83 research outputs found
Design of Lactococcus lactis Strains Producing Garvicin A and/or Garvicin Q, Either Alone or Together with Nisin A or Nisin Z and High Antimicrobial Activity against Lactococcus garvieae
Lactococcus garvieae is a main ichthyopathogen in rainbow trout (Oncorhynchus mykiss, Walbaum) farming, although bacteriocinogenic L. garvieae with antimicrobial activity against virulent strains of this species have also been identified. Some of the bacteriocins characterized, such as garvicin A (GarA) and garvicin Q (GarQ), may show potential for the control of the virulent L. garvieae in food, feed and other biotechnological applications. In this study, we report on the design of Lactococcus lactis strains that produce the bacteriocins GarA and/or GarQ, either alone or together with nisin A (NisA) or nisin Z (NisZ). Synthetic genes encoding the signal peptide of the lactococcal protein Usp45 (SPusp45), fused to mature GarA (lgnA) and/or mature GarQ (garQ) and their associated immunity genes (lgnI and garI, respectively), were cloned into the protein expression vectors pMG36c, which contains the P32 constitutive promoter, and pNZ8048c, which contains the inducible PnisA promoter. The transformation of recombinant vectors into lactococcal cells allowed for the production of GarA and/or GarQ by L. lactis subsp. cremoris NZ9000 and their co-production with NisA by Lactococcus lactis subsp. lactis DPC5598 and L. lactis subsp. lactis BB24. The strains L. lactis subsp. cremoris WA2-67 (pJFQI), a producer of GarQ and NisZ, and L. lactis subsp. cremoris WA2-67 (pJFQIAI), a producer of GarA, GarQ and NisZ, demonstrated the highest antimicrobial activity (5.1- to 10.7-fold and 17.3- to 68.2-fold, respectively) against virulent L. garvieae strains.Sección Dptal. de Nutrición y Ciencia de los Alimentos (Veterinaria)Fac. de VeterinariaTRUEMinisterio de Ciencia, Innovación y Universidades (MCIU)Universidad Complutense de Madrid and Banco de SantanderUniversidad Complutense de Madridpu
Automatic Bluefin Tuna (Thunnus thynnus) Biomass Estimation during Transfers Using Acoustic and Computer Vision Techniques
In this work, acoustic and computer vision techniques are combined to develop an automatic procedure for biomass estimation of tuna during transfers. A side scan sonar working at 200 kHz and a stereo camera, posi- tioned facing towards the surface to record the ventral aspect of fish, are set as acquisition equipment. Moreover, a floating structure has been devised to place the sensors between cages in transfers, creating a transfer canal that allows data acquisition while fish swim from donor to receiving cage. Biomass assessment is computed by counting transferred tuna and sizing a representative sample of the stock. The number of transferred tuna is automatically deduced from acoustic echograms by means of image processing techniques, whereas tuna size is computed from the stereo videos using our automatic computer vision procedure based on a deformable model of the fish ventral silhouette. The results show that the system achieves automatic tuna counting with error below 10%, achieving around 1% error in the best configuration, and automatic tuna sizing of more than 20% of the stock, with highly accurate Snout Fork Length estimation when compared to true data from harvests. These results fulfil the requirements imposed by International Commission for the Conservation of Atlantic Tunas for compliant transfer operations.Versión del editor1,42
Antimicrobial activity, antibiotic susceptibility and virulence factors of Lactic Acid Bacteria of aquatic origin intended for use as probiotics in aquaculture
Bluefin tuna (Thunnus thynnus) biomass estimation during transfers using acoustic and optic techniques
Our results show that the use of an acoustic transducer in transfers offers the possibility of performing an automatic counting with error below 10%, which is decreased to 1.2% after improving structure and algorithms. Moreover, the proposed procedure for automatic sizing using stereoscopic system achieved an accurate estimation of SFL distribution compared to true data from harvests, automatically measuring 20% of the fis
Immunomodulatory effects of bacteriocinogenic and non-bacteriocinogenic Lactococcus cremoris of aquatic origin on rainbow trout (Oncorhynchus mykiss, Walbaum)
11 Pág.Lactic Acid Bacteria (LAB) are a group of bacteria frequently proposed as probiotics in aquaculture, as their administration has shown to confer positive effects on the growth, survival rate to pathogens and immunological status of the fish. In this respect, the production of antimicrobial peptides (referred to as bacteriocins) by LAB is a common trait thoroughly documented, being regarded as a key probiotic antimicrobial strategy. Although some studies have pointed to the direct immunomodulatory effects of these bacteriocins in mammals, this has been largely unexplored in fish. To this aim, in the current study, we have investigated the immunomodulatory effects of bacteriocins, by comparing the effects of a wild type nisin Z-expressing Lactococcus cremoris strain of aquatic