New Transposon Tools Tailored for Metabolic Engineering of Gram-Negative Microbial Cell Factories

Re-programming microorganisms to modify their existing functions and/or to bestow bacteria with entirely new-to-Nature tasks have largely relied so far on specialized molecular biology tools. Such endeavors are not only relevant in the burgeoning metabolic engineering arena, but also instrumental to explore the functioning of complex regulatory networks from a fundamental point of view. À la carte modification of bacterial genomes thus calls for novel tools to make genetic manipulations easier. We propose the use of a series of new broad-host-range mini-Tn5 vectors, termed pBAMDs, for the delivery of gene(s) into the chromosome of Gram-negative bacteria and for generating saturated mutagenesis libraries in gene function studies. These delivery vectors endow the user with the possibility of easy cloning and subsequent insertion of functional cargoes with three different antibiotic resistance markers (kanamycin, streptomycin, and gentamicin). After validating the pBAMD vectors in the environmental bacterium Pseudomonas putida KT2440, their use was also illustrated by inserting the entire poly(3-hydroxybutyrate) (PHB) synthesis pathway from Cupriavidus necator in the chromosome of a phosphotransacetylase mutant of Escherichia coli. PHB is a completely biodegradable polyester with a number of industrial applications that make it attractive as a potential replacement of oil-based plastics. The non-selective nature of chromosomal insertions of the biosynthetic genes was evidenced by a large landscape of PHB synthesis levels in independent clones. One clone was selected and further characterized as a microbial cell factory for PHB accumulation, and it achieved polymer accumulation levels comparable to those of a plasmid-bearing recombinant. Taken together, our results demonstrate that the new mini-Tn5 vectors can be used to confer interesting phenotypes in Gram-negative bacteria that would be very difficult to engineer through direct manipulation of the structural genes

Overview of autosomal dominant polycystic kidney disease in the south of Spain

Introduction: Although autosomal dominant polycystic kidney disease is the most common hereditary kidney disease, available data tend to be limited to after initiation of renal replacement therapy. Objective: To ascertain an overview of autosomal dominant polycystic kidney disease within the health area of Granada in southern Spain. Materials and methods: From January 2007 to December 2016, we collected clinical, family and demographic information about all patients with autosomal dominant polycystic kidney disease, irrespective of whether or not they were treated with RRT, in the Granada health area. The computer software SPSS 15.0 and GenoPro were used. Results: 50.6% of the 1107 diagnosed patients were men. 99.1% were Caucasian and 4â6 generations/family were studied. The geographical distribution was heterogeneous. There was no family history in 2.43%. The mean age of diagnosis was 34.0 ± 17.80 years and the diagnosis was made after having offspring in 57.7% of cases. The main reason for diagnosis was family history (46.4%). The mean age of initiation of renal replacement therapy was 54.2 ± 11.05 years. 96.3% of the deceased had some degree of renal failure at the time of death. The mean age of death was 60.9 ± 14.10 years, the main cause of death being unknown in 33.5% of cases, followed by cardiovascular (27.8%). Conclusions: Cases and families were concentrated in certain geographical areas and a significant number of individuals were undiagnosed prior to cardiovascular death or diagnosed late after reproduction. Given that there is currently no curative treatment, the primary prevention strategy of preimplantation genetic diagnosis should play a leading role. Resumen: Introducción: La poliquistosis renal autosómica dominante es la enfermedad renal hereditaria más frecuente aunque los datos disponibles generalmente son tras el inicio del tratamiento renal sustitutivo. Objetivo: Conocer la situación global de la poliquistosis renal autosómica dominante en el ámbito sanitario de Granada. Material y métodos: Desde enero 2007 hasta diciembre 2016 hemos recogido información clínica, familiar y demográfica de todos los pacientes con poliquistosis renal autosómica dominante, estuvieran o no en tratamiento renal sustitutivo, atendidos en el área de Granada. Se han utilizado los programas informáticos SPSS 15.0 y GenoPro. Resultados: Mil ciento siete pacientes diagnosticados, el 50,6% son varones. Se han estudiado 4-6 generaciones/familia. El 99,1% de raza caucásica. Hay áreas geográficas con mayor concentración. No hay antecedentes familiares en el 2,43%. La edad media de diagnóstico es de 34 ± 17,8 años y en el 57,7% de los casos, el diagnóstico se produce después de tener descendencia. El principal motivo de diagnóstico son los antecedentes familiares (46,4%). La edad media de entrada en técnica es de 54,2 ± 11,05 años. El 96,3% de los fallecidos tenían algún grado de insuficiencia renal en el momento del exitus. La edad media del exitus es de 60,9 ± 14,10 años, siendo desconocida la principal causa de muerte (33,5%) seguida de la cardiovascular (27,8%). Conclusiones: Casos y familias se concentran en algunas áreas geográficas, un número importante de individuos están sin diagnosticar, fallecen antes por causa cardiovascular y se diagnostican tarde respecto al momento reproductivo. Dado que no hay tratamiento curativo, la estrategia de prevención primaria mediante el diagnóstico genético preimplantacional adquiere protagonismo. Keywords: Autosomal dominant polycystic kidney disease, Polycystic, Epidemiology, Palabras clave: Poliquistosis renal autosómica dominante, Poliquistosis, Epidemiologí