Desarrollo y evaluación de formulados de B. Thuringiensis contra Diatraea saccharalis

Para desarrollar una formulacio?n de Bacillus thurin- giensis para el control de Diatraea saccharalis esta- blecimos la cri?a masiva de D. saccharalis en el labo- ratorio. El ciclo de desarrollo consta de 36- 40 di?as bajo las condiciones operacionales de 26-27°C, una humedad relativa del 80% y un fotoperi?odo de 12/ 12 horas. Se probo? el efecto to?xico de las cepas GM7, GM10, GM34, HD2, HD9, HD29, HD37, HD59, HD73, HD133, HD137 y HD551, cuyas mortalidades bajo la dosis de 50 mg/ ml fueron de 62%, 69%, 77%, 37%, 11%, 57%, 43%%, 41%, 51%, 71%, 59% y 67% respectivamente. Las cepas ma?s to?xicas por orden de intensidad fueron la GM34, HD133, GM10, HD551 y GM7. Las LD50 obtenidas fueron: 33.21 mg/ ml para la cepa GM34, 67.22 mg/ ml para la cepa HD551, 85.63 mg/ ml para la cepa HD133, 95.99 mg/ ml para la cepa GM7, 104.99 mg/ ml para la cepa GM10, 65.91 mg/ ml para la combinacio?n de cepas GM10/ GM34 y 67.68 mg/ ml para la combinacio?n de cepas HD133/ HD551. Con esto la cepa ma?s to?xica de Bacillus thuringiensis resulta ser la GM34. El TL50 para esta cepa fue de 4.55 ± 0.67 di?as. Los soportes con la mayor accio?n fagoestimulante fueron la gelatina- panoja y gelatina- melaza. Las formulaciones granu- lares ma?s toxicas a nivel laboratorio son las constitui- das de gelatina- panoja- B.t., gelatina- melaza- B.t. y Leptinox?, causando un 40, 32, y 26% de morta- lidad a las 24 horas, incrementa?ndose a 100, 92 y 88% de mortalidad a los siete di?as. A nivel inverna- dero, los formulados ma?s efectivos fueron los con- formados por gelatina- melaza- B.t.- asperjable, gelatina- panoja- B.t.- asperjable y leptinox? asper- jable, produciendo el menor nu?mero de tallos afec- tados y de entrenudos afectados, refleja?ndose en un mayor desarrollo de las plantas

Memoria general del primer curso-taller: "Enfoques biotecnológicos para abordar enfermedades emergentes y re-emergentes transmitidas por mosquitos y garrapatas en el Noroeste de México". Cd. Juárez, Chihuahua, 2019

Las enfermedades transmitidas por artrópodos son una preocupación creciente de salud pública a nivel mundial, ya que, por factores antropogénicos, cada año los casos aumentan con tendencia exponencial. Estas enfermedades son transmitidas a los vertebrados por artrópodos hematófagos, entre los que destacan los mosquitos y garrapatas. Algunas de estas enfermedades, son el dengue, Zika, paludismo, filariasis y rickettsiosis. Debido a las condiciones fisiográficas, económicas y demográficas, México, incluyendo su zona noroeste, es una región donde estas enfermedades presentan ciclos activos de transmisión, generando cada vez estadísticas mas altas de incidencia y prevalencia. En el estado de Chihuahua, la información de estas enfermedades es muy escasa, y aunque se han realizado pocos trabajos donde ha sido detectada la presencia de arbovirus y rickettsiosis, estos estudios no han sido sistemáticos y representativos. En este contexto, se planteo la idea de realizar por primera vez en la Universidad Autónoma de Ciudad Juárez, un curso taller que tuviera como objetivo el dar a conocer, de manera teórica y practica, cuales son las herramientas biotecnológicas actuales y más precisas que se utilizan a nivel mundial en e diagnostico y para prevenir y anticipar la emergencia de mencionadas enfermedades. Este evento fue titulado “Enfoques biotecnológicos para abordar enfermedades emergentes y reemergentes transmitidas por mosquitos y garrapatas en el Noroeste de México”, y patrocinado por el Consejo Nacional de Ciencia y Tecnología (No. proyecto: 299242) en el marco de su convocatoria 2019 del Programa para Actividades Científicas, Tecnológicas y de Innovación (PACTI). Este curso taller se llevó a cabo los días 14, 15 y 22 de noviembre del 2019 en las instalaciones del Instituto de Ciencias Biomédicas de la Universidad Autónoma de Ciudad Juárez (ICB-UACJ), en Cd. Juárez, Chihuahua, México

