Development and standardization of a Loop-mediated isothermal amplification (LAMP) test for the detection of Babesia bigemina

Bovine babesiosis is a tick-borne disease caused by protozoan parasites of the genus Babesia. Babesia bigemina is one of the most prevalent and economically important parasite species that infects cattle because of its impact on the meat and milk production industry. Effective disease control strategies should include detection of reservoir animals and early and specific pathogen detection using rapid, economical, sensitive, and specific detection techniques. The loop-mediated isothermal amplification technique (LAMP) is a one-step molecular reaction that amplifies DNA sequences with high sensitivity and specificity under isothermal conditions and requires no special equipment. The results can be observed by the naked eye as color changes. The aim of this work was to develop and standardize the LAMP technique for B. bigemina detection and its visualization using hydroxynaphtol blue. For this situation, primers were designed from the conserved sequences of the B. bigemina ama-1 gene. The results showed that at 63 °C in 1 h and under standardized conditions, this technique could amplify B. bigemina DNA as indicated by the characteristic colorimetric change. Sensitivity evaluation indicated that DNA was amplified at a 0.00000001% parasitemia, and it was demonstrated that this technique specifically amplified the DNA of B. bigemina. Additionally, this technique could amplify DNA from 10 strains of B. bigemina from three different countries. It is concluded that the LAMP technique as modified in our case could specifically amplify B. bigemina DNA and shows high sensitivity, does not cross-react with related organisms, and the product is observed by 60 min of reaction time based on color changes. This report is the first LAMP report that uses sequences that are conserved between strains of the ama-1 gene, demonstrates the results by color changes using hydroxynaphtol blue. We propose LAMP as a rapid and economical alternative method for the molecular detection of B. bigemina.Fil: Lizarazo Zuluaga, Andrea P.. Universidad Autonoma de Queretaro.; MéxicoFil: Carvajal Gamez, Bertha I.. Universidad Autonoma de Queretaro.; MéxicoFil: Wilkowsky, Silvina Elizabeth. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Cravero, Silvio Lorenzo Pedro. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Trangoni, Marcos David. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Mosqueda, Juan. Universidad Autonoma de Queretaro.; Méxic

Babesia bovis AMA-1, MSA-2c and RAP-1 contain conserved B and T-cell epitopes, which generate neutralizing antibodies and a long-lasting Th1 immune response in vaccinated cattle

Vaccines against bovine babesiosis must, ideally, induce a humoral immune response characterized by neutralizing antibodies against conserved epitopes and a cellular Th1 immune response. In Babesia bovis, proteins such as AMA-1, MSA-2c, and RAP-1 have been characterized and antibodies against these proteins have shown a neutralizing effect, demonstrating the implication of B and T-cell epitopes in the immune response. There is evidence of the existence of B and T-cell epitopes in these proteins, however, it remains to be defined, the presence of conserved peptides in strains from around the world containing B and T-cell epitopes, and their role in the generation of a long-lasting immunity. The aim in this paper was to identify peptides of Babesia bovis AMA-1, MSA-2c, and RAP-1 that elicit a neutralizing and long-lasting Th1 immune response. Peptides containing B-cell epitopes of AMA-1, MSA-2c and RAP-1, were identified. The immune response generated by each peptide was characterized in cattle. All peptides tested induced antibodies that recognized intraerythrocytic parasites, however, only 5 peptides generated neutralizing antibodies in vitro: P2AMA-1 (6.28%), P3MSA-2c (10.27%), P4MSA-2c (10.42%), P1RAP-1 (32.45%), and P4RAP-1 (36.98%). When these neutralizing antibodies were evaluated as a pool, the inhibition percentage of invasion increased to 52.37%. When the T cellular response was evaluated, two peptides: P3MSA2c and P2AMA1 induced a higher percentage (>70%) of activated CD4 +/CD45RO+ T cells than unstimulated cells. Additionally, both peptides induced the production of gamma interferon (IFN-) in PBMCs from vaccinated cattle after one year proving the implication of a long-lasting Th1 immune response. In conclusion, we identified conserved peptides containing B and T-cell epitopes in antigens of B. bovis that elicit a Th1 immune response and showed evidence that peptides from the same protein elicit different immune responses, which has implication for vaccine development in bovine babesiosis.Instituto de PatobiologíaFil: Hidalgo-Ruiz, Mario. Universidad Autónoma de Querétaro. Facultad de Ciencias Naturales; MéxicoFil: Mejia-López, Susana. Universidad Autónoma de Querétaro. Facultad de Ciencias Naturales; MéxicoFil: Pérez-Serrano, Rosa M. Universidad Autónoma de Querétaro. Facultad de Medicina; MéxicoFil: Zaldívar-Lelo de Larrea, Guadalupe. Universidad Autónoma de Querétaro. Facultad de Medicina; MéxicoFil: Ganzinelli Sabrina Belen. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología Veterinaria (IPVET); ArgentinaFil: Ganzinelli Sabrina Belen. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Florin-Christensen, Monica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología Veterinaria (IPVET); ArgentinaFil: Florin-Christensen, Monica. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Suarez, Carlos Esteban. United States Department of Agricultural-Agricultural Research Service. Animal Disease Research Unit; Estados UnidosFil: Hernández-Ortiz, Rubén. Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP). Centro de Estudios e Investigaciones para el Desarrollo Docente (CENID). Salud Animal e Inocuidad; MéxicoFil: Mercado-Uriostegui, Miguel A. Universidad Autónoma de Querétaro. Facultad de Ciencias Naturales; MéxicoFil: Rodríguez-Torres, Angelina. Universidad Autónoma de Querétaro. Facultad de Ciencias Naturales; MéxicoFil: Carvajal-Gamez, Bertha I. Universidad Autónoma de Querétaro. Facultad de Ciencias Naturales; MéxicoFil: Camacho-Nuez, Minerva. Universidad Autónoma de la Ciudad de México. Posgrado en Ciencias Genómicas; MéxicoFil: Wilkowsky, Silvina Elizabeth. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular (IABIMO); ArgentinaFil: Mosqueda, Juan. Universidad Autónoma de Querétaro. Facultad de Ciencias Naturales; Méxic