Composición química y revisión de las propiedades acaricidas de los aceites esenciales de Melinis minutiflora y Lantana camara / Chemical composition and review of the acaricidal properties of the essential oils of Melinis minutiflora and Lantana camara

The present study determined the volatile chemical components of the essential oils (EA) of the Melinis minutiflora and Lantana camara species, by means of gas chromatography coupled to a mass spectrometer, the species were collected in the cantons of Quilanga and Loja, the extraction was carried out by steam distillation. In the essential oil (EA) of M. minutiflora, 20 compounds were identified, representing 93.21%, the compounds in the highest concentration: 1-tetradecanol (16.30%), (E) -cariophylene (12.44%), germacrene D (10.99%), (E) -nerolidol (8.28%), δ-cadinene (5.61%), α-humulene (5.36%), viridiflorol (4.78%) and (Z) -ß-farnesene (4.76%). In the AE of L. camara, 68 compounds were identified, representing 96.54%, the compounds with the highest concentration (E) -caryophyllene (15.46%), germacrene D (12.21%), α-humulene (9.92%), bicyclogermacrene (7.06 %), γ-terpinene (5.97%) and germacrene B (4.66%). The species M. minutifloraand L. Camarahave repellent, acaricidal properties in adult larvae of Amblyomma cajennense and Rhipicephalus (Boophylus) microplus.

El presente estudio determinó los componentes químicos volátiles de los aceites esenciales (AEs) de las especies Melinis minutiflora y Lantana camara, mediante cromatografía de gases acoplado a espectrómetro de masas, las especies se recolectaron en los cantones de Quilanga y Loja, la extracción se hizo mediante destilación por arrastre de vapor. En el aceite esencial (AE) de M. minutiflora se identificaron 20 compuestos, representan el93,21%, los compuestos en mayor concentración: 1-tetradecanol (16,30%), (E)-cariofileno (12,44 %), germacreno D (10,99%), (E)-nerolidol (8,28 %), δ-cadineno (5,61 %), α-humuleno (5,36 %), viridiflorol (4,78 %) y (Z)-ß-farneseno (4,76 %). En el AE de L. camara se identificaron 68 compuestos, representan el 96,54%, los compuestos en mayor concentración (E)-cariofileno (15,46%), germacreno D (12,21%), α-humuleno (9,92%), bicyclogermacreno (7,06%), γ-terpineno (5,97%) y germacreno B (4,66%); las especies M. minutiflora y L. cámara, presentan propiedades repelentes, acaricidas en larvas, adultas de Amblyomma cajennense y Rhipicephalus (Boophylus) microplus.

Apicomplexans in Goat: Prevalence of Neospora caninum, Toxoplasma gondii, Cryptosporidium spp., Eimeria spp. and Risk Factors in Farms from Ecuador.

Neospora caninum, Toxoplasma gondii, Cryptosporidium and Eimeria cause severe impacts on the productivity of goat herds. The objectives of the present study were to establish the prevalence of these apicomplexans in goat farms from Ecuador; to evaluate a rapid test for Cryptosporidium diagnosis and to identify the risk factors associated with the infections. A questionnaire was designed to obtain information from 24 goat farms from Zapotillo, Garza Real, Cazaderos, Limones and Paletillas parishes in Ecuador. Blood (n = 388) and feces (n = 391) samples were collected. Indirect ELISA and standard parasitological assays were carried out to evaluate the seroprevalence of N. caninum and T. gondii and to detect oocysts of Cryptosporidium and Eimeria. The overall prevalence values of N. caninum and T. gondii were 12.11% and 18.20%, Cryptosporidium spp. and Eimeria spp. oocysts were detected in 10.49% and 89.51% of the total samples. A low correlation value was found between the results obtained by Ziehl-Nielsen and the rapid test. The multinomial logistic regression analysis revealed that vitamin supplementation, age of diarrhea, frequency of deworming, pasture area, presence of artiodactyls, domestic fowl, administration of sulfas, age group, body condition, abortions, type of pastures and the presence of cattle were risk factors according to the parasite species.

Acaricidal Efficacy of Plants from Ecuador, Ambrosia peruviana (Asteraceae) and Lepechinia mutica (Lamiaceae) against Larvae and Engorged Adult Females of the Common Cattle Tick, Rhipicephalus microplus.

