Prevalence of camel trypanosomosis and herders' knowledge, attitude, and practices towards the disease in the pastoral area of southern Ethiopia.

BACKGROUND: Surra is a parasitic disease caused by Trypanosoma evansi that threatens the health and productivity of camels. Despite its significant impact on camels in Ethiopia, surra has not received as much attention as diseases in cattle and other domestic animals. The objective of the study was to estimate the prevalence of surra, identify the potential risk factors and assess the traditional knowledge, attitude and practices of camel herders towards the disease. METHODS: The study used a parasitological and participatory epidemiological (PE) approach. Between February and July 2022, a total of 335 blood samples were collected from camels across three districts and tested using the buffy coat technique. The PE investigation involved six key informant groups consisting of 8 to 12 key persons, and used a semi-structured interview and various PE tools and principles. RESULT: The study found that the prevalence of surra among examined camels was 3.9% (95% CI: 2.1-6.5). The prevalence was significantly higher in camels with a poor body condition score (BCS) (OR = 9.3; 95% CI: 1.8-47.5; p = 0.008) compared with camels with a good BCS. However, district, age, sex, and ethnicity had no effect on the prevalence of surra (p > 0.05). The study also found that the packed cell volume (PCV) was significantly lower (p < 0.0001) in parasitaemic animals (18.92 ± 2.63) than in aparasitaemic animals (25.13 ± 4.56). Camels with poor BCS (22.7 ± 3.5) had a significantly (p < 0.001) lower mean PCV than camels with good BCS (26.2 ± 5.0). The PE investigation showed that all the camel herders were well aware of surra, known locally as Dhukana. The clinical symptoms, the season of high incidence, routes of transmission, impact on production, and control methods were accurately described. Moreover, this study emphasized that surra is the primary disease affecting camel health and productivity. CONCLUSION: The study identified a moderate prevalence of surra in the research area. To reduce surra incidence and associated losses, enhancing veterinary services and providing support for proper camel husbandry practices in the region is recommended. Additionally, future studies should consider using more sensitive and specific techniques like serological and molecular assays, as this study relied on microscopy only.

Extracellular vesicles released by Trypanosoma evansi: induction analysis and proteomics.

Trypanosoma evansi is a unicellular protozoan responsible for causing a disease known as "surra," which is found in different regions of the world and primarily affects horses and camels. Few information is known about virulence factors released from the parasite within the animals. The organism can secrete extracellular vesicles (EVs), which transport a variety of molecules, including proteins. Before being considered exclusively as a means for eliminating unwanted substances, extracellular vesicles (EVs) have emerged as key players in intercellular communication, facilitating interactions between cells, host cells, and parasites, and even between parasites themselves. Thus, they may be used as potential biomarkers. This study aimed to assess the induction of EVs production by Ca+2, conduct a proteomic analysis of the EVs released by T. evansi, and identify epitopes that could serve as biomarkers. The findings indicated that Ca+2 is not an effective promoter of vesiculation in T. evansi. Furthermore, the proteomic analysis has identified multiple proteins that have been investigated as biomarkers or vaccine antigens, previously. A total of 442 proteins were identified, with 7 of them specifically recognizing 9 epitopes that are unique to T. evansi. At least one of these epitopes of TevSTIB805.9.11580 have been previously identified, which increases the possibility of further investigating its potential as a biomarker.

Surra-affected dromedary camels show reduced numbers of blood B-cells and in vitro evidence of Trypanosoma-induced B cell death.

