Morphological and molecular characteristics of a Trypanosoma sp. from triatomines (Triatoma rubrofasciata) in China.

BACKGROUND: Triatomines (kissing bugs) are natural vectors of trypanosomes, which are single-celled parasitic protozoans, such as Trypanosoma cruzi, T. conorhini and T. rangeli. The understanding of the transmission cycle of T. conorhini and Triatoma rubrofasciata in China is not fully known. METHODS: The parasites in the faeces and intestinal contents of the Tr. rubrofasciata were collected, and morphology indices were measured under a microscope to determine the species. DNA was extracted from the samples, and fragments of 18S rRNA, heat shock protein 70 (HSP70) and glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) were amplified and sequenced. The obtained sequences were then identified using the BLAST search engine, followed by several phylogenetic analyses. Finally, laboratory infections were conducted to test whether Tr. rubrofasciata transmit the parasite to rats (or mice) through bites. Moreover, 135 Tr. rubrofasciata samples were collected from the Guangxi region and were used in assays to investigate the prevalence of trypanosome infection. RESULTS: Trypanosoma sp. were found in the faeces and intestinal contents of Tr. rubrofasciata, which were collected in the Guangxi region of southern China and mostly exhibited characteristics typical of epimastigotes, such as the presence of a nucleus, a free flagellum and a kinetoplast. The body length ranged from 6.3 to 33.9 µm, the flagellum length ranged from 8.7 to 29.8 µm, the nucleus index was 0.6 and the kinetoplast length was -4.6. BLAST analysis revealed that the 18S rRNA, HSP70 and gGAPDH sequences of Trypanosoma sp. exhibited the highest degree of similarity with those of T. conorhini (99.7%, 99.0% and 99.0%, respectively) and formed a well-supported clade close to T. conorhini and T. vespertilionis but were distinct from those of T. rangeli and T. cruzi. Laboratory experiments revealed that both rats and mice developed low parasitaemia after inoculation with Trypanosoma sp. and laboratory-fed Tr. rubrofasciata became infected after feeding on trypanosome-positive rats and mice. However, the infected Tr. rubrofasciata did not transmit Trypanosoma sp. to their offspring. Moreover, our investigation revealed a high prevalence of Trypanosoma sp. infection in Tr. rubrofasciata, with up to 36.3% of specimens tested in the field being infected. CONCLUSIONS: Our study is the first to provide a solid record of T. conorhini from Tr. rubrofasciata in China with morphological and molecular evidence. This Chinese T. conorhini is unlikely to have spread through transovarial transmission in Tr. rubrofasciata, but instead, it is more likely that the parasite is transmitted between Tr. rubrofasciata and mice (or rats). However, there was a high prevalence of T. conorhini in the Tr. rubrofasciata from our collection sites and numerous human cases of Tr. rubrofasciata bites were recorded. Moreover, whether these T. conorhini strains are pathogenic to humans has not been investigated.

Tabanus chrysurus is a potential biological vector of Trypanosoma (Megatrypanum) theileri in Japan.

Several species of horse flies (Diptera: Tabanidae) are known as vectors of Trypanosoma (Megatrypanum) theileri and T. theileri-like trypanosomes; these host-parasite relationships were established based on the developmental stages of these parasites discovered in the hindgut of horse flies. T. theileri and T. theileri-like trypanosomes have been detected in cattle and wild deer in Japan; however, the vector horse fly species remains unidentified. Therefore, in this study, we aimed to identify the potential horse fly species serving as vectors of T. theileri in Japan. A total of 176 horse flies were collected between June to September 2020 and 2021 in Tokachi, Hokkaido, Japan. The T. theileri infection in the captured horse flies was determined by PCR and microscopic analyses of their midgut and hindgut. Additionally, the trypanosome, microscopically detected in a horse fly, was molecularly characterized and phylogenetically analyzed using 18S rRNA and partial cathepsin L-like protein gene (CATL) sequence of the trypanosome. The microscopy and PCR analyses revealed 0.57% and 35.8% prevalence of T. theileri in horse flies, respectively. Epimastigote stages of T. theileri, adhered to the hindgut epithelial cells of Tabanus chrysurus via flagella or actively moving in the lumen of the gut, were detected. Phylogenetic analysis revealed the connection of isolated trypanosomes with T. theileri in the TthI clade. These results suggest that Ta. chrysurus is a potential vector of T. theileri.

