Author: MOISES MARTINEZ VELAZQUEZ
MOISES MARTINEZ VELAZQUEZ (2014)
The cattle tick Rhipicephalus (Boophilus) microplus is the most economically important ectoparasite
affecting the cattle industry in tropical and subtropical areas around the world. The principal method of tick control
has relied mainly on the use of chemical acaricides, including ivermectin; however, cattle tick populations resistant
to ivermectin have recently been reported in Brazil, Mexico, and Uruguay. Currently, the molecular basis for ivermectin
susceptibility and resistance are not well understood in R. microplus. This prompted us to search for potential molecular
targets for ivermectin. Here, we report the cloning and molecular characterization of a R. microplus glycine-like receptor
(RmGlyR) gene. The characterized mRNA encodes for a 464-amino acid polypeptide, which contains features common
to ligand-gated ion channels, such as a large N-terminal extracellular domain, four transmembrane domains,
a large intracellular loop and a short C-terminal extracellular domain. The deduced amino acid sequence showed
around 30% identity to GlyRs from some invertebrate and vertebrate organisms. The polypeptide also contains the
PAR motif, which is important for forming anion channels, and a conserved glycine residue at the third transmembrane
domain, which is essential for high ivermectin sensitivity. PCR analyses showed that RmGlyR is expressed at egg, larval
and adult developmental stages. Our findings suggest that the deduced receptor is an additional molecular target to
ivermectin and it might be involved in ivermectin resistance in R. microplus.
MOISES MARTINEZ VELAZQUEZ (2016)
Adulticidal and oviposition- and hatching-altering activities of essential oil extracted
from Mexican oregano leaves (Lippia graveolens H.B.K.) (OEO) were evaluated on engorged
adult female Rhipicephalus microplus ticks using the adult immersion test bioassay. Twofold
dilutions of OEO were tested from a starting dilution of 10% down to 1.25%. Results
showed 100% adulticidal activity at 10% OEO concentration and oviposition inhibition of
65.8% and 40.9% at 5.0% and 2.5% OEO concentration, respectively. Egg hatching inhibition
was achieved by 26.0% and 11.5% at 5.0% and 2.5% OEO concentration, respectively. These
effects could be attributed to OEO major components: thymol, carvacrol and p-cymene,
which together account for more than 60.0% of the OEO chemical composition. Mexican
oregano could represent a potential source for development of alternative tick control agents.
"The cattle tick Rhipicephalus (Boophilus) microplus is the most important health problem for livestock at tropical and subtropical areas. Because of its hematofagous behavior, pathogen transmission, acaricide resistance, environmental impact and public health, new strategies for tick control are required. Vaccines, constitute a cost-effective and environment friendly alter-native. The Bm86 tick antigen, originally identified in R. microplus, is the constituent of the only commercialized anti-tick vaccine. Nowadays, tick subolesin has been considered an important candidate. The aim of this study was to clone and charac-terize a recombinant peptide derived from the gen Sub in order to express it in Escherichia coli. The recombinant peptide was labeled with a polihistidine tag and identified by a monoclonal antibody against the tag after PAGE separation, purified by Ni affinity chromatography, and analyzed by the cluster analysis of variations with regards to ten different tick strains including Mexican ticks. Analysis of variations show, different clusters suggesting regional specific variations among Mexican strains, with probable implications on regional variability on protection efficiency. The tick protective antigen, subolesin, is a promising antigen and the use of immunogenic peptides predicted from in silico analysis approached in this study can be an alternative to improve the efficiency of tick vaccines in the future.".
"The cattle tick Rhipicephalus microplus economically impacts cattle production in tropical and subtropical regions of the world. The recombinant R. microplus Subolesin antigen has been shown to protect cattle against tick infestations. In this study, we searched in silico protective epitopes in the subolesin gene and a recombinant peptide containing the
predicted epitopes was expressed, and evaluated against a tick challenge. Two different epitope types, linear B-cells and conformational discontinuous epitopes, were predicted using bioinformatics strategies, in order to synthesize the recombinant peptide. Two Eightmonth-old calves European crossbred were immunized with two subcutaneous doses of the subolesin recombinant peptide, emulsified with Montanide ISA 50 V as an adjuvant, at 30-day intervals. The tick challenge was conducted with 5 000 R. microplus larvae/animal. ELISA test was used to evaluate the IgG immune response elicited against the peptide. After tick challenge, reduction in the number of engorged females (79%), and reduction in egg hatching (30%) was observed in tick population fed on immunized calves with regards to an untreated
control group. The results showed a potential higher effect on tick reproduction for the recombinant peptide compared to other studies reported with Subolesin protein, demonstrating that the use of bioinformatics strategies to predict protective epitopes may lead to improve the immune response elicited against tick recombinant peptides and therefore to prevent cattle tick infestations.".
HUGO ESPINOSA ANDREWS Zaira Yunuen García Carvajal ERISTEO GARCIA MARQUEZ ORFIL GONZALEZ REYNOSO ROBERTO OLIVARES HERNANDEZ María del Refugio Ramos_Jerz CLAUDIA YURITZI FIGUEROA HERNANDEZ Rodrigo Alonso Villegas ERIKA NAHOMY MARINO MARMOLEJO MARISELA GONZALEZ AVILA SARA ELISA HERRERA RODRIGUEZ FLOR YOHANA FLORES HERNANDEZ Eduardo Padilla Camberos Jorge Bravo Madrigal MOISES MARTINEZ VELAZQUEZ RODOLFO HERNANDEZ GUTIERREZ EVANGELINA ESMERALDA QUIÑONES AGUILAR Gabriel Rincón Enríquez JUDITH ESMERALDA URIAS SILVAS LUIS ALFONSO MOJICA CONTRERAS SOCORRO JOSEFINA VILLANUEVA RODRIGUEZ José Daniel Padilla de la Rosa BRENDA SAN PABLO OSORIO JESUS RAFAEL TRINIDAD CRUZ GLADYS PAEZ HERNANDEZ ROSA JARUMY LOPEZ RIVERA ALBERTINA CARDENAS VARGAS María Gretel Michel Barba KARINA ESMERALDA ENRIQUEZ RAMIREZ Alma Rosa Oaxaca Camacho (2017)
Los compuestos bioactivos son componentes esenciales y no esenciales (por ejemplo, vitaminas o polifenoles, prebióticos, probióticos, etc.) que se producen en la naturaleza, son parte de la cadena alimentaria y pueden demostrar que tienen un efecto sobre la salud humana. La dieta no sólo proporciona nutrientes adecuados para satisfacer los requisitos metabólicos, sino que también puede contribuir a la mejora de la salud humana. En consecuencia, los compuestos bioactivos que se cree que benefician a la salud humana necesitan ser identificados y desarrollados para el mercado de alimentos para complementar una dieta equilibrada. La evaluación de la eficacia y seguridad de estos compuestos bioactivos naturales representa un desafío para los científicos.