Interspecies DNA acquisition by a naturally competent Acinetobacter baumannii strain

The human pathogen Acinetobacter baumannii possesses high genetic plasticity and frequently acquires antimicrobial resistance genes. Here we investigated the role of natural transformation in these processes. Genomic DNA from different sources, including from carbapenem-resistant Klebsiella pneumoniae strains, was mixed with A. baumannii A118 cells. Selected transformants were analysed by whole-genome sequencing. In addition, bioinformatics analyses and in silico gene flow prediction were also performed to support the experimental results. Transformant strains included some that became resistant to carbapenems or changed their antimicrobial susceptibility profile. Foreign DNA acquisition was confirmed by whole-genome analysis. The acquired DNA most frequently identified corresponded to mobile genetic elements, antimicrobial resistance genes and operons involved in metabolism. Bioinformatics analyses and in silico gene flow prediction showed continued exchange of genetic material between A. baumannii and K. pneumoniae when they share the same habitat. Natural transformation plays an important role in the plasticity of A. baumannii and concomitantly in the emergence of multidrug-resistant strains.Fil: Traglia, German Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Place, Kori. California State University; Estados UnidosFil: Dotto, Cristian Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Fernandez, Jennifer. California State University; Estados UnidosFil: Montaña, Sabrina Daiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Bahiense, Camila dos Santos. California State University; Estados UnidosFil: Soler Bistue, Alfonso J. C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Iriarte, Andres. Universidad de la Republica. Facultad de Medicina; UruguayFil: Perez, Federico. Louis Stokes Cleveland Department Of Veterans Affairs; Estados UnidosFil: Tolmasky, Marcelo E.. California State University; Estados UnidosFil: Bonomo, Robert A.. Louis Stokes Cleveland Department Of Veterans Affairs; Estados UnidosFil: Melano, Roberto Gustavo. Public Health Ontario Laboratories; CanadáFil: Ramirez, Maria Soledad. California State University; Estados Unido

Concienciación y difusión para la apropiación de un secado solar adecuado

Los objetivos son: a) investigar sobre el proceso de secado; b) desarrollar un Prototipo Productivo como modelo demostrativo “trasladable” para mejorar los procesos de secado; c) experimentar y evaluar dicho sistema; d) difundir, capacitar y formar sobre el secado solar; e) generar y desarrollar instancias e instrumentos para estas acciones; f) incorporar técnicas y procedimientos constructivos y de secado solar sencillos. La metodología es la Investigación-Acción Participativa. Los resultados son: a) investigación sobre secado solar y un sistema tecnológico para ello; b) experimentación del prototipo; c) transferencia de procesos y productos de la investigación; d) alcances del trabajo. Si bien existen otros prototipos más eficientes, se utiliza el adoptado como elemento que posibilita la iniciación en los temas abordados y sistemas posibles y por su fácil construcción y traslado, bajo costo ($350) y factibilidad de ejecución con materiales locales; conceptos expresados por los propios participantes en las diferentes acciones desarrolladas.The objectives are: a) to investigate the drying process; b) to develop a Prototype Productive as a “portable” demonstrative model for the drying processes improvement; c) to experiment and evaluate this system; d) to disseminate and train about solar drying; e) build and develop instances and instruments for these actions; f) incorporate simple constructive techniques and solar drying procedures. There are other more efficient prototypes but the system used was adopted like as an element which enables the initiation into the themes and possible systems and it is easily constructed and transportable, with low costs ($ 350) and feasibility of implementation with local materials, concepts expressed by the participants of the different actions developed.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Concienciación y difusión para la apropiación de un secado solar adecuado