Epidemiological study on cattle trypanosomiasis and its vectors distributions in the Gambella regional state, southwestern Ethiopia.

African animal trypanosomosis is a parasitic disease that causes significant economic losses in livestock due to anaemia, loss of condition, emaciation, and mortality. It is a key impediment to increased cattle output and productivity in Ethiopia. Cross-sectional entomological and parasitological studies were performed in the Gambella Region state of southwestern Ethiopia to estimate the prevalence of bovine trypanosomosis, apparent fly density, and potential risk factors. Blood samples were taken from 546 cattle for the parasitological study and analyzed using the buffy coat technique and stained with Giemsa. A total of 189 biconical (89) and NGU (100) traps were deployed in the specified districts for the entomological survey. The overall prevalence of trypanosomosis at the animal level was 5.5% (95% CI: 3.86-7.75). Trypanosoma vivax (50.0%), T. congolense (30.0%), T. brucei (20.0%), and no mixed trypanosome species were found. The prevalence of trypanosomosis was significantly (p < 0.05) affected by altitude, body score conditions, age, mean packed cell volume (PCV), and peasant associations, while sex and coat color had no significant effect. According to the entomological survey results, a total of 2303 flies were captured and identified as tsetse (Glossina pallidipes (5.3%)) and G. fuscipes fuscipes (3.3%) and other biting flies (Tabanus (60.1%) and Stomoxys (31.3%)). In the current study, the overall apparent density was 4.1 flies/trap/day. This study shows that trypanosomosis remains a significant cattle disease in the Gambella regional state even during the dry season. Thus, the findings support the necessity to improve vector and parasite control measures in the area.

A Survey on Trypanosoma evansi (Kinetoplastida, Trypanosomatidae) Infection in Domestic Animals in a Surra Endemic Area of Southern Algeria.

Background: Trypanosoma (T.) evansi infection is endemic in dromedary camels (Camelus dromedaries) of southern Algeria. Materials and Methods: In order to assess the presence of T. evansi in other domestic animals living together with dromedary camels, a study was conducted in the wilayate of Béchar, El Bayadh, Ouargla and Tamanrasset, between 2015 and 2017. Authorisation to conduct the survey was obtained from the Direction des Services Vétérinaires (DSV, Ministry of Agriculture, Rural Development and Fisheries). A total of 190 animals were sampled, including 42 cattle (Bos taurus), 11 dogs (Canis familiaris), 44 horses (Equus caballus), 3 donkeys (Equus asinus) and 1 mule, 49 goats (Capra hircus) and 40 sheep (Ovis aries). These animals were examined by parasitological (Giemsa stained thin smear, GST), serological (card agglutination test for trypanosomosis (CATT/T. evansi), enzyme-linked immunosorbent assay/Variant Surface Glycoprotein/Rode Trypanozoon antigen type 1.2 [ELISA/VSG RoTat 1.2], immune trypanolysis [TL]) and molecular tests (T. evansi type A specific RoTat 1.2 PCR). Results and Conclusions: The CATT/T. evansi was positive in 10/42 cattle, 0/11 dogs, 2/48 equids, 27/49 goats and 15/40 sheep. On the other hand, 20/38 cattle, 1/9 dogs, 21/42 equids, 17/44 goats and 31/39 sheep were positive in ELISA/VSG RoTat 1.2. However, no single animal was positive in TL. In addition, the T. evansi parasite could not be demonstrated by either GST or RoTat 1.2 PCR in any of the examined animals. This may suggest cross-reactions of CATT/T. evansi and ELISA/VSG RoTat 1.2 with other pathogenic or commensal trypanosome species such as T. vivax or other parasites. Based on these data, in particular taking into account the high specificity of the TL for T. evansi type A, this study does not support the hypothesis that T. evansi circulates in the studied domestic animal species and that they would act as reservoirs for the parasite that causes trypanosomosis in dromedary camels.

