Search

Antibacterial therapy is still in many cases the only way to control bacterial disease outbreaks, with relevant economic issues. Nevertheless, this necessity should also be well balanced with other relevant aspects such as suitability, efficacy and refinement of the treatments but also with consumer and environmental welfare. With this aim, the literature pertaining to the use of antibacterials (i.e. oxytetracycline, oxolinic acid, flumequine and potentiated sulphonamides) in Mediterranean farmed European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) was reviewed and addressed. Knowledge of drug pharmacokinetics along with the related legislation is also presented. The main criteria, technical aspects and constraints affecting the design of an appropriate antibacterial therapy are also discussed. An evaluation of available bibliography revealed the existence of considerable information on several registered antibacterials, while it is limited for others. Typically, minimum inhibitory concentrations (MIC) have been used as a reference for antibacterial selection. However, the methodologies used for MIC assessment require refinement and more sophisticated data such as epidemiological cut‐off breakpoint values. Due to the characteristics of farming systems, antibacterials are mostly delivered through medicated feeds. The large number of production units and number of fish per unit, together with a limited timeframe margin for efficient therapy, makes Mediterranean gilthead seabream and European seabass, one of the best examples where the metaphylactic concept has to be considered in aquatic medicine. The information presented in this review should guide future action taken to fulfil research gaps and promote effective and prudent antibacterial practices.

This is the first report of Arcobacter spp. in rectal fecal samples from healthy water buffaloes (Bubalus bubalis) reared on a dairy farm. Arcobacter species were isolated after enrichment, and isolates were identified at species level by multiplex-polymerase chain reaction assay. Thirty samples were examined and Arcobacter spp. were isolated from 96.7% of water buffaloes tested: 38 Arcobacter spp. isolates were obtained, with A. cryaerophilus as the dominant species followed by A. butzleri and A. skirrowii. Nine animals (31%) were colonized by more than one Arcobacter species. The present study indicates that water buffaloes can harbor a variety of Arcobacter spp. and that healthy buffaloes may act as hosts. Water buffalo fecal shedding of Arcobacter spp. may be of significance to human health, considering the potential fecal contamination during harvesting of raw milk and slaughtering.

This study investigated the presence of Arcobacter species in two cheese factories; a total of twentytwo environmental samples and ten food samples were collected from an artisanal and an industrial cheese factory; Arcobacter species were isolated after enrichment, and isolates were identified at species level by multiplex-polymerase chain reaction assay. In the artisanal cheese factory Arcobacter spp. were isolated from several environmental samples, cow and water buffalo raw milk and ricotta cheese. In the industrial plant Arcobacter spp. were isolated from surfaces not in contact with food and from a cleaned surface in contact with food; no Arcobacter spp. was isolated from food. All isolates were identified as A. butzleri. To our knowledge this is a first report of the presence of A. butzleri in a ready to eat cheese produced for retail and, in addition, the isolation of A. butzleri in food processing surfaces in the two cheese factories could be assessed as a source of potential contamination for cheeses.

Il presente studio ha valutato la presenza di specie di Arcobacter in due caseifici; ventidue campioni ambientali e dieci campioni alimentari sono stati raccolti presso un caseificio artigianale ed uno industriale; la ricerca di Arcobacter spp. è stata effettuata tramite arricchimento e gli isolati sono stati identificati mediante multiplex-PCR. Ceppi di Arcobacter spp. sono stati isolati, nel caseificio artigianale, in numerosi campioni ambientali, di latte crudo vaccino e bufalino e ricotta mentre, nello stabilimento industriale, in alcuni campioni di superfici a contatto e non a contatto con alimenti; nessun Arcobacter spp. è stato rilevato in campioni alimentari. Tutti gli isolati sono stati identificati come A. butzleri. Il presente studio è il primo report della presenza di A. butzleri in un formaggio pronto per la vendita al dettaglio; l'isolamento di A. butzleri in superfici di lavorazione di entrambi i caseifici potrebbe essere una potenziale fonte di contaminazione per la produzione di formaggi.