Control measures against common cattle tick Rhipicephalus microplus are of the upmost importance because of considerable, deleterious impact on a farm's economy. Due to resistance phenomena to synthetic acaricides being a constraint in affected farms, the search for plant derivatives as acaricides has increased dramatically in recent years. In this work, essential oils obtained from two Ecuadorian plants, Ambrosia peruviana and Lepechinia mutica (EOAp, EOLm), traditionally used as insecticides in indigenous communities, were studied on larvae and engorged females at the parasitic stages of R. microplus. Larvae and females were treated with five (0.0625, 0.125, 0.25, 0.50 and 1%) and six concentrations (0.125, 0.25, 0.50, 1, 2 and 4%), respectively, of each EOsAp/Lm. A 98-99% larval mortality was achieved with 0.5% of both EOsAp/Lm. EOAp inhibited oviposition and egg hatching up to 82% and 80%, respectively, and had an overall efficacy of 93.12%. Efficacy of EOLm was 72.84%, due to the low influence of EOLm on reproductive parameters. By steam distillation and GC-MS analysis, γ-Curcumene was identified as the main constituent (52.02%) in the EOAp and Shyobunol (10.80%) in EOLm. The results suggest that major components of both essential oils should be further studied as promissory acaricides against R. microplus.

Acaricidal effect of Schinus molle (Anacardiaceae) essential oil on unengorged larvae and engorged adult females of Rhipicephalus sanguineus (Acari: Ixodidae).

The current concern about resistance to acaricides and the impact of toxic waste on the environment has led to the search of vegetal alternatives in the control of the brown tick of the dog Rhipicephalus sanguineus. Schinus molle L. (Anacardiaceae) derivatives have been associated with insecticidal, antimicrobial and antiprotozoal activities and essential oil showed to be lethal to R. microplus larvae. This study aimed at evaluating the acaricidal effect of essential oil of S. molle (EOSm) on engorged adult females and larval stages of R. sanguineus. One-hundred engorged females were obtained from the ears, interdigital spaces, neck, groin and base of the tail of two cross-bred dogs. The larvae package test was accomplished with 21-day-old larvae and five concentrations (v/v) of EOSm (0.125, 0.25, 0.50, 1 and 2%) in an anionic detergent, a synthetic acaricide (cypermethrin) and detergent and deionized water as controls. The immersion adult test was carried out with nine concentrations (0.125, 0.25, 0.50, 1, 2, 4, 8, 16, 20%) of the EOSm. At the concentration of 2%, EOSm caused 99.3% of larval mortality. In adults, inhibition of oviposition, egg hatching (EH) and reproductive efficiency (RE) values were dose-dependent from 4 to 20% EOSm; the lowest values of EH (29.62) and RE (22.61) were achieved with 20% EOSm. Strong and negative correlations were found between concentration of EOSm and EH (r = - 0.948) and between concentration of EOSm and RE (r = - 0.985). This study demonstrated for the first time the acaricidal effect of EOSm on larvae and reproductive parameters of engorged adult females of R. sanguineus.

Serological evidence of Anaplasma spp. in small ruminants from Venezuela using recombinant MSP5 in immunoenzymatic assay / 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.

Anaplasma 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.

Parasitological and molecular characterization of a venezuelan isolate of babesia canis / Caracterización parasitológica y molecular de un aislado venezolano de Babesia canis

Babesiosis is one of the most important tick-borne hemoprotozoan diseases that affects dogs worldwide. In the last years, there has been a sharp increase in positive cases of Babesia canis infection in the Falcon State, Venezuela. Although recent studies conducted in South America suggest that B. canis vogeli might be the species present in Venezuela, no data on the pathogenesis and molecular characteristics of Venezuelan piroplasms are available at this moment. By this reason the present work was undertaken to describe the evolution of an experimental infection induced in dogs, as well as the first molecular characterization of the 18S rRNA gene of the Venezuelan B. canis isolate used for inoculating the experimental animals. Experimental infection was carried out in four dogs, two of them splenectomized. The animals were inoculated with 1 x 10(6) B. canis infected-red blood cells. Parasitemia, packed cell volume and body temperature were measured daily. Prepatent period of the infection oscillated between 2-6 days. All of the inoculated dogs developed a mild-type disease. Symptoms of canine piroplasmosis were moderate, and main clinical findings consisted in low parasitemia, short febrile period and slight anaemia. Imidocarb dipropionate showed to be the treatment of choice, since it cleared parasites from blood, as demonstrated by PCR assays. The partial sequence of the ssu rRNA gene of the Venezuelan piroplasm showed 100% identity with a Brazilian isolate of Babesia canis vogeli, which is in full concordance with the clinical signs caused by this subspecies in the experimental animals, as well as those reported previously by other authors.