Seroprevalence of trypanosomosis and associated risk factors in cattle from coast and amazonian provinces of Ecuador.

Trypanosomosis is a tropical disease caused by various protozoan haemoparasites, which affects wild and domestic animals, the latter ones related to worldwide livestock production systems. Species such as Trypanosoma vivax and Trypanosoma evansi have been described using serological and molecular tools in several countries from South and Central America. However, Ecuador presents a relevant knowledge gap in the associated general epidemiology and risk factors of the disease. Therefore, the objective of this study was to determine the seroprevalence of trypanosomosis in cattle from different regions of Ecuador. 745 serum samples from 7 Coastal and 3 Amazon provinces were screened for IgG anti-Trypanosoma spp. antibodies, using an in-house indirect ELISA. The seropositivity was explored and associated with several variables such as sex, age, breed, region, management, and province, using statistical tools. The general seroprevalence of trypanosomosis was 19.1% (95% CI: 16.30-22.1%). The Amazonian provinces of Sucumbíos and Napo and the Coastal province of Esmeraldas presented the highest seroprevalence values of 36.7% (95% CI: 27.67-46.47%), 23.64% (95% CI: 16.06-32.68%) and 25% (95% CI: 15.99-35.94%), respectively. Statistical significance was found for the region, province, and management variables, indicating as relevant risk factors the extensive management and Amazon location of the cattle analyzed. Specific actions should be taken to identify the exact species on reservoirs and susceptible hosts, evaluate the implication of farm management and cattle movement as risk factors, and implement surveillance and treatment plans for affected herds.

Gallium maltolate, a promising low toxicity drug with curative effect on mice chronically infected with Trypanosoma evansi.

Trypanosoma evansi is a flagellate protozoan that infects a wide range of hosts, especially horses. Clinically, the infection is characterized by rapid weight loss, anemia and mobility disorders. This study evaluated the efficacy of treatment gallium maltolate (GaM) in rats infected with T. evansi in the acute and chronic phases of the disease and its influence on the enzyme and blood parameters. 48 animals (Rattus norvegicus) were divided into 8 groups (A-H) of 6 animals each, namely: A: (negative control) uninfected; B: acutely infected positive control; C: chronically infected positive control; D: acutely infected, treated with GaM for 7 days post infection (p.i.); E: acutely infected treated with GaM for 3 days before infection (b.i) and 7 days p.i.; F: chronically infected, treated with GaM for 7 days p.i.; G: chronically infected, treated with GaM for 3 days b.i. and 7 days p.i.; and H: uninfected treated with GaM for 10 days. Acute infected animals (B, D and E) had a progressive increase in parasitemia and were died or euthanized before completing treatment days (5th days p.i.) as they had high parasitemia (over 100 field trypanosomes in the blood smear). Thus, it can be concluded that GaM was not effective against an acute infection. In untreated chronically infected animals (C) the parasitemia also increased progressively and they were euthanized on the 7th day p.i.. The chronically infected and treated animals (F and G) showed low parasitemia and after treatment became negative, showing no trypanosomes in the bloodstream until the 50th day of the experiment. Thus, we conclude that GaM was effective against chronic infections. In uninfected and treated animals (H) hematological, biochemical and enzymatic parameters had no significant changes when compared to the negative control group (A) demonstrating the low toxicity of GaM.

Parasitological, Serological and Molecular Prevalence of Trypanosoma evansi among Arabian Camels (Camelus dromedaries) with Evaluation of Antitrypanosomal Drugs.

