Editorial: Microbial Taxonomy, Phylogeny and Biodiversity

The great diversity of microbial life is the remaining majorreservoir of unknown biologicaldiversity on Earth. To understand this vast, but largely unperceived diversity with its untappedgenetic, enzymatic and industrial potential, microbial systematics is undergoing a revolutionarychange in its approach to describe novel taxa based on genomic/envirogenomic information(Rosselló-Móra and Whitman, 2019)S

Photobacterium damselae subsp. piscicida: an integrated view of a bacterial fish pathogen

Pasteurellosis, or pseudotuberculosis, is a bacterial septicaemia caused by the halophilic bacterium Photobacterium damselae subsp. piscicida (formerly Pasteurella piscicida). Although this disease was first described in wild populations of white perch and striped bass, currently the natural hosts of the pathogen are a wide variety of marine fish. The disease has great economic impact bothin Japan, where it affects mainly yellowtail cultures, and in the Mediterranean area, due to the losses it causes in seabream and seabass farms. This microorganism serves as a perfect model to study a bacterial fish pathogen, either at an applied level, to resolve or to mitigate the high economic losses of fish farmers, or at a basic level, for a better understanding of P. damselae subsp. piscicida biology. This article discusses the methods employed in our laboratory to study the causative agent of pasteurellosis. It reviews important aspects, from the diverse procedures for the detection and isolation of the pathogen to the latest molecular studies that have allowed its correct taxonomic allocation. Characterization of some virulence mechanisms and the available methods to prevent the disease are also presented

Global market: shellfish imports as a source of reemerging food-borne hepatitis A virus infections in Spain

A total of 16 mollusk imports from South America to Spain, including clam and scallop species, were analyzed for hepatitis A virus (HAV), due to the great concern about this type of food after an important hepatitis A outbreak in eastern Spain in September 1999. In addition, clams from the stock that had caused the outbreak were also tested. Of the 17 stocks, four were positive for the presence of HAV RNA as demonstrated by RT-PCR and Southern hybridization. Contradictory analyses confirmed the results of the primary tests in all cases. The findings obtained in this work strongly support the role of mollusk imports from endemic areas of HAV as an important vehicle of hepatitis A, and demonstrate the imperative need for sanitary control measures to prevent future outbreaks of this disease

Inhibitory activity of Phaeobacter strains against aquaculture pathogenic bacteria

A total of 523 bacterial strains were isolated during a 4-year period from mollusc hatcheries (flat oyster and clams) in Galicia (NW Spain). All of the strains were tested for their antibacterial activity against three larval pathogens (Vibrio anguillarum USC-72, V. neptunius PP-145.98, and Vibrio sp. PP-203). Of the isolates, 52 inhibited at least one of the target strains, and 11 inhibited all of them. The main source of active strains was oyster larvae, followed by water, tank surfaces, spat, and broodstock. Four similar strains, belonging to the genus Phaeobacter, showed the strongest activity. Strain PP-154, selected as representative of this group, displayed a wide spectrum of inhibitory activity against aquaculture pathogens, especially against members of the genus Vibrio, which is responsible for the most larval deaths. The inhibitory ability of such strain on solid medium was confirmed in seawater experiments, and the optimal conditions for antibacterial activity were established. These strains are promising probiotics for aquaculture facilities. Their potential benefit is based on the capacity to control the proliferation of a variety of aquaculture bacterial pathogens in mollusc larval cultures. [Int Microbiol 2009; 12(2):107-114

Solar water disinfection (SODIS): Impact on hepatitis A virus and on a human Norovirus surrogate under natural solar conditions