La babesiosis, causada por un hemoparásito trasmitido a través de las garrapatas, es una de las enfermedades más importantes que afectan a los caninos mundialmente. En los últimos años se ha observado un aumento abrupto de los casos positivos a Babesia canis en el estado Falcón, Venezuela. Aunque los estudios recientes realizados en Suramérica sugieren que Babesia canis vogeli pudiera ser la especie presente en Venezuela, no existen datos disponibles sobre la patogénesis y las características moleculares de los piroplasmas venezolanos. Por esta razón se realizó el presente estudio, a fin de describir la evolución de una infección experimental inducida en caninos, así como realizar la primera caracterización molecular del gen 18S ARNr del aislado venezolano de Babesia canis utilizado para inocular los animales experimentales. La infección experimental se llevó a cabo en cuatro caninos, dos de ellos esplenectomizados. Los animales fueron inoculados 1 x 10(6) eritrocitos infectados con Babesia canis. La parasitemia, el hematocrito y la temperatura corporal fueron evaluados diariamente. El período prepatente de la infección osciló entre 2 y 6 días. Todos los caninos inoculados desarrollaron una enfermedad leve. Los síntomas de la babesiosis fueron moderados y los principales hallazgos consistieron en baja parasitemia, período febril corto y anemia leve. Se demostró, a través de las pruebas de PCR, la efectividad del dipropionato de imidocarb como tratamiento de elección para la eliminación de los parásitos sanguíneos. La secuencia parcial de la ssu rARN del piroplasma venezolano mostró 100% de identidad con un aislado brasileño de Babesia canis vogeli, lo que coincide plenamente con los síntomas causados por esta subespecie en los animales experimentales, así como por lo reportado previamente por otros autores.

Respuestas inflamatorias y de anticuerpos contra Cladophialophora carrionii en caprinos / Inflamatory and Antibody Responses against Cladophialophora carrionii in Goats

Cladophialophora carrionii es un hongo dimórfico con melanina que causa en humanos una micosis profunda, localizada y crónica llamada cromomicosis, y se adquiere a través de la inoculación con espinas de cactáceas infectadas. El estado Falcón es una zona endémica para esta enfermedad, donde las poblaciones están integradas principalmente por campesinos criadores de caprinos. El objetivo de este trabajo fue evaluar la respuesta inmunitaria humoral e inflamatoria contra C. carrionii en caprinos con el fin de conocer la interacción hospedador-parásito en un animal usualmente considerado como resistente a la infección, a pesar de su exposición permanente a las espinas infectadas. Se inocularon seis cabritos con 1×10(6) células de C. carrionii, vía subcutánea, en la tabla del cuello. Se midió la temperatura corporal de cada animal y se tomaron muestras de sangre completa y suero para análisis hematológicos y ensayos inmunoenzimáticos (ELISA) dos veces a la semana. Se midió el diámetro de la piel 24 y 48 horas después de la inoculación. La respuesta inflamatoria en el sitio de inoculación fue notoria a las 48 horas. No hubo respuesta significativa de anticuerpos en los animales inoculados a partir de los 50 días post-inoculación. Se confirma que la respuesta celular es importante en la resistencia contra C. carrionii, pero la respuesta de anticuerpos parece no ser relevante en esta especie animal.

Cladophialophora carrionii is a dimorphic fungus with melanin which causes a deep, localized and chronic mycosis in humans, named chromomycosis, acquired through inoculation with cactuses infected-spines. Falcon state is an endemic zone to this disease, where human populations make use of goat breeding as their main way of living. The objective of this work was to evaluate both humoral immune and inflammatory responses against C. carrionii in goats to improve knowledge about host-parasite interactions in a species usually considered as infection-resistant, in spite of permanent exposition to infected spines. Six kids were inoculated with 1 ×10(6) cells of C. carrionii, by subcutaneous route on the neck. Blood and sera samples for hematological and immunoenzimatic tests were taken and body temperature was also measured. The diameter of the inoculated skin was also evaluated 24 and 48 hours post-inoculation. Inflammatory response was considerable at 48 hours. There was no valuable response of antibodies. It is established that inflammatory response is important in resistance against C. carrionii, but antibody response seems not to be relevant for this animal specie.

[The goat: approach to an animal model in human chromomycosis]. / El caprino: aproximación a un modelo animal en la cromomicosis humana.

