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Eight genetically modified potato lines with cry1Ac gene from Bacillus thuringiensis of the Colombian varieties Diacol Capiro and Parda Pastusa that show high resistance to Tecia solanivora in the laboratory were evaluated under greenhouse conditions. The following agronomic traits were evaluated: plant height, growth habit, canopy structure, number of stems per plant, flowering, form and size of the mini-tubers, skin texture, skin color, pulp color, presence of abnormalities, and experimental performance. It was established that at least one of the transgenic lines studied has great potential for further study, bearing no morphological variability with respect to the unmodified control line.

OBJETIVO: Estimar la incidencia de infección por Helicobacter pylori en una cohorte de infantes del estado de Morelos. MATERIAL Y MÉTODOS: Se estudió una cohorte de 110 niños sanos, en el Hospital del Niño Morelense, en Cuernavaca, Morelos, México, de 1997 a 1999, y se obtuvo suero materno al inicio del estudio y de los infantes a los dos, seis, 18 y 24 meses de vida. La presencia de la infección por H. pylori se determinó mediante la prueba de ELISA. Con un cuestionario se registraron datos socioeconómicos y clínicos. Mediante prueba exacta de Fisher se determinó si había asociación entre cada una de las diferentes variables y la presencia de infección por H. pylori. RESULTADOS: De las madres, 66.6% fueron seropositivas para H. pylori, mientras que sólo lo fueron seis niños (5.5%). Dos de esos casos provenían de madres infectadas, ambos revirtieron antes de los dos años de vida, no así los otros cuatro infantes. Aunque no fueron estadísticamente significativos, el nacimiento por vía vaginal y que el hogar sea habitado por más de cinco personas, pueden ser factores de riesgo para la adquisición temprana de H. pylori. CONCLUSIONES: A pesar de la alta prevalencia de infección por H. pylori reportada previamente en niños mexicanos, en esta población se encontró una incidencia baja de infección en lactantes hasta los dos años de edad. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.html

Helicobacter pylori have coevolved with mankind since its origins, adapting to different human groups. In America, H. pylori has evolved into several subpopulations. We analysed the genome of 154 Colombian strains along with 1,091 strains from worldwide populations to discern the ancestry and adaption to Colombian people. Population structure and ancestry was inferred with FineStructure and ChromoPainter. Phylogenetic relationship and the relative effect of recombination were analysing the core SNPs. Also, a Fst index was calculated to identify the gene variants with the strongest fixation in the Colombian subpopulations compared to their parent population hspSWEurope. FineStructure allowed the identification of two Colombian subpopulations, the previously described hspSWEuropeColombia and a novel subpopulation named hspColombia, that included three subgroups following their geographic origin. Colombian subpopulations represent an admixture of European, African and Indigenous ancestry; although some genomes showed a high proportion of self identity, suggesting an advanced adaption to these mestizo Colombian groups. We found that recombination is more important that punctual mutations in H. pylori genome diversity, 13.9 more important in hspSWEurope, 12.5 in hspSWEColombia and 10.5 in hspColombia, reflecting the divergence of these subpopulations. Fst analysis identified 82 SNPs fixed in 26 genes of the hspColombia subpopulation that encode for outer membrane and central metabolism proteins. Strongest fixation indexes were identified in genes encoding HofC, HopE, FrpB-4 and Sialidase A. These findings demonstrate that H. pylori has evolved in Colombia to give rise to subpopulations with a self identity ancestry, reflected in allele changes on genes encoding for outer membrane proteins.

Gastric cancer is a leading cause of cancer mortality and health disparities in Latinos. We evaluated gastric intratumoral heterogeneity using multiregional sequencing of >700 cancer genes in 115 tumor biopsies from 32 patients, 29 who were Latinos. Analyses focused on comparisons with The Cancer Genome Atlas (TCGA) and on mutation clonality, druggability, and signatures. We found that only approximately 30% of all mutations were clonal and that only 61% of the known TCGA gastric cancer drivers harbored clonal mutations. Multiple clonal mutations were found in new candidate gastric cancer drivers such as EYS, FAT4, PCDHA1, RAD50, EXO1, RECQL4, and FSIP2. The genomically stable (GS) molecular subtype, which has the worse prognosis, was identified in 48% of our Latino patients, a fraction that was >2.3-fold higher than in TCGA Asian and White patients. Only a third of all tumors harbored clonal pathogenic mutations in druggable genes, with most (93%) GS tumors lacking actionable clonal mutations. Mutation signature analyses revealed that, in microsatellite-stable (MSS) tumors, DNA repair mutations were common for both tumor initiation and progression, while tobacco, POLE, and inflammation signatures likely initiate carcinogenesis. MSS tumor progression was likely driven by aging- and aflatoxin-associated mutations, as these latter changes were usually nonclonal. In microsatellite-unstable tumors, nonclonal tobacco-associated mutations were common. Our study, therefore, contributed to advancing gastric cancer molecular diagnostics and suggests clonal status is important to understanding gastric tumorigenesis. Our findings of a higher frequency of a poor prognosis associated molecular subtype in Latinos and a possible new aflatoxin gastric cancer etiology also advance cancer disparities research.SignificanceOur study contributes to advancing our knowledge of gastric carcinogenesis, diagnostics, and cancer health disparities.

