Trypanosoma vivax Adhesion to Red Blood Cells in Experimentally Infected Sheep

Trypanosomosis, a globally occurring parasitic disease, poses as a major obstacle to livestock production in tropical and subtropical regions resulting in tangible economic losses. In Latin America including Venezuela, trypanosomosis of ruminants is mainly caused by Trypanosoma vivax. Biologically active substances produced from trypanosomes, as well as host-trypanosome cellular interactions, contribute to the pathogenesis of anemia in an infection. The aim of this study was to examine with a scanning electron microscope the cellular interactions and alterations in ovine red blood cells (RBC) experimentally infected with T. vivax. Ovine infection resulted in changes of RBC shape as well as the formation of surface holes or vesicles. A frequent observation was the adhesion to the ovine RBC by the trypanosome's free flagellum, cell body, or attached flagellum in a process mediated by the filopodia emission from the trypanosome surface. The observed RBC alterations are caused by mechanical and biochemical damage from host-parasite interactions occurring in the bloodstream. The altered erythrocytes are prone to mononuclear phagocytic removal contributing to the hematocrit decrease during infection.This research was supported by Project G-98003462-Fondo Nacional de Ciencia, Tecnología e Innovación (FONACIT), Caracas, Venezuela, and the Instituto de Estudios Científicos y Tecnológicos from Universidad Nacional Experimental Simón Rodríguez. The authors thank Beatriz Cajade for critical reading of this paper.S

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

In vivo survival time and cryopreservation of trypanosoma vivax

Uno de los problemas más comunes del trabajo con Trypanosoma vivax, es la supervivencia y criopreservación de este protozoario, lo cual origina pérdida de aislados de campo y errores en exámenes parasitológicos. Se propone evaluar la supervivencia in vivo en condiciones de campo y criopreservación de T. vivax. Para determinar la supervivencia, la sangre se sometió a temperatura ambiente y refrigeración a 4°C, luego se determinó la sobrevivencia en el tiempo. Para el estudio de criopreservación, se emplearon dos crioprotectores de diferente naturaleza química: glicerol 10% y DMSO 5% de concentración final. Además, la criopreservación se realizó bajo tres condiciones de almacenamiento en nitrógeno líquido: 1) fase gaseosa 2) líquida y 3) combinación de ambas. Durante la evaluación de la supervivencia, se observó que la sobrevivencia de T. vivax en sangre refrigerada disminuyó significativamente (P<0,01), en comparación con aquellas sometidas a temperatura ambiente. Sin embargo, la sobrevivencia de éstos últimos comienza a disminuir luego de 6 horas, aunque algunos hemoparásitos permanecieron viables hasta 24 horas post-recolección. Para evaluar la criopreservación, al cabo de dos semanas, se descongelaron los crioviales, se determinó la sobrevivencia, resultando negativas las muestras sometidas a congelamiento directo en fase líquida. Los otros dos métodos empleados, resultaron similares (estadísticamente no significativos), el glicerol 10% resultó con mayor número de parásitos viables. En conclusión, se determinó que, las muestras infectadas con T. vivax deben evaluarse antes de 8 horas post-recolección y mantenerlas a temperatura ambiente. Por otra parte, el congelamiento debe realizarse en primera instancia en fase gaseosa o combinación gaseosa/líquida, empleando glicerol 10%. Estos resultados, permiten sugerir la mejor metodología a ser empleada para la supervivencia de los parásitos antes de exámenes parasitológicos directos, así como también las condiciones óptimas para la criopreservación del Trypanosoma [email protected] of the common problems working with Trypanosoma vivax is its survival and cryopreservation, which originates loss of field isolates and parasitological examinations mistakes. The aim of this paper was to study the best methodologies for in vivo survival under field conditions and cryopreservation of the T. vivax. In order to study complete blood survival of T. vivax, two surviving conditions were tested at: room temperature and refrigeration at 4°C. The result shows that surviving in cooled sampled diminished significantly (P<0.01) compare with room temperature. Nevertheless, surviving of room temperature parasite begins to diminish after 6 hours, although some parasites remained viable up to 24 hours post-harvesting. Cryopreservation studies were made under three liquid nitrogen storage conditions: 1) gaseous phase 2) liquid and 3) gaseous/ liquid phase combination (glycerol 10% and DMSO 5%, were used as cryoprotectants). After two weeks and defrost the survive of T. vivax from cryovials determined. The result show that: a) direct freezing in liquid phase samples were negative and b) the other two methodology were positive and statistically similar, glycerol 10% resulted with the greatest number of viable parasites. In conclusion, these results suggest that the best methodologies for conservation under field conditions, were that the samples infected with T. vivax must be evaluated before 8 hours post-harvesting at room temperature and cryopreservation condition of the T. vivax, must be made in gaseous phase or gaseous/liquid phase combination

Evidencia serológica de Anaplasma spp. en pequeños rumiantes de Venezuela utilizando MSP5 recombinante en ensayos inmunoenzimáticos

