Autochthonous Trypanosoma spp. in European Mammals: A Brief Journey amongst the Neglected Trypanosomes

Current Status of Trypanosoma grosi and Babesia microti in Small Mammals in the Republic of Korea

Small mammals, such as rodents and shrews, are natural reservoir hosts of zoonotic diseases, including parasitic protozoa. To assess the risk of rodent-borne parasitic protozoa in the Republic of Korea (ROK), this study investigated the status of parasitic protozoa, namely Trypanosoma, Babesia, and Theileria, in small mammals. In total, 331 blood samples from small mammals were analyzed for parasites using PCR and sequenced. Samples were positive for Trypanosoma grosi (23.9%; n = 79) and Babesia microti (10%; n = 33) but not Theileria. Small mammals from Seogwipo-si showed the highest infection rate of T. grosi (48.4%), while the highest B. microti infection rate was observed in those from Gangneung-si (25.6%). Sequence data revealed T. grosi to be of the AKHA strain. Phylogenetic analysis of B. microti revealed the US and Kobe genotypes. B. microti US-type-infected small mammals were detected throughout the country, but the Kobe type was only detected in Seogwipo-si. To our knowledge, this is the first nationwide survey that confirmed T. grosi and B. microti infections at the species level in small mammals in the ROK and identified the Kobe type of B. microti. These results provide valuable information for further molecular epidemiological studies on these parasites.

An Atlas of Surra in Spain: A Tool to Support Epidemiological Investigations and Disease Control

Trypanosomosis is a global animal issue, causing significant economic losses, particularly in Africa. In Spain, only one pathogenic species, Trypanosoma evansi, has been identified so far. It was first detected in a dromedary camel in the Canary Islands in 1997. Since then, numerous cases of the disease, known as Surra, have been diagnosed, prompting various studies and efforts in control and surveillance. Given the lack of a comprehensive database that consolidates the most relevant data in this area, the development of a national atlas, with a focus on the Canary Islands, to incorporate all available information on T. evansi in Spain became a necessity. For the development of the atlas, a repository was constructed, encompassing a range of datasets and documents spanning from 1997 to 2022. Information from each source, and in particular georeferenced locations and results of blood tests on animals, were extracted and integrated into a comprehensive database. A total of 31 sources were analysed, providing a total of 99 georeferenced locations and 12,433 animal samples. Out of these samples, 601 (mostly from dromedaries) were found to be positive for T. evansi. The Card Agglutination Test for T. evansi (CATT/T. evansi), a serological test, was the most commonly used diagnostic method, and it showed a higher prevalence for all tested animal species. Positive cases were mainly concentrated in the Canary Islands, specifically in the eastern islands, with isolated cases found in the province of Alicante (Iberian Peninsula). This atlas provides an overview of the history and occurrence of Surra in Spain, and it represents a valuable tool for future control initiatives and for research. Still, the need for more studies remains, especially for further testing of potential hosts other than camelids and for the examination of their potential transmission vectors.

Trypanosoma lewisi in blood of Rattus rattus complex residing in human settlements, Nakhon Si Thammarat, Thailand: Microscopic and molecular investigations

Trypanosomes are blood parasites infected in various mammals, including rats. The presence of rats in human settlements can increase the chance of Trypanosoma transmission to humans. The molecular study of multispacer in Trypanosoma spp. in naturally infected rodents in Thailand is scanty. The objective of this study was to detect Trypanosoma in the blood of the captured rats in Nakhon Si Thammarat, Thailand, using microscopic and molecular techniques. This was a cross-sectional study conducted in human settlement areas. Ninety-nine blood samples were collected using cardiac puncture. A blood sample was smeared on a glass slide and examined using a compound light microscope and a scanning electron microscope. Moreover, polymerase chain reaction was applied to detect Trypanosoma evansi and T. lewisi in the blood. An additional primer set was used to confirm the species of the detected trypanosome. Approximately 18% of the rats had positive Trypanosoma infections. All Trypanosoma-positive blood samples were matched with sequences of T. lewisi. The stumpy form of trypanosome had higher nucleus related parameters than the slender form. Interestingly, the partial sequences of the alpha-tubulin gene of T. lewisi were first reported in the naturally infected RrC in this study. Based on the results obtained, T. lewisi biology, particularly the virulent components and route of transmission, pathogenesis, and in vitro experiments, are strongly recommended for further study.