Trypanosomosis due to Trypanosoma evansi (surra) is one of the most important diseases with a significant impact on camel health and production. Trypanosoma-induced immunosuppression mechanisms, which are key factors of disease pathogenesis, have been characterized in several animal species. The present study investigated, therefore, the impact of trypanosomosis on the immunophenotype of blood leukocytes in camels. For this, the relative and absolute values of blood leukocyte populations, their expression pattern of cell surface molecules, and the numbers of the main lymphocyte subsets were compared between healthy camels and camels with clinical symptoms of chronic surra and serological evidence of exposure to Trypanosoma infection. Leukocytes were separated from the blood of healthy and diseased camels, labeled with fluorochrome-conjugated antibodies, and analyzed by flow cytometry. Compared to healthy camels, the leukogram of diseased camels was characterized by a slightly increased leukocyte count with moderate neutrophilia and monocytosis indicating a chronic inflammatory pattern that may reflect tissue injury due to the long-lasting inflammation. In addition, the analysis of lymphocyte subsets revealed a lower number and percentage of B cells in diseased than healthy camels. In vitro incubation of camel mononuclear cells with fluorochrome-labeled T. evansi revealed a higher capacity of camel B cells than T cells to bind the parasite in vitro. Furthermore, cell viability analysis of camel PBMC incubated in vitro with T. evansi whole parasites but not the purified antigens resulted in Trypanosoma-induced apoptosis and necrosis of camel B cells. Here we demonstrate an association between trypanosomosis in camels and reduced numbers of blood B cells. In vitro analysis supports a high potential of T. evansi to bind to camel B cells and induce their elimination by apoptosis and necrosis.

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.

In vitro anti-trypanosomal effect of ivermectin on Trypanosoma evansi by targeting multiple metabolic pathways.

High cytotoxicity and increasing resistance reports of existing chemotherapeutic agents against T. evansi have raised the demand for novel, potent, and high therapeutic index molecules for the treatment of surra in animals. In this regard, repurposing approach of drug discovery has provided an opportunity to explore the therapeutic potential of existing drugs against new organism. With this objective, the macrocyclic lactone representative, ivermectin, has been investigated for the efficacy against T. evansi in the axenic culture medium. To elucidate the potential target of ivermectin in T. evansi, mRNA expression profile of 13 important drug target genes has been studied at 12, 24, and 48 h interval. In the in vitro growth inhibition assay, ivermectin inhibited T. evansi growth and multiplication significantly (p < 0.001) with IC50 values of 13.82 µM, indicating potent trypanocidal activity. Cytotoxicity assays on equine peripheral blood mononuclear cells (PBMCs) and Vero cell line showed that ivermectin affected the viability of cells with a half-maximal cytotoxic concentration (CC50) at 17.48 and 22.05 µM, respectively. Data generated showed there was significant down-regulation of hexokinase (p < 0.001), ESAG8 (p < 0.001), aurora kinase (p < 0.001), casein kinase 1 (p < 0.001), topoisomerase II (p < 0.001), calcium ATPase 1 (p < 0.001), ribonucleotide reductase I (p < 0.05), and ornithine decarboxylase (p < 0.01). The mRNA expression of oligopeptidase B remains refractory to the exposure of the ivermectin. The arginine kinase 1 and ribonucleotide reductase II showed up-regulation on treatment with ivermectin. The ivermectin was found to affect glycolytic pathways, ATP-dependent calcium ATPase, cellular kinases, and other pathway involved in proliferation and maintenance of internal homeostasis of T. evansi. These data imply that intervention with alternate strategies like nano-formulation, nano-carriers, and nano-delivery or identification of ivermectin homologs with low cytotoxicity and high bioavailability can be explored in the future as an alternate treatment for surra in animals.

Seroprevalence and immunological characterization of Trypanosoma evansi infection in livestock of four agro-climatic zones of Himachal Pradesh, India.

