ABSTRACT
Abstract The GSTT1 and GSTM1 genes are key molecules in cellular detoxification. Null variants in these genes are associated with increase susceptibility to developing different types of cancers. The aim of this study was to determine the prevalence of GSTT1 and GSTM1 null genotypes in Mestizo and Amerindian individuals from the Northwestern region of Mexico, and to compare them with those reported worldwide. GSTT1 and GSTM1 null variants were genotyped by multiplex PCR in 211 Mestizos and 211 Amerindian individuals. Studies reporting on frequency of GSTT1 and GSTM1 null variants worldwide were identified by a PubMed search and their geographic distribution were analyzed. We found no significant differences in the frequency of the null genotype for GSTT1 and GSM1 genes between Mestizo and Amerindian individuals. Worldwide frequencies of the GSTT1 and GSTM1 null genotypes ranges from 0.10 to 0.51, and from 0.11 to 0.67, respectively. Interestingly, in most countries the frequency of the GSTT1 null genotype is common or frequent (76%), whereas the frequency of the GSMT1 null genotype is very frequent or extremely frequent (86%). Thus, ethnic-dependent differences in the prevalence of GSTT1 and GSTM1 null variants may influence the effect of environmental carcinogens in cancer risk.
ABSTRACT
En este estudio se reportan las colectas de triatominos realizadas en los estados mexicanos de Chihuahua y Aguascalientes, de los cuales se carecía de datos recientes sobre presencia e infección por Trypanosoma cruzi en triatominos vectores de la enfermedad de Chagas. En Chihuahua se colectaron exclusivamente ejemplares adultos de Triatoma recurva y de Meccus phyllosomus longipennis, con porcentajes de infección por Trypanosoma cruzi de 5,17% y 12,5%, respectivamente. En Aguascalientes se colectaron ejemplares adultos y ninfas sólo de M. p. longipennis, con un porcentaje de infección por T. cruzi de 96,7%. Los resultados indican nula colonización de la vivienda por triatominos en el área de estudio en Chihuahua, así como bajo riesgo de infección por T. cruzi. En contraste, en el área de estudio en Aguascalientes se prevé riesgo alto de infección por T. cruzi a la población. Se requiere de investigaciones entomológicas adicionales en las áreas de estudio para clarificar el riesgo de transmisión vectorial de T. cruzi a los humanos y reservorios animales.
On this study are reported some collections of triatomines from the Mexican states of Chihuahua and Aguascalientes, where recent data about vector infection by Trypanosoma cruzi was not available. In the state of Chihuahua only adult specimens of Triatoma recurva and of Meccus phyllosomus longipennis were collected. Percentages of infection by T. cruzi were respectively 5.17% and 12.5%. In the state of Aguascalientes adult as well nymph specimens of M. p. longipennis were collected. Percentage of infection by T. cruzi reached 96.7%. Our results show a null colonization of human dwellings by triatomines in the study area of the state of Chihuahua, as well as low risk of infection by T. cruzi for the inhabitants of that area. On the other hand, in the study area in the state of Aguascalientes, the risk of infection by T. cruzi was high for inhabitants of the area. Complementary entomological studies are necessary to establish the proper risk of infection by vectorial transmission of T. cruzi to human and animal reservoir host in the two studied areas.