamoeba coli were the most prevalent protozoa (found in 44% and 20.7% of the SAC enrolled); as for helminths, Ascaris lumbricoides and Hymenolepis nana were diagnosed in 14.5% and 3.3% of the children, respectively, followed by Trichuris trichiura 1.4%, Enterobius vermicularis 1.4%, Strongyloides stercoralis 0.7% and hookworms 0.7%.

Molecular characterization of Blastocystis positive samples evidenced three different subtypes (ST1, ST2, ST3) highlighting the risk of transmission also from animal reservoir. We found a significant difference in the distribution of intestinal parasitic infection (IPIs) by ecological zone (44/74. 59% in Andean highlands, 94/170, 88% in tropical lowlands and 88/94, 94% in the Yungas, p < 0.001). Access to potable water (OR 0.1 95%CI 0.02–0.5, p = 0.004) and the habit of boiling drinking water (OR 0.3, 95% CI 0.2–0.7, p = 0.004) showed an independent association with a lower risk of all IPIs and STHs, respectively. The very low prevalence of STH infections of moderate heavy intensity demonstrate that periodical deworming has been successful in reducing the morbidity due to these parasites, however the high prevalence of protozoa demonstrate that sanitation is still problematic and there is a relevant contamination of the environment with human faeces.

Significant efforts are still needed to reduce IPIs transmission and to improve health and sanitation in this area.

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In the Department of La Paz, the current overall STH among school-age children prevalence is high (17.1%), with a patchy distribution throughout the region.

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The prevalence of STH infections of moderate and heavy intensity shows that the morbidity due to these parasites has not been eliminated yet.

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The preventive chemotherapy coverage should be significantly improved in all the at-risk populations, and strategy of PC delivery should be tailored to local conditions.

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Updated epidemiological information is crucial to inform policy for STH control.

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Significant efforts are still needed to reduce transmission and to improve health and sanitation in this area. Interventions should be inspired by the WASH principles, endorsed by the WHO.

Effect of an Arthrobotrys musiformis (Fungi: Orbiliales) culture filtrate on the population of gastrointestinal parasitic nematode eggs in faeces of grazing lambs

This study assessed the anthelmintic activity of the oral administration of a free-spore culture filtrate of the nematophagous fungus (NF) Arthrobotrys musiformis (M-10) on gastrointestinal parasitic nematodes (GIN) in naturally infected lambs. The fungus was grown on potato-dextrose agar plates (PDA) and transferred to a fermented rice medium (FRM). After 40-day incubation the total amount of FRM with the growing fungi was transferred to a flask shaker with distilled water for a 24 h period. The fungus was centrifuged and filtered. Three groups of six naturally-infected lambs (>1000 epg) each were treated once as follows: Group 1) 63.8 mg/kg A. musiformis culture filtrate (CF) (per os); Group 2) Levamisole 7.5 mg/ml (intramuscularly), Group 3) 15 ml of distilled water (per os). Faecal samples were individually collected on days -2, 0, 2, 4, 6, 8 and 10 after treatment. For each experimental group, mean egg shedding was calculated and transformed (log 10 [epg + 1]). Means between the fungal filtrate group and the negative control were analysed using a T-Student Test. The faecal egg count reduction test (FECRT) was performed in groups treated with CF and Levamisole in relation to the control group (water) were 36.8-57.4% and 89-95.4%, respectively., although due to the difference between groups, no statistical significance was found (p > 0.05). The use of A. musiformis CF appears to be a good alternative treatment, although, more studies should be performed to establish the use of these fungal products as potential tools for GIN control.

Nano-Leish-IL: A novel iron oxide-based nanocomposite drug platform for effective treatment of cutaneous leishmaniasis

Kinetoplastids are infamous parasites that include trypanosomes and Leishmania species. Here, we developed an anti-Leishmania nano-drug using ultra-small functional maghemite (γ-Fe₂O₃) nanoparticles (NPs) that were surface-doped by [CeL_n]^3/4+ to enable effective binding of the polycationic polyethylenebyimine (PEI) polymer by coordinative chemistry. This resulting nano-drug is cytolytic in-vitro to both Trypanosoma brucei parasites, the causative agent of sleeping sickness, as well as to three Leishmania species. The nano-drug induces the rupture of the single lysosome present in these parasites attributed to the PEI, leading to cytolysis. To evaluate the efficacy of a "cream-based" version of the nano-drug, which was termed "Nano-Leish-IL" for topical treatment of cutaneous leishmaniasis (CL), we developed a rapid screening method utilizing T. brucei parasites involved in social motility and demonstrated that functional NPs arrested the migration of the parasites. This assay presents a surrogate system to rapidly examine the efficacy of "cream-based" drugs in topical preparations against leishmaniasis, and possibly other dermal infectious diseases. The resulting Nano-Leish-IL topical preparation eliminated L. major infection in mice. Thus, this study presents a novel efficient nano-drug targeting the single lysosome of kinetoplastid parasites.