Trypanosoma evansi, a hemoflagellate protozoan parasite, causes wasting disease called surra in wide range of animals. Although the organism has been reported from various parts of India, data generated from organized epidemiological study is still in infancy in majority states of India. In the present study, livestock of Himachal Pradesh, India, was targeted for epidemiological investigation of T. evansi infections. A total of 440 equines and 444 cattle serum samples were collected from four agro-climatic zones. Furthermore, serum samples of 280 buffaloes from three different agro-climatic zones of Himachal Pradesh were also collected and evaluated for the presence of T. evansi infection by indirect ELISA. Data generated showed higher prevalence in buffalo (23.57%) followed by cattle (22.52%) and equines (1.82%). Disease was found to be more prevalent (P < 0.01) in cattle of lower altitude as compared to those of higher altitudes. No significant variation was seen in prevalence of disease on the basis of age and sex of the animals. Serum biochemical analysis revealed increased levels of BUN in T. evansi-infected equines. Levels of liver function enzymes such as ALT/GGT and AST were found to be significantly elevated (P < 0.01) in seropositive animals whereas glucose levels were significantly lower in surra-seropositive animals as compared to seronegative animals. Immunoblot analysis of whole cell lysate (WCL) antigen of T. evansi using surra-seropositive samples of equines showed immunodominant bands in the range of 100-25 kDa. Bovine-seropositive samples recognized polypeptide bands in the range of 85-32 kDa, including protein clusters of 52-55 and 48-46 kDa. Polypeptide cluster of 62-66 kDa was found common in seropositive samples of bovines and equines from all agro-climatic zones. T. evansi was found to be highly prevalent in livestock of Himachal Pradesh, and thus, there is dire need for designing of proper control strategies against surra.

Parasitological, serological, and molecular survey of trypanosomosis (Surra) in camels slaughtered in northwestern Nigeria.

Surra is a parasitic disease caused by Trypanosoma evansi and transmitted non-cyclically by biting flies. The disease significantly affects the health, productivity, and market value of camels thereby constituting a major constraint to food safety, security, and economy. This is the first study on the prevalence of surra in northwestern Nigeria, using a range of diagnostic tests along the parasitological-serological-molecular continuum hence, emphasizing it as a major enzootic risk for camels in Nigeria. In this cross-sectional study, 600 blood samples were collected from camels at major abattoirs in northwestern Nigeria and evaluated for the prevalence of T. evansi using parasitological (Giemsa staining), serological (CATT/T. evansi), and molecular (VSG-PCR and sequencing) methods. The overall prevalence of surra recorded in this study was 5.3%, 11.5%, and 22.5% using Giemsa-stained blood smears, CATT/T. evansi, and VSG-PCR respectively. However, higher prevalence rates at 6.0%, 13.7%, and 26.7% by Giemsa-stained blood smears, CATT/T. evansi, and VSG-PCR were recorded in Katsina State compared with results from Kano State. A significantly (p < 0.05) higher prevalence by VSG-PCR was observed when compared with both parasitological and serological methods used. Although age and body condition scores were associated (p < 0.05) with surra prevalence in sampled camels, no seasonal association (p > 0.05) was recorded. Sequencing of the VSG region of Trypanosoma spp. Further confirmed the presence of T. evansi as the aetiological agent of surra from the sampled camels. Findings from this study call for the implementation of adequate control measures aimed at reducing the impact of T. evansi infections on camel production in Nigeria.

Nanotechnology enabled the enhancement of antitrypanosomal activity of piperine against Trypanosoma evansi.

Nanoencapsulation is the promising approach to enhance the therapeutic potential of a drug. In the present investigation, piperine-loaded nanocapsules (NCs) was prepared and evaluated for antitrypanosomal activity against the parasite Trypanosoma evansi, a causative agent of trypanosomiasis. Piperine, a bioactive compound was selected as an alternative for drugs that have been used for the treatment of the disease from decades to overcome the toxic effects or drug resistance effect. Moreover, piperine has reported to possess therapeutic potential against other Trypanosoma spp. and has also been reported to cause reactive oxygen species (ROS) mediated effect in cancer cells that was the other reason for the selection. To date, piperine and its nanoformulations have not been evaluated for their growth inhibitory effect against T. evansi. Piperine-loaded NCs exhibited more significant antitrypanosomal effect at approximately three-times less IC50 value 5.04 µM as compared to piperine (IC50-14.45 µM). Moreover, increased production of reactive oxygen species observed in the case of piperine-loaded NCs as that of pure piperine in the axenic culture of T. evansi. Furthermore, different concentrations of piperine-loaded NCs showed less cytotoxicity on horse peripheral blood mononuclear cells as liken to pure piperine. In conclusion, our results demonstrated that piperine-loaded NCs induced more generation of ROS that contributed inhibitory effect on the growth of Trypanosoma evansi as compared to pure drug.