Anaplasma marginale causes a disease in cattle characterized by fever, anemia and decrease in milk and meat production. Small ruminants do not show signs of disease when infected, but it has been suggested they could act as reservoirs. Goat and sheep breeding is socially and economically important in arid and semi-arid areas in Venezuela, and these species often share space and food with cattle. The aim of this work was to detect antibodies against Anaplasma spp. in Venezuelan goat and sheep flocks. To accomplish this goal, an indirect ELISA using recombinant MSP5 as antigen of A. marginale was performed. Sera obtained from experimental infection in goat and a hyperimmune sheep serum were used as positive controls. Blood sera were obtained from 45 sheep and 48 goats located in Guárico State, an endemic area to bovine anaplasmosis. After standardization of assay for each species, 80.46% of the sheep and 59.25% of the goat sera showed to have antibodies against MSP5. No signs of clinical disease were detected in sampled animals. These results suggest that small ruminants could harbour A. marginale and consequently may be reservoirs for neighbouring cattle if appropriate vectors are present. The development of clinical diseases caused by A. marginale under stress situations and the existence of other Anaplasma species (e.g. A. ovis) in small ruminants should also be investigated.506 - [email protected] marginale ocasiona una enfermedad en los bovinos caracterizada por fiebre, anemia y disminución de la producción de leche y carne. Los pequeños rumiantes generalmente no muestran signos clínicos, por lo que pudieran actuar como reservorio. En Venezuela, los ovinos y caprinos tienen gran importancia económica y socialmente en zonas áridas y semi- áridas e incluso, en muchas ocasiones comparten su espacio y alimento con los bovinos. El objetivo de este trabajo fue detectar anticuerpos contra Anaplasma spp. en rebaños de ovinos y caprinos. Para ello, se estandarizó un ELISA indirecto con la MSP5 recombinante de A. marginale, empleando sueros provenientes de infecciones experimentales en caprinos y un suero hiperinmune ovino como controles positivos. Posteriormente, fueron obtenidos sueros sanguíneos de 45 ovinos y 48 caprinos localizados en una zona endémica a anaplasmosis bovina del estado Guárico. De estos, 80,46% de los ovinos y 59,25% de los caprinos presentaron anticuerpos que reconocieron la MSP5, sin embargo, ninguno de estos animales positivos presentaron signos clínicos de la enfermedad. Estos resultados sugieren que los pequeños rumiantes son portadores de A. marginale y por ende, pueden estar actuando como reservorio de la enfermedad para los bovinos en el caso que se encuentren los vectores apropiados. Por lo tanto, se debe profundizar en los estudios sobre el desarrollo de sintomatología clínica en condiciones de estrés y la existencia de otras especies de Anaplasma (como A. ovis) en los ovinos y caprinos de Venezuela

Trypanosoma vivax

Trypanosomosis, a globally occurring parasitic disease, poses as a major obstacle to livestock production in tropical and subtropical regions resulting in tangible economic losses. In Latin America including Venezuela, trypanosomosis of ruminants is mainly caused by Trypanosoma vivax. Biologically active substances produced from trypanosomes, as well as host-trypanosome cellular interactions, contribute to the pathogenesis of anemia in an infection. The aim of this study was to examine with a scanning electron microscope the cellular interactions and alterations in ovine red blood cells (RBC) experimentally infected with T. vivax. Ovine infection resulted in changes of RBC shape as well as the formation of surface holes or vesicles. A frequent observation was the adhesion to the ovine RBC by the trypanosome’s free flagellum, cell body, or attached flagellum in a process mediated by the filopodia emission from the trypanosome surface. The observed RBC alterations are caused by mechanical and biochemical damage from host-parasite interactions occurring in the bloodstream. The altered erythrocytes are prone to mononuclear phagocytic removal contributing to the hematocrit decrease during infection