This study evaluates the effectiveness of solar water disinfection (SODIS) in the reduction and inactivation of hepatitis A virus (HAV) and of the human Norovirus surrogate, murine Norovirus (MNV-1), under natural solar conditions. Experiments were performed in 330 ml polyethylene terephthalate (PET) bottles containing HAV or MNV-1 contaminated waters (103 PFU/ml) that were exposed to natural sunlight for 2 to 8 h. Parallel experiments under controlled temperature and/or in darkness conditions were also included. Samples were concentrated by electropositive charged filters and analysed by RT-real time PCR (RT-qPCR) and infectivity assays. Temperature reached in bottles throughout the exposure period ranged from 22 to 40ºC. After 8 h of solar exposure (cumulative UV dose of ~828 kJ/m2 and UV irradiance of ~20 kJ/l), the results showed significant (P < 0.05) reductions from 4.0 (±0.56) ×104 to 3.15 (±0.69) × 103 RNA copies/100 ml (92.1%, 1.1 log) for HAV and from 5.91 (±0.59) × 104 to 9.24 (±3.91) × 103 RNA copies/100 ml (84.4%, 0.81 log) for MNV-1. SODIS conditions induced a loss of infectivity between 33.4% and 83.4% after 4 to 8 h in HAV trials, and between 33.4% and 66.7% after 6 h to 8 h in MNV-1 trials. The results obtained indicated a greater importance of sunlight radiation over the temperature as the main factor for viral reduction. [Int Microbiol 2015; 18(1):41-49]Keywords: Solar water disinfection (SODIS) · water disinfection · hepatitis A virus (HAV) · murine Norovirus (MNV-1

Characterization of the microbiota associated to Pecten maximus gonads using 454-pyrosequencing

A next-generation sequencing (NGS) approach was used to study the microbiota associated to Pecten maximus broodstock, applying pyrosequencing of PCR-amplified V1-V4 16S rRNA gene regions. We analysed the resident bacterial communities in female and male scallop gonads before and after spawning. DNA samples were amplified and quality-filtered reads were assigned to family and genus taxonomic levels using the Ribosomal Database Project classifier. A total of 18,520 sequences were detected, belonging to 13 phyla, including Proteobacteria (55%), Bacteroidetes (11,7%), Firmicutes (3%), Actinobacteria (2%) and Spirochaetes (1,2%), and 110 genera. The major fraction of the sequences detected corresponded to Proteobacteria, Beta- and Gammaprotebacteria being the most abundant classes. The microbiota of P. maximus gonad harbour a wide diversity, however differences on male and female samples were observed, where female gonad samples show a larger number of genera and families. The dominant bacterial genera appeared to be Delftia, Acinetobacter, Hydrotalea, Aquabacterium, Bacillus, Sediminibacterium, Sphingomonas, and Pseudomonas that were present among the four analysed samples. This next generation sequencing technique, applied for the first time in P. maximus (great scallop) gonads was useful for the study of the bacterial communities in this mollusc, unravelling the great bacterial diversity in its microbiota. [Int Microbiol 19(2): 93-99(2016)]Keywords: Pecten maximus · gonads microbiota · next-generation sequencing (NGS) · molluscs pathogens · aquacultur

Assessment of human enteric viruses in cultured and wild bivalve molluscs

Standard and real-time reverse transcription-PCR (rRT-PCR) procedures were used to monitor cultured and wild bivalve molluscs from the Ría de Vigo (NW Spain) for the main human enteric RNA viruses, specifically, norovirus (NoV), hepatitis Avirus (HAV), astrovirus (AsV), rotavirus (RT), enterovirus (EV), and Aichi virus (AiV). The results showed the presence of at least one enteric virus in 63.4% of the 41 samples analyzed. NoV GII was the most prevalent virus, detected in 53.7% of the samples, while NoV GI, AsV, EV, and RV were found at lower percentages (7.3, 12.2, 12.2, and 4.9%, respectively). In general, samples obtained in the wild were more frequently contaminated than those from cultured (70.6 vs. 58.3%) molluscs and were more readily contaminated with more than one virus. However, NoV GI was detected in similar amounts in cultured and wild samples (6.4 × 102 to 3.3 × 103 RNA copies per gram of digestive tissue) while the concentrations of NoV GII were higher in cultured (from 5.6 × 101 to 1.5 × 104 RNA copies per gram of digestive tissue) than in wild (from 1.3 × 102 to 3.4 × 104 RNA copies per gram of digestive tissue) samples. [Int Microbiol 2009; 12(3):145-151

La intervención psicopedagógica socio-comunitaria en un centro educativo de secundaria del distrito V