Drug-induced reactive oxygen species-mediated inhibitory effect on growth of Trypanosoma evansi in axenic culture system.

Trypanosoma evansi, an extracellular haemoflagellate, has a wide range of hosts receptive and susceptible to infection, in which it revealed highly inconsistent clinical effects. Drugs used for the treatment of trypanosomosis have been utilized for more than five decades and have several problems like local and systemic toxicity. In the present investigation, imatinib and sorafenib were selected as drugs as they are reported to have the potential to cause reactive oxygen species (ROS)-mediated effect in cancer cells. Both have also been reported to have potential against T. brucei, T. cruzi and Leishmania donovani. To date, imatinib and sorafenib have not evaluated for their growth inhibitory effect against T. evansi. Imatinib and sorafenib showed significant (p < 0.001) inhibition on parasite growth and multiplication with IC50 (50% inhibitory concentration) values 6.12 µM and 0.33 µM respectively against T. evansi. Both the drug molecules demonstrated for the generation of ROS in T. evansi and were found up to 65% increased level of ROS as compared with negative control in the axenic culture system. Furthermore, different concentrations of imatinib and sorafenib were found non-toxic on horse peripheral blood mononuclear cells and Vero cell lines. Also, in conclusion, our results demonstrated that imatinib- and sorafenib-induced generation of ROS contributed inhibitory effect on the growth of Trypanosoma evansi in an axenic culture system.

Adaptation and evaluation of an ELISA for Trypanosoma evansi infection (surra) in elephants and its application to a serological survey in Thailand.

Trypanosoma evansi, the causative agent of surra, is widespread in domestic livestock and wildlife in South East Asia. Surra can affect cattle, buffaloes, horses and also Asian elephants (Elephas maximus). Despite the 'threatened to extinction' CITES status of elephant, surra's impact has not been thoroughly assessed yet in this species. This work offers to adapt an antibody enzyme-linked immunosorbent assay (ELISA) protocol, to detect Trypanosoma evansi antibodies in elephant serum. The test was validated with 365 negative-reference samples, which allowed the determination of a 16% positive threshold. The test was applied to a serological survey including 375 individuals. The estimated global seroprevalence was 2·1% (95% CI 1·1-4·2%). Therefore, surra does not appear to be endemic in Thai domestic elephants, but occasional outbreaks were reported to our laboratory during the survey period. These outbreaks seemed to be linked to close proximity to cattle or buffaloes, and led to severe clinical signs in elephants. Frequent relapses were observed after treatment with diminazene aceturate, the only trypanocide drug currently available in Thailand. Therefore, care should be taken to keep elephants away from bovine reservoirs, and to monitor the disease in this endangered species. ELISA proved to be reliable for screening purposes as well as for post-treatment monitoring.

The utility of an rTeGM6-4r-based immunochromatographic test for the serological diagnosis of non-tsetse-transmitted equine trypanosomosis in rural areas of Mongolia.