The safety of raw milk sold in Northern Italy was investigated in relation to hygiene quality parameters and presence of Salmonella spp., Listeria monocytogenes, thermotolerant Campylobacter, and Verocytotoxin producing Escherichia coli O157:H7. The performance of different analytical methods used—official culture method (ISO), modified Bacteriological Analytical Manual cultural method (mBAM), and polymerase chain reaction (PCR)— was evaluated. The presence of Mycobacterium avium subsp. paratuberculosis (Map) was investigated only by PCR. All samples met regulations for alkaline phosphatase and inhibitory substance, while 18% and 44.8% of samples collected from vending machines had, respectively, somatic cell count (SCC) > 300,000/mL and total bacterial count (TBC) > 50,000CFU/mL. The correlation between hygienic quality parameters in samples collected from bulk tank and vending machines showed a significant increase of TBC in vending machines meaning that raw milk was mishandled during distribution and sale. All pathogens investigated were detected in raw milk sold at vending machines; a total of five samples (5%) had at least one pathogen, of which two were detected by PCR and three by mBAM. None of the samples was positive by cultural ISO methods. Even if the comparison of analytical methods showed that none performs significantly better than the others, testing a higher volume of milk (25 versus 210 mL) affects significantly the detection rate of pathogens. Three samples (3%) were positive for Map, suggesting that raw milk is a significant source of Map exposure for consumers. The observed TBC increase and the detection of several pathogenic bacteria pose questions on the safety of raw milk; the use of ISO seems inefficient in detecting a low contamination level of pathogens in milk and consequently not appropriate as official method for testing. In order to ensure consumer’s safety, a new approach for the raw milk chain is required.

Aim: To report the growth of glucosidase and phospholipase positive bacteria on agar Listeria according to Ottaviani and Agosti (ALOA) different from Liste- ria monocytogenes, Listeria ivanovii and Bacillus cereus. Methods and Results: Raw water-buffalo milk was analysed according to EN ISO 11290. Streaking of Fraser broth on ALOA resulted in green colonies with an opaque halo after 48 h at 30°C. Colonies were transferred onto Tryptone soya yeast extract agar and showed cultural characteristics atypical for L. mono- cytogenes. Results of confirmation tests according to EN ISO 11290 method: negative haemolysis test, weak positive camp test in correspondence with Sta- phylococcus aureus, no fermentation of rhamnose, fermentation of xylose. Gram staining showed tapered, curved, Gram-positive rods with subterminal to ter- minal ellipsoidal spores, 0Æ5–0Æ7 lm diameter 4–5 lm. API 50CH CHB kit (99Æ9% percentage of identification) and the sequence of the 833 bp PCR prod- uct (portion of 16S rRNA, generic primers 1492-r; p27-f) showed 97% identity with Bacillus circulans ATCC 4513 (GenBank AY724690). Conclusions: Some B. circulans strains can grow on ALOA, according to ISO 11290, confirmation tests readily differentiate B. circulans from L. monocytogenes. Significance and Impact of the Study: The different morphology of the colo- nies must be kept in mind to select true L. monocytogenes for confirmation test and to avoid overestimation of L. monocytogenes count.

L’intensificazione delle attività di maricoltura, intese sia come produzioni d’avannotteria sia come produzioni d’ingrasso, comporta il frequente verificarsi di condizioni predisponenti l’emergenza di malattie diffusive, fra cui in primis quelle di natura batterica. Per tale motivo nelle specie ittiche allevate nel bacino del Mediterraneo, nonostante le patologie batteriche di maggior impatto economico vengano riferite ad un numero ristretto di agenti eziologici [es. Photobacterium damselae subsp. piscicida, Listonella (Vibrio) anguillarum e Tenacibaculum maritimum], si sta registrando una crescente attenzione verso quegli agenti batterici patogeni opportunisti o non usuali che possono determinare malattia sotto la spinta di fattori ambientali e gestionali predisponenti. A tale proposito si segnalano alcuni episodi di malattia osservati nel periodo 2009-2011 in spigole (Dicentrarchus labrax) ed orate (Sparus aurata) allevati in Italia, nel corso dei quali sono state isolate specie batteriche fino ad oggi ritenute di non comune riscontro nella maricoltura nazionale, quali in particolare Vibrio splendidus, V. harveyi, V. mediterranei, Shewanella putrefaciens, Aeromonas salmonicida subsp. salmonicida e A. sobria. Vengono riportate le osservazioni cliniche e anatomopatologiche correlate agli episodi morbosi presi in considerazione. Vibrio splendidus è stato isolato in una decina di casi in corso di episodi di mortalità larvale verificatisi in spigole ed orate in diverse avannotterie italiane e, sempre a livello sistemico, anche da spigole di taglia commerciale che mostravano mortalità a stillicidio in presenza di grave malattia branchiale, ascite, splenomegalia ed ectasia del tratto gastro-intestinale. Già segnalato quale agente causale di gravi episodi patologici in larve di merluzzo (Gadus morhua) e rombo (Psetta maxima) allevati rispettivamente in Norvegia ed in Spagna, V. splendidus potrebbe quindi avere un ruolo eziologico di rilievo nel determinismo di malattia anche in pesci marini mediterranei. L’isolamento di Vibrio harveyi è stato condotto a livello cutaneo e sistemico da due riproduttori di spigola che presentavano al decesso gravi lesioni cutanee quali ulcere profonde ed estese aree necrotiche, similmente a quanto già riportato in recenti segnalazioni condotte nel Mediterraneo su orate e spigole. Shewanella putrefaciens è stata isolata a livello sistemico in due casi, sia da avannotti che da soggetti adulti di spigola che presentavano concomitanti infezioni parassitarie (es. parassitosi branchiali da Ichthyobodo sp.) o batteriche. Sebbene descritto quale agente patogeno opportunista soprattutto in pesci dulciacquicoli, questo microrganismo è stato segnalato recentemente quale agente di malattia anche in pesci marini d’allevamento. Di particolare interesse appare l’isolamento di Aeromonas salmonicida subsp. salmonicida nel corso di un episodio morboso osservato in spigole adulte allevate a terra che presentavano lieve mortalità, splenomegalia e congestione cerebrale. Parallelamente, la stessa specie è stata isolata da giovanili di spigola allevati in gabbia in Croazia che presentavano splenomegalia associata a moderata mortalità. Ben descritto quale agente patogeno in salmonidi allevati sia in acqua dolce sia in mare e nel rombo allevato in areali atlantici, A. salmonicida subsp. salmonicida potrebbe rappresentare un futuro fattore di rischio sanitario per la maricoltura mediterranea. Sono poi da segnalare alcuni isolamenti di A. sobria, A. veronii biovar veronii e V. mediterranei condotti in corso di episodi morbosi registrati in situazioni di elevata densità di biomassa e/o di concomitanti fattori stressanti di natura ambientale che hanno rappresentato senz’altro importanti condizioni predisponenti l’insorgenza della malattia. Obiettivo comune dei laboratori diagnostici e di ricerca operanti nel campo dell’ittiopatologia in Italia dovrebbe essere quello di raccogliere e conservare gli isolati di questi “potenziali patogeni emergenti” al fine di condurne la caratterizzazione geno-fenotipica ai fini epidemiologici, studiarne i fattori di virulenza e patogenicità e monitorarne l’eventuale profilo di antibiotico resistenza.