PURPOSE: This study was carried out to assess the prevalence of Trypanosoma evansi infection in naturally diseased Dromedary camels in Dammam, Eastern region of Saudi Arabia. The detection of Trypanosoma evansi was performed using the parasitological, serological, and molecular diagnosis and a comparison between such methods were analyzed. In addition, evaluation of therapeutic efficacy of selected antitrypanosomal drugs, cymelarsan and quinapyrmine (aquin-1.5), was trialed for treatment of diagnosed infected cases. METHODS: A total 350 randomly selected camels were evaluated using thin blood smear (TBS), RoTat1.2 PCR and CATT/T. evansi techniques. RESULTS: The total prevalence was 6.9%, 7.7%, and 32.8% by TBS, RoTat1.2 PCR and CATT/T. evansi techniques, respectively. Although PCR detect T. evansi in more samples than TBS, the agreement was good (K = 0.9). Among the CATT/T. evansi results, PCR detect T. evansi in 12 and 15 CATT positive and negative camels, respectively, with low agreement (Kappa = 0.1). The use of cymelarsan and quinapyramine sulfate in the treatment of naturally infected cases demonstrated a very efficient therapeutic response. CONCLUSION: It was found that 1. Comparing the CATT/T. evansi and PCR results, the positivity of CATT was higher than PCR detection, while the agreement was poor (K = 0.1). 2. Cymelarsan and aquin-1.5 proved to be effective in the treatment of naturally infected camels, but cymelarsan presented with higher effectiveness (100%) than aquin-treated camels (83.3%). a 3. The use of cymelarsan and CATT is recommended for disease treatment and control.

In vitro trypanocidal potency and in vivo treatment efficacy of oligomeric ethylene glycol-tethered nitrofurantoin derivatives.

African trypanosomiasis is a significant vector-borne disease of humans and animals in the tsetse fly belt of Africa, particularly affecting production animals such as cattle, and thus, hindering food security. Trypanosoma congolense (T. congolense), the causative agent of nagana, is livestock's most virulent trypanosome species. There is currently no vaccine against trypanosomiasis; its treatment relies solely on chemotherapy. However, pathogenic resistance has been established against trypanocidal agents in clinical use. This underscores the need to develop new therapeutics to curb trypanosomiasis. Many nitroheterocyclic drugs or compounds, including nitrofurantoin, possess antiparasitic activities in addition to their clinical use as antibiotics. The current study evaluated the in vitro trypanocidal potency and in vivo treatment efficacy of previously synthesized antileishmanial active oligomeric ethylene glycol derivatives of nitrofurantoin. The trypanocidal potency of analogues 2a-o varied among the trypanosome species; however, T. congolense strain IL3000 was more susceptible to these drug candidates than the other human and animal trypanosomes. The arylated analogues 2k (IC50 0.04 µM; SI >6365) and 2l (IC50 0.06 µM; SI 4133) featuring 4-chlorophenoxy and 4-nitrophenoxy moieties, respectively, were revealed as the most promising antitrypanosomal agents of all analogues against T. congolense strain IL3000 trypomastigotes with nanomolar activities. In a preliminary in vivo study involving T. congolense strain IL3000 infected BALB/c mice, the oral administration of 100 mg/kg/day of 2k caused prolonged survival up to 18 days post-infection relative to the infected but untreated control mice which survived 9 days post-infection. However, no cure was achieved due to its poor solubility in the in vivo testing medium, assumably leading to low oral bioavailability. These results confirm the importance of the physicochemical properties lipophilicity and water solubility in attaining not only in vitro trypanocidal potency but also in vivo treatment efficacy. Future work will focus on the chemical optimization of 2k through the investigation of analogues containing solubilizing groups at certain positions on the core structure to improve solubility in the in vivo testing medium which, in the current investigation, is the biggest stumbling block in successfully treating either animal or human Trypanosoma infections.

Molecular detection and internal transcribed spacer-1 sequence diversity of Trypanosoma evansi in goats from Cavite, Philippines.

Goat production is an important source of livelihood and food. Goats may serve as reservoir of surra affecting livestock production. Here, forty-two free-roaming goats from Cavite, Philippines were screened using two primer sets, Trypanosoma brucei minisatellite chromosome for initial detection and the internal transcribed spacer 1 (ITS-1) to determine phylogeny. Initial PCR detection showed that 19/42 (45%) goats were positive, much higher than the rate previously reported in goats from Cebu (34%). The infectivity rate was higher in male (56%) than in female (42%) and the rate was higher in young ≤1 year old (100%) than in adult >1 year old (43%). Phylogenetic analysis of the ITS-1 sequences between T. evansi goat samples and other isolates indicate potential interspecies transmission.

