Clinicopathological alterations in wild mammals from the reservoir system of Trypanosoma cruzi:a scoping review

Trypanosoma cruzi is the etiologic agent of Chagas disease.This flagellated protozoan is transmitted to humans as well as different species of domestic and wild animals via vectors from the Reduviidae family(known as"kissing bugs").Despite the fact that hundreds of species of wild mammals are part of the reservoir system,the morphologi-cal changes and clinical manifestations resulting from the pathogenesis of the infection have been largely neglected.The aim of this review is to systematically compile the available information regarding clinicopathological altera-tions in wild mammals due to natural infection by T.cruzi.Information was obtained from six online bibliographic data search platforms,resulting in the identification of 29 publications that met the inclusion criteria.Mortality was the most common clinical manifestation,cardiac damage was the main finding at necropsy,and lymphoplas-macytic inflammation was the most frequent microscopic injury.Thus,regardless of its role as a reservoir,T.cruzi has the potential to affect the health status of wild mammals,a situation that highlights the need for further research to analyze,measure,and compare its effects at both the individual and population levels.

Anti-trypanosomal effect of Peristrophe bicalyculata extract on Trypanosoma brucei brucei-infected rats

Objective:To investigate thein vitroandin vivoeffect of whole plant extracts ofPeristrophe bicalyculataonTrypanosoma brucei brucei-infected rats.Methods:The experiment wasdivided into two phases:In the first phase,the anti-trypanosomal activity of the hot water,cold water,methanol and butanol extracts of the whole plant were determined by incubatingwithTrypanosoma brucei brucei.The cold water extract was partially-purified and the anti-trypanosomal activity of the fractions determined.In the second phase,Trypanosoma brucei brucei-infected rats were treated with fraction 2c for nine days.Packed cell volume(PCV),highdensity lipoprotein(HDL),low density lipoprotein(LDL),total cholesterol(TC),triacylglycerol(TAG),aspartate aminotransferase,alanine aminotransferases(ALT),alkaline phosphatase(ALP),total and direct bilirubin levels were determined at the end of the experiment.Results:Cold water extract immobilized 90%of the parasites after 60 min of incubation,and fraction 2ccompletely immobilized the parasites after 35 min.It significantly increased PCV inTrypanosoma brucei brucei-infected rats.Decreased TC,TAG,HDL and LDL levels of infected rats increasedsignificantly when rats were treated with the fraction,while elevated levels of total bilirubinand ALT also decreased.The difference in urea,direct bilirubin and ALP was not significantwhen infected rats were compared to rats in other groups.Conclusions:The ability of the plantto ameliorate the infection-induced biochemical changes calls for detailed investigation of thepotentials of the plant for antitrypanosomiasis drug delivery.

Anti-trypanosomal Activity of Bufonidae(Toad)Venom Crude Extract on Trypanosoma brucei brucei in Swiss Mice

Trypanosomiasis afflicts about 6~7 million people globally and to a large extent impedes livestock production in Africa.Naturally,trypanosomal parasites undergo genetic mutation and have developed resistance over a wide range of therapies.The utilization of animals and plants products has presented therapeutic potential for identifying novel anti-trypanosomal drugs.This study evaluated toad venom for anti-trypanosomal potency in-vivo in Swiss mice.Toads were collected from July to August 2019.The acute oral toxicity and biochemical characterization of the toad venom were determined.The experimental mice were administered various doses(130 mg/kg,173 mg/kg and 217 mg/kg)of the toad venom crude extract and 0.75 mg/mL of Diamizan Plus standard drug for the treatment of trypanosomiasis,once daily for 3 days.The in-vivo anti-trypanosomal activity was evaluated by a curative test,after infecting the mice with Trypanosoma brucei brucei.The pre-patent period was 72 hours before treatment commenced.The overall results showed that trypanosomal load was highest in the control group while the group treated with Diamizan drug had the least trypanosomal load.As such,the mean trypanosomal load in relation to treatments showed a very high significant difference(P<0.05).Also,the mean trypanosomal load in Swiss mice in relation to the highest dosage of toad venom versus Diamizan drug showed a very high significant difference(P<0.05).The mean change in relation to the haematological parameters across treatments groups varied significantly(P<0.05)with the exception of Hb which showed no significant difference(P>0.05)across treatment groups.The over 50%reduction in the trypanosomal load in the 130 mg/kg group in comparison with the control group brings to bare the anti-trypanosomal potency of the toad venom.The anti-trypanosomal activity demonstrated by the toad venom has provided basis for development of new therapeutic agents from different toad species.The study recommends further studies(both in-vivo and in-vitro)followed by the characterization of the active compounds present in the toad venom responsible for the anti-tyrpanosomal activity observed alongside the management and conservation of these species.