Our previous studies report epidemics of non-tsetse-transmitted equine trypanosomosis in Mongolia. However, the current status of non-tsetse-transmitted equine trypanosomosis endemicity remains to be clarified in some parts of Mongolia. We previously reported the potential application of rTeGM6-4r-based diagnostic tools, an rTeGM6-4r-based immunochromatographic test (ICT) and an enzyme-linked immunosorbent assay (ELISA), in the serological surveillance of equine trypanosomosis in Mongolia. In the present study, the utility of the rTeGM6-4r-based ICT was validated. The rTeGM6-4r-based ICT accurately diagnosed positive reference sera that had been prepared from dourine horses in Mongolia, similarly to the rTeGM6-4r-based ELISA. The diagnostic performance of the rTeGM6-4r-based ICT was maintained when the strips were preserved for at least 2 months under dry conditions. The ICT detected 42 positive serum samples from a total of 1701 equine sera that had been collected from all 21 provinces of Mongolia. The κ-value, sensitivity and specificity of rTeGM6-4r-based ICT were 0.58, 50.0% (95% CI, 37.7-62.3%) and 99.3% (95% CI, 98.7-99.6%), respectively, in comparison to the rTeGM6-4r-based ELISA. Our field-friendly rTeGM6-4r-based ICT was found to be useful for the serological diagnosis of non-tsetse-transmitted equine trypanosomosis in rural areas of Mongolia.

Comparative seroprevalence and risk factor analysis of Trypanosoma evansi infection in equines from different agro-climatic zones of Punjab (India).

As parasitaemia is low and fluctuating during the chronic stage of infection, accurate detection of Trypanosoma evansi in blood is difficult. The primary aims of this investigation were to assess for the first time the seroprevalence of T. evansi in all agro-climatic zones of Punjab, by indirect enzyme-linked immunosorbent assay (iELISA) and card agglutination test (CATT/T. evansi), and to evaluate the risk factors associated with latent trypanosomosis. A total of 319 equine serum samples collected from 12 districts of Punjab (India) belonging to different agro-climatic zones revealed 39 (12.23%) and 9 (2.82%) samples to be positive by CATT/T. evansi and iELISA, respectively. The highest prevalence was recorded from the Ludhiana district (42.86% and 7.14% by CATT/T. evansi and iELISA, respectively) in the central plain zone (for which the overall prevalence was 15% and 4.17%, respectively). There was fair agreement between the tests for the detection of T. evansi (kappa = 0.345). Species was the most influential risk factor for infection, with odds ratios (ORs) of 2.81 and 5.63 for donkeys/ mules, in comparison with horses, by CATT/T. evansi and iELISA, respectively. The female equine population (OR = 3.13, 95% confidence interval [CI] = 1.32-7.67 [CATT]) was found to be at a higher risk of seropositivity for T. evansi, particularly on 'unorganised' (inappropriately managed) farms (OR = 3.18, 95% CI = 1.53- 6.65 [CATT]) and among animals used for commercial purposes (OR = 2.51, 95% CI = 1.20-5.21 [CATT]). In conclusion, to declare disease-free status, use of the iELISA followed by retesting of suspect samples by CATT/T. evansi is suggested.

La détection minutieuse de Trypanosoma evansi dans le sang est difficile en raison du nombre faible et fluctuant de parasites pendant la phase chronique de l'infection. L'étude présentée par les auteurs vise, d'une part, à réaliser une première évaluation de la prévalence sérologique de T. evansi dans chacune des zones agro-climatiques du Pendjab en utilisant une épreuve immuno-enzymatique (ELISA) indirecte et le test d'agglutination sur carte pour la trypanosomose (CATT/T. evansi) et, d'autre part, à évaluer les facteurs de risque associés à une présence inapparente de la trypanosomose. Au total, sur les 319 sérums d'équidés prélevés dans 12 districts du Pendjab (Inde) appartenant à des zones agro-climatiques différentes, 39 échantillons (12,23 %) ont donné des résultats positifs avec le CATT/T. evansi et 9 échantillons (2,82 %) ont donné des résultats positifs à l'ELISA indirecte. La prévalence la plus élevée a été enregistrée dans le district de Ludhiana (42,86 % de résultats positifs avec le CATT/T. evansi et 7,14 % de résultats positifs avec l'ELISA indirecte) dans la zone des plaines centrales (où la prévalence globale s'élevait, suivant les méthodes de test, à 15 % et 4,17 %, respectivement). La détection de T. evansi par les deux tests a été concordante (kappa = 0,345). Le facteur de risque ayant le plus d'influence sur la probabilité d'infection était l'espèce, ce risque étant plus élevé chez les ânes et les mulets que chez les chevaux (rapport de cotes [odds ratio, OR] de 2,81 [CATT/T. evansi] et de 5,63 [ELISA indirecte]). Les femelles présentaient également un risque plus élevé de posséder des anticorps anti-T. evansi que les mâles (OR = 3,13 ; intervalle de confiance [IC] à 95 % : 1,32­7,67 [CATT]), en particulier dans les élevages « informels ¼ (sans gestion sanitaire) (OR = 3,18 ; IC à 95 % : 1,53­6,65 [CATT]) ainsi que parmi les animaux utilisés à des fins commerciales (OR = 2,51 ; IC à 95 % : 1,20­5,21 [CATT]). En conclusion, pour la démonstration de l'absence d'anticorps, les auteurs recommandent d'utiliser l'ELISA indirecte puis de soumettre les échantillons douteux à un test de confirmation au moyen du CATT/T. evansi.