Metallic Nanoparticles and Core-Shell Nanosystems in the Treatment, Diagnosis, and Prevention of Parasitic Diseases

The usage of nanotechnology in the fight against parasitic diseases is in the early stages of development, but it brings hopes that this new field will provide a solution to target the early stages of parasitosis, compensate for the lack of vaccines for most parasitic diseases, and also provide new treatment options for diseases in which parasites show increased resistance to current drugs. The huge physicochemical diversity of nanomaterials developed so far, mainly for antibacterial and anti-cancer therapies, requires additional studies to determine their antiparasitic potential. When designing metallic nanoparticles (MeNPs) and specific nanosystems, such as complexes of MeNPs, with the shell of attached drugs, several physicochemical properties need to be considered. The most important are: size, shape, surface charge, type of surfactants that control their dispersion, and shell molecules that should assure specific molecular interaction with targeted molecules of parasites' cells. Therefore, it can be expected that the development of antiparasitic drugs using strategies provided by nanotechnology and the use of nanomaterials for diagnostic purposes will soon provide new and effective methods of antiparasitic therapy and effective diagnostic tools that will improve the prevention and reduce the morbidity and mortality caused by these diseases.

Molecular pathogen screening of louse flies (Diptera: Hippoboscidae) from domestic and wild ruminants in Austria

BACKGROUND

Hippoboscid flies (Diptera: Hippoboscidae), also known as louse flies or keds, are obligate blood-sucking ectoparasites of animals, and accidentally of humans. The potential role of hippoboscids as vectors of human and veterinary pathogens is being increasingly investigated, but the presence and distribution of infectious agents in louse flies is still unknown in parts of Europe. Here, we report the use of molecular genetics to detect and characterize vector-borne pathogens in hippoboscid flies infesting domestic and wild animals in Austria.

METHODS

Louse flies were collected from naturally infested cattle (n = 25), sheep (n = 3), and red deer (n = 12) across Austria between 2015 and 2019. Individual insects were morphologically identified to species level and subjected to DNA extraction for molecular pathogen screening and barcoding. Genomic DNA from each louse fly was screened for Borrelia spp., Bartonella spp., Trypanosomatida, Anaplasmataceae, Filarioidea and Piroplasmida. Obtained sequences of Trypanosomatida and Bartonella spp. were further characterized by phylogenetic and haplotype networking analyses.

RESULTS

A total of 282 hippoboscid flies corresponding to three species were identified: Hippobosca equina (n = 62) collected from cattle, Melophagus ovinus (n = 100) from sheep and Lipoptena cervi (n = 120) from red deer (Cervus elaphus). Molecular screening revealed pathogen DNA in 54.3% of hippoboscids, including infections with single (63.39%), two (30.71%) and up to three (5.90%) distinct pathogens in the same individual. Bartonella DNA was detected in 36.9% of the louse flies. Lipoptena cervi were infected with 10 distinct and previously unreported Bartonella sp. haplotypes, some closely associated with strains of zoonotic potential. DNA of trypanosomatids was identified in 34% of hippoboscids, including the first description of Trypanosoma sp. in H. equina. Anaplasmataceae DNA (Wolbachia spp.) was detected only in M. ovinus (16%), while < 1% of the louse flies were positive for Borrelia spp. and Filarioidea. All hippoboscids were negative for Piroplasmida.

CONCLUSIONS

Molecular genetic screening confirmed the presence of several pathogens in hippoboscids infesting domestic and wild ruminants in Austria, including novel pathogen haplotypes of zoonotic potential (e.g. Bartonella spp.) and the first report of Trypanosoma sp. in H. equina, suggesting a potential role of this louse fly as vector of animal trypanosomatids. Experimental transmission studies and expanded monitoring of hippoboscid flies and hippoboscid-associated pathogens are warranted to clarify the competence of these ectoparasites as vectors of infectious agents in a One-Health context.

A Four-Year Survey of Hemoparasites from Nocturnal Raptors (Strigiformes) Confirms a Relation between Leucocytozoon and Low Hematocrit and Body Condition Scores of Parasitized Birds

Most hemoparasites hosted by wild birds appear to be harmless, but most of the blood parasite studies in avian wildlife are mainly focused on passerines or migratory species. This study aimed to assess the occurrence of blood parasites in nocturnal raptors (Strigiformes order) and their effect on hematological parameters. A total of 134 blood samples were collected during a four-year period for hematological analysis and hemoparasite detection and quantification by microscopical examination of the samples. Overall, the occurrence of hemoparasites was 35.1%, with Leucocytozoon being the most frequently detected (32.1%), followed by Haemoproteus (11.2%), Trypanosoma and Plasmodium (2.2% each). Among the different bird species, the Eurasian eagle-owl (Bubo bubo) showed the highest blood parasite positivity (94.7%). In barn owls, the positive birds displayed a lower hematocrit measurement and body condition score than the non-parasitized ones (p = 0.007 and p = 0.005, respectively), especially those parasitized by Leucocytozoon. Moreover, the analysis of the magnitude of this association revealed that the presence of hemoparasites is five times more frequent in barn owls with a 2/5 body condition score. Despite the host-parasite coevolution in Strigiformes, our results show a correlation between the presence of hemoparasites and some health parameters, including blood parameters.