Vector saliva controlled inflammatory response of the host may represent the Achilles heel during pathogen transmission

Infection with vector-borne pathogens starts with the inoculation of these pathogens during blood feeding. In endemic regions, the population is regularly bitten by naive vectors, implicating a permanent stimulation of the immune system by the vector saliva itself (pre-immune context). Comparatively, the number of bites received by exposed individuals from non-infected vectors is much higher than the bites from infected ones. Therefore, vector saliva and the immunological response in the skin may play an important role, so far underestimated, in the establishment of anti-pathogen immunity in endemic areas. Hence, the parasite biology and the disease pathogenesis in “saliva-primed” and “saliva-unprimed” individuals must be different. This integrated view on how the pathogen evolves within the host together with vector salivary components, which are known to be endowed with a variety of pharmacological and immunological properties, must remain the focus of any investigational study dealing with vector-borne diseases.

Considering this three-way partnership, the host skin (immune system), the pathogen, and the vector saliva, the approach that consists in the validation of vector saliva as a source of molecular entities with anti-disease vaccine potential has been recently a subject of active and fruitful investigation. As an example, the vaccination with maxadilan, a potent vasodilator peptide extracted from the saliva of the sand fly Lutzomyia longipalpis, was able to protect against infection with various leishmanial parasites. More interestingly, a universal mosquito saliva vaccine that may potentially protect against a range of mosquito-borne infections including malaria, dengue, Zika, chikungunya and yellow fever. In this review, we highlight the key role played by the immunobiology of vector saliva in shaping the outcome of vector-borne diseases and discuss the value of studying diseases in the light of intimate cross talk among the pathogen, the vector saliva, and the host immune mechanisms.

Respiratory Tract Disorders in Fishes

"The piscine respiratory system is represented by gills. Gill diseases are extremely common and may be caused by a large variety of etiologic agents. The gills are in direct contact with water and reflect its quality, for example, pollution, and they also must face the presence of biotic agents, such as viruses, bacteria, fungi, and parasites. Evolution has established many defense mechanisms to combat these agents. Failure of these mechanisms is life-threatening for the fish, due to impaired respiration. Gills are relatively easily accessible for clinical examination and sampling, which facilitates intravital diagnosis."

The roles of parasite-derived extracellular vesicles in disease and host-parasite communication

In recent years, several parasites have been shown to interact with their hosts through intra- and inter-community communication mechanisms, which were identified to be mediated by extracellular vesicles (EVs) through various uptake mechanisms. EVs are a heterogenous group of nanoparticles (~30-5000 nm) classified into three main types according to their size and biogenesis. EVs contain proteins, lipids, nucleic acids and metabolites from the cell of origin which are essential for genetic exchange, biomarker identification and diagnosis of pathological diseases. As important "forward lines of parasite infectivity", the parasite-secreted EVs function as information transmitters in the early-stage of host-parasite interaction and subsequent host-cell colonization. For this review, we summarize from the literature the relevance of EVs to the pathogenesis and development of human parasitic protistan diseases such as giardiasis, leishmaniasis, amoebiasis, malaria and Blastocystis-mediated gut pathology. Specific in vitro and in vivo interactions of the parasite-EVs and the host, with the reported cellular and immunological outcomes are discussed in this review. EVs have great potential to be further developed as diagnostic, immunomodulation and therapeutic alternatives to fill the knowledge gaps in the current parasitic diseases discussed in this review. Nanomedicine and vaccine development could be explored, with the utilization and/or modification of the parasitic EVs as novel treatment and prevention strategies.

An alien parasite affects local fauna-Confirmation of Sinergasilus major (Copepoda: Ergasilidae) switching hosts and infecting native Silurus glanis (Actinopterygii: Siluridae) in Hungary

In 2016, an intense copepod infection was recorded from a reservoir in proximity to the Danube River in Hungary from visibly emaciated wels catfish, Silurus glanis. The parasite-induced pathology was described but parasite identity was not conclusive. Additional sample collections in 2017 and 2018 allowed for identification using both light and scanning electron microscopy, alongside genetic characterisation. The copepods were confirmed to be ergasilids, Sinergasilus major, distinctly different from any previous infection on silurids in Europe. This is the first record of this parasite from Hungary and the first host record from wels catfish.

