Search

Samples of serum, kidney and skin and intestinal mucus of sea bass (Dicentrachus labrax, Moronidae) fed a diet enriched with increasing concentrations of the yeast Saccharomyces cerevisiae var. boulardii as a probiotic were examined for their antibacterial properties, compared to a control group fed without yeast supplementation. Antibacterial activity was found in all the samples, although not related with the used yeast concentrations.

In this study has been analyzed the genetic potential (rDNA) versus expression (crDNA) of microbial populations associated to gills of living mussel Mytilus galloprovincialis (Bivalvia: Mytilidae) in natural environment. Data obtained (16S rDNA/crDNA clones libraries) showed as sequences mainly related to Bacteroides/Chlorobi, Firmicutes and Gamma-Proteobacteria groups are specific in live mussels. It is presumed that further studies of microbial population structure with culture-independent methods will demonstrate the active interactions (symbiosis) between filter-feeding organisms and gill-associated bacteria.

In the last years aquaculture has contributed significantly to reduce the hunger worldwide. One of the major treats in the development of a massive production is linked to the outbreak of diseases and the abuse of antibiotics, that is to avoid because of the acquisition of antibiotic resistance. For these reasons recently probiotics are used as alternative measures to control the fish diseases. Fish possess specific intestinal microbiota consisting of aerobic, facultative anaerobic and obligate anaerobic bacteria so we make this study in order to find some probiotic candidates that have an antagonistic action against fish pathogens. Adults of Sparus aurata farmed in intensive plant were sacrificed and 40 bacterial strains were isolated from GI tract. All the strains were tested against three fish pathogens: Vibrio anguillarum, Photobacterium damselae subsp. piscicida and Pseudomonas anguilliseptica. Results showed that only 3 candidates respectively called (SA7, SA10, and SA20) showed an inhibitory activity against the selected fish pathogens bacteria. The candidates probionts were identified by the 16S rRNA gene sequenced-based. The three candidates inhibited the Gram negative fish pathogens after 24 -48 h of incubation at 24°C and for these reasons could be used as probiotics to added into the food to enhance the immune defence of fish.

The study investigate the time of leaching of DEHP and the risk of accumulation in tissues.

Interleukins IL-1beta and IL-10 expression in Dicentrarchus labrax (Teleostei, Moronidae) during the late phase of a naturally occurring infection caused by Vibrio anguillarum has been investigated. Results obtained show, the fourth day of infection, a differential expression of IL-1? just in head kidney, while IL-10 is still actively expressed in the intestine, head kidney and gills.

The present study assesses how stocking density affected the physiological response of cage farmed Sparus aurata (Teleostei, Sparidae). Overall, the results of biochemical and immunological parameters indicated a higher welfare level in gilthead seabream reared at lower density.

Growth, haematological (haematocrit), biochemical (serum cortisol and glucose), and non-specific immune (lysozyme, serum haemolytic and haemagglutinating activities, extracellular respiratory burst activity) parameters, were monitored in European sea bass Dicentrarchus labrax and blackspot sea bream Pagellus bogaraveo subjected to a 31 days starvation compared to fed fish, to assess the responses to feed deprivation of these health status indicators. While haematocrit, serum cortisol, glucose and haemolytic activity of both species did not undergo significant variation following starvation, probably due to the short period applied, some non- specific immune parameters were affected significantly. In the starved sea bass, mucus lysozyme content doubled (1.8 U/mL) compared to the initial value. Haemagglutinating activity was significantly lower in starved sea bass than in fed fish after 31 days. In blackspot sea bream, a slight, not significant, reduction in haemagglutinating activity occurred 11 days after starvation. Respiratory burst activity decreased significantly in the starved fish. In spite of the limited number of examined parameters, the opportunity to use a panel of several indicators to obtain a more complete picture of health status in fish was underlined.

A fasting-refeeding experiment was carried out in red porgy, Pagrus pagrus (Teleostei, Sparidae) to assess the effect of a 21 day- starvation period on some physiological parameters. Both haematological and biochemical parameters and digestive enzyme patterns were considered. Results showed that starvation resulted in a general, although not significant, decrease of digestive enzyme levels, with a recovery to initial values after refeeding. No significant changes were observed in both haematological and biochemical parameters

The aim of this study is to investigate growth, haematological, biochemical and immunological parameters of European sea bass, Dicentrarchus labrax (Teleostei, Moronidae) farmed in submersible and surface cages in order to compare physiological status under different rearing conditions. Results obtained suggest mariculture in submerged cages as a promising system that allows to minimize stress and that, hence, promotes fish welfare.

Seabass (Dicentrarchus labrax, Moronidae), European eel (Anguilla anguilla, Anguillidae) and blackspot seabream (Pagellus bogaraveo, Sparidae) were checked for their antibacterial and haemolytic properties. The highest antibacterial activity was found in blackspot seabream and European eel sera against Vibrio alginolyticus and in seabass kidney against Photobacterium damselae subsp. piscicida.

viene riportato un caso di infezione oculare in un esemplare adulto di Seriola dumerilii mantenuta in un impianto di acquacoltura. l'esame microbiologico ha mostrato la presenza di ceppi Gram positivi ed ha permesso la diagnosi di lattococcosi oculare.

The physiological effects of acute stress (induced by an intraperitoneal injection) on the haematocrit, haemoglobin, serum cortisol and glucose, haemagglutinins and lysozyme were investigated in juvenile sea bass Dicentrarchus labrax. A total of 40 fish were subjected to an intraperitoneal injection. Eight fish were sampled at 0, 2, 4, 24 and 48 h after acute stress and compared to unstressed fish (controls) sacrificed at the same times. Intraperitoneal injection resulted in significant changes in cortisol and glucose 4 and 2 hours after exposure to stress, respectively, but not in haematocrit and haemoglobin levels. No significant differences between stressed and control fish were recorded for lysozyme content and haemagglutinating activity throughout the experiment. In juvenile sea bass acute stress caused by intraperitoneal injection was mostly associated with the increase in common stress indicators (cortisol and glucose), while no clear response in terms of non-specific immune parameters was evidenced. Key Words: Dicentrarchus labrax, acute stress, intraperitoneal injection was mostly associated with the increase in common stress indicators (cortisol and glucose), while no clear response in terms of non-specific immune parameters was evidenced.

Progetto MESSA A PUNTO DI SISTEMI INNOVATIVI DI GESTIONE E MONITORAGGIO AMBIENTALE DI GABBIE DI ALLEVAMENTO OFF-SHORE E VERIFICA DELLE PRESTAZIONI

Melicerthus (Penaeus) kerathurus commonly named "caramote prawn", is a specimen very appreciated and recently proposed as a new species for reproduction. The hatching and larval stages are very sensitive to the microbial attack and the mortality is higher than the other stages of life. Vibriosis is the bacterial disease most common in larvae and post-larvae causing high mortality (about 80%) in few time, the species involved in this pathology are Vibrio alginolyticus, V. parahaemolyticus e Listonella (Vibrio) anguillarum, these Vibrios act as opportunistic bacteria and in stress conditions become dangerous for fish health. Here we reported a Brown Spot Disease episode occurred during a controlled reproduction experiment of M. kerathurus. Adult specimens showed brown-green ulcers on carapace, thorax, abdomen and in same specimens on pereiopods. Sampling of lesions and water has been effectuated to identify the pathogen agent by microbial and histochemical methods. The results showed that all subjects were infected by V. alginolyticus and that confirm the opportunistic "nature" of this bacteria, that in stress conditions (sub-optimal environment, low water quality, high stock density or high manipulation) become pathogen.