| Abstrakt: |
Vibriospp. have emerged as a serious threat to human health worldwide. V. parahaemolyticus, V. cholerae, and V. vulnificuspose a considerable public health risk in Tunisia because they cause sporadic and epidemic foodborne infections associated with the consumption of raw or undercooked contaminated seafood. More recently, toxR-positive V. alginolyticuswas also reported to be a potential source of contaminated seafood. A total of 247 samples, including 113 fishes (Labrus viridis, Penaeus kerathurus, Diplodus annularis, Diplodus sparaillon, Scorparna porcus, Sarpa salpa, Dentex dentex, Scorparna scrofa, Sardinella aurita, Trachurus trachurus, Synodus saurus, Pagellus erythrinus, and Metapenaeus monoceros), 83 clams (Ruditapes decussatusspecies), 30 seawater samples, and 21 sediment samples were analyzed using traditional culture methods (ISO/TS 21872-1; International Organization for Standardization 2007) and a conventional PCR method for Vibriospp. identification. A rapid, sensitive, and highly reproducible real-time PCR assay was developed to detect the three major Vibriospp. pathogenic for humans in Tunisian seafood products and sediments. A conventional culture method found 102 (41.3%) of 247 analyzed samples positive for Vibriospp.; a conventional PCR method found 126 (51%) of the 247 samples positive. Real-time PCR assay found 126 (51.1%) samples positive; V. alginolyticustoxRwas the most common, found in 99 (78.57%) of samples, followed by V. parahaemolyticusin 26 (20.63%) and V. choleraein 1 (0.7%). All culture-positive samples were PCR positive. However, 24 samples that were positive by conventional PCR and real-time PCR were culture negative. Our findings indicate that retail seafood is commonly contaminated with Vibriospp. and presents a potential risk to human health in Tunisia. These data also indicate that real-time PCR can provide sensitive species-specific detection of Vibriospp. in seafood without prior isolation and characterization of the bacteria by traditional microbiological methods. |
