Preliminary investigation on the microbiological quality of edible marine gastropods of the Adriatic Sea, Italy.

According to the European Legislation, marine gastropods placed unprocessed on the market must comply with the same requirements established for live bivalve molluscs but, being considered not filterfeeding and unable to concentrate fecal contaminants, they may be harvested outside the classified areas. Despite this statement, little scientific information is available on the microbiological quality of these animals. The aim of the present study was to investigate 28 batches of edible snails of the Adriatic Sea, namely Nassarius mutabilis and Bolinus brandaris, with respect to i) smell and viability, by a method here reported; ii) the bacterial component of the whole body referred to E. coli, Vibrio spp., V. parahaemolyticus, V. vulnificus, V. cholerae and V. alginolyticus. A total of 21 batches of N. mutabilis and 7 batches of B. brandaris were analyzed. Batches of both species retrieved from the primary production were all largely composed of viable animals, had saltwater/neutral smell, and showed mean value of Vibrio spp. of 5,34 and 5,79 log10 UFC g-1 in N. mutabilis and B. brandaris respectively. 47% of the batches of N. mutabilis retrieved from the market, were largely composed of dead animals, had acrid/nasty smell, and showed mean value of Vibrio spp. of 6,53 log10 UFC g-1. E. coli, V. vulnificus and V. cholerae were never detected, but all samples were positive for V. alginolyticus. One sample of B. brandaris was positive for V. parahaemolyticus genotyped by PCR at the specie level (ToxR+) and positive for the thermostable direct hemolysin gene (tdh+)

Indagine preliminare sulla componente batterica di gasteropodi marini eduli dell\u2019Adriatico

INDAGINE PRELIMINARE SULLA COMPONENTE BATTERICA DI GASTEROPODI MARINI EDULI DELL\u2019ADRIATICO Patrizia Serratore, Emanuele Zavatta, Giorgia Bignami, Luna Lorito Dipartimento di Scienze Mediche Veterinarie \u2013 Universit\ue0 di Bologna 1. Scopo Il Reg. CE 558/2010 dispone che la cattura dei gasteropodi marini, assimilati dal Reg. CE 853/2004 ai molluschi bivalvi vivi, pu\uf2 avvenire al di fuori delle aree classificare, in quanto non essendo filtratori non accumulano microrganismi contaminanti di origine fecale. Nonostante questo assunto, va rilevato che le conoscenze scientifiche sul microbiota dei gasteropodi marini eduli sono molto scarse, inoltre manca un metodo standardizzato per verificarne la vitalit\ue0 in commercio. Lo stesso Food and Veterinary Office comunitario rileva che i Controlli Ufficiali negli Stati membri risultano totalmente assenti o comunque inappropriati. Al fine di implementare le opportune pratiche ispettive, \ue8 necessario sviluppare indagini mirate sul piano della sicurezza alimentare di questi prodotti. Il presente studio offre un primo contributo di conoscenza sulla componente batterica associata a due specie dell\u2019Adriatico, Nassarius mutabilis e Bolinus brandaris, proponendo un metodo ispettivo per la verifica della vitalit\ue0. 2. Metodi Complessivamente sono stati analizzati 21 lotti di Nassarius mutabilis e 7 di Bolinus brandaris. La vitalit\ue0 \ue8 stata verificata mediante aspersione con sale da cucina, metodo messo a punto dal nostro laboratorio. Le unit\ue0 campionarie, dopo accurato risciacquo in acqua marina sterile, sono state sottoposte ad analisi batteriologiche: enumerazione di Vibrio spp., come componente autoctona, su Thiosulfate-Citrate-Bile salts-Sucrose Agar NaCl 3% finale, incubato a 20\ub0C per 3-5 gg; ricerca mirata di V. parahaemolyticus, V. vulnificus, V. cholerae e V. alginolyticus su CHROMagar Vibrio incubato a 37\ub0C per 24 h, e caratterizzazione fenotipica e genomica degli isolati (metodo interno); enumerazione di E. coli, come criterio di sicurezza, con metodo ISO 16649-2:2001. 3. Risultati Tutti i lotti acquisiti direttamente dal produttore hanno rivelato odore di salso o neutro e gli animali hanno reagito immediatamente all\u2019aspersione con sale con estroflessione del piede e movimenti attivi (Nassarius) o abbondante emissione di schiuma (Bolinus), presentando valori medi di Vibrio spp. simili, rispettivamente 5,34 log10 e 5,79 log10. Tra i lotti di Nassarius reperiti in commercio (N=17), il 47% (N=8) ha rivelato odore salso pungente o nettamente sgradevole, con reazione al sale molto scarsa o assente, presentando valori medi di Vibrio spp. pari a 6,53 log10. Tutti i campioni sono risultati negativi per E. coli, V. vulnificus e V. cholerae, ma positivi per V. alginolyticus. Un campione di Bolinus \ue8 risultato positivo per V. parahaemolyticus, con genotipo potenzialmente patogeno (ToxR+, tdh+). 4. Conclusioni I lotti di entrambe le specie reperiti alla produzione sono risultati tutti vitali, mentre il 47% dei lotti di Bolinus reperiti in commercio \ue8 risultato non conforme, in quanto composto in prevalenza o totalmente da individui morti. La mancata evidenziazione di E. coli pare giustificare il disposto del Reg. CE 558/2010. Tuttavia, i valori medi relativi a Vibrio spp. del prodotto vitale, ed ancor pi\uf9 del prodotto disvitale/morto, sono risultati superiori a quelli riscontrati nel bivalve R. philippinarum nel medesimo areale, pari a 4.69 log10. In termini di sicurezza alimentare, questa condizione di polimicrobismo in animali non filtratori necessita di ulteriori studi, sia in relazione ai target potenzialmente patogeni che in relazione ai possibili effetti del catabolismo batterico aspecifico in relazione alla produzione di amine biogene