Effect of diminazene aceturate,levamisole and vitamin C combination therapy in rats experimentally infected with Trypanosoma brucei brucei

Objective:To investigate the effect of diminazene aceturale(DA) alone or in combination with either levamisole and/or Vitamin C in albino rats experimentally infected with Trypanosoma brucei brucei.Methods:Thirty adult male albino rats,randomly assigned into 6 groups(A—F) of 5rats each were used.They were either infected with 1×10~a trypanosomes intraperitoneally(groups A-E) or uninfected(group F).The different groups were treated respectively as follows:group A-with 3.5 mg/kg DA;group B-3.5 mg/kg DA and 7.5 mg/kg levamisole;group C-3.S mg/kg DA and 100 mg/kg vitamin C;and group D-3.S mg/kg DA and 7.S mg/kg levamisole and 100 mg/kg vitamin C.Croup E was left untreated.Parameters assessed include:rectal temperature,body weight changes,packed cell volume(PCV),Haemoglobin concentration(Hb),total leucocyte count(TLC) differential leucocyte count(DLC),parasitaemia,clinical signs and survivability.Results:Average pre-patent period of 5 days was recorded.Parasites in the blood were cleared in all treated groups(A-D) within 48 hours post treatment(PT).Untreated rats in group E died between25 and 32 days post infection(PI).Relapse was not recorded in all the treated groups(A-D).The initial reduction in PCV,Hb,TLC and increases in rectal temperature following infection were reversed by the treatments.The rats that received drug combinations(groups B,C and D)showed faster and higher recovery rates than the uninfected control and group A.Conclusions:Levamisole and/or Vitamin C combination with DA were more effective in the treatment of rats infected with Trypanosoma brucei brucei.

Unlocking the in vitro anti-Trypanosoma cruzi activity of halophyte plants from the southern Portugal

Objective:To evaluate the in vitro anti-Trypanosoma cruzi（T.cruzi） activity of organic extracts prepared from halophyte species collected in the southern coast of Portugal（Algarve）,and chemically characterize the most active samples.Methods:Acetone,dichloromethane and methanol extracts were prepared from 31 halophyte species and tested in vitro against trypomastigotes and intracellular amastigotes of the Tulahuen strain of T.cruzi.The most active extract was fractionated by preparative HPLC-DAD,affording 11 fractions.The most selective fraction was fully characterized by 1H-NMR.Results:From 94 samples tested,one was active,namely the root dichloromethane extract of Juncus acutus(IC50 < 20 μg/mL).This extract was fractionated by HPLC,affording 11 fractions,one of them containing only a pure compound（juncunol）,and tested for anti-parasitic activity.Fraction 8(IC50 = 4.1 μg/mL) was the most active,and was further characterized by 1H-NMR.The major compounds were phenanthrenes,9,10-dihydrophenanthrenes and benzocoumarins.Conclusion:Our results suggest that the compounds identified in fraction 8 are likely responsible for the observed anti parasitic activity.Further research is in progress aiming to isolate and identify the specific active molecules.To the best of our knowledge,this is the first report on the in vitro anti T.cruzi activity of halophyte species.