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First record of Sinergasilus major from wels catfish (Silurus glanis).

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First record of S. major from Hungary.

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Light and scanning eletron microscopy support identification of S. major.

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100% similarity of the 18S rDNA provides significant confidence to the identification of the copepods as S. major.

Distribution, prevalence and intensity of moose nose bot fly (Cephenemyia ulrichii) larvae in moose (Alces alces) from Norway

High host density combined with climate change may lead to invasion of harmful parasites in cervid (host) populations. Bot flies (Diptera: Oestridae) are a group of ectoparasites that may have strong impact on their hosts, but data on the current distribution, prevalence and intensity of the moose nose bot fly (Cephenemyia ulrichii) in Scandinavia are lacking. We estimated prevalence and intensity of nose bot fly larvae in 30 moose from southern and 79 moose from central Norway. All larvae detected were identified as the moose nose bot fly. We found surprisingly high prevalence in these areas, which are up to 1300 km south-southwest of the first published location in Norway and west of the distribution in Sweden. Prevalence (0.44-1.00) was higher in areas with higher moose density. Parasite intensity in hunter killed moose was higher in central Norway (mean 5.7) than southern Norway (mean 2.9), and in both regions higher in calves and yearlings than adults. Fallen moose had higher parasite intensity (mean 9.8) compared to hunter killed moose in the subsample from central Norway, suggesting a link to host condition or behavior. Our study provides evidence of parasite range expansion, and establishing monitoring appears urgent to better understand impact on host populations.

Diphyllobothrium sprakeri n. sp. (Cestoda: Diphyllobothriidae): a hidden broad tapeworm from sea lions off North and South America

BACKGROUND

The systematic of several marine diphyllobothriid tapeworms of pinnipeds has been revised in recent years. However, 20 species of Diphyllobothrium from phocids and otariids are still recognized as incertae sedis. We describe a new species of Diphyllobothrium from the intestine of California sea lions Zalophus californianus (Lesson) (type-host) and South American sea lions Otaria flavescens (Shaw).

METHODS

Zalophus californianus from the Pacific coast of the USA and O. flavescens from Peru and Argentina were screened for parasites. Partial fragments of the large ribosomal subunit gene (lsrDNA) and the cytochrome c oxidase subunit 1 (cox1) mitochondrial gene were amplified for 22 isolates. Properly fixed material from California sea lions was examined using light and scanning electron microscopy.

RESULTS

A total of four lsrDNA and 21 cox1 sequences were generated and aligned with published sequences of other diphyllobothriid taxa. Based on cox1 sequences, four diphyllobothriid tapeworms from O. flavescens in Peru were found to be conspecific with Adenocephalus pacificus Nybelin, 1931. The other newly generated sequences fall into a well-supported clade with sequences of a putative new species previously identified as Diphyllobothrium sp. 1. from Z. californianus and O. flavescens. A new species, Diphyllobothrium sprakeri n. sp., is proposed for tapeworms of this clade.

CONCLUSIONS

Diphyllobothrium sprakeri n. sp. is the first diphyllobothriid species described from Z. californianus from the Pacific coast of North America, but O. flavescens from Argentina, Chile and Peru was confirmed as an additional host. The present study molecularly confirmed the first coinfection of two diphyllobothriid species in sea lions from the Southern Hemisphere.

Checklist of digenean trematodes of Iran

Digeneans are an important class of trematodes which infect variety of animals ranging from vertebrates (mainly final hosts) to invertebrates (mainly as intermediate hosts). Additionally, some of these parasites are zoonotic and one health importance. Diversity of digeneans in Iran and reports of several zoonotic cases show the importance of these parasites in this country. This is the checklist of digenean parasites reported from Iran representing a total of 118 species, from 105 genera, 43 families, 21 subfamilies, and 3 orders that are reported from 139 species of different hosts including humans. Some of the most important final number of families, genera, and species reported in Iran fauna include: Fasciolidae, Genus: Fasciola, Fasciola gigantica, Fasciola hepatica, Family: Dicrocoeliidae, Genus: Dicrocoelium, Dicrocoelium dendriticum, Family: Diplostomidae, Genus: Diplostomum, Diplostomum spathaceum, Family: Heterophyidae, Genus: Haplorchis, Haplorchis taichui, Family: Notocotylidae, Genus: Notocotylu, Notocotylus aegyptiacus, Family: Bucephalidae, Genus: Rhipidocotyle, Rhipidocotyle illense.

