Immunological control of ticks and tick-borne diseases that impact cattle health and production

International audienceThe cattle industry is one of the most important agroeconomic activities in Mexico. The national herd is estimated to include approximately 33.5. million head of cattle. Ticks and tick-borne diseases are principal factors with a negative impact on cattle health and production. The most economically important tick species parasitizing cattle in Mexico are Rhipicephalus microplus, R. annulatus, and Amblyomma mixtum. Parasitism by ticks affects cattle health and production directly. Morbidity and mortality caused by tickborne diseases augment the detrimental effect of tick infestation in cattle. Bovine babesiosis and anaplasmosis are the most important tick-borne diseases of cattle, which are caused by infectious agents transmitted by R. microplus and R. annulatus. However, there are no prophylactic therapies to control bovine babesiosis and anaplasmosis. Chemical control is the most common way to treat animals against ticks, and the use of acaricides can also help manage tick-borne diseases. However, the evolution of resistance to acaricides among cattle tick populations renders chemical control ineffective; which represents a challenge for sustainable ticks and tick-borne diseases control. The only anti-tick vaccine commercially available globally is based on the recombinant antigen Bm86. Because of its mode of immunity against R. microplus and R. annulatus, the Bm86-based vaccine also decreases the exposition of bovines to babesiosis and anaplasmosis. Research with Bm86-based vaccines documented high efficacy against R. annulatus, the efficacy levels against R. microplus varies according to the geographic origin of tick populations, and there is not effect against other ticks species such as Amblyomma spp. The impact of ticks and tick-borne diseases, the problem of chemical control due to acaricide resistance, and progress with anti-tick vaccine research efforts in Mexico are reviewed herein

Hap2, a novel gene in Babesia bigemina is expressed in tick stages, and specific antibodies block zygote formation

Abstract Background Bovine babesiosis is a tick-borne disease caused by the protozoan parasites of the genus Babesia. In their host vector, Babesia spp. undergo sexual reproduction. Therefore, the development of sexual stages and the subsequent formation of the zygote are essential for the parasite to invade the intestinal cells of the vector tick and continue its life-cycle. HAP2/GCS1 is a protein identified in plants, protozoan parasites and other organisms that has an important role during membrane fusion in fertilization processes. The identification and characterization of HAP-2 protein in Babesia would be very significant to understand the biology of the parasite and to develop a transmission-blocking vaccine in the future. Results To isolate and sequence the hap2 gene DNA from an infected bovine with Babesia bigemina was purified. The hap2 gene was amplified, cloned and sequenced. The sequences of hap2 from four geographically different strains showed high conservation at the amino acid level, including the typical structure with a signal peptide and the HAP2/GSC domain. Antisera anti-HAP2 against the conserved extracellular region of the HAP2 amino acid sequence were obtained from rabbits. The expression of hap2 in the host and vector tissues was analyzed by using semi-quantitative RT-PCR, and the protein was examined by western blot and immunofluorescence. Based on the RT-PCR and WB results, HAP2 is expressed in both, sexual stages induced in vitro, and in infected ticks as well. We did not detect any expression in asexual erythrocytic stages of B. bigemina, relevantly anti-HAP2 specific antibodies were able to block zygotes formation in vitro. Conclusion Babesia bigemina HAP2 is expressed only in tick-infecting stages, and specific antibodies block zygote formation. Further studies regarding the function of HAP2 during tick infection may provide new insights into the molecular mechanisms of sexual reproduction of the parasite

Additional file 1: Figure S1. of Hap2, a novel gene in Babesia bigemina is expressed in tick stages, and specific antibodies block zygote formation

Alignment of the HAP2 putative amino acid sequences. a Comparison of the amino-acid sequences of HAP2 in several B. bigemina strains from different geographical regions; sequence alignment was performed in Clustal Omega at http://www.ebi.ac.uk/Tools/msa/clustalo/ . Shadow background indicates the area of HAP2/GCS domain. The sequences corresponding to the synthetic peptides (pep2 and pep3) are shown by an upper line. The TDM is shown in darker grey, and the basic amino acids residues are shown at C-terminus. (PDF 110 kb