Detection of anti-Trypanosoma spp. antibodies in cattle from southern Brazil.

Bovine trypanosomosis, caused by Trypanosoma vivax, is a disease that originated in Africa and currently affects cattle in several South American countries, including almost all Brazilian states. Despite the reports on T. vivax infection in southern Brazil, data on its circulation status is currently unavailable. In this study, we aimed to detect anti-Trypanosoma spp. IgG antibodies in cattle from Rio Grande do Sul and suggest areas with T. vivax transmission risk. A total of 691 serum samples from cattle in the intermediate regions of Rio Grande do Sul were analyzed using indirect immunofluorescence assay (IFA). The overall seroprevalence of anti-Trypanosoma antibodies in cattle was 24.6% (170/691). The detection rate ranged from 0-37.3%, with a high prevalence in the intermediate regions of Ijuí (37.3%), Uruguaiana (30.7%), and Passo Fundo (28.9%). Thus, these regions were suggested as possible bovine trypanosomosis risk areas due to the high seroprevalence. This is the first serological study to determine Trypanosoma spp. infection status in cattle from Rio Grande do Sul, providing data on the epidemiology of trypanosomosis in the state.

Trypanosome diversity in small mammals in Uganda and the spread of Trypanosoma lewisi to native species.

Uganda's diverse small mammalian fauna thrives due to its rich habitat diversity, which hosts a wide range of blood parasites, including trypanosomes, particularly the subgenus Herpetosoma typical for rodent hosts. We screened a total of 711 small mammals from various habitats for trypanosomes, with 253 microscopically examined blood smears and 458 tissue samples tested by nested PCR of the 18S rRNA gene. Of 51 rodent and 12 shrew species tested, microscopic screening reaches 7% overall prevalence (with four rodent species positive out of 15 and none of the shrew species out of four), while nested PCR indicated a prevalence of 13% (17 rodent and five shrew species positive out of 49 and 10, respectively). We identified 27 genotypes representing 11 trypanosome species, of which the majority (24 genotypes/9 species) belong to the Herpetosoma subgenus. Among these, we detected 15 new genotypes and two putative new species, labeled AF24 (found in Lophuromys woosnami) and AF25 (in Graphiurus murinus). Our finding of three new genotypes of the previously detected species AF01 belonging to the subgenus Ornithotrypanum in two Grammomys species and Oenomys hypoxanthus clearly indicates the consistent occurrence of this avian trypanosome in African small mammals. Additionally, in Aethomys hindei, we detected the putative new species of the subgenus Aneza. Within the T. lewisi subclade, we detected eleven genotypes, including six new; however, only the genotype AF05b from Mus and Rattus represents the invasive T. lewisi. Our study has improved our understanding of trypanosome diversity in African small mammals. The detection of T. lewisi in native small mammals expands the range of host species and highlighting the need for a broader approach to the epidemiology of T. lewisi.

A review on acute phase response in parasitic blood diseases of ruminants.

Parasitic blood diseases (theileriosis, babesiosis, anaplasmosis, and trypanosomiasis) are common in regions where the distributions of the hosts, parasites, and vectors are convergent. They endanger animal production, and a few are also harmful to public health. The acute phase reaction (APR) is a complex, non-specific reaction that occurs in various events, including surgical trauma, infection, stress, inflammation, and neoplasia. To understand pathogenesis, we must study APR effects and acute phase proteins (APPs) alterations in naturally occurring and experimental infections. The elevation of haptoglobin (Hp), Serum amyloid A (SAA), and fibrinogen concentrations was markedly significant in bovine and ovine theileriosis. Hp, SAA, ceruloplasmin, and fibrinogen concentrations in anaplasmosis were dramatically elevated. A significant increase in SAA was observed in bovine babesiosis, while ovine babesiosis showed a significant rise in sialic acid levels. In cases of trypanosomiasis caused by T. vivax, there have been reports of elevated levels of Hp, complement C3, and antitrypsin. Improving our understanding of APR could result in more effective methods for diagnosis, treatment, control, and eradication of diseases. The article provides an overview of APPs alterations and other inflammation-related parameters (some cytokines, adenosine deaminase, and sialic acids) in parasitic blood diseases of ruminants.