Trypanosoma rangeli:growth in mammalian cells in vitro and action of a repositioned drug(17-AAG)and a natural extract(Artemisia sp.essential oil)

Trypanosoma rangeli and T.cruzi are both parasitic unicellular species that infect humans.Unlike T.cruzi,the causative agent of Chagas disease,T.rangeli is an infective and non-pathogenic parasite for humans,but pathogenic for vectors from the Rhodnius genus.Because both species can coexist in different hosts and overlap their infective cycles but very little is known about the infection of T.rangeli in mammalian cells,we decided to characterize both the development of this parasite in cell culture and the effect of therapeutic agents with potential trypanocidal action on it.We found that T.rangeli exhibits a cycle of infection in Vero cells similar to that for T.cruzi and that the repurposed drug,17-AAG,and the natural extract Artemisia sp.essential oil produce a toxic effect on epimastigotes showing a trypanocidal action from the fifth day of culture.Both treatments also affected the infection of trypomastigotes and reduced the capacity of replication of amastigotes of T.rangeli.Since T.cruzi/T.rangeli coinfection cases have been reported,the finding of drugs with potential activity against both species could be significant in the future.Furthermore,studies of susceptibility of both species to drugs could also help to know the different mechanisms of pathogenicity in humans displayed by T.cruzi that are absent in T.rangeli.

Detection of Trypanosoma spp. in Bandicota indica from the Thai-Myanmar border area, Mae Sot District Tak Province, Thailand

Objective:To investigate the prevalence of trypanosome infection and their phylogeny in Bandicota indica rats from the cadmium-contaminated area of Mae Sot and the Myanmar border.Methods:Blood samples were taken from 100 animals,and parasite infection was examined by light microscopy observation and polymerase chain reaction(PCR)studies.Results:Trypanosoma spp.infection was found in 20%of the thin blood smear samples.PCR showed positive 623 bp DNA bands in 21 samples(21%).The sequencing analysis showed that all of the samples(100%)had the Trypanasoma lewisi 18 S ribosomal RNA gene.Phylogenetic analysis confirmed that these 16 isolates of Trypanosoma spp.were closely related to Trypanasoma lewisi.Conclusions:Molecular detection using PCR is as effective as conventional light microscopy analysis.This study confirms that trypanosomal infection in rodents is still high;therefore,fleas as their vectors need to be controlled in order to prevent transmission to humans.

Saponins-rich fraction of Calotropis procera leaves elicit no antitrypanosomal activityin a rat model

Objective:To examine thein vitroandin vivoanti-Trypanosoma evansi(T.evansi)activity ofsaponins-rich fraction ofCalotropis procera(cpsf)leaves as well as the effect of the fraction onthe parasite-induced anemia.Methods:A 60-minutes time course experiment was conductedwith various concentrations of the fraction using a 96-well microtiter plate technique,andsubsequently used to treat experimentallyT.evansiinfected rats at 100 and 200 mg/kg bodyweight.Index of anemia was analyzed in all animals during the experiment.Results:The cpsfdid not demonstrate anin vitroantitrypanosomal activity.Further,the cpsf treatments did notsignificantly(P>0.05)keep the parasites lower than the infected untreated groups.At the end ofthe experiment,allT.evansiinfected rats developed anemia whose severity was not significantly(P>0.05)ameliorated by the cpsf treatment.Conclusions:It was concluded that saponins derivedfromCalotropis proceraleaves could not elicitin vitroandin vivoactivities againstT.evansi.

Achillea fragrantissima,rich in flavonoids and tannins,potentiates the activity of diminazine aceturate against Trypanosoma evansi in rats