La detección precisa de Trypanosoma evansi en la sangre resulta difícil porque en la fase crónica de la infección la parasitemia es baja y fluctuante. Los autores describen una investigación encaminada principalmente a determinar por primera vez la seroprevalencia de T. evansi en todas las zonas agroclimáticas del Punjab por ensayo inmunoenzimático indirecto (ELISAi) y por aglutinación en placa, así como los factores de riesgo asociados a la tripanosomosis latente. De un total de 319 muestras de suero equino procedentes de 12 distritos del Punjab (India) situados en diferentes zonas agroclimáticas, la aglutinación en placa deparó resultado positivo en 39 de ellas (un 12,23%) y el ELISAi en 9 (2,82%). El máximo nivel de prevalencia se registró en el distrito de Ludhiana (42,86% y 7,14% por aglutinación en placa y ELISAi, respectivamente), sito en la zona de la planicie central (que en conjunto deparó una prevalencia del 15% y el 4,17%, respectivamente). Ambas pruebas resultaron bastante coincidentes por lo que respecta a la detección de T. evansi (coeficiente kappa = 0,345). El factor de riesgo más influyente resultó ser la especie: en comparación con los caballos, los asnos o mulas presentaban una razón de probabilidad (RP) de 2,81 y 5,63 para la aglutinación en placa y el ELISAi respectivamente. Se observó que la población de yeguas (RP = 3,13; intervalo de confianza [IC] al 95% = 1,32­7,67 [aglutinación en placa]) presentaba un riesgo más elevado de seropositividad para T. evansi, especialmente en explotaciones «desorganizadas¼ (mal gestionadas) (RP = 3,18; IC 95% = 1,53­6,65 [aglutinación en placa]) y entre los animales utilizados con fines comerciales (RP = 2,51; IC 95% = 1,20­5,21 [aglutinación en placa]). Los autores concluyen proponiendo que, a los efectos de declarar la ausencia de enfermedad, se utilice en primer lugar el ELISAi, seguido de la prueba de aglutinación en placa para las muestras sospechosas.

FIRST REPORT OF TRYPANOSOMA EVANSI INFECTION (SURRA) IN A PUMA (FELIS CONCOLOR) OF LAHORE ZOO, PAKISTAN.