origin to those exerted by a non-bacteriocinogenic isogenic mutant and a recombinant nisin Z, garvicin A and Q-producer multi-bacteriocinogenic strain. The transcriptional response elicited by the different strains in the rainbow trout intestinal epithelial cell line (RTgutGC) and in splenic leukocytes showed significant differences. Yet the adherence capacity to RTgutGC was similar for all strains. In splenocyte cultures, we also determined the effects of the different strains on the proliferation and survival of IgM+ B cells. Finally, while the different LAB elicited respiratory burst activity similarly, the bacteriocinogenic strains showed an increased ability to induce the production of nitric oxide (NO). The results obtained reveal a superior capacity of the bacteriocinogenic strains to modulate different immune functions, pointing to a direct immunomodulatory role of the bacteriocins, mainly nisin Z.This work was supported by the Ministerio de Ciencia e Innovación (MICINN, Madrid, Spain) (projects RTI2018-094907-B-I00, and PID2020-113268RB-I00), and the Universidad Complutense de Madrid (UCM) (project FEI16/54). DC was supported by a contract from the project RTI2018-094907-B-I00. JF was supported by a FEI16/54 contract and held a predoctoral contract from UCM. LD-F was supported by a contract from the “Programa Investigo” (Ministerio de Trabajo y Economía Social, Madrid, Spain), funded by the EU (NextGenerationEU). JB was supported by the Atracción de Talento, program of the Comunidad de Madrid, Spain (2018-T1/BIO-10158).Peer reviewe
Cranial and extracranial giant cell arteritis do not exhibit differences in the IL6 -174 G/C gene polymorphism
Since interleukin-6 (IL-6) is a pivotal proinflammatory cytokine implicated in the pathogenesis of giant cell arteritis (GCA), we aimed to determine the potential association of the functional IL6 -174 G/C polymorphism with GCA as well as if the single base change variation at the promoter region in the human IL-6 gene may account for differences in the clinical spectrum of GCA between cranial and extracranial large vessel vasculitis (LVV)-GCA
Cranial and extracranial large-vessel giant cell arteritis share a genetic pattern of interferon-gamma pathway
OBJECTIVES: Two main different clinical phenotypes of giant cell arteritis (GCA) have been described, the classic cranial pattern and the extracranial large-vessel (LV) pattern. Since interferon gamma (IFNG) has shown to be a pivotal cytokine in the pathophysiology of GCA, our aim was to evaluate for the first time the influence of IFNG and IFNG receptor 1 (IFNGR1) polymorphisms in the different clinical phenotypes of GCA. METHODS: Two IFNG polymorphisms (rs2069718 G/A and rs1861493 A/G) and one polymorphism in IFNGR1 (rs1327474 G/A) were genotyped in 191 patients with biopsy-proven cranial GCA, 109 with extracranial LV-GCA and 490 healthy controls. A comparative study was conducted between patients with cranial and extracranial LV-GCA. RESULTS: No significant differences in genotype, allele, and haplotype frequencies of IFNG polymorphisms were found between GCA patients with the classic cranial pattern and the extracranial LV-GCA pattern. Similar results were found for genotype and allele frequencies of IFNGR1 polymorphism. It was also the case when patients with extracranial LV-GCA were compared with healthy controls. CONCLUSIONS: Our results show that IFNG and IFNGR1 polymorphisms do not influence the clinical phenotype of expression of GCA. Classic cranial GCA and extracranial LV-GCA seem to share a genetic pattern of IFNG pathway
The presence of both HLA-DRB1[*]04:01 and HLA-B[*]15:01 increases the susceptibility to cranial and extracranial giant cell arteritis.
Objectives: To determine if patients with the predominant extracranial large-vessel-vasculitis (LVV) pattern of giant cell arteritis (GCA) have a distinctive HLA-B association, different from that reported in biopsy-proven cranial GCA patients. In a further step we assessed if the combination of HLA-B and HLA-DRB1 alleles confers an increased risk for GCA susceptibility, either for the cranial and extracranial LVV phenotypes.
Methods: A total of 184 patients with biopsy-proven cranial GCA, 105 with LVV-GCA and 486 healthy controls were included in our study. We compared HLA-B phenotype frequencies between the three groups.
Results: HLA-B*15 phenotype was significantly increased in patients with classic cranial GCA compared to controls (14.7% versus 5.8%, respectively; p<0.01; OR [95% CI] =2.81 [1.54-5.11]). It was mainly due to the HLA-B*15:01 allele (12.5% versus 4.0%, respectively; p<0.01; OR [95% CI] =3.51 [1.77-6.99]) and remained statistically significant after Bonferroni correction. Similar HLA-B*15 association was observed in patients with the LVV-GCA (11.4% versus 5.8%, p=0.04, OR [95% CI] =2.11 [1.04-4.30]). This association was also mainly due to the HLA-B*15:01 allele (10.5% versus 4.0%, respectively; p=0.0054; OR [95% CI] =2.88 [1.19-6.59]). Noteworthy, the presence of HLA-B*15:01 together with HLA-DRB1*04:01 led to an increased risk of developing both cranial and extracranial LVV-GCA.