Surveillance and control of Trypanosoma evansi in the canary Islands: A descriptive analysis.

This study examines the occurrence of Surra, a disease caused by Trypanosoma evansi, in camels in the Canary Islands. The 1997 detection of T. evansi in camels in the Canary Islands led to the implementation of an initial control program, resulting in a decrease in prevalence. Following an outbreak in 2014, and due to the impossibility of eradicating it using the conventional measures, a lazaret was set up to separate positive and suspicious animals, in addition to the control measures previously implemented. Stomoxys calcitrans was the only vector captured, and no other animals tested were found to be positive for T. evansi. In November 2019, the last camels that tested serologically positive were detected; however, since February 2018, no camels that tested positive for PCR have been found in the farms were the outbreak was detected, suggesting that the sanitary measures implemented are adequate. The duration of the outbreak control and potential eradication for the disease has yet to be established. This study provides evidence to facilitate the control of African Animal Trypanosomosis in endemic areas of the world, which may contribute to revise the World Organization for Animal Health (WOAH) protocol to implement recommendations of surveillance and control strategies for animal Trypanosomosis in camels.

Molecular and hematological investigation of Trypanosoma evansi infection in Iranian one-humped camels (Camelus dromedarius).

Trypanosoma species cause animal trypanosomiasis that infects many animals. Trypanosoma evansi is an organism that infects camels. There are many economic problems associated with this disease, including lower milk and meat yields and abortions. The purpose of the current survey was molecular study of the presence of Trypanosoma in dromedary camel blood in the south of Iran, and its effects on the hematologic, and some acute-phase protein changes. Blood samples were aseptically collected from the jugular vein of dromedary camels (n = 100; aged from 1 to 6 years) originating from Fars Province in EDTA-coated vacutainers. Genomic DNA from 100 µL of the whole blood was extracted and amplified using a PCR assay based on ITS1, 5.8S, and ITS2 ribosomal regions. Also, the PCR products obtained were sequenced. Moreover, the changes in hematological parameters and serum acute-phase proteins (serum amyloid A, alpha-1 acid glycoprotein, and haptoglobin) were measured. Among 100 tested blood, nine samples (9%, 95% CI: 4.2-16.4%) were found positive by the PCR assay. The phylogenetic tree and blast analysis showed four different genotypes closely related to the strains (accession numbers: JN896754 and JN896755) previously reported from dromedary camels in Yazd Province, center Iran. Based on hematological analysis, normocytic and normochromic anemia and lymphocytosis were detected in the PCR-positive cases compared with the negative group. Furthermore, alpha-1 acid glycoprotein was significantly increased in the positive cases. There was a substantial and positive relation between the number of lymphocytes, and the levels of alpha-1 acid glycoprotein and serum amyloid A in the blood (p = 0.045, r = 0.223 and p = 0.036, r = 0.234, respectively). A noticeable frequency of T. evansi infection was reported in dromedary camels in south Iran. This is the first report on the genetic diversity of T. evansi in this region. There was a significant association among Trypanosoma infection, lymphocytosis, and alpha-1 acid glycoprotein. Trypanosoma-positive camels had a significant decrease in hematocrit (HCT), hemoglobin (Hb), and red blood cell (RBC) values compared to the non-infected group. Further experimental studies are needed to elucidate the hematological and acute-phase protein alteration during a different phase of Trypanosoma spp. infection.

Validation of in vitro-produced and freeze-dried whole cell lysate antigens for ELISA Trypanosoma evansi antibody detection in camels.