Preliminary study on the antimicrobial susceptibility pattern related to the genotype of Vibrio vulnificus strains isolated in the north-western Adriatic Sea coastal area

V. vulnificus is a Gram-negative bacterium, commonly found in estuarine and coastal habitats, that can infect humans through seafood consumption or wound exposure. This study represents the first attempt to correlate the genotype of Vibrio vulnificus strains isolated in the north-western Adriatic Sea coastal area, with their antimicrobial susceptibility patterns. On the whole, 40 V. vulnificus strains, isolated from shellfish (n=20), different coastal water bodies (n=19), and the blood of a Carretta carretta turtle (n=1), were utilized. All strains were positive for the species-specific genes vvhA and hsp, with high variability for other markers: 55% (22 out of 40) resulted of the environmental (E) genotype (vcgE, 16S rRNA type A, CPS2 or CPS0), 10% (4 out of 40) of the clinical (C) genotype (vcgC, 16S rRNA type B, CPS1), and 35% (14 out of 40) of the mixed (M) genotype, possessing both E and C markers. The antimicrobial susceptibility was assayed by the diffusion method on agar, according to the Clinical Laboratory Standards Institute (CLSI), utilizing the following commercial disks (Oxoid): ampicillin (AMP), ampicillin- sulbactam (SAM), piperacillin (PRL), cefazolin (KZ), cefotaxime(CTX), ceftazidime( CAZ), imipenem (IPM), meropenem (MEM), amikacin (AK), gentamicin(CN), tetracycline(TE), ciprofloxacin (CIP), levofloxacin (LEV), trimethoprim-sulfamethoxazole (SXT), and chloramphenicol (C). 75% of the strains, (n=30) including all C strains, was sensitive to all the tested antibiotics, whereas E strains showed intermediate sensitivity to AK (2 strains), CIP and CAZ (1 strain), TE (1 strain) and resistance to KZ (1 strain), and 4 M strains showed I to AK

Preliminary study on the antimicrobial susceptibility pattern related to the genotype of Vibrio vulnificus strains isolated in the north-western Adriatic Sea coastal area

V. vulnificus is a Gram-negative bacterium, commonly found in estuarine and coastal habitats, that can infect humans through seafood consumption or wound exposure. This study represents the first attempt to correlate the genotype of Vibrio vulnificus strains isolated in the north-western Adriatic Sea coastal area, with their antimicrobial susceptibility patterns. On the whole, 40 V. vulnificus strains, isolated from shellfish (n=20), different coastal water bodies (n=19), and the blood of a Carretta carretta turtle (n=1), were utilized. All strains were positive for the species-specific genes vvhA and hsp, with high variability for other markers: 55% (22 out of 40) resulted of the environmental (E) genotype (vcgE, 16S rRNA type A, CPS2 or CPS0), 10% (4 out of 40) of the clinical (C) genotype (vcgC, 16S rRNA type B, CPS1), and 35% (14 out of 40) of the mixed (M) genotype, possessing both E and C markers. The antimicrobial susceptibility was assayed by the diffusion method on agar, according to the Clinical Laboratory Standards Institute (CLSI), utilizing the following commercial disks (Oxoid): ampicillin (AMP), ampicillin- sulbactam (SAM), piperacillin (PRL), cefazolin (KZ), cefotaxime(CTX), ceftazidime( CAZ), imipenem (IPM), meropenem (MEM), amikacin (AK), gentamicin(CN), tetracycline(TE), ciprofloxacin (CIP), levofloxacin (LEV), trimethoprim-sulfamethoxazole (SXT), and chloramphenicol (C). 75% of the strains, (n=30) including all C strains, was sensitive to all the tested antibiotics, whereas E strains showed intermediate sensitivity to AK (2 strains), CIP and CAZ (1 strain), TE (1 strain) and resistance to KZ (1 strain), and 4 M strains showed I to AK

First multi-year retrospective study on Vibrio parahaemolyticus and Vibrio vulnificus prevalence in Ruditapes philippinarum in Sacca di Goro, Italy

The present work describes a retrospective study aiming to verify a possible correlation between the environmental conditions (temperature, salinity and dissolved oxygen), the abundance of Vibrio spp., and the prevalence of V. parahaemolyticus and V. vulnificus in the Manila clam R. philippinarum harvested in Sacca di Goro, Emilia-Romagna Region, Northern Italy. On the whole, 104 samples, collected in the period 2007-2015 and submitted to microbiological analyses (isolation and genotyping), have been reconsidered for Vibrio spp. load, V. parahaemolyticus prevalence (total, gene marker toxRP; potentially pathogenic, gene markers tdh and/or trh) and V. vulnificus prevalence (total, gene markers vvhA and hsp) together with environmental data obtained from the monitoring activity of the Emilia-Romagna Regional Agency for the prevention, the environment and the energy (ARPAE). Environmental data have been processed to calculate the median of each, assessing the seasonal range of seawater temperature (warmer months: April-October, T\ub0C >16.45\ub0C; cooler months November-March, T\ub0C 27 psu), and dissolved oxygen (8.2 mg/L). Total V. vulnificus, total and potentially pathogenic V. parahaemolyticus were present respectively in the 11,5%, 29,8% and 6,7% of the samples. The Vibrio spp. load (mean value of 4.69\ub10.65 log10 CFUg-1) and the prevalence of potentially pathogenic V. parahaemolyticus, were not significantly correlated to the environmental conditions (P>0.05), whereas the prevalence of both total V. vulnificus and total V. parahaemolyticus was significantly higher in the warmer period (P0.05)