Los objetivos son: a) investigar sobre el proceso de secado; b) desarrollar un Prototipo Productivo como modelo demostrativo “trasladable” para mejorar los procesos de secado; c) experimentar y evaluar dicho sistema; d) difundir, capacitar y formar sobre el secado solar; e) generar y desarrollar instancias e instrumentos para estas acciones; f) incorporar técnicas y procedimientos constructivos y de secado solar sencillos. La metodología es la Investigación-Acción Participativa. Los resultados son: a) investigación sobre secado solar y un sistema tecnológico para ello; b) experimentación del prototipo; c) transferencia de procesos y productos de la investigación; d) alcances del trabajo. Si bien existen otros prototipos más eficientes, se utiliza el adoptado como elemento que posibilita la iniciación en los temas abordados y sistemas posibles y por su fácil construcción y traslado, bajo costo ($350) y factibilidad de ejecución con materiales locales; conceptos expresados por los propios participantes en las diferentes acciones desarrolladas.The objectives are: a) to investigate the drying process; b) to develop a Prototype Productive as a “portable” demonstrative model for the drying processes improvement; c) to experiment and evaluate this system; d) to disseminate and train about solar drying; e) build and develop instances and instruments for these actions; f) incorporate simple constructive techniques and solar drying procedures. There are other more efficient prototypes but the system used was adopted like as an element which enables the initiation into the themes and possible systems and it is easily constructed and transportable, with low costs ($ 350) and feasibility of implementation with local materials, concepts expressed by the participants of the different actions developed.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Concienciación y difusión para la apropiación de un secado solar adecuado

Los objetivos son: a) investigar sobre el proceso de secado; b) desarrollar un Prototipo Productivo como modelo demostrativo “trasladable” para mejorar los procesos de secado; c) experimentar y evaluar dicho sistema; d) difundir, capacitar y formar sobre el secado solar; e) generar y desarrollar instancias e instrumentos para estas acciones; f) incorporar técnicas y procedimientos constructivos y de secado solar sencillos. La metodología es la Investigación-Acción Participativa. Los resultados son: a) investigación sobre secado solar y un sistema tecnológico para ello; b) experimentación del prototipo; c) transferencia de procesos y productos de la investigación; d) alcances del trabajo. Si bien existen otros prototipos más eficientes, se utiliza el adoptado como elemento que posibilita la iniciación en los temas abordados y sistemas posibles y por su fácil construcción y traslado, bajo costo ($350) y factibilidad de ejecución con materiales locales; conceptos expresados por los propios participantes en las diferentes acciones desarrolladas.The objectives are: a) to investigate the drying process; b) to develop a Prototype Productive as a “portable” demonstrative model for the drying processes improvement; c) to experiment and evaluate this system; d) to disseminate and train about solar drying; e) build and develop instances and instruments for these actions; f) incorporate simple constructive techniques and solar drying procedures. There are other more efficient prototypes but the system used was adopted like as an element which enables the initiation into the themes and possible systems and it is easily constructed and transportable, with low costs ($ 350) and feasibility of implementation with local materials, concepts expressed by the participants of the different actions developed.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Performance characteristics of next-generation sequencing for the detection of antimicrobial resistance determinants in Escherichia coli genomes and metagenomes

Short-read sequencing can provide detection of multiple genomic determinants of antimicrobial resistance from single bacterial genomes and metagenomic samples. Despite its increasing application in human, animal, and environmental microbiology, including human clinical trials, the performance of short-read Illumina sequencing for antimicrobial resistance gene (ARG) detection, including resistance-conferring single nucleotide polymorphisms (SNPs), has not been systematically characterized. Using paired-end 2 x 150 bp (base pair) Illumina sequencing and an assembly-based method for ARG prediction, we determined sensitivity, positive predictive value (PPV), and sequencing depths required for ARG detection in an Escherichia coli isolate of sequence type (ST) 38 spiked into a synthetic microbial community at varying abundances. Approximately 300,000 reads or 15x genome coverage was sufficient to detect ARGs in E. coli ST38, with comparable sensitivity and PPV to ~100x genome coverage. Using metagenome assembly of mixed microbial communities, ARG detection at E. coli relative abundances of 1% would require assembly of approximately 30 million reads to achieve 15x target coverage. The minimum sequencing depths were validated using public data sets of 948 E. coli genomes and 10 metagenomic rectal swab samples. A read-based approach using k-mer alignment (KMA) for ARG prediction did not substantially improve minimum sequencing depths for ARG detection compared to assembly of the E. coli ST38 genome or the combined metagenomic samples. Analysis of sequencing depths from recent studies assessing ARG content in metagenomic samples demonstrated that sequencing depths had a median estimated detection frequency of 84% (interquartile range: 30%-92%) for a relative abundance of 1%. IMPORTANCE Systematically determining Illumina sequencing performance characteristics for detection of ARGs in metagenomic samples is essential to inform study design and appraisal of human, animal, and environmental metagenomic antimicrobial resistance studies. In this study, we quantified the performance characteristics of ARG detection in E. coli genomes and metagenomes and established a benchmark of ~15x coverage for ARG detection for E. coli in metagenomes. We demonstrate that for low relative abundances, sequencing depths of ~30 million reads or more may be required for adequate sensitivity for many applications

