Seafood products are widely consumed all around the world and play a significant role on the economic market. Bacteria of the Vibrio genus can contaminate seafood and thus pose a risk to human health. Three main Vibrio species, V. cholerae, V. parahaemolyticus and V. vulnificus, are potentially pathogenic to humans. These species are responsible for a dramatic increase of seafood-borne infections worldwide. Hence, early detection of total and pathogenic Vibrio is needed and should rely on quick and effective methods. This review aims to present the standard methods FDA-BAM, ISO/TS 21872–1:2007 and TS 21872–2:2007 and compare them to recent molecular biology methods including endpoint PCR, quantitative real-time PCR (qPCR) and PCR-derived methods with a focus on LAMP (loop-mediated isothermal amplification). The available methods presented here are dedicated to the detection and identification of the Vibrio species of interest in seafood.

Analysis of the genetic locus encompassing a cell wall polysaccharide (CWPS) biosynthesis operon of eight strains of Lactococcus lactis , identified as belonging to the same CWPS type C genotype, revealed the presence of a variable region among the strains examined. The results allowed the identification of five subgroups of the C type named subtypes C ₁ to C ₅ . This variable region contains genes encoding glycosyltransferases that display low or no sequence homology between the subgroups. In this study, we purified an acidic polysaccharide from the cell wall of L. lactis 3107 (subtype C ₂ ) and confirmed that it is structurally different from the previously established CWPS of subtype C ₁ L. lactis MG1363. The CWPS of L. lactis 3107 is composed of pentasaccharide repeating units linked by phosphodiester bonds with the structure 6-α-Glc-3-β-Gal f -3-β-GlcNAc-2-β-Gal f -6-α-GlcNAc-1- P . Combinations of genes from the variable region of subtype C ₂ were introduced into a mutant of subtype C ₁ L. lactis NZ9000 deficient in CWPS biosynthesis. The resulting recombinant mutant synthesized a polysaccharide with a composition characteristic of that of subtype C ₂ L. lactis 3107 and not wild-type C ₁ L. lactis NZ9000. By challenging the recombinant mutant with various lactococcal phages, we demonstrated that CWPS is the host cell surface receptor of tested bacteriophages of both the P335 and 936 groups and that differences between the CWPS structures play a crucial role in determining phage host range . IMPORTANCE Despite the efforts of nearly 80 years of lactococcal phage research, the precise nature of the cell surface receptors of the P335 and 936 phage group receptors has remained elusive. This work demonstrates the molecular nature of a P335 group receptor while bolstering the evidence of its role in host recognition by phages of the 936 group and at least partially explains why such phages have a very narrow host range. The information generated will be instrumental in understanding the molecular mechanisms of how phages recognize specific saccharidic receptors located on the surface of their bacterial host.

The ability to form biofilms is important for environmental survival, transmission, and infectivity of Vibrio cholerae, the causative agent of cholera in humans. To form biofilms, V. cholerae produces an extracellular matrix composed of proteins, nucleic acids and a glycoconjugate, termed Vibrio exopolysaccharide (VPS). Here, we present the data on isolation and characterization of the polysaccharide part of the VPS (VPS-PS), which has the following structure: where α-D-Glc is partially (∼20%) replaced with α-D-GlcNAc. α-GulNAcAGly is an amide between 2-acetamido-2-deoxy-α-guluronic acid and glycine. Apparently, the polysaccharide is bound to a yet unidentified component, which gives it high viscosity and completely suppresses any NMR signals belonging to the sugar chains of the VPS. The only reliable method to remove this component at present is a treatment of the whole glycoconjugate with concentrated hydrochloric acid.