Genetic Basis of Tetracycline Resistance in Bifidobacterium animalis subsp lactis

All strains of Bifidobacterium animalis subsp. lactis described to date show medium level resistance to tetracycline. Screening of 26 strains from a variety of sources revealed the presence of tet(W) in all isolates. A transposase gene upstream of tet(W) was found in all strains, and both genes were cotranscribed in strain IPLAIC4. Mutants with increased tetracycline resistance as well as tetracycline-sensitive mutants of IPLAIC4 were isolated and genetically characterized. The native tet(W) gene was able to restore the resistance phenotype to a mutant with an alteration in tet(W) by functional complementation, indicating that tet(W) is necessary and sufficient for the tetracycline resistance seen in B. animalis subsp. lactis

Methanogen communities in stools of humans of different age and health status and co-occurrence with bacteria

Hydrogenotrophic methanogens live in a synthrophic relationship with the human gut microbiota as the terminal part of the anaerobic food chain. Methanobrevibacter smithii of the Methanobacteriales is the prevailing archaeal species. Recently, methylotrophic archaea of the novel order Methanomassiliicoccales were isolated from human stools. Few data exist on the prevalence, abundance, persistence and ecology of these methanogens in humans. This study investigated methanogen communities in 26 healthy and obese children (8-14 years) and 18 adults (28-78 years) using quantitative PCR. Samples were obtained from nine females before and after giving birth. Bacterial groups linked to the abundance of methanogens in adult females were identified using a 16S rRNA gene amplicon data set. A total of 89% and 65% of adults and children, respectively, carried Methanobacteriales. Methanomassiliicoccales were recovered from 50% of the adults and one child. Mean relative abundance of Methanomassiliicoccales in adults was lower than that of Methanobacteriales (0.10% versus 0.52%). Both Methanobacteriales and Methanomassiliicoccales formed stable communities in females before and after giving birth. Methanobacteriales co-occurred with bacterial taxonomic groups associated with the trophic chain from carbohydrate degradation to hydrogen and formate formation. Relative abundance was inversely correlated to Blautia. Negative correlation with little characterized groups within the Clostridiales indicated possible interactions of Methanomassiliicoccales with the bacterial communit

Precisión del test de eclosión de huevos para el diagnóstico de la resistencia antihelmíntica en condiciones de campo

Publishe

Didactic programming for technology, programming and robotics in 3º ESO

Máster Universitario en Formación del Profesorado de ESO, Bachillerato, Formación Profesional y Enseñanza de Idiomas. Especialidad en Tecnología (M090