Conclusions: Susceptibility to GCA is strongly related to the HLA region, regardless of the clinical phenotype of expression of the disease.This work was partially supported by RETICS Programs, RD08/0075 (RIER), RD12/0009/0013 and
RD16/0012 from ‘‘Instituto de Salud Carlos III’’ (ISCIII) (Spain). However, this research did not receive any specific
grant from funding agencies in the commercial or not-for-profit sectors
Proyecto BIACOP: estimación de biomasa en jaulas de Atún Rojo con métodos acústicos y ópticos
Este proyecto tiene como objeto final la configuración de un sistema que proporcione la estimación del número y la biomasa de atunes de forma automática en entornos semi-controlados. Para ello se llevarán a cabo desarrollos, que configuren la integración de los datos obtenidos por sistemas acústicos y ópticos en dicho entornos. En concreto este proyecto pretende:
- Desarrollar un sistema automático que sea capaz de estimar la distribución de tallas y pesos de los atunes que habitan en una jaula flotante.
- Desarrollar un sistema automático que cuantifique las capturas, tanto del número de individuos capturados como de la distribución de sus tallas y pesos, y por tanto de la biomasa total, durante el proceso de transferencia de los atunes entre jaulas.
Para conseguir los objetivos será necesario realizar:
1. Una selección de componentes hardware y software que tengan un rendimiento apropiado para adquirir datos acústicos y ópticos en el medio marino
2. Fases de adquisición y almacenamiento de datos acústicos y ópticos para configurar bases de datos cuyo objetivos serán: a) evaluar las diferentes versiones del sistema durante la fase de desarrollo b) confeccionar estadísticas de valores y parámetros relacionales
3. Fases de pruebas y validación de los equipos y métodos desarrollados en situaciones reales de funcionamiento
4. Diseño e integración de aquellos elementos hardware del sistema acústico y del sistema de visión por computador que resulten necesarios para la configuración del sistema final
5. Implementación y desarrollo de algoritmos, tanto para el procesamiento de los datos acústicos, como para el procesamiento y análisis de las imágenes adquiridas, necesarios para el funcionamiento de la aplicación y del sistema final propuesto
Las ventajas del sistema resultante frente a los ya existentes son:
1. Sistema totalmente automático: El sistema detectará de forma automática instantáneas adecuadas de los atunes en las que sea correcto adquirir valores biométricos de los mismos para caracterizar su talla y su peso. Para ello será necesario el procesamiento y sincronización de la señal acústica y óptica.
2. Sistema de gran precisión: El trabajar con dos tipos de datos (acústico y óptico) sobre los mismos individuos nos permite verificar los valores estimados sobre sus características biométricas y conseguir una mayor precisión y ajuste.
3. Sistema tolerante con aguas turbias o con poca transparencia: Los sistemas acústicos obtienen información con independencia de la turbidez o claridad del agua. El trabajar con datos acústicos nos permite dar referencias al sistema de visión sobre distancias de individuos detectados, consiguiendo una mejor aproximación del procesamiento de imágenes realizado.
4. Sistema respetuoso con el bienestar animal y su desarrollo: En este proyecto se propone un sistema no invasivo. Nuestro sistema estará dotado únicamente de los elementos tecnológicos y acústicos necesarios para extraer datos y del soporte de los mismos, y en todo caso del sistema de sujeción que confiera la necesaria estabilidad de los mismos.
5. Sistema para ventanas de transferencia de tamaño adecuado al atún rojo: La tecnología acústica proporciona información complementaria a los sistemas ópticos. La utilización de ambas tecnologías permitiría complementar la utilización de un sistema óptico estereoscópico, y mejorar la amplitud del campo efectivo de nuestro sistema, pudiendo prescindir de la información estereoscópica en los casos en que las distancias de trabajo dificultan su aplicación, o incluso ofrecer información puramente acústica.
RESULTADOS
La medida estereoscópica ventral automatizada de atunes en jaulas y transferencias ofrece nformación biométrica sin errores accidentales asociados a la medida del operador.
Nuevas relaciones biométricas pueden estudiarse a partir de las herramientas desarrolladas.
La utilización de una estructura de paso entre jaulas posibilita la instalación de sensores en posiciones estables y la repetibilidad de las condiciones de medida
El uso de un transductor acústico en las transferencias ofrece el conteo automático con errores menores al 10 %Comisión Europea mediante la decisión ejecutiva de la Comisión de la UE de 10 de julio de 2013 (2013/410/UE), relativa a una participación financiera de la Unión en los programas de control de la actividad pesquera realizados por los estados miembros
Procedimiento para la determinación de biomasa de atunes en una zona de agua y sistema correspondiente
- …