136 research outputs found
Lymphocystis virus disease
No full textLymphocystis disease (LCD) is a chronic self-limiting disease involving a number of teleost species throughout the world. It is caused by the lymphocystis disease virus (LCDV) and characterized by white nodules affecting the fish's skin/fins. Although LCD is frequently benign, it may be responsible for economic losses related to poor growth, nonmarketability of diseased fish, and secondary bacterial infections. Currently, no specific prevention or therapeutic methods are available, and the control is based on the application of a biosecurity program including disinfection procedures, screening and quarantine of fish stocks that have to be introduced. Recent studies showed that LCDV causes systemic infection, and surviving fish can become asymptomatic carriers, thus presenting new challenges in the control of LCD. This chapter reviews the literature providing an overview of this insidious disease, including recent insights on pathogenesis and epidemiology, available methods for the diagnosis and future prospects to improve LCD control
Short note: Infliximab recovery in a simulated intestinal fluid of the upper intestine tract
No full textBACKGROUND: The oral administration of Infliximab (IFX) antibody would ensure a direct action on inflamed intestinal tissues without side effects. Thus, investigations about its resilience within the intestinal environment are required. OBJECTIVE: Quantify the IFX recovery in a simulated upper intestinal environment. METHODS: IFX was incubated for different times until 120 min in simulated intestinal fluid (SIF) which differed (i) for pH (7.2 vs 6.8, Exp 1), (ii) for addition or not with pancreatin (Exp 2) and (iii) for addition or not with bovine serum albumin in presence of pancreatin (BSA, Exp 3). RESULTS: In Exp 1 the IFX incubated without pancreatin was degraded by about 15% by SIF pH change from 7.2 to 6.8 and after 120 min it was reduced by about 20%. In Exp 2 the presence of pancreatin determined an intense and rapid IFX degradation (recovery < 33%, within 30 min), but when BSA was added to simulate the presence of food protein (Exp 3) the IFX half-life ranged between 59 and 70 min. CONCLUSIONS: A discrete in vitro stability of IFX in the upper intestine environment was demonstrated, if food protein is available and competes with pancreatin proteases
IMMUNOHISTOCHEMICAL DEMONSTRATION OF CD35 AND CD16 RECEPTORS IN DEVELOPMENTAL STAGES OF SEA BASS (D. LABRAX)
No full textThe study of teleosts immune system is useful to better understand its involvement inthe prevention of infectious diseases. Additionally, such studies are important from aphylogenetic point of view, since fish are the first animals that, in the evolutionaryprocess, show aspects of innate and adaptive immune response comparable to thosepresent in higher vertebrates. In mammals, phagocytosis is a prerogative ofmacrophages and neutrophil granulocytes. At the moment, some fish cell populationsinvolved in this activity are still under investigation, due to the evident morphologicalheterogeneity of leucocytes among different species and to the lack of specific surfacemarkers for fish phagocytes. A crucial role in the phagocytosis activation can beattributed to the membrane receptors for complement and immunoglobulin Fc. Inmammals four types of receptors for C3 have been identified, namely CR1, CR2, CR3and CR4. CR1 (CD35) is expressed by neutrophils, eosinophils and some B and Tsub-populations. It promotes the link to and phagocytosis of particles opsonised byC3b and C4b fractions. FcR" (CD16) is expressed by several hemopoietic cells(macrophages and lymphocytes) and its role is fundamental for the cellular immuneresponse mediated by immunoglobulins (removing of immune-complexes oropsonised particles by phagocytosis). Investigations dealing with the identification ofthese receptors in teleosts are recent and concern a limited number of species:rainbow trout, catfish, carp, zebrafish. These studies have mainly focused on aspectsof CR1 and FcR phylogenesis, as well as structural/functional homologies withmammalians. From the literature there is no evidence of investigations dedicated tothe identification of CR1 and FcR in marine teleosts, and also there are no dataregarding the immunohistochemical localization of cells presenting these CDs. Thepresent paper is aimed to the demonstrations of CD16 and CD35 immune-receptors intissues of sea bass (Dicentrarchus labrax) at different developmental stages.Histological sections obtained from tissue specimens collected from sea bassfingerlings were submitted to immunohistochemical analysis by use of the followingantibodies: goat polyclonal to CD35 (CR1); rabbit polyclonal to CD16 (FcR). Thereaction was developed by ABComplex peroxidase and DAB. As a result of theantibodies employed, even if specific for mammalian receptors, allowed the detectionof cell populations in different tissues, and also the chronology of appearance wasdescribed. In synthesis, CD16 was detectable in thymus, gills and skin starting from50dph, and in the digestive system starting from 90 dph. CD35 was detectable inseveral organs (thymus, gills, pancreas, skin, stomach, gut) starting from 47 dph, andlater in spleen and pyloric caeca. Moreover, the morphology of CD16+ and CD35+cells colonizing various tissues was described, allowing the discrimination of at leastthree different cell populations: CD16+ cells, morphologically similar to macrophagesor dendritic cells (APCs), with non granular cytoplasm; CD35+ cells,morphologically similar to macrophages or dendritic cells (APCs), with non granularcytoplasm; CD35+ cells, morphologically similar to eosinophilic granulocytes orEGCs, with granular cytoplasm. These populations were particularly consistent inthymus (among the primary lymphoid organs), skin and digestive tract (mucosaeassociate lymphoid tissue). Based on their morphology and specific localization, ahypothesis concerning their role as phagocytes and antigen presenting cells will bediscussed.[...