Swine as biomedical animal model for T-cell research-Success and potential for transmittable and non-transmittable human diseases

Swine is biologically one of the most relevant large animal models for biomedical research. With its use as food animal that can be exploited as a free cell and tissue source for research and its high susceptibility to human diseases, swine additionally represent an excellent option for both the 3R principle and One Health research. One of the previously most limiting factors of the pig model was its arguably limited immunological toolbox. Yet, in the last decade, this toolbox has vastly improved including the ability to study porcine T-cells. This review summarizes the swine model for biomedical research with focus on T cells. It first contrasts the swine model to the more commonly used mouse and non-human primate model before describing the current capabilities to characterize and extend our knowledge on porcine T cells. Thereafter, it not only reflects on previous biomedical T-cell research but also extends into areas in which more in-depth T-cell analyses could strongly benefit biomedical research. While the former should inform on the successes of biomedical T-cell research in swine, the latter shall inspire swine T-cell researchers to find collaborations with researchers working in other areas - such as nutrition, allergy, cancer, transplantation, infectious diseases, or vaccine development.

Determinants of lungworm specificity in five cetacean species in the western Mediterranean

BACKGROUND

Current data about Pseudaliidae show contrasting patterns of host specificity between congeneric species. We investigated how both contact and compatibility between hosts and parasites contributed to the patterns of lungworm infection observed in a community of five species of cetaceans in the western Mediterranean.

METHODS

The lungs of 119 striped dolphins Stenella coeruleoalba, 18 bottlenose dolphins Tursiops truncatus, 7 Risso's dolphins Grampus griseus, 7 long-finned pilot whales Globicephala melas, and 6 common dolphins Delphinus delphis were analysed for lungworms. Parasites were identified by morphology and analysis of ITS2 sequences using both maximum likelihood and Bayesian inference methods. Body length was used as a proxy for lungworm species fitness in different hosts and compared with Kruskal-Wallis tests. Infection parameters were compared between cetacean species using Fisher's exact tests and Kruskal-Wallis tests. Phylogenetic specificity was explored by collating the overall lungworm species prevalence values in hosts from previous surveys in various localities. To explore the relative importance of vertical and horizontal transmission, Spearman's rank correlation was used to look for an association between host size and lungworm burden. A Mantel test was used to explore the association between lungworm species similarity and prey overlap using dietary data.

RESULTS

Halocercus delphini had higher infection levels in striped dolphins and common dolphins; Stenurus ovatus had higher infection levels in bottlenose dolphins; and Stenurus globicephalae had higher infection levels in long-finned pilot whales. These results are congruent with findings on a global scale. Morphometric comparison showed that the larger nematodes were found in the same host species that had the highest parasite burden. Lungworms were found in neonatal striped dolphins and a Risso's dolphin, and there was a weak but significant correlation between host size and parasite burden in striped dolphins and bottlenose dolphins. There was also a weak but significant association between prey overlap and lungworm species similarity.

CONCLUSIONS

Data indicate that phylogenetic specificity has an important role in governing host-parasite associations, as indicated by the higher infection levels and larger nematode size in certain hosts. However, diet can also influence infection patterns in these preferred hosts and contribute to less severe infections in other hosts.

Predictors of helminth parasite infection in female chacma baboons (Papio ursinus)

Helminth parasite infection can impose major consequences on host fitness. Several factors, including individual characteristics of hosts, environmental conditions, and patterns of coinfection, are thought to drive variation in parasite risk. Here, we report on four key drivers of parasite infection-phase of reproduction, steroid hormone profiles, rainfall, and patterns of coinfection-in a population of wild female chacma baboons (Papio ursinus) in South Africa. We collected data on reproductive state and hormone profiles over a 3-year span, and quantified helminth parasite burdens in 2955 fecal samples from 24 female baboons. On a host level, we found that baboons are sensitive to parasite infection during the costliest phases of the reproductive cycle: pregnant females harbored higher intensities of Protospirura eggs than cycling and lactating females; lactating and cycling females had a higher probability of Oesophagostomum infection than pregnant females; and cycling females exhibited lower Trichuris egg counts than pregnant and lactating females. Steroid hormones were associated with both immunoenhancing and immunosuppressive properties: females with high glucocorticoid concentrations exhibited high intensities of Trichuris eggs but were at low risk of Oesophagostomum infection; females with high estrogen and progestagen concentrations exhibited high helminth parasite richness; and females with high progestagen concentrations were at high risk of Oesophagostomum infection but exhibited low Protospirura egg counts. We observed an interaction between host reproductive state and progestagen concentrations in infection intensity of Protospirura: pregnant females exhibited higher intensities and non-pregnant females exhibited lower intensities of Protospirura eggs with increasing progestagen concentrations. At a population level, rainfall patterns were dominant drivers of parasite risk. Lastly, helminth parasites exhibited positive covariance, suggesting that infection probability increases if a host already harbors one or more parasite taxa. Together, our results provide a holistic perspective of factors that shape variation in parasite risk in a wild population of animals.