Trypanosoma evansi is a blood parasite responsible for surra in mammals, with a high impact in camels and horses. The WOAH-recommended reference method for detecting immunoglobulin G directed against T. evansi is ELISA, using whole cell lysate antigens (WCLAs). WCLAs are prepared with T. evansi produced in laboratory rodents, separated from blood cells using DE-cellulose anion exchange chromatography. As parasite lysates are fragile, antigens are preserved frozen pending use. For these reasons and others, T. evansi WCLAs are not commercially available. They are produced in small quantities, in a limited number of specialized laboratories, and they require a reliable and expensive cold chain for their shipment. In this study, we assessed and validated in vitro production of T. evansi and lyophilization of WCLAs in comparison with the reference method using frozen WCLAs prepared with parasites produced in rodents. Using a set of 400 samples monthly collected from 12 naturally infected camels followed-up for 1384 days, and two batches of referenced serum samples (infected, n = 12; non-infected, n = 15), statistical studies on qualitative and semi-quantitative results of the ELISAs did not show any significant difference when comparing the four combinations of parasites produced in vivo or in vitro, and frozen or freeze-dried WCLSAs. A repeatability study (28 repeats in 9 serum samples) was fully satisfying (p-value = 0.055). With the more convenient in vitro-produced freeze-dried WCLAs it was possible to: (i) avoid the ethical concern of in vivo production, (ii) improve the standardization of antigen production, (iii) secure antigen preservation during shipment and (iv) save a considerable amount of money (DE52-cellulose and dry-ice cold chain being avoided). Additional studies with other Trypanosoma spp are required for further extending ELISA to regional laboratories in enzootic areas, especially in view of the current progress in the "Progressive Control Pathway" (PCP) for trypanosomes in Africa.

Molecular and genetic diversity in isolates of Trypanosoma evansi from naturally infected horse and dogs by using RoTat 1.2 VSG gene in Madhya Pradesh, India.

BACKGROUND: Trypanosoma evansi is a protozoan parasite that can infect a wide range of animals and is widespread around the world. In this study, we analyzed four fatal cases of T. evansi infection using clinical, parasitological, and molecular approaches. We also explored the genetic diversity, demographic history, and population-genetic structure of T. evansi using available Rode Trypanozoon antigenic type (RoTat) 1.2 gene sequences. METHODS AND RESULTS: Clinical findings of infected animals revealed high fever, anemia, weakness, and anorexia. The animals were treated with diminazene aceturate, which was moderately effective, and hematobiochemical parameters showed changes in hemoglobin and glucose levels. The molecular and genetic diversity of T. evansi was analyzed using the RoTat 1.2 VSG gene. Phylogenetic and haplotype analysis revealed two distinct clusters of T. evansi circulating in India. The genetic diversity indices, neutrality tests, gene flow, and genetic differentiation outcomes confirmed the genetic diversity of the T. evansi population, with a lack of uniformity. The identification of two distinct clusters, exhibiting differential demographic histories and evolutionary forces, implies that the clusters may have undergone independent evolutionary trajectories or experienced different environmental pressures. CONCLUSION: The present findings underlined the need of an early and precise diagnosis in order to treat and control T. evansi infections, and the RoTat 1.2 VSG gene is an important genetic marker for understanding the genetic diversity and evolutionary history of T. evansi. This knowledge can be used to create tailored strategies to control and manage the infection in an endemic region.

Genotyping of Trypanosoma brucei evansi in Egyptian camels: detection of a different non-RoTat 1.2 Trypanosoma brucei evansi in Egyptian camels.