The European INCO-DEV BOMOSA Project (Integrating BOMOSA cage fish farming systems in reservoirs, ponds and temporary water bodies in Eastern Africa) intends to establish small scale fish farming in marginal water bodies in Kenya, Uganda and Ethiopia, creating rural aquaculture networks with the aim to economically integrate aquaculture with agriculture. In order to study veterinary and public health aspects in Bomosa fish farming systems, a parasitological survey on wild and cultured tilapias (Oreochromis niloticus niloticus) has been carried out from March 2007 to October 2008. A total of 982 tilapias - 685 from Kenya, 222 from Uganda and 75 from Ethiopia - were sampled and subjected to complete parasitological examination. During the survey, fish from different environments (258 from open water reservoirs, 445 from ponds and 279 from BOMOSA cages) were sampled in order to evaluate the factors which could influence the parasite diffusion and outbreak of diseases. Quantitative data, such as prevalence, intensity and abundance, and qualitative data are presented together with the main abiotic and biotic risk factors identified as relevant for veterinary and public health aspects in tilapia aquaculture.

The atypical mycobacteriosis should be considered zoonotic agents, since they can penetrate through skin wounds and abrasions, causing the formation of granuloma in the skin. The purpose of this work is to evaluate the susceptibility to certain antibiotics of Mycobacterium marinum, one of the most important zoonosis agent among non-tuberculous mycobacteria. All strains were susceptible to ethanbutol, while only 6 were sensitive to rifampicin. 90% of strains were resistant to isoniazid, while 8 strains out of 10 were resistant to streptomycin.

Silurus glanis or European catfish belongs to the family Siluridae. It eat mainly fish, but also crustaceans, annelids, and insect larvae. From February 2007 to February 2009 105 samples of European catfish from the Po River were examined. Bacteriological examination was performed, the bacterium most frequently isolated was Aeromonas hydrophila. The presence of European catfish in our rivers is a threat to the indigenous populatins of fish and could alter the environmental balance, leading to a reduction in the number of species and individuals.

During 2007-2008 a survey aimed to investigate the diffusion of mycobacteria infections in Italian aquaculture was carried out. A total of 565 farmed fish, coming from 45 marine and freshwater farming systems, were examined. Mycobacterium marinum was isolated from striped bass showing symptoms and lesions referable to mycobacteriosis, and from European sea bass showing only histological lesions. Furthermore M. gordonae was isolated from 1 carp, M. fortuitum from i Siberian sturgeon and 1 rainbow trout, and Mycobacterium spp. from 2 European sea bass, always without macroscopical and microscopical lesions referable to mycobacteriosis.