Managed bumble bees acquire parasites from their foraging environment: A case study on parasite spillback

The use of commercially reared bumble bees in agricultural environments has been recognized as a potential threat to wild pollinators due to competition, genetic contamination, and most notably, disease transmission. Higher parasite prevalence near greenhouses where managed bumble bees are used has been linked to parasite spillover from managed to wild bees. However, pathogen transmission is not unidirectional, and can also flow from wild to managed bees. These newly infected managed bees can subsequently re-infect (other) wild bees, in a process known as spillback, which is an alternative explanation for the increased parasite prevalence near greenhouses. Reducing parasite prevalence in managed bees is key to controlling host-parasite dynamics in cases of spillover; in spillback, producing managed bees that are resilient to infection is important. Here we establish that the managed bumble bee Bombus terrestris can acquire parasites from their foraging environment, which is the major infection route for Apicystis spp. and Crithidia spp., but not for Nosema spp.. Managed B. terrestris were found to have a higher prevalence of Crithdia and a higher load of Apicystis than local wild conspecifics, showing that for these parasites, spillback is a possible risk scenario.

The occurrence and clinical importance of infectious stage of Echinocephalus (Nematoda: Gnathostomidae) larvae in selected Australian edible fish

Cases of gnathostomiasis, an infection caused by consuming infected seafood, have been reported in Australia. However, doubt exists over the validity of these diagnoses as there are no reports of Gnathostoma spp. in Australian teleost fish. Also, the diagnoses in human cases were based on a serological test developed in Thailand. The specificity and sensitivity of this test in non-endemic areas are uncertain. Interestingly, parasites belonging to the genus Echinocephalus, which morphologically are very similar to Gnathostomum, are commonly found in Australian fish and shellfish and can potentially infect humans. The aim of this study was to determine the occurrence of these zoonotic nematodes within commercial fish and to characterise nematode larvae in order to provide insights into the specific identity of the potential causative agents of gnathostomiasis in Australia. Six edible fish species (n = 163) were examined. Gnathostomid-type larvae were found only in Acanthopagrus australis and Rhabdosargus sarba. Detailed examination and sequence data suggested parasite larvae belonged to the genus Echinocephalus. Further investigation of the occurrence of zoonotic nematodes within marine environments and observation of their spatial and temporal patterns will help raise awareness of the significance of this food safety issue within global fishing industries and health sectors. The accurate identification of zoonotic nematodes is a key component of disease surveillance and control. This information can also be used to develop specific and sensitive diagnostic test.

Outbreak of hirudiniasis in aquarium-reared albino red-bellied pacu Piaractus brachypomus

We report hirudiniasis caused by the leech Hemiclepsis marginata asiatica Moore, 1924 in albino red-bellied pacu (pirapitinga) Piaractus brachypomus (Cuvier, 1818), constituting the first documentation of a freshwater fish species being affected in India. The outbreak occurred in a tank of an aquarium-fish retailer; infested fish appeared asphyxiated, unable to swim or swimming upside down, with cloudy eyes and body with thick mucus secretion. The prevalence and mortality was 100%, with a mean intensity of 81 leeches per fish. The histopathology of the morbid fish revealed degenerative necrosis, eosinophilic infiltration in the muscle tissue and haemorrhages in the fin membrane. The leech mitochondrial 18S rDNA and 12S rDNA genes were characterised and submitted to GenBank under accession numbers MN380443 (18S) and MK733282 (12S). A maximum likelihood tree was constructed using 12S rDNA gene sequences to demonstrate the phylogenetic position of Hemiclepsis marginata asiatica among its congeners.