Eco-mechanical index for structural concrete
No full textDesign and production of industrial components and materials are nowadays a compromise between the required performances and the environmental impact. In the case of structural concrete, the existing eco- logical approaches are mainly focused on sustainability, regardless of mechanical performances. Tailoring a new generation of concretes, capable of maintaining acceptable mechanical properties with a reduced ecological impact, is therefore the big challenge that construction industry has to face. Accordingly, new instruments, based on both mechanical and environmental performances, need to be introduced in place of the classical life cycle assessment procedure. This is the case of the so-called eco-mechanical index (EMI), described in the present paper and applied to different series of plain and fiber-reinforced self- compacting concretes. The basic mechanical properties, such as compression and flexural strengths, and the related post-peak curves, are taken into account by the proposed EMI. Conversely, water, embod- ied energy consumption and the amount of carbon dioxide, necessary for the production of concrete, are here assumed to represent the environmental performance. As a result, in presence of fiber-reinforced concrete, despite the higher ecological impact than plain concrete, the best eco-mechanical performances are generally measured at each stage of concrete lif
IMPACT OF WATER TEMPERATURE ON THE SEA BASS (D. LABRAX) RESPONSIVENESS TO IN FIELD VACCINATION AGAINST VIBRIOSIS/PHOTOBACTERIOSIS
No full textRoutinely sea bass vaccination programs against Vibriosis/Photobacteriosis include the immersion of fish at 1–2 g in aqueous vaccine prior to transportation to floating cages, followed by an intraperitoneal (ip) administration of water-oil based vaccine at 20–25 g, which usually coincides with fish sizing. The most suitable period for the latter treatment would range from spring to summer, considering that the best antibody response both in terms of level and rapidity is detectable in sea bass immunized at 24°C (Cecchini & Saroglia, 2002). Still the time required to vaccinate all the farmed stocks sometimes exceeds the optimal period, and vaccination has to be carried even during winter season. For this reason, the objective of the present investigation was to explore the opportunity to get effective immune responses after a vaccination at sub-optimal temperatures (14°-16°C). The efficacy of the bivalent (Vibrio-Photobacterium) commercial vaccine AlphaJect 2000TM (Pharmaq AS) was assessed in the field (CROMARIS, Mala Lamjana Croatia), by submitting cage reared sea bass (size range 80-145 g) to sedation and ip vaccination (0.1 ml/fish) at different temperature ranges during autumn/winter/summer 2017-2018. Serum sampling was performed in each cage at T0 (intended as pre-vaccination control) and at 500° day post vaccination (this could vary between 32 and 38 days post vaccination, depending on the water T°). Parallel samplings were performed also in cages not submitted to vaccination. In detail, 30 randomly selected individuals/cage/sampling time were submitted to sedation and then sampled in order to obtain the serum. The specific antibodies (IgM) raised against one of the two target antigens (V. anguillarum O1), being part of the formulation, were determined by E.L.I.S.A. accordingly to the protocol of Galeotti et al., (2013). As far as we know there are not information on the vaccination effectiveness in sea bass against bacterial diseases (such as Vibriosis or Photobacteriosis) at different temperatures, and the present investigation represented a preliminary approach to this issue. The specific IgM titration performed on pre-vaccination samples showed their negativity (O.D. values often lower than those recorded in the “blank” wells, or negligible). The i.p. vaccination performed in winter months at temperatures near to 14-16°C triggered a synthesis of specific IgM to V. anguillarum O1 only in a limited number of individuals among those vaccinated, highlighting that there is an evident individual variability in terms of response to vaccination. If we exclude the limited role ascribable to non-appropriate vaccine provision, based on our findings we can assert that there is a relevant difference in the individual “immune efficiency” at low temperatures, possibly limiting the uniformity of fish batches responsiveness after the treatment. On the contrary the ip vaccination performed in summer, at temperatures ranging between 21,4-23,8 (average 22,6) promoted a remarkable synthesis of specific IgM to V. anguillarum O1 in almost all the fish under study, suggesting the requirement of specific (optimal) temperatures enabling fish to benefit from the immunization treatment
Effetto di diete integrate con carvacrolo su risposta immunitaria e resistenza a VIBRIO ANGUILLARUM del branzino (Dicentrarchus labrax)
No full textIl carvacrolo (2-metil-5-(1-metil)-fenolo), derivato fenolico contenuto in alta
percentuale negli oli essenziali di origano e timo (fam. Labiatae), è un additivo alimentare ufficialmente riconosciuto da FAO/WHO, Consiglio d’Europa, U.S. FDA, al quale sono attribuite funzioni di promotore della
crescita (animali da reddito), antimicrobico, anti-infiammatorio, immunomodulante (medicina umana e veterinaria).