Clonal dissemination of Klebsiella pneumoniae ST258 harbouring KPC-2 in Argentina

AbstractThe present work describes the abrupt emergence of Klebsiella pneumoniae carbapenemase (KPC) and characterizes the first 79 KPC-producing enterobacteria from Argentina (isolated from 2006 to 2010). The emergence of blaKPC-2 was characterized by two patterns of dispersion: the first was the sporadic occurrence in diverse enterobacteria from distant geographical regions, harbouring plasmids of different incompatibility groups and blaKPC-2 in an unusual genetic environment flanked by ISKpn8-ΔblaTEM-1 and ISKpn6-like. blaKPC-2 was associated with IncL/M transferable plasmids; the second was the abrupt clonal spread of K. pneumoniae ST258 harbouring blaKPC-2 in Tn4401a

Preclinical immunotherapy with Cytokine-Induced Killer lymphocytes against epithelial ovarian cancer

Despite improvements in surgery and medical treatments, epithelial ovarian cancer (EOC) remains the most lethal gynaecological malignancy. Aim of this study is to investigate the preclinical immunotherapy activity of cytokine-induced killer lymphocytes (CIK) against epithelial ovarian cancers, focusing on platinum-resistant settings. We generated CIK ex vivo starting from human peripheral blood samples (PBMCs) collected from EOC patients. Their antitumor activity was tested in vitro and in vivo against platinum-resistant patient-derived ovarian cancer cells (pdOVCs) and a Patient Derived Xenograft (PDX), respectively. CIK were efficiently generated (48 fold median ex vivo expansion) from EOC patients; pdOVCs lines (n = 9) were successfully generated from metastatic ascites; the expression of CIK target molecules by pdOVC confirmed pre and post treatment in vitro with carboplatin. The results indicate that patient-derived CIK effectively killed autologous pdOVCs in vitro. Such intense activity was maintained against a subset of pdOVC that survived in vitro treatment with carboplatin. Moreover, CIK antitumor activity and tumor homing was confirmed in vivo within an EOC PDX model. Our preliminary data suggest that CIK are active in platinum resistant ovarian cancer models and should be therefore further investigated as a new therapeutic option in this extremely challenging setting

Molecular Characteristics of Extended-Spectrum Beta-Lactamases and qnr Determinants in Enterobacter Species from Japan

The incidence of extended-spectrum β-lactamases (ESBLs) has been increasing worldwide, but screening criteria for detection of ESBLs are not standardized for AmpC-producing Enterobacteriaceae such as Enterobacter species. In this study, we investigated the prevalence of ESBLs and/or AmpC β-lactamases in Japanese clinical isolates of Enterobacter spp. and the association of plasmid-mediated quinolone resistance (PMQR) determinants with ESBL producers. A total of 364 clinical isolates of Enterobacter spp. collected throughout Japan between November 2009 and January 2010 were studied. ESBL-producing strains were assessed by the CLSI confirmatory test and the boronic acid disk test. PCR and sequencing were performed to detect CTX-M, TEM, and SHV type ESBLs and PMQR determinants. For ESBL-producing Enterobacter spp., pulsed-field gel electrophoresis (PFGE) was performed using XbaI restriction enzyme. Of the 364 isolates, 22 (6.0%) were ESBL producers. Seven isolates of Enterobacter cloacae produced CTX-M-3, followed by two isolates producing SHV-12. Two isolates of Enterobacter aerogenes produced CTX-M-2. Of the 22 ESBL producers, 21 had the AmpC enzyme, and six met the criteria for ESBL production in the boronic acid test. We found a significant association of qnrS with CTX-M-3-producing E. cloacae. The 11 ESBL-producing Enterobacter spp. possessing blaCTX-M, blaSHV, or blaTEM were divided into six unique PFGE types. This is the first report about the prevalence of qnr determinants among ESBL-producing Enterobacter spp. from Japan. Our results suggest that ESBL-producing Enterobacter spp. with qnr determinants are spreading in Japan