Extraction and quantification of DNA bovine of straws semen criopreserved

El semen criopreservado viene diluido con Tris, ácido cítrico, fructosa, glicerol, leche descremada en polvo y yema de huevo. Para extraer el ADN del semen es necesario eliminar el ADN exógeno, esto no se logra con las técnicas normales de extracción con semen fresco, por lo que es necesario recurrir a las técnicas forenses. El objetivo del presente estudio fue evaluar tres protocolos para la extracción de ADN de semen bovino criopreservado. El estudio se realizó en el laboratorio de fitopatología vegetal del Colegio de Postgraduados. Se utilizaron pajillas de ½ mL y ¼ mL. Las variables evaluadas fueron; Tiempo de ejecución del protocolo (T), pureza del ADN y concentración de ADN. Las técnicas evaluadas fueron: Tratamiento1: Yoshida et al. (1995). Tratamiento2: Penacino (1997). Tratamiento3: Técnica rápida de Penacino (1997). El menor tiempo para ejecución del protocolo fue para el tratamiento tres con 100 minutos. Los carriles 1 al 4 y 7 al 10, se observa la presencia de proteína. Cuando se utilizaron una o dos pajillas de ¼ mL se observa poca proteína y mejor calidad del ADN. En carriles del uno al 10, los valores de la relación A260/A280 son inferiores 0.1. Los carriles 12 y 17 presentan valores cercanos al rango de pureza. Se concluye que para la extracción de ADN de semen bovino criopreservado se debe utilizar una pajilla de ¼ mL por muestra con la técnica Penacino (1997), y dos pajillas de ¼ mL por muestra para la técnica rápida Penacino (1997).The semen criopreserved comes diluted with tris, citric acid, fructose, glicerol, milk skimmed in powder and yolk of egg. To extract the DNA of the semen it is necessary to eliminate the ADN exogen, this is not achieved with the normal technique of extraction with fresh semen, for what it is necessary to resort to the forensic techniques. The objective of the present study was to evaluate three protocols for DNA's extraction of bovine semen criopreserved. The study was realized in the laboratory of vegetable fitopatology of Colegio de Postgraduados. They were in use straws of ½ mL and ¼ mL. The evaluated variables were; Time of execution of the protocol (T), purity of the DNA and DNA's concentration. The evaluated techniques were: Treatment1: Yoshida et al. (1995). Treatment2: Penacino (1997). Treatment3: Penacino (1997)'s rapid Technique. The minor time for execution of the protocol was for the treatment three with 100 minutes. The rails 1 to 4 and 7 to 10, is observed the presence of protein. When one or two was in use straws of ¼ mL is observed few protein and better quality of the DNA. In rails of one to 10, the values of the relation A260/A280 are low 0.1. The rails 12 and 17 present values near to the range of purity. There concludes that for DNA's extraction of bovine semen criopreserved must use a straw of ¼ mL for sample with the technique Penacino (1997), and two straws of ¼ mL for sample for the rapid technique Penacino (1997)