La ricerca è stata finalizzata a valutare l'effetto dell’integrazione dietetica (0,025 e 0,05% della dieta) di carvacrolo sulle performances di crescita, sulla
risposta immunitaria umorale (proteine totali, immunoglobuline totali, attività del lisozima), sulla risposta immunitaria cellulare (fagocitosi, burst respiratorio, contenuto di perossidasi, pinocitosi) e sulla resistenza a Listonella (Vibrio) anguillarum sierotipo O1 nel branzino (Dicentrarchus labrax
).
Nove gruppi di giovanili di branzino (69,2 ± 0,22 g) sono stati mantenuti in condizioni controllate di allevamento e alimentati con le diete sperimentali per 9 settimane. L'inclusione di carvacrolo nella dieta non ha inciso negativamente sulla sopravvivenza dei pesci, sul comportamento alimentare, sulle performances di crescita, espresse come aumento di peso, tasso di
crescita specifico, fattore di conversione (P>0,05). Similmente, la somministrazione di carvacrolo non ha determinato differenze significative nel rendimento della carcassa, negli indici viscerosomatico ed
epatosomatico, nel tenore di grasso periviscerale (P>0,05). Il siero (10 sogg/dieta) e i leucociti di rene anteriore (5 sogg/dieta) sono stati prelevati dopo 1, 4 e 8 settimane di alimentazione. Le due dosi di carvacrolo hanno indotto una significativa diminuzione delle proteine, delle immunoglobul
ine e dell’attività del lisozima nel siero (P<0,01), hanno stimolato solo moderatamente la fagocitosi e la pinocitosi dei leucociti mentre non hanno modificato il contenuto di perossidasi dei leucociti. Nel corso della prova la produzione di ROS da parte dei leucociti è risultata minore nei branzini alimentati con il carvacrolo rispetto a quanto rilevato nei soggetti di controllo, e significativamente più bassa (P<0,05) in quelli alimentati per 7 giorni con la dose 0,05%. Questi risultati suggeriscono che il carvacr
olo somministrato con la dieta agisce come antiossidante, piuttosto che come promotore della risposta immunitaria aspecifica del branzino.
Dopo 8 settimane di alimentazione, i branzini sono stati sottoposti ad infezioni sperimentali per via intraperitoneale con L. (V.) anguillarum
(6x10 6 UFC/ml, 200 μl/sogg, >DL50; 2x10 6 UFC/ml, 200 μl/sogg, <DL
50). Come atteso, l’esposizione dei soggetti sperimentali alla dose infettante superiore alla DL50 non ha consentito di rilevare protezione nei confronti del patogeno, per entrambi i livelli di carvacrolo somministrati. Nel caso dell’infezione con dose inferiore alla DL50 il tasso di mortalità cumulativa nei pesci alimentati con entrambe le dosi di carvacrolo è risultato minore rispetto a quello dei soggetti non trattati. Il valore di RPS (percentuale relativa di sopravvivenza) era pari al 75% nei soggetti alimentati con carvacrolo allo 0,025% e al31% nei soggetti alimentati con carvacrolo allo 0,05%. La protezione conferita da questo derivato fenolico sembra dipendere principalmente dalla sua azione antibatterica, sebbene siano necessari ulteriori approfondimenti per spiegare l’apparente minore efficacia della dose più alta
Monitoraggio dell'espressione citochinica in corso di vaccinazione polivalente della spigola (Dicentrarchus labrax, L. 1758) contro Photobacterium damselae subsp. piscicida e Listonella anguillarum
No full textSea bass (Dicentrarchus labrax, L. 1758) is the most important fish species in the Mediterranean aquaculture and the fight against Vibriosis and Pasteurellosis is a prior objective for the economy in marine aquaculture. Vaccination would be an ideal tool to prevent these infectious diseases, but it still requires optimization. The study of the immune response induced by infection and vaccination is an important tool for evaluation of vaccine protocol efficacy. Cytokine expression analysis, in this respect, can provide a useful contribution to the study of the mechanisms involved in the immune response activated by infections and vaccinations.
This research was aimed to develop an assay for absolute quantification of 3 seabass cytokines and to apply it during polyvalent vaccination against Photobacterium damselae subsp. piscicida (Phdp) and Listonella anguillarum to measure immune response. The method has proved to be sensitive, reproducible and accurate for the quantification of mRNA coding IL-1β, IL-6 and IL-8 seabass cytokines. The analysis of cytokine gene expression during polyvalent vaccination against Phdp and L. anguillarum showed a correlation between cytokine gene upregulation and the percentage of survival after challenge with L. anguillarum in subjects vaccinated intraperitoneally suggesting the involvement of these cytokines in the immune mechanisms protecting the fish against this infection. Upregulation of the three cytokines investigated was also observed in the seabass during Phdp infection in analogy with what has been previously observed in other species. Further studies will be necessary to identify effective methods for the administration of polyvalent vaccine other than intraperitoneal route
- …