Discovery of Novel Viruses in <i>Culicoides</i> Biting Midges in Chihuahua, Mexico

Biting midges (Culicoides) are vectors of many pathogens of medical and veterinary importance, but their viromes are poorly characterized compared to certain other hematophagous arthropods, e.g., mosquitoes and ticks. The goal of this study was to use metagenomics to identify viruses in Culicoides from Mexico. A total of 457 adult midges were collected in Chihuahua, northern Mexico, in 2020 and 2021, and all were identified as female Culicoides reevesi. The midges were sorted into five pools and homogenized. An aliquot of each homogenate was subjected to polyethylene glycol precipitation to enrich for virions, then total RNA was extracted and analyzed by unbiased high-throughput sequencing. We identified six novel viruses that are characteristic of viruses from five families (Nodaviridae, Partitiviridae, Solemoviridae, Tombusviridae, and Totiviridae) and one novel virus that is too divergent from all classified viruses to be assigned to an established family. The newly discovered viruses are phylogenetically distinct from their closest known relatives, and their minimal infection rates in female C. reevesi range from 0.22 to 1.09. No previously known viruses were detected, presumably because viral metagenomics had never before been used to study Culicoides from the Western Hemisphere. To conclude, we discovered multiple novel viruses in C. reevesi from Mexico, expanding our knowledge of arthropod viral diversity and evolution

Arbovirus Surveillance near the Mexico–U.S. Border: Isolation and Sequence Analysis of Chikungunya Virus from Patients with Dengue-like Symptoms in Reynosa, Tamaulipas

A total of 1,090 residents of the city of Reynosa, Tamaulipas, on the Mexico–U.S. border presented at hospitals and clinics of the Secretariat of Health, Mexico, in 2015 with symptoms characteristic of dengue. Dengue virus (DENV) antigen was detected by enzyme-linked immunosorbent assay in acute sera from 134 (12.3%) patients. Sera from select patients (N = 34) were also tested for chikungunya virus (CHIKV) RNA by quantitative reverse transcription–polymerase chain reaction. Thirteen (38.2%) patients, including five DENV antigen-positive patients, were positive. Sera from three CHIKV RNA-positive patients were further assayed by virus isolation in cell culture and CHIKV was recovered on each occasion. The genome of one isolate and structural genes of the other two isolates were sequenced. In conclusion, we present evidence of CHIKV and DENV coinfections in patients who live near the Mexico–U.S. border and provide the first genome sequence of a CHIKV isolate from northern Mexico

Surveillance for Flaviviruses Near the Mexico-U.S. Border: Co-circulation of Dengue Virus Serotypes 1, 2, and 3 and West Nile Virus in Tamaulipas, Northern Mexico, 2014-2016

A clinical, serological, and molecular investigation was performed to determine the presence of dengue virus (DENV) and other flaviviruses among residents of the city of Reynosa, Tamaulipas, on the Mexico–U.S. border in 2014–2016. The sample population consisted of 2,355 patients with suspected dengue, in addition to 346 asymptomatic individuals recruited during a household-based epidemiological investigation designed to identify flavivirus seroconversions. Sera were collected from patients with suspected dengue in the acute phase of illness and from asymptomatic individuals at enrollment and every 5–7 months for 19 months. Sera from suspected dengue patients were tested for DENV antigen by enzyme-linked immunosorbent assay (ELISA), and select antigen-positive sera were further tested using a serotype-specific, quantitative reverse transcription–polymerase chain reaction. Sera from the household cohort were tested for flavivirus-reactive antibodies by immunoglobulin (Ig) M and IgG ELISAs using DENV antigen. A total of 418 (17.7%) patients with suspected dengue had laboratory-confirmed DENV infections, including 82 patients who were positive for DENV RNA. The most frequently detected serotype was DENV-1 (61 patients), followed by DENV-2 (16 patients) and DENV-3 (five patients). A total of 217 (62.7%) asymptomatic individuals had flavivirus-reactive antibodies at enrollment, and nine flavivirus-naïve individuals seroconverted. Sera from a subset of dengue patients and household participants, including all those who seroconverted, were further tested by plaque reduction neutralization test, resulting in the detection of antibodies to DENV-1, DENV-2, and West Nile virus. In summary, we provide evidence for the co-circulation of multiple flaviviruses in Reynosa, Tamaulipas, on the Mexico–U.S. border