8 research outputs found
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