Objective:To evaluate activity of methanol extract of Achillea fragrantissima(meth)(A.fragrantissima) alone or in combination with diminazine aceturate(DA) against Trypanosoma evansi in experimentally infected rats.Methods:Sixty adult male Wister albino rats were divided equally into 6 groups(A-F).Rats in groups A-E were experimentally infected with T.evansi and those in group F were uninfected.The groups were treated respectively as follows:group A- with 3.5 mg/kg DA;group B- with 1 000 mg/kg meth,A.fragrantissima;group C-3.5mg/kg DA plus 500 mg/kg meth A.fragrantissima;group D-3.5 mg/kg DA plus 1 000 mg/kg meth A.fragrantissima.Group E was left untreated.Parasitaemia,survivability,packed cell volume,hemoglobin concentration,total leucocytes count,lymphocyte count,and serum malondialdehyde and reduced glutathione(GSH) levels were estimated.Phytochemical screening of meth A.fragrantissima was also performed.Results:The phytochemical analysis of the meth A.fragrantissima indicated a higher content from polyphenols tannins and non tannins and flavonoids.The efficacy percentage against trypanosomiasis in groups A to E was respectively as follows 80,40,90.100,0.The administration of meth-A.fragrantissima(1000)mg/kg b.wt.) produced a moderate efficacy against trypanosomiasis.Untreated rats in group E died between 25 and 30 d post infection.The rats given DA and meth A.fragrantissima combinations(C and D) showed faster and higher recovery rates than the uninfected control and groups A and B.The initial reduction in packed cell volume,hemoglobin,total leucocytes count,increases in serum malondialdehyde and decreases in GSH levels were reversed by the treatments.C onclusions:The administration of the methanol extracts of A.fragrantissima and DA combination therapy was more effective than each product alone in the treatment of rats infected with Trypanosoma evansi and further studies are required to isolate more active ingredients.

Experimental Trypanosoma brucei infection at immediate post partum period:effects on dam and the offspring

Objective:To investigate the effects of immediate post-partum infection with Trypanosoma brucei（T.brucei） on dam and offspring.Methods:Sixty female Albino rats（Rattus norvegicus） weighing between 130-170 g were used as animal model.The animals were divided as follows: 25 infected between 1-5 days post partum;10 infected unbred as positive controls;and 25 uninfected as negative controls.The following parameters were evaluated:packed cell volume （PCV）,level of parasitaemia,survival time,litter size and litter weight at birth and on days 7, 14 and 21 post delivery,using conventional methods.Possible trans-mammary transmission of infection to litter through milk was also assessed.Results:The results showed a comparatively （P【0.05） higher mean PCV value for the uninfected negative control on the 8 day post infection compared with the infected groups which corresponded with the increasing level of parasitaemia in the two infected groups.Mean litter size and litter weights were higher（P【0.05） in the uninfected controls on the 21st day.Survival time in the infected groups were similar.No evidence of trans-mammary transfer of infection was recorded.Conclusion:T.brucei infection during immediate post partum period is detrimental to the dam and impairs growth of the offspring.

Specific primers design based on the superoxide dismutase b gene for Trypanosoma cruzi as a screening tool:Validation method using strains from Colombia classified according to their discrete typing unit

Objective:To classify 21 new isolates of Trypanosoma cruai(T.cruzi) according to the Discrete Typing Unit(DTU) which they belong to,as well as tune up a new pair of primers designed to detect the parasite in biological samples.Methods:Strains were isolated,DNA extracted,and classified by using three Polymerase Chain Reactions(PCR).Subsequently this DNA was used along with other isolates of various biological samples,for a new PCR using primers designed.Finally,the amplified fragments were sequenced.Results:It was observed the predominance of DTU i in Colombia,as well as the specificity of our primers for detection of T.cruzi,while no band was obtained when other species were used.Conclusions:This work reveals the genetic variability of 21 new isolates of T.cruzi in Colombia.Our primers confirmed their specificity for detecting the presence of T.cruzi.

Hematological and serum biochemical aspects associated with a camel(Camelus dromedarius)naturally infected by Trypanosoma evansi with severe parasitemia in Semnan,Iran

