Global transcriptome analysis of Lactococcus garvieae strains in response to temperature

Lactococcus garvieae is an important fish and an opportunistic human pathogen. The genomic sequences of several L. garvieae strains have been recently published, opening the possibility of global studies on the biology of this pathogen. In this study, a whole genome DNA microarray of two strains of L. garvieae was designed and validated. This DNA microarray was used to investigate the effects of growth temperature (18°C and 37°C) on the transcriptome of two clinical strains of L. garvieae that were isolated from fish (Lg8831) and from a human case of septicemia (Lg21881). The transcriptome profiles evidenced a strain-specific response to temperature, which was more evident at 18°C. Among the most significant findings, Lg8831 was found to up-regulate at 18°C several genes encoding different cold-shock and cold-induced proteins involved in an efficient adaptive response of this strain to low-temperature conditions. Another relevant result was the description, for the first time, of respiratory metabolism in L. garvieae, whose gene expression regulation was temperature-dependent in Lg21881. This study provides new insights about how environmental factors such as temperature can affect L. garvieae gene expression. These data could improve our understanding of the regulatory networks and adaptive biology of this important pathogen

Clonal and plasmid-mediated flow of ESBL/AmpC genes in Escherichia coli in a commercial laying hen farm

Resistance to third- and fourth-generation cephalosporins in Escherichia coli is mainly due to extended-spectrum beta-lactamases (ESBL) and AmpC cephalosporinases, which have been increasingly reported, mainly in isolates from humans and poultry. The aim of this study was to address the flow of antimicrobial resistance determinants in the full laying hen production cycle (four batches followed from day-old chicks to 83/84-week-old layers), using cephalosporinresistant E. coli as a model and their characterization using whole genome sequencing (WGS). Fifteen out of 22 samples analysed yielded growth on MacConkey agar with cefotaxime (1 mg/L). Of these, 141 isolates were identified as E. coli and 47 were characterized by WGS. Genes detected were three ESBL (blaCTX-M-1 (n = 19); blaCTX-M-14 (n = 1); and blaSHV-12 (n = 9)) and one AmpC (blaCMY-2 (n = 13)). Some isolates only harboured blaTEM-1B (n = 2) or blaTEM-1D (n = 1). IncI1 plasmids were the main platform for ESBL/AmpC genes. In addition, five clones were identified harbouring blaCTX-M-1 (two), blaSHV-12 (one) and blaCMY-2 (two), drawing a clone-plasmid mixed flow model. Gene blaCTX-M-1 was found in the chromosomal DNA of clone 1 over 14 months, and in IncI1/ST3 plasmids over six months; over six months blaSHV-12 was found harboured by clone 3 (IncI1/ST26 plasmids), and 15 months later in a non-replicon detected plasmid. Finally, blaCMY-2 spread for at least 16 months, mainly by IncK2 (including clone 4) and IncI1/ST12 (clone 5) plasmids. Proper use of antimicrobials should be combined with other farm management strategies for the effective control of cephalosporin-resistant E. coli isolates in commercial layer farms

Utilization of lactose and presence of the phospho-β-galactosidase (lacG) gene in Lactococcus garvieae isolates from different sources

This study evaluates the utilization of lactose (Lac) and the presence of the phospho-β-galactosidase (lacG) gene as markers for distinguishing between fish (Lac-/lacG-) and dairy isolates (Lac+/lacG+) of Lactococcus garvieae, using a panel of L. garvieae isolates from different sources. None of the fish isolates produced acid from lactose (Lac-), however Lac-/lacG- isolates were observed in pigs, cows, birds and humans. Most of the dairy isolates (77.8%) were Lac+/lacG+, but some dairy isolates did not produce acid from this sugar. Data in the present study show that the ability to metabolize lactose and the presence of the lacG gene are heterogeneously scattered among L. garvieae isolates of different sources. Therefore, the use of these criteria as markers to differentiate between L. garvieae isolates of dairy and fish origin should be considered with caution

La innovación educativa aplicada a la Ictiopatología

Se ha elaborado un material aplicable a la docencia y que puede favorecer el ejercicio profesional de un veterinario y de otras áreas dedicados a la Acuicultura. Además, tiene el valor añadido de ser una colaboración entre docentes pertenecientes a dos Universidades

Inmunotrivial: un juego de autoevaluación para el aprendizaje de la inmunología

Hoy en día la Inmunología es un instrumento fundamental de la medicina moderna, ya que posibilita la comprensión de los mecanismos de acción de los agentes patógenos y de la respuesta de defensa del organismo frente a ellos. Por tanto, el conocimiento de la Inmunología es vital para los profesionales de distintos ámbitos relacionados con Ciencias de la Salud: médicos, odontólogos, farmacéuticos, biólogos, veterinarios. Por otra parte, el proceso de adaptación curricular al EEES implica una tendencia al aprendizaje de forma más autónoma y al empleo de las nuevas tecnologías a nuestro alcance. Por estos motivos, y con la experiencia que nos proporcionan nuestras actividades tanto de investigación como docentes en Inmunología, así como la experiencia adquirida en la elaboración de nuevos materiales docentes, como el «Manual de Inmunología Veterinaria» (2007, Pearson/Prentice Hall), y el CD «Microbiología Veterinaria. Laboratorio Virtual» (2007, UCM/Editorial Complutense), nos hemos planteado un nuevo reto: el diseño de material de autoevaluación en Inmunología. Se trata de una aplicación informática con formato de juego, en el que el estudiante pone a prueba sus conocimientos en Inmunología de una manera divertida, estimulando el autoaprendizaje y la autoevaluación