In Falcon State, Venezuela, human chromomycosis is mainly caused by a dimorphic fungus, Cladophialophora carrionii. Xerophytes plants are common in the State and goat breeding in an extensive system as the main way of living. There are not published reports of chromomycosis in goats, despite the fact of their permanent exposition to fungus by accidental inoculation with infected spines. To evaluate parasitic transformation to sclerotic cells, length of fungus-surviving period and histopathological lesions, goats of five months of age were inoculated with 1 x 10(6) cells of C. carrionii by subcutaneous route in the neck and biopsies at 10, 19, 30 and 60 days from inoculated places were performed. Tissues were analyzed by (a) direct test with KOH 10%; (b) inoculation in Saboraud dextrose culture and (c) histopathological techniques. Hyphae and sclerotic cells were observed on tissues treated with KOH 10%; growing of fungus was detected in specific medium up to four weeks post-inoculation. Tissue pathology showed necrotic foci, mixed polymorphonuclear infiltrate, predominance of mononuclear cells, lymphocytes, plasmocytes, cosinophils and giant cells, hyphae and sclerotic cells in each one of samples. C. carrionii caused cellular reactions in goats as those seen in humans at the first stages of infection; however, animals did not develop the typical macroscopic lesions of the human disease.

El caprino: aproximación a un modelo animal en la cromomicosis humana / The goat: approach to an animal model in human chromomycosis

En el estado Falcón, Venezuela, la cromomicosis es causada principalmente por un hongo dimórfico, Cladophialophora carrionii. Las zonas endémicas tienen predominio de vegetación xerófita de espinar y la principal ocupación es la cría de caprinos en forma extensiva. La literatura especializada no reporta lesiones compatibles con cromomicosis en estos animales, a pesar de su exposición permanente a la inoculación accidental con las espinas de cáctaceas infectadas por el hongo. A fin de evaluar la posible transformación parasitaria a células escleróticas, el tiempo de viabilidad del hongo y las alteraciones histopatológicas en caprinos, se inocularon cabritos de cinco meses de edad con 1×106 células de C. carrionii, vía subcutánea en la tabla del cuello y se realizaron biopsias a los 10, 19, 30 y 60 días post-inoculación en los sitios de inyección. El tejido obtenido fue analizado por a) examen directo con KOH al 10 por ciento, b) retrocultivo y microcultivo en Sabouraud dextrosa y c) técnicas histopatológicas. Se observaron hifas y células escleróticas al examen directo, crecimiento en los cultivos con sobrevivencia del hongo hasta las cuatro semanas post-inoculación y cadenas ramificadas típicas de las formas filamentosas de C. carrionii. La evaluación histopatológica mostró necrosis central, infiltrado inflamatorio mixto, predominio de mononucleares, linfocitos, plasmocitos y células gigantes, hifas y cuerpos escleróticos en todas las muestras. C. carrionii ocasionó en esta especie animal una reacción celular intradérmica similar a la observada en el humano en la primera etapa de la infección, aunque no se observaron las lesiones macroscópicas típicas de esta enfermedad en humanos

[Prevalence of Anaplasma marginale and specific antibodies in new born calves]. / Prevalencia de Anaplasma marginale y anticuerpos específicos en becerros neonatos.

Anaplasma marginale is an intraerythrocytic rickettsia that affects the cattle and constitute a constraint for its production. The transplacental transmission of A. marginale could be of importance under field conditions, but until now no data is available to interpret its relevance in Venezuela. The goal of this work was to evaluate both the presence of A. marginale and the antibody response against the rickettsia in new born calves. Fourteen calves, one week old, were simultaneously bled for parasitological tests, packed cell volume measurement and to obtain sera for immunoenzymatic assays. All the animals showed parasitemia between seventeen and thirty days old. The antibody IgM and IgG response at this time was low. Probably, these calves acquired A. marginale infection through transplacental route and a very low level of immunity by the colostrum.

Prevalencia de Anaplasma marginale y anticuerpos específicos en becerros neonatos / Prevalence of Anaplasma marginale and specific antibodies in new born calves

Anaplasma marginale is an intraerythrocytic rickettsia that affects the cattle and constitute a constraint for its production. The transplacental transmission of A. marginale could be of importance under field conditions, but until now no data is available to interpret its relevance in Venezuela. The goal of this work was to evaluate both the presence of A. marginale and the antibody response against the rickettsia in new born calves. Fourteen calves, one week old, were simultaneously bled for parasitological tests, packed cell volume measurement and to obtain sera for immunoenzymatic assays. All the animals showed parasitemia between seventeen and thirty days old. The antibody IgM and IgG response at this time was low. Probably, these calves acquired A. marginale infection through transplacental route and a very low level of immunity by the colostrum.