Extracción y cuantificación de ADN de pajillas de semen bovino criopreservado

The semen criopreserved comes diluted with tris, citric acid, fructose, glicerol, milk skimmed in powder and yolk of egg. To extract the DNA of the semen it is necessary to eliminate the ADN exogen, this is not achieved with the normal technique of extraction with fresh semen, for what it is necessary to resort to the forensic techniques. The objective of the present study was to evaluate three protocols for DNA's extraction of bovine semen criopreserved. The study was realized in the laboratory of vegetable fitopatology of Colegio de Postgraduados. They were in use straws of ½ mL and ¼ mL. The evaluated variables were; Time of execution of the protocol (T), purity of the DNA and DNA's concentration. The evaluated techniques were: Treatment1: Yoshida et al. (1995). Treatment2: Penacino (1997). Treatment3: Penacino (1997)'s rapid Technique. The minor time for execution of the protocol was for the treatment three with 100 minutes. The rails 1 to 4 and 7 to 10, is observed the presence of protein. When one or two was in use straws of ¼ mL is observed few protein and better quality of the DNA. In rails of one to 10, the values of the relation A260/A280 are low 0.1. The rails 12 and 17 present values near to the range of purity. There concludes that for DNA's extraction of bovine semen criopreserved must use a straw of ¼ mL for sample with the technique Penacino (1997), and two straws of ¼ mL for sample for the rapid technique Penacino (1997).El semen criopreservado viene diluido con Tris, ácido cítrico, fructosa, glicerol, leche descremada en polvo y yema de huevo. Para extraer el ADN del semen es necesario eliminar el ADN exógeno, esto no se logra con las técnicas normales de extracción con semen fresco, por lo que es necesario recurrir a las técnicas forenses. El objetivo del presente estudio fue evaluar tres protocolos para la extracción de ADN de semen bovino criopreservado. El estudio se realizó en el laboratorio de fitopatología vegetal del Colegio de Postgraduados. Se utilizaron pajillas de ½ mL y ¼ mL. Las variables evaluadas fueron; Tiempo de ejecución del protocolo (T), pureza del ADN y concentración de ADN. Las técnicas evaluadas fueron: Tratamiento1: Yoshida et al. (1995). Tratamiento2: Penacino (1997). Tratamiento3: Técnica rápida de Penacino (1997). El menor tiempo para ejecución del protocolo fue para el tratamiento tres con 100 minutos. Los carriles 1 al 4 y 7 al 10, se observa la presencia de proteína. Cuando se utilizaron una o dos pajillas de ¼ mL se observa poca proteína y mejor calidad del ADN. En carriles del uno al 10, los valores de la relación A260/A280 son inferiores 0.1. Los carriles 12 y 17 presentan valores cercanos al rango de pureza. Se concluye que para la extracción de ADN de semen bovino criopreservado se debe utilizar una pajilla de ¼ mL por muestra con la técnica Penacino (1997), y dos pajillas de ¼ mL por muestra para la técnica rápida Penacino (1997)

Caracterización reproductiva de toros Bos taurus y Bos indicus y sus cruzas en un sistema de monta natural y sin reposo sexual en el trópico Mexicano

The objective was to determine the bull reproductive capacity of Bos taurus (Bt), Bos indicus (Bi) and their crosses (Bt-Bi) in service in a natural mating system without sexual rest, in the central depression of the Chiapas state. Two hundred twenty two stallions were sampled. The treatments were: Bt, Bi and Bt-Bi. There were two stages in the experiment, in the first one, the treatment proportion was determined and in the second stage, the reproductive behaviour and spermatic viability was evaluated. The response variables were: species (SP), age, corporal condition (CC), scrotal circumference (SC), ejaculation volume (EVOL), pH, aspect (ASPEC), colour (COLOR), mass motility (MM), individual motility (IM), spermatic concentration (SPERCON), abnormalities (ABNOR) and observations (OBS). The 77% of bulls were Bt, of these, 71% correspond to American Swiss race. Significant statistical differences were found (P<0.05) for age and SPERCON, there were no significant statistical differences found (p>0.10) for CC, SC, EVOL, pH, MM, IM and ABNOR. The means and the bull percentage with azoosperm problems and primary and secondary abnormalities could be due to that the evaluation was carried out in the low water season and during the warmest months of the year and the bulls were in service and without sexual rest. It was concluded that the superiority in SPERCON of the Bt-Bi in comparison with Bi, could be due to a vigour hybrid effect.El objetivo fue determinar la capacidad reproductiva de toros Bos Taurus (Bt) Bos indicus (Bi) y sus cruzas (Bt-Bi) en servicio, en sistema de monta natural y sin descanso sexual, en la depresión central del estado de Chiapas, México. Se muestrearon 223 sementales mediante tres tratamientos: Bt, Bi y Bt-Bi). El experimento consistió de dos etapas, en la primera se determinó la proporción de los tratamientos y en la segunda etapa el comportamiento reproductivo y viabilidad espermática. Las variables respuesta fueron: especie (ESP), edad, condición corporal (CC), circunferencia escrotal (CE), volumen de eyaculado (VOL), pH, aspecto (ASPEC), color (COLOR), motilidad masal (MM), motilidad individual (MI), concentración espermática (CONCES), anormalidades (ANOR) y observaciones (OBS). El 77% de los toros son Bt, de estos, el 71% corresponden a la raza Suizo Americano. Se encontró diferencias estadísticas significativas (P<0,05) para edad y CONCES, no se encontró diferencias estadísticas significativas (p>0,10) para CC, CE, VOL, pH, MM, MI y ANOR. Los promedios encontrados y el porcentaje de toros con problemas de azoospermia y anormalidades primarias y secundarias, pudieran deberse a que la evaluación se realizó en la época de estiaje y eran los meses más calurosos y a que los toros estaban en servicio y sin descanso sexual. Se concluye que la superioridad en CONCES de Bt-Bi en comparación con Bi, pudo deberse a un efecto de heterosis