The blood protozoan Trypanosoma evansi, which is transmitted by biting flies, is frequently neglected due to subclinical infections. This report describes a case of trypanosomiasis due to T. evansi in a 9-yr-old male puma (Felis concolor) housed at the Lahore Zoo in Pakistan. Early in January 2015, this male puma presented with chronic lethargy, weight loss, incoordination, hyperthermia, anorexia, sunken eyes, and unthriftiness. Microscopic examination of Giemsa-stained blood smears showed numerous Trypanosoma parasites. The puma was treated with diminazene aceturate subcutaneously twice. A few days later, a blood smear examination showed absence of trypanosomes. Five months later the cat presented with acute epistaxis and died. Postmortem examination showed emaciation, pale liver and kidneys, and hemorrhages on the spleen. Examination of a blood smear taken at the time of death showed numerous Trypanosoma parasites. PCR testing confirmed the presence of Trypanosoma DNA. DNA sequencing of two amplicons confirmed the presence of Trypanosoma in the blood smears with a 98-99% identity with the previously identified GenBank sequences. A phylogenetic tree was then constructed. Further studies are needed to improve our knowledge about the epidemiology and pathogenesis of T. evansi infection in wild animal species.

A nanotechnology based new approach for Trypanosoma evansi chemotherapy: In vitro and vivo trypanocidal effect of (-)-α-bisabolol.

The aim of this study was to evaluate the in vitro and in vivo susceptibility of Trypanosoma evansi to α-Bisabolol and solid lipid nanoparticles containing α-Bisabolol (SLN-B). In vitro, a trypanocidal effect of α-Bisabolol and SLN-B was observed when used at 0.5, 1 and 2% concentrations, i.e., the concentrations of 1 and 2% showed a faster trypanocidal effect when compared to chemotherapy (diminazene aceturate - D.A.). T. evansi infected mice were treated with α-Bisabolol and SLN-B at a dose of 1.0 mL kg-1 during seven days via oral gavage. In vivo, treatment with SLN-B, D.A. and D.A. associated with SLN-B were able to increase (p < 0.05) the pre-patent period and longevity when compared to positive control (infected and untreated animals), but showed no curative efficacy. T. evansi infected mice treated with D.A. associate with SLN-B, where a curative efficacy of 50% was found, a much better result when D. A and SLN-B were used alone (16.66%). In summary, the association with D. A + SLN-B can be used as an alternative to improve the therapeutic effectiveness of D.A., and for treatment of infected animals with T. evansi. Also, the nanotechnology associated with natural products arises an important alternative for the improve the trypanocidal action.

Single point mutations in ATP synthase compensate for mitochondrial genome loss in trypanosomes.

Viability of the tsetse fly-transmitted African trypanosome Trypanosoma brucei depends on maintenance and expression of its kinetoplast (kDNA), the mitochondrial genome of this parasite and a putative target for veterinary and human antitrypanosomatid drugs. However, the closely related animal pathogens T. evansi and T. equiperdum are transmitted independently of tsetse flies and survive without a functional kinetoplast for reasons that have remained unclear. Here, we provide definitive evidence that single amino acid changes in the nuclearly encoded F1FO-ATPase subunit γ can compensate for complete physical loss of kDNA in these parasites. Our results provide insight into the molecular mechanism of compensation for kDNA loss by showing FO-independent generation of the mitochondrial membrane potential with increased dependence on the ADP/ATP carrier. Our findings also suggest that, in the pathogenic bloodstream stage of T. brucei, the huge and energetically demanding apparatus required for kDNA maintenance and expression serves the production of a single F1FO-ATPase subunit. These results have important implications for drug discovery and our understanding of the evolution of these parasites.

Prevalence of camel trypanosomosis (surra) and associated risk factors in Borena zone, southern Ethiopia.

A study was made to determine the prevalence of camel trypanosomosis (surra) and its associated risk factors in Borena zone, southern Ethiopia during 2013-2014. A total of 2400 blood samples were collected and examined by the buffy coat and thin blood film laboratory methods, and data were analyzed using the SPSS statistical software. The overall prevalence of camel trypanosomosis in the area was found to be 2.33 %. Prevalence was significantly different among the surveyed districts (P = 0.000), the pastoral associations (F = 6.408, P = 0.000), altitudinal divisions (P = 0.000), age groups (P = 0.034), and between animals possessing packed cell volume (PCV) values greater than 25 % and less than 25 % (P = 0.000); whereas, prevalence of the disease was not statistically significantly different between the sexes (P = 0.311) and among the body condition score groups (P = 0.739). The PCV of trypanosome positive and trypanosome negative camels differ significantly (P = 0.001), and prevalence of trypanosomosis was seen to be negatively correlated with packed cell volume (r = -0.069, P = 0.000) revealing the effect of camel trypanosomosis on anemia state of parasitized animals. In conclusion, camel trypanosomosis is a serious and economically important disease hampering camel production and productivity in southern Ethiopia. Further studies involving more sensitive molecular techniques to reveal the precise magnitude of the disease and to identify the vector species of the parasite are recommended.