Proteínas inmunorreactivas de trypanosoma vivax

Bovine trypanosomosis, caused by Trypanosoma vivax has a significant negative impact on livestock. This research was performed with the aim of determining the immunoreactive proteins present in T. vivax. Thus, five sheep were experimentally infected with T. vivax TvZC1 isolate. Animal number 1 was used as the source of the trypanosomes and to prepare the soluble extract of parasites. Sheep numbers 2 to 5 were monitored for eight weeks and sera was obtained every two weeks for immunodetection. Parasites obtained from animal 1 were analyzed for T. vivax proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot (WB). The WB analysis showed three immunodominant proteins with a molecular mass of 42, 64 and 72 kDa, approximately. The 64 kDa protein was recognized by every animal during the complete infection period. The 72 kDa protein only was detected by animals 2, 3 and 5 during the infection course, whereas in animal 4 it was only detected during the 6th and 8th weeks post infection. Moreover, the 42 kDa polypeptide was slightly immunorecognized by animals 2, 3 and 4 during the complete infection period, but in animal 5 only it was identified during the 2nd week post infection. It is assumed that the 42 kDa protein is the VSG of T. vivax, which resulted in a low antigenic capacity, contrary to the protein of 64 kDa which showed a high antigenic capacity and cross-reactivity with Trypanosoma [email protected] tripanosomiasis bovina, causada por Trypanosoma vivax tiene un impacto negativo significativo en la ganadería. Esta investigación se realizó con el objetivo de determinar las proteínas inmunorreactivas de T. vivax. Para esto, cinco ovejas se infectaron experimentalmente con un aislado de T. vivax, denominado TvZC1. El animal número 1 se utilizó como fuente de los tripanosomas y para la obtención del extracto de proteínas soluble de parásitos. Los ovinos enumerados del 2 al 5 se mantuvieron infectados durante ocho semanas y se obtuvieron sueros cada dos semanas para realizar la inmunodetección. Los parásitos obtenidos del animal número 1 fueron analizados por electroforesis en geles de poliacrilamida (SDS-PAGE) y Western blot (WB) para obtener el perfil de proteínas antigénicas. El análisis WB mostró tres proteínas inmunodominantes con una masa molecular aproximada de 42; 64 y 72 kDa. La proteína de 64 kDa fue reconocida en todos los animales durante todo el período de infección, mientras que la de 72 kDa sólo fue detectada por los animales 2; 3 y 5 durante el período de infección completa, mientras que en el animal número 4 solo se detectó durante la sexta y octava semanas de la infección. Por otra parte, el polipéptido de 42 kDa fue immunoreconocido ligeramente por los animales 2; 3 y 4 durante el período de infección completa, en el animal 5 solo fue identificada durante la segunda semana post-infección. Se asume que la proteína de 42 kDa es la VSG de T. vivax, la cual resultó en una baja capacidad antigénica, contrario a la proteína de 64 kDa que mostró una alta capacidad antigénica, además de demostrar reactividad cruzada con Trypanosoma evans

Immune response of sheep (ovis aries) to two venezuelan trypanosoma vivax isolates.

La tripanosomosis bovina causada por Trypanosoma vivax tiene un gran impacto económico en la industria ganadera de los países tropicales. Debido a la escasa información existente sobre la respuesta inmunitaria inducida por este parásito en rumiantes, se planificó la presente investigación con la finalidad de evaluar y comparar la respuesta inmunitaria de ovinos infectados experimentalmente con dos aislados de T. vivax. Ambos aislados fueron obtenidos de diferentes zonas geográficas de Venezuela (TvLIEM176 proveniente del estado Trujillo y TvMT1 del estado Monagas). Tres ovinos fueron inoculados con cada aislado y tres sirvieron como control para un total de nueve animales. Cada tres días (d), durante un periodo de 60 d se tomaron muestras de suero para realizar la prueba de ELISAi (para determinar la presencia de anticuerpos anti-Trypanosoma spp.), y sangre para evaluar la parasitemia y realizar un contaje total y diferencial de leucocitos. Los animales del grupo inoculado con el aislado TvMT1 mostraron mayores niveles de anticuerpos antitripanosoma que los animales del grupo TvLIEM176, mientras que la parasitemia se comportó de manera inversa, ya que el aislado TvLIEM176 produjo mayores niveles de parasitemia que TvMT1. Además, el aislado TvLIEM176 originó linfopenia durante los d 12 al 36 postinfeccion, mientras que el aislado TvMT1 no. Por lo tanto, se demostró que la respuesta inmunitaria humoral de los dos aislados de T. vivax en ovinos fue diferente, la cual puede deberse a una inmunosupresión causada por el aislado TvLIEM176 al inducir [email protected] trypanosomosis caused by Trypanosoma vivax, has a significant negative impact on livestock. Due to the limited information on the immune response against this parasite in ruminants, the present investigation was undertaken with the aim to evaluate and compare the immune response of sheep experimentally infected with two T. vivax isolates. The isolates were obtained from different geographic areas of Venezuela (TvLIEM176 from Trujillo State and TvMT1 from Monagas State). Three sheep were inoculated with each isolate and three others were used as controls for a total of nine animals. Every three days (d), during a period of 60 d, blood and serum samples were taken to determine anti-Trypanosoma spp. antibodies (by iELISA), parasitemia, white blood cell count and a leukocyte profile. TvMT1inoculated animals showed higher levels of antibodies than TvLIEM176-infected animals, although parasitaemia behaved inversely. The TvLIEM176 isolate produced higher levels of parasitemia than the TvMT1 isolate. In addition, lymphopenia was observed in TvLIEM176-infected sheep from day 12 to 36 postinfection, while lymphopenia was not shown in TvMT1-infected animals. It was demonstrated that the humoral immune response against both T. vivax isolates in sheep was different, which may be related to immunosuppression caused by TvLIEM176 isolate due to production of lymphopenia

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved