Surgical implantation of electronic tags does not induce medium-term effect: insights from growth and stress physiological profile in two marine fish species

Abstract Background Telemetry applied to aquatic organisms has recently developed greatly. Physiological sensors have been increasingly used as tools for fish welfare monitoring. However, for the technology to be used as a reliable welfare indicator, it is important that the tagging procedure does not disrupt fish physiology, behaviour and performance. In this communication, we share our medium-term data on stress physiological profile and growth performance after surgical tag implantation in two important marine fish species for European aquaculture, the sea bream (Sparus aurata) and the European sea bass (Dicentrarchus labrax). Results Blood samples after surgical tag implantation (46 days for the sea bream and 95 days for the sea bass) revealed no differences between tagged and untagged fish in cortisol, glucose and lactate levels, suggesting that the tag implantation does not induce prolonged stress in these species. Moreover, the specific growth rates were similar in the tagged and untagged fish of both species. Conclusion Surgical tag implantation does not have medium-term consequences for the stress physiology and growth performance of these two marine fish species in a controlled environment. These observations support the use of accelerometer tags as valuable tools for welfare monitoring in aquaculture conditions. This study also shows that tagged fish can be sampled during experiments and considered a representative portion of the population, as they display growth and physiological parameters comparable to those of untagged fish

High incidence of antibiotic multi-resistant bacteria in coastal areas dedicated to fish farming

Marine bacteria exposed to antibiotics in fish farms can acquire antimicrobial resistance by mobile genetic elements and horizontal gene transfer. A total of 872 autochthonous marine bacterial strains was isolated from samples collected from four different fish farms located at northern and southern Italian Adriatic Sea. Resistance to only tetracycline (17%) and to trimethoprim–sulfadiazine (7%) were the most frequent patterns obtained, while flumequine resistance has recorded in only 0.3% of the strains. Comparing strains isolated from coastal areas and fish farms, a significant higher incidence (4% versus 10%) of multi-resistant strains in aquaculture centers was found. Significant differences in antibiotic resistance incidence were also detected among the four fish farms due probably to different approaches in farm management and the more or less frequent use of antibiotics. Antibiotic-resistant and multiresistant strains isolated constitute an environmental reservoir directly involved in the seafood chain and might represent a public health concern

Genomic Sequencing of Ranaviruses Isolated from Edible Frogs (Pelophylax esculentus)

Ranaviruses were isolated from wild edible frogs (Pelophylax esculentus)during epizootics in Denmark and Italy. Phylogenomic analyses revealed that these isolates are closely related and belong to a clade of ranaviruses that includes the Andrias davidianus ranavirus (ADRV), common midwife toad ranavirus (CMTV), Testudo hermanni ranavirus (THRV), and pike-perch iridovirus (PPIV)

Farmed fish welfare during slaughter in Italy: survey on stunning and killing methods and indicators of unconsciousness

Information on slaughter procedures for farmed fish in aquaculture is limited, both in Europe and in Italy, due to a general lack of field data. The aim of this study was to gather information on the procedures used to slaughter fish in Italy and to discuss them considering the WOAH and EFSA recommendations on fish welfare. Using a questionnaire survey, data were collected by official veterinarians in 64 slaughtering facilities where 20 different species of fish were slaughtered. The main species slaughtered were rainbow trout (Oncorhynchus mykiss; 29/64), followed by European sea bass (Dicentrarchus labrax; 21/64), sea bream (Sparus aurata; 21/64), Arctic char (Salvelinus alpinus; 14/64), European eel (Anguilla anguilla; 11/64), sturgeon (Acipenser spp; 11/64), common carp (Cyprinus carpio; 6/64), and brown trout (Salmo trutta fario L.; 5/64). The most applied stunning/killing methods were “asphyxia in ice/thermal shock” and “electric in water bath,” followed by “percussion,” “asphyxia in air,” and “electric dry system.” After the application of the method, the assessment of the fish level of unconsciousness was practiced in 72% of the facilities using more than one indicator, with “breathing” and “coordinated movements” the most practiced. The collected data showed a discrepancy between the available recommendations about the welfare of fish at slaughter and what is practiced in many production sites, but for many species precise recommendations are still not available

Epidemiological cut-off values for Vibrio anguillarum MIC and disc diffusion data generated by standardised methods

This work aims to generate the data needed to set epidemiological cut-off values for minimum inhibitory concentration (MIC) and disc-diffusion zone measurements of Vibrio anguillarum. A total of 261 unique isolates were tested, applying standard methods specifying incubation at 28°C for 24−28 h. Aggregated MIC distributions for a total of 247 isolates were determined in 9 laboratories for 11 agents. Data aggregations of the disc zone for the 10 agents analysed contained between 157 and 218 observations made by 4 to 7 laboratories. Acceptable ranges for quality control (QC) reference strains were available for 7 agents and the related multi-laboratory aggregated data were censored, excluding the data of a laboratory that failed to meet QC requirements. Statistical methods were applied to calculate epidemiological cut-off values. Cut-off values for MIC data were calculated for florfenicol (≤1 μg ml−1), gentamicin (≤4 μg ml−1), oxytetracycline (≤0.25 μg ml−1) and trimethoprim/sulfamethoxazole (≤0.125/2.38 μg ml−1). The cut-off values for disc zone data were calculated for enrofloxacin (≥29 mm), florfenicol (≥27 mm), gentamicin (≥19 mm), oxolinic acid (≥24 mm), oxytetracycline (≥24 mm) and trimethoprim/sulfamethoxazole (≥26 mm). MIC and disc-diffusion zone data for the other agents where not supported by QC, thus yielding only provisional cutoff values (meropenem, ceftazidime). Regardless of whether QC is available, some of the aggregated MIC distributions (enrofloxacin, oxolinic acid), disc zone (sulfamethoxazole), and MIC and disc-diffusion distributions (ampicillin, chloramphenicol) did not meet the statistical requirements. The data produced will be submitted to the Clinical Laboratory Standards Institute for their consideration in setting international consensus epidemiological cut-off values.publishedVersio

Valutazione dell\u2019antibiogramma mediante un sistema inpiastra di isolati di Lactococcus garvieae da trote iridea(Oncorhynchus mykiss) allevate nel Nord Italia

SUMMARY \u2013 Lactococcosis due to Lactococcus garvieae is presently the most important bacterial disease in rainbow trout (Oncorhynchus mykiss) reared in Italy. Although good results have been obtained with vaccination, it is often necessary to use pharmaceuticals. Howere unsatisfactory results are often obtained as a result of the increasing resistance of this pathogen to antibiotic therapy. The aim of this work was to antibiogram evaluation by a plate system of some veterinarian chemotherapeutics (Enrofloxacin, Gentamicin, Ceftiofur, Neomycin, Erythromycin, Oxytetracycline, Tetracycline, Amoxicillin, Spectinomycin, Sulphadimetoxin, Sulphamethoxazole + Trimethoprim, Sarafloxacin, Sulphathiazole, Penicillin, Streptomycin, Novobiocin, Tylosine, Clindamycin) against 50 L. garvieae isolates obtained from North Italian trout farms from 1993 to 2004. All isolates were resistant to Sulphonamides, Tylosine and Sarafloxacin, while good results were obtained with Erythromycin and beta lactams (Amoxicillin and Penicillin). Our results offer some indications about the best chemotherapeutics most likely to be efficient feed when a disease outbreak is occurs

Occurrence and molecular characterisation of Vibrio parahaemolyticus in crustaceans commercialised in Venice area, Italy

Infections due to the pathogenic human vibrios, Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus, are mainly associated with consumption of raw or partially cooked bivalve molluscs. At present, little is known about the presence of Vibrio species in crustaceans and the risk of vibriosis associated with the consumption of these products. The aim of the present study was to evaluate the prevalence and concentration of the main pathogenic Vibrio spp. in samples of crustaceans (n = 143) commonly eaten in Italy, taking into account the effects of different variables such as crustacean species, storage conditions and geographic origin. Subsequently, the potential pathogenicity of V. parahaemolyticus strains isolated from crustaceans (n = 88) was investigated, considering the classic virulence factors (tdh and trh genes) and four genes coding for relevant proteins of the type III secretion systems 2 (T3SS2 alpha and T3SS2 beta). In this study, the presence of V. cholerae and V. vulnificus was never detected, whereas 40 samples (28%) were positive for V. parahaemolyticus with an overall prevalence of 41% in refrigerated products and 8% in frozen products. The highest prevalence and average contamination levels were detected in Crangon crangon (prevalence 58% and median value 3400 MPN/g) and in products from the northern Adriatic Sea (35%), with the samples from the northern Venetian Lagoon reaching a median value of 1375 MPN/g. While genetic analysis confirmed absence of the tdh gene, three of the isolates contained the trh gene and, simultaneously, the T3SS2 beta genes. Moreover three possibly clonal tdh-negative/trh-negative isolates carried the T3SS2 alpha apparatus. The detection of both T3SS2 alpha and T3SS2 beta apparatuses in V. parahaemolyticus strains isolated from crustaceans emphasised the importance of considering new genetic markers associated with virulence besides the classical factors. Moreover this study represents the first report dealing with Vibrio spp. in crustaceans in Italy, and it may provide useful information for the development of sanitary surveillance plans to prevent the risk of vibriosis in seafood consumers

MANUALE PER LA GESTIONE DEL CONTROLLO DEL BENESSERE DEI PESCI DURANTE IL TRASPORTO SU STRADA: REGOLAMENTO n. 1/2005 CE del Consiglio, del 22 Dicembre 2004 sulla protezione degli animali durante il trasporto e le operazioni correlate

L’acquacoltura ha sempre rappresentato un’importante attività di allevamento animale e mai come oggi ha assunto un’importanza crescente dovuta ad una sempre maggior domanda di consumo annuo pro capite di pesce che, tuttavia, ha comportato una contestuale diminuzione dell’apporto della pesca. La movimentazione di pesce vivo è parte integrante della attività di piscicoltura in tutta Europa.   Negli ultimi decenni in Italia l’allevamento del pesce e di altre specie acquatiche è stato in costante aumento, stabilizzandosi solo negli ultimi anni. Si è registrato un sempre maggiore interesse alle pratiche di acquacoltura utilizzate e ai relativi problemi di benessere dei pesci da parte del legislatore, nel campo della ricerca e da parte dei consumatori. I dati dimostrano che l’acquacoltura è un settore in crescita: nell’anno 2016 sono stati trasportati e introdotti in Italia oltre 72 milioni di Kg. di pesce vivo (35.5% trote – 14.6% spigole e orate – 4% pesce gatto e anguille) e si prevede che a livello mondiale nel 2030 il 60% del pesce consumato sarà di allevamento. In Italia le specie più trasportate sono le orate, le spigole nelle fasi giovanili e le trote.   La maggior parte delle specie di pesce che sono allevate vengono spostate almeno una volta durante il loro ciclo produttivo, mentre alcuni animali vengono movimentati più volte. In acquacoltura sono allevate e trasportate oltre 60 specie diverse di pesci (oltre 30 specie in Europa). Se ne deduce che quantità di animali trasportati e la e la lunghezza durata del viaggio possono variare considerevolmente, in funzione del ciclo produttivo e delle necessità commerciali, che talvolta possono cambiare anche nel corso dello stesso anno. Il trasporto dei pesci è forse il più difficile e delicato rispetto alle altre specie di vertebrati, per cui ne deriva che un piccolissimo errore nelle varie fasi di trasporto ne comprometterebbe il benessere degli animali nonché una perdita economica nel settore.   L’azione di protezione e di mantenimento delle condizioni di benessere del pesce vivo durante le operazioni di trasporto, che dovrebbe essere un dovere morale dell’allevatore e/o autotrasportatore, è un obbligo sancito dalla legislazione vigente e comporta una responsabilità legale sia degli operatori del settore, sia delle autorità competenti preposte ai controlli, le quali devono avere una alta professionalità e competenza nel corso delle operazioni ispettive e di vigilanza. Nelle attività di trasporto del pesce, è necessario eseguire le operazioni secondo specifici protocolli operativi, allo scopo di non pregiudicare lo stato di salute e indirettamente anche il valore economico degli animali oggetto di movimentazione. E’ rilevante quindi che gli operatori e il personale addetto siano formati e preparati per garantire ai pesci un trasporto senza stress. A tal proposito è importante sottolineare l’importanza fondamentale della figura del veterinario, il quale rappresenta oggi la sola figura professionale e con competenze scientifiche a cui la legge attribuisce il compito-dovere di verifica e di controllo delle condizioni degli animali e dei loro prodotti, nello specifico anche del pesce, ivi compresi i provvedimenti a tutela della protezione del benessere dell’animale durante il trasporto e che comportano, inoltre, anche la valutazione delle condizioni di dolore, stress, o sofferenze evitabili nel corso delle operazioni. Con il presente ‘Manuale’, vengono riportate una serie di misure specifiche da applicare nella gestione del trasporto su strada del pesce vivo, al fine di definire ed individuare le condizioni ottimali di benessere nel corso delle movimentazioni