Oxidative Stress in the Heart of Rats Infected with Trypanosoma evansi.

This study was conducted to investigate the occurrence of oxidative stress in the heart tissue of rats infected with Trypanosoma evansi. Rats were divided into 2 groups (A and B) with 12 animals each, and further subdivided into 4 subgroups (A1 and A2, 6 animals/each; and B1 and B2, 6 animals/each). Animals in the groups B1 and B2 were subcutaneously inoculated with T. evansi. Thiobarbituric acid reactive substances (TBARS), superoxide dismutase activity (SOD), glutathione S-transferase activity (GST), reduced glutathione activity (GSH), and non-protein thiols (NPSH) in the heart tissue were evaluated. At day 5 and 15 post-infection (PI), an increase in the TBARS levels and a decrease in the SOD activity (P<0.05) were observed. GSH and GST activities were decreased in infected animals at day 15 PI (P<0.05). Considering the proper functioning of the heart, it is possible that the changes in the activity of these enzymes involved in the oxidative stress may be related, at least in part, in the pathophysiology of rats infected with T. evansi.

Enzymatic activities linked to cardiac energy metabolism of Trypanosoma evansi-infected rats and their possible functional correlations to disease pathogenesis.

The aim of this study was to investigate the activities of important enzymes involved in the phosphoryl transfer network (adenylate kinase and creatine kinase (CK)), lactate dehydrogenase (LDH), respiratory chain complexes and biomarkers of cardiac function in rat experimentally infected by Trypanosoma evansi. Rat heart samples were evaluated at 5 and 15 days post-infection (PI). At 5 day PI, there was an increase in LDH and CK activities, and a decrease in respiratory chain complexes II, IV and succinate dehydrogenase activities. In addition, on day 15 PI, a decrease in the respiratory chain complex IV activity was observed. Biomarkers of cardiac function were higher in infected animals on days 5 and 15 PI. Considering the importance of the energy metabolism for heart function, it is possible that the changes in the enzymatic activities involved in the cardiac phosphotransfer network and the decrease in respiratory chain might be involved partially in the role of biomarkers of cardiac function of T. evansi-infected rats.

Relationship between behavioral alterations and activities of adenylate kinase and creatine kinase in brain of rats infected by Trypanosoma evansi.

The aim of this study was to investigate the behavioral assessment and activities of important enzymes involved in the phosphoryl transfer network in rat brains that were experimentally infected with Trypanosoma evansi. Behavioral assessment (cognitive performance), pro-inflammatory cytokines in serum and activities of adenylate kinase (AK), pyruvate kinase (PK), and creatine kinase (CK) in brain were evaluated at 5 and 15 days post-infection (PI). Here we demonstrate a cognitive impairment in the rats infected with T. evansi. At 5 and 15 days PI, a memory deficit and a depressant activity were demonstrated by an inhibition avoidance test and increase in the immobility time in a tail suspension test, respectively. On day 5 PI, a decrease in the CK activity and an increase in the AK activity were observed. On day 15 PI, an increase in the CK activity and a decrease in the AK activity were observed. Considering the importance of energy metabolism for brain functioning, it is possible that the changes in the activity of enzymes involved in the cerebral phosphotransfer network and an increase in the proinflammatory cytokines (TNF and IFN) may be involved at least in part in the cognitive impairment in infected rats with T. evansi.