Comparative genomics and evolutionary analysis of Lactococcus garvieae isolated from human endocarditis

This is an open-access article distributed under the terms of the Creative Commons Attribution NonCommercial License. This article was made open access via a Publish and Read agreement between the Microbiology Society and the corresponding author’s institution. This work was supported by the Spanish Ministry of Science, Innovation, and Universities [RTI2018-098530-B-I00 and BFU2017-89594-R]. C-F.C. was supported by the Spanish Ministry of Science, Innovation, and Universities [BES-2015-074204].Lactococcus garvieae is a well-known pathogen of fish, but is rarely involved in infections in humans and other mammals. In humans, the main clinical manifestation of L. garvieae infections is endocarditis usually related to the ingestion of contaminated food, such as undercooked fish and shellfish. This study presents the first complete genomic sequence of a clinical L. garvieae strain isolated from a patient with endocarditis and its comparative analysis with other genomes. This human isolate contains a circular chromosome of 2 099 060 bp and one plasmid of 50 557 bp. In comparison with other fully sequenced L. garvieae strains, the chromosomal DNA of L. garvieae Lg-Granada carries a low proportion of insertion sequence elements and a higher number of putative prophages. Our results show that, in general, L. garvieae is a highly recombinogenic species with an open pangenome in which almost 30 % of its genome has undergone horizontal transfers. Within the genus Lactococcus, L. lactis is the main donor of genetic components to L. garvieae but, taking Lg-Granada as a representative, this bacterium tends to import more genes from Bacilli taxa than from other Lactococcus species.Ministerio de Ciencia, Innovación y UniversidadesDepto. de Sanidad AnimalCentro de Vigilancia Sanitaria Veterinaria (VISAVET)Fac. de VeterinariaTRUEpu

Spleen and head kidney differential gene expression patterns in trout infected with Lactococcus garvieae correlate with spleen granulomas

Authors’ contributions AG and MMB designed the study. RC, AG and JC did most of the array experiments and performed the statistical analyses. AG, MMB, JFFG carried out the infection experiments and cared for the fsh. ARB performed the histopathological studies. LJ performed the statistical analyses. The manuscript was written by AG and RC, and critically reviewed by JC, MMB and JFFG who contributed to writing the manuscript. All authors read and approved the final manuscript.Lactococcus garvieae is a significant pathogen in aquaculture with a potential zoonotic risk. To begin to characterize the late immune response of trout to lactococcosis, we selected infected individuals showing clinical signs of lactococcosis. At the time lactococcosis clinical signs appeared, infection by L. garvieae induced a robust inflammatory response in the spleen of rainbow trout, which correlated with abundant granulomatous lesions. The response in kidney goes in parallel with that of spleen, and most of the gene regulations are similar in both organs. A correlation existed between the early inflammatory granulomas in spleen (containing macrophages with internalized L. garvieae) and up-regulated gene sets, which defined the presence of macrophages and neutrophils. This is the first analysis of the immune transcriptome of rainbow trout following L. garvieae infection during the initiation of adaptive immune mechanisms and shows a ranscriptome induction of antibody response by both IgM (+) and IgT (+) spleen B cells to respond to systemic infection. These results increase our understanding of lactococcosis and pave the way for future research to improve control measures of lactococcosis on fish farms.Ministerio Español de Economía y Competitividad (AGL 2012-35419 y AGL2014-51773-C3-3-R )Comunidad de Madrid (S2013/ABI-2747 (TAVS-CAM))Unión EuropeaDepto. de Sanidad AnimalFac. de VeterinariaTRUEpu

Laboratorio virtual de microbiología veterinaria

Para el Proyecto de Innovación Educativa se ha realizado un CD como complemento a las prácticas de la Licenciatura de Veterinaria que tienen un componente microbiológico. Incluye aspectos fundamentales del ejercicio profesional (Toma de Muestras, Bioseguridad, Laboratorio de Virología), pero que con las infraestructuras actuales es casi imposible presentarlos al alumno de forma eficaz y personalizada. Para su desarrollo hemos elaborado el material escrito, apoyándolo con imágenes y videos explicativos. La confección del CD en sí ha sido realizada por una empresa de informática, siguiendo nuestras especificaciones y requerimientos.Depto. de Sanidad AnimalFac. de VeterinariaTRUEpu