Reproductive characterization of Bos taurus and Bos indicus bulls and their crosses in a natural mating system and without sexual rest in the Mexican tropic

El objetivo fue determinar la capacidad reproductiva de toros Bos taurus (Bt), Bos indicus (Bi) y sus cruzas (Bt-Bi) en servicio, en sistema de monta natural y sin descanso sexual, en la depresión central del estado de Chiapas, México. Se muestrearon 223 sementales mediante tres tratamientos: Bt, Bi y Bt-Bi). El experimento consistió de dos etapas, en la primera se determinó la proporción de los tratamientos y en la segunda etapa el comportamiento reproductivo y viabilidad espermática. Las variables respuesta fueron: especie (ESP), edad, condición corporal (CC), circunferencia escrotal (CE), volumen de eyaculado (VOL), pH, aspecto (ASPEC), color (COLOR), motilidad masal (MM), motilidad individual (MI), concentración espermática (CONCES), anormalidades (ANOR) y observaciones (OBS). El 77% de los toros son Bt, de estos, el 71% corresponden a la raza Suizo Americano. Se encontró diferencias estadísticas significativas (P<0,05) para edad y CONCES, no se encontró diferencias estadísticas significativas (p>0,10) para CC, CE, VOL, pH, MM, MI y ANOR. Los promedios encontrados y el porcentaje de toros con problemas de azoospermia y anormalidades primarias y secundarias, pudieran deberse a que la evaluación se realizó en la época de estiaje y eran los meses más calurosos y a que los toros estaban en servicio y sin descanso sexual. Se concluye que la superioridad en CONCES de Bt-Bi en comparación con Bi, pudo deberse a un efecto de heterosis.The objective was to determine the bull reproductive capacity of Bos taurus (Bt), Bos indicus (Bi) and their crosses (Bt-Bi) in service in a natural mating system without sexual rest, in the central depression of the Chiapas state. Two hundred twenty two stallions were sampled. The treatments were: Bt, Bi and Bt-Bi. There were two stages in the experiment, in the first one, the treatment proportion was determined and in the second stage, the reproductive behaviour and spermatic viability was evaluated. The response variables were: species (SP), age, corporal condition (CC), scrotal circumference (SC), ejaculation volume (EVOL), pH, aspect (ASPEC), colour (COLOR), mass motility (MM), individual motility (IM), spermatic concentration (SPERCON), abnormalities (ABNOR) and observations (OBS). The 77% of bulls were Bt, of these, 71% correspond to American Swiss race. Significant statistical differences were found (P<0.05) for age and SPERCON, there were no significant statistical differences found (p>0.10) for CC, SC, EVOL, pH, MM, IM and ABNOR. The means and the bull percentage with azoosperm problems and primary and secondary abnormalities could be due to that the evaluation was carried out in the low water season and during the warmest months of the year and the bulls were in service and without sexual rest. It was concluded that the superiority in SPERCON of the Bt-Bi in comparison with Bi, could be due to a vigour hybrid effect