OBJETIVO: Investigar mediante métodos serológicos la infección por B burgdorferi en individuos del Distrito Federal y la zona noreste de México. MATERIAL Y MÉTODOS: Se obtuvo una muestra representativa de sueros del Distrito Federal y la zona noreste de México, obtenidas en la Encuesta Seroepidemiológica Nacional de 1987-1988. Se detectaron anticuerpos IgG vs B burgdorferi por ELISA, confirmados con Western blot. En este trabajo se utilizó estadística descriptiva. RESULTADOS: Fueron estudiados 2 346 sueros; 297 (12.6%) fueron positivos por inmunoensayo enzimático, y 122/297 fueron confirmados por Western blot. La seroprevalencia fue de 3.43% en el Distrito Federal y 6.2% en la zona noreste del país. Tamaulipas fue el estado con la seroprevalencia más alta. CONCLUSIONES: La prevalencia de casos seropositivos sugieren que la infección por B burgdorferi ocurre en el noreste de México y el Distrito Federal. Es necesario identificar casos clínicos y buscar el vector infectado para confirmar la presencia de la enfermedad de Lyme en México.

Hungatella hathewayi has been observed to be a member of the gut microbiome. Unfortunately, little is known about this organism in spite of being associated with human fatalities; it is important to understand virulence mechanisms and epidemiological prospective to cause disease. In this study, a patient with chronic neurologic symptoms presented to the clinic with subsequent isolation of a strain with phenotypic characteristics suggestive of Clostridium difficile. However, whole-genome sequence found the organism to be H. hathewayi. Analysis including publicly available Hungatella genomes found substantial genomic differences as compared to the type strain, indicating this isolate was not C. difficile. We examined the whole-genome of Hungatella species and related genera, using comparative genomics to fully examine species identification and toxin production. Orthogonal phylogenetic using the 16S rRNA gene and entire genome analyses that included genome distance analyses using Genome-to-Genome Distance (GGDC), Average Nucleotide Identity (ANI), and a pan-genome analysis with inclusion of available public genomes determined the speciation to be Hungatella. Two clearly differentiated groups were identified, one including a reference H. hathewayi genome (strain DSM-13,479) and a second group that was determined to be H. effluvii, which included our clinical isolate. Also, some genomes reported as H. hathewayi were found to belong to other genera, including Clostridium and Faecalicatena. We show that the Hungatella species have an open pan-genome reflecting high genomic diversity. This study highlights the importance of correctly assigning taxonomic identification, particularly in disease-associated strains, to better understand virulence and therapeutic options.

Klebsiella pneumoniae is recognized as a common cause of nosocomial infections and outbreaks causing pneumonia, septicemia, and urinary tract infections. This opportunistic bacterium shows an increasing acquisition of antibiotic-resistance genes, which complicates treatment of infections. Hence, fast reliable strain typing methods are paramount for the study of this opportunistic pathogens multi-drug resistance genetic profiles. In this study, thirty-eight strains of K. pneumoniae isolated from the blood of pediatric patients were characterized by whole-genome sequencing and genomic clustering methods. Genes encoding β-lactamase were found in all the bacterial isolates, among which the bla SHV variant was the most prevalent (53%). Moreover, genes encoding virulence factors such as fimbriae, capsule, outer membrane proteins, T4SS and siderophores were investigated. Additionally, a multi-locus sequence typing (MLST) analysis revealed 24 distinct sequence types identified within the isolates, among which the most frequently represented were ST76 (16%) and ST70 (11%). Based on LPS structure, serotypes O1 and O3 were the most prevalent, accounting for approximately 63% of all infections. The virulence capsular types K10, K136, and K2 were present in 16, 13, and 8% of the isolates, respectively. Phylogenomic analysis based on virtual genome fingerprints correlated with the MLST data. The phylogenomic reconstruction also denoted association between strains with a higher abundance of virulence genes and virulent serotypes compared to strains that do not possess these traits. This study highlights the value of whole-genomic sequencing in the surveillance of virulence attributes among clinical K. pneumoniae strains.