Objective:To determine the presence of Trypanosoma eransi(T.evansi) and the effect of trypanosomosis on hemato-biochemical profile of dromedary camels in Semnan,Iran,which has not been reported yet.Methods:To perform this project,blood samples were collected by venipuncture into plain and EDTA-K2-containing vacutainer tubes from 21 dromedary camels(12 males and 9 females) aged3—18 years,from 4 different regions of Semnan.Results:Microscopic examination of stained thin blood smears revealed the presence of T.evansi in one of the samples.However,it should be noted that this sample showed a very high parasitemia(more than 5 trypomastigote were visible per microscopic field with MGG,1000×.This heavy parasitemia was associated with an 18-year-old female camel that showed symptoms of corneal opacity,intense emaciation and pale mucous membranes.Comparison of hematological and serum biochemical profiles between the camel infected by T.eransi and uninfected camels indicated anemia,leukocytosis,hyperproteinemia.hypoalbuminemia,hyperglobulinemia,reduction A/G ratio,increased a,,p and globulins and decreased of a,globulins and increased the concentration of gumma-glutamyl transferase enzyme.Conclusions:Results of the present study revealed that trypanosomosis was present in dromedary camels of Semnan,Iran(infection rate is 4.76%) and hemato-biochemical parameters were markedly affected by camel trypanosomosis.

Canova medication changes TNF-α and IL-10 serum levels in mice infected with Trypanosoma cruzi Y strain

Objective:To identify whether Canova medication changes TNF-α and IL-10 serum levels in mice infected with Trypanosoma cruzi Y strain.Methods:Animals were divided into five groups:non-treated infected animals(I); benznidazole-treated infected animals(Bz; 100 mg/kg body weight,single daily dose by gavage); Canova medication(CM) treated infected animals(CM;0.2 mL/animal,single daily dose by gavage); benznidazole- and Canova medication–treated infected animals with the above-mentioned dose(Bz+CM);and non-infected animals(C).TNF-α and IL-10 levels were determined in serum aliquots after 4,7,10,13,and 29 days of infection.An ELISA technique was employed with R&D System Inc.antibody pairs.Results:A high increase in TNF-α and IL-10 levels occurred in the infected and CM-treated groups within the treatment employed on the 10 th day after infection,coupled with a IL-10 decrease on the 13 th day after infection when compared with the other experimental groups.Conclusions:CM may change the balance between plasma cytokine levels(TNF-α and IL-10) in mice infected with Y strain T.cruzi,with important consequences leading towards a more severe infection.

Regulation of RNA binding proteins in trypanosomatid protozoan parasites

Posttranscriptional mechanisms have a critical role in the overall outcome of gene expression. These mechanisms are especially relevant in protozoa from the genus Trypanosoma, which is composed by death threatening parasites affecting people in Sub-saharan Africa or in the Americas. In these parasites the classic view of regulation of transcription initiation to modulate the products of a given gene cannot be applied. This is due to the presence of transcription start sites that give rise to long polycistronic units that need to be processed costranscriptionally by trans-splicing and polyadenylation to give mature monocistronic mRNAs. Posttranscriptional mechanisms such as mRNA degradation and translational repression are responsible for the final synthesis of the required protein products. In this context, RNA-binding proteins(RBPs) in trypanosomes have a relevant role as modulators of mRNA abundance and translational repression by associating to the 3' untranslated regions in mRNA. Many different RBPs have been proposed to modulate cohorts of mRNAs in trypanosomes. However, the current understanding of their functions lacks a dynamic view on the different steps at which these RBPs are regulated. Here, we discuss different evidences to propose regulatory events for different RBPs in these parasites. These events vary from regulated developmental expression, to biogenesis of cytoplasmic ribonucleoprotein complexes in the nucleus, and condensation of RBPs and mRNA into large cytoplasmic granules. Finally, we discuss how newly identified posttranslational modifications of RBPs and mRNA metabolism-related proteins could have an enormous impact on the modulation of m RNA abundance. To understand these modifications is especially relevant in these parasites due to the fact that the enzymes involved could be interesting targets for drug therapy.