[Resumo] A presente experiencia básase nun Proxecto de Intervención do Servicio Comunitario do Distrito V de A Coruña en convenio ca Universidade de A Coruña. Partindo da necesidade de analizar o sistema educativo e en concreto, o cumplimento dos seus obxectivos para coas necesidades socio-comunitarias, proponse poñer en marcha un proceso de intervención que redunde na participación dos suxeitos inmersos nel (profesores/as, alumnos/as, comunidade representada polas APAs e Administración educativa) na búsqueda da solución dos propios problemas e do compromiso persoal, a través da dinámica do grupo, para realizalo. Persíguese con iso a toma de conciencia das dificultades individuales e a xeración da autocapacidade para resolvelas. Xunto con iso trátase de educar ou crear hábitos de autonomía, cooperación e axuda, básicos e imprescindibles para o desenvolvemento na comunidade na que viven. Nesta comunicación preséntanse os datos recollidos a través dos alumnos/as. Neles se reflexan as súas necesidades e as solucións que propoñen para a millora da calidade do sistema educativo no que están inmersos, que, por suposto, redundará no seu futuro social e comunitario. Das súas sugerencias pode derivarse toda unha serie de conclusións moi operativas e básicas para a posta en marcha dun proceso educativo con mínimas garantías de éxito e calidad

<i>Vibrio breoganii</i> sp. nov., a non-motile, alginolytic, marine bacterium within the <i>Vibrio halioticoli</i> clade

Seven non-motile, facultatively anaerobic, alginolytic marine bacteria were isolated from the cultured clams Ruditapes philippinarum and Ruditapes decussatus. Phylogenetic analysis based on 16S rRNA gene sequences showed that these marine bacteria were closely related to the recently described species Vibrio comitans, Vibrio rarus and Vibrio inusitatus (=99.0?% sequence similarity). Phylogenetic analysis based on the housekeeping genes rpoA, recA and atpA grouped the isolates together and allocated them to the Vibrio halioticoli species group. Amplified fragment length polymorphism DNA fingerprinting also grouped them together and enabled them to be differentiated from recognized species of the V. halioticoli clade. DNA–DNA hybridizations showed that the isolates belonged to a novel species; phenotypic features such as the ability to grow at 4 °C and in the presence of 6?% NaCl also enabled them to be separated from other species. The DNA G+C content of RD 15.11T is 44.4 mol%. The genotypic and phenotypic data showed that the isolates represent a novel species in the V. halioticoli clade. The name Vibrio breoganii sp. nov. is proposed, with RD 15.11T (=CECT 7222T =LMG 23858T) as the type strain

Microflora associated with healthy and diseased turbot (Scophthalmus maximus) from three farms in northwest Spain

14 páginas, 4 tablas, 3 figurasA comparative analysis of the microbiological quality of three turbot (Scophthabnus maximus) farms (A, B, and C) located in Galicia (northwest Spain) is given. The microbial load and types of bacteria in the internal organs (liver and kidney) of apparently healthy fish was monitored over a year, and all the disease problems occurring during this survey were analyzed. The percentage of healthy turbot in which positive bacterial growth was obtained was relatively high in the three ongrowing facilities. Farm A exhibited the poorest conditions of fish health with an average of 42% fish infected, while farm B showed the best microbiological quality with 27% of turbot harbouring bacteria in the internal organs. In all three farms, a wide range of bacteria was found in healthy turbot with Vibrio ( V. splendidus-V pelagius, Vjisheri-V harveyi and Vibrio spp.) and Pseudomonas spp. being the predominant groups comprising at least 80% of the total bacterial isolates in each farm. The highest number of pathological problems (22 ) with the most diverse bacterial flora occurred in farm A. Vibrio spp. and Pseudomonas spp. were the most prevalent bacteria recovered from diseased turbot. Haemorrhages in palate and jaws, tail and fins, and ulcerative lesions were the most frequent external clinical signs of diseased fish recorded in the three farms. However, it was not possible to associate a particular bacterial species with a specific pathology. Routine use in farm A of oxolinic acid and nitrofurantoin may have led to the development in the Vibrio strains of resistances to both chemotherapeutants (up to 25%).This study was supported by Grants MAR 9 l- 1133~CO2-0 1 and MAR 89- 0270 from the Comision Interministerial de Ciencia y Tecnologia (CICYT), XUGA 8030389 from Xunta de Galicia (Spain), and EUREKA project No. EU-347, between Spain and Norway.Peer reviewe