First Molecular Identification of Trypanosomes and Absence of Babesia sp. DNA in Faeces of Non-Human Primates in the Ecuadorian Amazon

Trypanosomes are a group of pathogens distributed in the continents of Africa, America, Asia and Europe, and they affect all vertebrates including the neotropical primate group. Information about the trypanosome's diversity, phylogeny, ecology and pathology in non-human primates (NHPs) from the neotropical region is scarce. The objective of the study was to identify Trypanosoma and Babesia molecularly in NHPs under the phylogenetic species concept. We extracted DNA from a total of 76 faecal samples collected between 2019 and 2021, from a total of 11 non-human primate species of which 46 are from captive NHPs and 30 are free-living NHPs in the Western Amazon region of Ecuador. We did not detect DNA of Babesia sp. by polymerase chain reaction test in any of the faecal samples. However, the nested-PCR-based method revealed Trypanosoma parasites by ITS gene amplification in two faecal samples; one for the species Leontocebus lagonotus (from the captive population) and a second one for Cebus albifrons (from the free-ranging population). Maximum parsimony and likelihood methods with the Kimura2+G+I model inferred the evolutionary history of the two records, which showed an evolutionary relationship with the genus Trypanosoma. Two sequences are monophyletic with Trypanosoma. However, the number of sequences available in GenBank for their species identification is limited. The two samples present different molecular identifications and evolutionary origins in the tree topology. We are most likely referring to two different species, and two different localities of infection. We suggest that health management protocols should be implemented to prevent the transmission of blood-borne pathogens such as Trypanosoma sp. among captive populations. In addition, these protocols also protect the personnel of wildlife rehabilitation centers working in close proximity to NHPs and vice versa.

First Report of Anuran Trypanosoma DNA in Flat-Tailed House Geckos (Reptilia: Gekkonidae) Collected from Southern Thailand: No Evidence as a Reservoir for Human Trypanosomatids

Over the years, cases of autochthonous leishmaniasis have been dramatically increasing in Thailand. Recently, several publications have claimed certain species of the phlebotomine sand flies and biting midges potentially serve as natural vectors of Leishmania and Trypanosoma species in this country. However, more information regarding the vector–parasite relationships, as well as their natural reservoirs in the country, still needs to be explored. Herein, we hypothesized that synanthropic reptiles in the leishmaniasis-affected area might be a natural reservoir for these parasites. In this present study, a total of nineteen flat-tailed house geckos were collected from the house of a leishmaniasis patient in Songkhla province, southern Thailand, and then dissected for their visceral organs for parasite detection. Small subunit ribosomal RNA (SSU rRNA) gene and internal transcribed spacer 1 (ITS-1)-specific amplifications were conducted to verify the presence of Trypanosoma and Leishmania parasites, respectively. Only Trypanosoma DNA was screened positive in eight gecko individuals by SSU rRNA-PCR in at least one visceral organ (4, 4, and 6 of the heart, liver, and spleen, respectively) and phylogenetically related to the anuran Trypanosoma spp. (An04/Frog1 clade) previously detected in three Asian sand fly species (Phlebotomus kazeruni, Sergentomyia indica, and Se. khawi). Hence, our data indicate the first detection of anuran Trypanosoma sp. in the flat-tailed house geckos from southern Thailand. Essentially, it can be inferred that there is no evidence for the flat-tailed house gecko (Hemidactylus platyurus) as a natural reservoir of human pathogenic trypanosomatids in the leishmaniasis-affected area of southern Thailand.

First case report on molecular detection of Trypanosoma lewisi in an urban rat in Kelantan, Malaysia: An accidental finding

Objective:

This case report highlights the first detection of Trypanosoma lewisi, a blood protozoan parasite found in an urban rat in Kota Bharu, Kelantan.

Materials and Methods:

Rat trapping was carried out within the Kota Bharu vicinity near a local wet market. A total of 38 rats were captured and subjected to peripheral blood smearing using Giemsa stain. Positive rats were sent for histopathological analysis for the evaluation of the organ samples.

Results:

The presence of trypanosomes was found in one sample from a blood smear. This was connected to a histological lesion on kidney tissues, which revealed a high concentration of trypanosomes. Additionally, the positive sample was confirmed as T. lewisi based on molecular diagnosis via polymerase chain reaction and subsequent sequencing and phylogenetic analysis.

Conclusions:

This finding serves as a baseline for further surveillance on T. lewisi population among urban rats in Kelantan and possible zoonotic transmission to humans.