Ultrastructural and enzymatic alterations in the ovary of Rhodnius prolixus infected with Trypanosoma rangeli

Objective:To investigate the morphological structure of ovarian follicular cells and biochemical parameters of both ovaries and fat bodies(sites of vitellogenesis)from Rhodnius(R.)prolixus infected with Trypanosoma(T.)rangeli.Methods:Adult virgin females of R.prolixus were fed upon a membrane apparatus containing heat-inactivated citrated rabbit blood and a suspension of T.rangeli epimastigotes(Macias strain).Females from the control group and all the males received parasite-free blood.Transmission electron microscopy was used to reveal the morphological aspects of ovarian follicle cells in both control and parasite-infected groups.Protein profile,proteolytic activities and Western blotting analyses were performed in either ovary or fat body samples of control and parasite-infected groups.Results:According to the ultrastructural data,T.rangeli infection elicited a degeneration process in the ovarian follicular cells of R.prolixus.Proteolytic assays indicated a reduction in the activity of aspartic peptidases in the ovary and fat body from parasite-infected group,while a significant increase in the cysteine peptidase activity was measured in both insect organs.Additionally,immunoblotting revealed that vitellogenin was overexpressed in the ovary of parasite-infected insects.Conclusions:T.rangeli infection seems to elicit an early programmed cell death in the ovarian follicle cells as well as induces the modulation on the activities of different peptidase classes in either ovaries or fat bodies and the overexpression of the vitellogenin in the ovary of R.prolixus.

Molecular Diagnosis of Subclinical African Trypanosoma vivax Infection and Association with Physiological Indices and Serum Metabolites in Extensively Managed Goats in the Tropics

Trypanosomosis remains a major challenge to livestock production in much of tropical Sub-Saharan Africa, while diagnosis and treatment still depend on inefficient parasitological techniques. Endemic infections depend on animal reservoirs with subclinical parasitemia. We report molecular diagnosis of subclinical Trypanosoma vivax (T. vivax) infection using polymerase chain reaction (PCR) for the first time in Nigerian goats and associate parasite presence with gross physiological traits and serum metabolites in extensively managed Nigerian goats. PCR was used to amplify a 400 bp DNA fragment of the parasite genome in 205 goats across three geographical zones of the country. Results showed a high subclinical infection rate (SCIR) of 71.7% in the total goats examined. Overall SCIRs of 71%, 75.9% and 55.6% were recorded in West African Dwarf, Red Sokoto and Sahel goats respectively, while geographical SCIRs were 71.2% (Southwest), 75% (Northwest) and 70% (Northeast). T. vivax presence had significant (P 0.05) effect on respiratory rate and is associated with higher creatinine levels in sera. Logistic regression analyses with Hosmer-Lemeshow goodness-of-fit showed that respiratory rate is the most important predictive trait for the presence of T. vivax infection (P 0.05). Goats appear to be a viable reservoir for T. vivax infection of other livestock. Molecular diagnosis of subclinical trypanosomosis using PCR could be useful for large scale epidemiological studies, early diagnosis of subclinical infection and treatment of the disease in extensively managed tropical goats.

Antitrypanosomal Activity of a Semi-Purified Subfraction Rich in Labdane Sesquiterpenes, Obtained from Flowers of Anthemis Tinctoria, Against Trypanosoma Cruzi

In Brazil and several other Latin American countries, Chagas' disease still constitutes a serious medical and social problem, and there is a need to develop new, more-potent drugs with fewer side effects to effectively treat this disease. We investigated the antitrypanosomal effect of a crude extract, fractions, and a semi-purified subfraction rich in a mix- ture of isomeric labdane sesquiterpenes, obtained from flowers of Anthemis tinctoria, against Trypanosoma cruzi. In epimastigote forms, the aqueous crude extract, dichloromethane fraction, and semi-purified subfraction showed a dose-dependent inhibitory activity, with IC50 of 2.3 μg/ml, 1.8 μg/ml, and 0.2 μg/ml, respectively. In the interaction in- dex, the semi-purified subfraction showed a reduction in both the percentage of infected LLCMK2 cells and the mean number of amastigotes per infected cell. The cytotoxicity evaluation demonstrated that the cytotoxic concentrations of the semi-purified subfraction were higher for LLCMK2 cells than for the protozoans, with a selectivity index of 35.0. Epimastigote forms treated with the semi-purified subfraction showed ultrastructural and morphological alterations such as rounding of the cells and bleb formation in the flagellum and cytoplasmic membrane. These results show that the flowers from A. tinctoria may be a source of new drugs with antiprotozoal activity. However, additional in vitro and in vivo studies are needed to validate the use of A. tinctoria in the treatment of Chagas’ disease.