Trypanosoma brucei evansi (T. b. evansi) is an enzootic organism found in Egyptian camels, which genetically classified into types A and B. To detect the parasite genotype circulating in Egyptian camels, we collected 94 blood samples from three distant districts and subjected them to different PCR assays; T. brucei repeat (TBR), internal transcribed spacer-1 (ITS-1), and variable surface glycoproteins (VSG) (RoTat 1. 2, JN 2118Hu) and EVAB PCRs. The highest prevalence was obtained with TBR (80/91; 87.9%), followed by ITS-1 (52/91; 57.1%), VSG JN 2118Hu (42/91; 46.2%), and VSG RoTat 1. 2 (34/91; 37.4%). We reported a different non-RoTat 1. 2 T. b. evansi for the first time in Egyptian camels. Results showed that 47 (58.7%) out of 80 samples were classified as T. b. evansi. Of these, 14 (29.8%) were RoTat 1. 2 type, 13 (27.6%) were non-RoTat 1. 2 type, and 20 (42.6%) samples were from mixed infection with both types. All samples were tested negative with EVAB PCR. RoTat 1. 2 T. b. evansi was the most prevalent in Giza and El Nubariyah, whereas, in Aswan, the only type detected was non-RoTat 1. 2 T. b. evansi. The nucleotide sequences of the VSG RoTat 1.2 and JN 2118Hu PCR products were submitted to DNA Data Bank of Japan (DDBJ) and GenBank under the accession numbers LC738852, and (OP800400-OP800403). Further research is required to increase the sample size and verify the new sequences to corroborate the prevalence of a new variant of non-RoTat 1.2 T. b. evansi in Egypt.

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.

Morphological, serological, molecular detection, and phylogenetic analysis of Trypanosoma evansi in horses of different regions in Iran.

Trypanosoma evansi, the causative agent of "surra" is enzootic in Iran. The current study aimed to detect T. evansi in horses from different regions of Iran using morphological, serological, and molecular methods. In 2021, 400 blood samples were collected from horses in eight regions. Eighty horses showed clinical signs such as cachexia (n = 64), fever (n = 36), foot edema (n = 40), and abdominal edema (n = 32), and 320 horses appeared healthy. All samples from the studied regions were evaluated for the presence of trypanosomes using direct analysis of blood smears, mercuric chloride, and PCR-based tests. In total, 12% (95% CI: ± 3.1%), 21% (95% CI: ± 3.9%), and 21% (84) of animals were positive for Trypanosoma in microscopic, serologic, and molecular analyses, respectively. All animals positive for SSU rDNA PCR were from Qom, Semnan, and Golestan regions. Further molecular analyses on 84 PCR-positive horses revealed that 29 horses scored positive in PCR using primers of trypanozoon species and 5 scored positive in PCR using primers of Trypanosoma evansi type A. All samples (n = 5) were from Qom region. The 205-bp fragments of T. evansi RoTat 1.2VSG (accession numbers: ON017789-93) analyzed and compared to other isolates sequence from GenBank BLAST search. It has close similarities with isolates from Pakistan, Egypt, Malaysia, Kenya, and India. Data herein demonstrated that horses from Iran were at high risk of T. evansi infection. Comprehensive control programs, such as those based on the application of repellants and traps, and also, compliance with quarantine standards are recommended for minimizing the risk of the infection.

Parasitological, molecular, and epidemiological investigation of Trypanosoma evansi infection among dromedary camels in Balochistan province.

Surra is a zoonotic disease caused by Trypanosoma evansi (T. evansi), which affects a wide variety of animals worldwide. The disease has a severe impact on the productivity, health, and working capacity of camels and causes mortality and extensive economic losses if not diagnosed early. This is the first comprehensive report on the prevalence of T. evansi infection in dromedaries in Balochistan province. In the present study, 393 blood samples (indigenous, n = 240; imported, n=153) were collected from one-humped camels (Camelus dromedarius) and were tested by molecular methods to estimate the prevalence of T. evansi in three districts (Pishin, Nushki, and Lasbella) of Balochistan province. The overall prevalence of T. evansi among examined camel samples was 28.24% (95% confidence interval (CI): 24.02-32.89%). The risk of T. evansi infection in adult camels (> 10 years) is higher than that in young ones (odd-ration (OR) = 2.7; 95% CI: 1.3357-5.3164%). Moreover, male camels were six times more likely to get an infection than female camels. The detection of T. evansi infection in camels sampled in summer and spring was 3.12- and 5.10-fold higher, respectively, than in camels sampled in winter. In conclusion, our findings showed a high rate of T. evansi infection in camels from the three districts. Our study emphasizes the need for a strict surveillance program and risk assessment studies as prerequisites for control measures.