Antibody delivery into viable epimastigotes of <i>Trypanosoma cruzi</i>as a tool to study the parasite biology

American trypanosomiasis is a zoonosis of worldwide medical importance and currently there is no effective treatment in chronic patients, hence the importance of the study of protein function of the parasite with the objective of finding new drug targets and to know better the biology of the agent causal (Trypano-soma cruzi). T. cruzi is an RNAi-negative parasite, therefore the silencing genes strategies by RNAi is not possible;for that reason, antibodies may be taken as a tool for studying the parasite proteins function by blocking these molecules with specific antibodies. The aim of this work was to establish a methodology for antibody delivery (antibody transfection) into viable parasites. We used anti-cyclin-A antibody (human origin) in western blot assay with epimastigote of T. cruzi proteins and this recognized a ~55 kDa polypeptide. Several methods for antibody transfection (electroporation, saponin permeabilization and a lipid-based formulation) were tested. The first two methods were unsuccessful. In electroporation was impossible to visualize the antibody inside parasites and with saponin permeabilization, antibodies were successfully introduced, but with loss of parasites viability. The lipid-based formulation method forms noncovalent complexes with antibodies. These complexes are internalized by cells and antibodies are released into the cytoplasm. With this method, a successful antibody delivery was achieved. Anti-cyclin antibodies were visualized in the cytoplasm from fixed transfected parasites (immunofluorescence assays). At 24 h post-transfection, parasites maintained their viability (90%) and were able to arrest the cell cycle in G0/G1-phase of cultured epimastigotes (cell population increased in G0/G1-phase from 50.5% to 66.2% and decreased in S-phase from 47.2% to 26%). It was also observed that anti-cyclin-A antibodies inhibit the parasite population doubling (p T. cruzi, with a simple and cheap technique, which will allows carrying out further studies of this protozoan.

MRI Signal Abnormalities of the Optic Tracts, a Marker of Meningoencephalitis Caused by Trypanosoma Gambiense (TG)—A Delayed Patho-Radlological Correlation

Parasitic meningoencephalitis presents several etiologies which sometimes depend on their geographical location. They require thorough blood and cerebrospinal fluid check-up for directing an efficient treatment. Clinicians and radiologists are constantly looking for specific signs that could point to a particular etiology. The meningoencephalitis caused by Human African Trypanosomiasis (HAT) due to Trypanosoma brucei gambiense (TG) is a rare disease characterized by a slow progression, over years sometimes. Its non-specific presentation either clinically or in imaging can lead to misdiagnosis and thus, delay the treatment. However, involvement of the optic tracts seems to be characteristic of this condition, on old data from animal experimentation and recent high-field MRI data. MRI is the best current technique to explore the brain, cranial nerves, and visual pathways. In this article, we are going to present two observations of meningoencephalitis caused by HAT and then discuss some specific aspects of this neglected and re-emerging disease.

<i>Trypanosoma evansi</i>: A Qualitative and Quantitative Ultrastructural Analysis of the Spleen during Experimental Murine Infections

A murine model is used to study qualitatively and quantitatively the splenic ultrastructural changes induced by two Trypanosoma evansi strains derived from naturally infected local equine hosts (Equusasinus and E. caballus);T. evansi causes ultrastructural modifications in the spleen of the infected mice. The modifications include tissular disorganization, fibrosis, mitochondrial swelling, apoptosis and necrosis. The initial phases of the infection are quite similar, whereas the final phases differ qualitatively depending on the strain’s source. The ultrastructural quantitative changes were studied in the reticular splenocytes covering alterations in the area of the cytoplasm and nucleus. Analysis of the results shows the induction of various splenic alterations caused by local T. evansi strains. Also, it was documented that discriminative time modulation, as well as progressive tissular, cellular and subcellular changes, are more associated with derived infections from E. caballus strain.