Virulence‐associated factors in Vibrio cholerae non‐O1/non‐O139 and V. mimicus strains isolated in ornamental fish species

Abstract

During recent decades, ornamental fish have proven to be one of the fastest growing categories of pets in Europe. In this framework, we evaluated both the potential pathogenic and zoonotic risks caused by 53 Vibrio cholerae non-O1/non-O139 and a Vibrio mimicus strain isolated from ornamental fish species mostly originating from South-East Asia countries between 2000 and 2015 in Italy. All the strains were firstly identified at species level by biochemical, phylogenetic and mass spectrometry (matrix-assisted laser desorption ionization time of flight) methods, and then studied to reveal the presence of the main virulence and colonization-associated factors, as ctxA, ace, zot, stn/sto, toxR, rtxA, hlyA and tcpA by multiplex and single endpoint PCR assays. Findings showed that 21 of 54 strains harboured at least one virulence factor with a predominance for the toxR , rtxA and hlyAET genotype. Interestingly, the V. mimicus strain harboured the colonization factor and the CTX prophage receptor, tcpA, indicating the ability to capture and integrate it in its genome increasing its pathogenicity. Although these enterotoxins can sporadically cause gastroenteritis, the results highlight their probable involvement in causing severe implications for public health, suggesting the need for an European microbiological monitoring.

Virulence, antimicrobial and heavy metal tolerance, and genetic diversity of Vibrio cholerae recovered from commonly consumed freshwater fish

“…Continuous monitoring of V. cholerae contamination in aquatic products and identification of risk factors (e.g., virulence and transmissibility of antimicrobial resistance and heavy metal tolerance) are crucial for assuring food safety. To date, a few studies have been conducted to characterize V. cholerae in fish (Lan and Love 2012; Runft et al 2014; Senderovich et al 2010; Traore et al 2014; Zago et al 2017). In this study, V. cholerae was isolated and characterized from the four commonly consumed freshwater fish ( A .…”

Simple Visualized Detection Method of Virulence-Associated Genes of Vibrio cholerae by Loop-Mediated Isothermal Amplification

“…To date, many methods have been developed for effective detection of O1/O139 V. cholerae contamination in food. Compared with the conventional culture-based microbiological detection assays, molecular biology-based methods are more rapid and sensitive, such as PCR (Kumar et al, 2010;Zago et al, 2017), real-time PCR (Garrido-Maestu et al, 2015;Casasola-Rodriguez et al, 2018), multiplex PCR (Bwire et al, 2018;Vu et al, 2018), oligonucleotide array hybridization (Nasrabadi et al, 2017), strand displacement amplification (SDA) (Phillips et al, 2018), rolling circle amplification (RCA) (Osterberg et al, 2014), cross-priming amplification (CPA) (Zhang et al, 2015), and nucleic acid sequence-based amplification (NASBA) (Fykse et al, 2012). Nevertheless, these methods require expensive equipments, which limit their wide application, particularly in on-site testing and large-scale survey.…”

Accumulating evidence suggests that some waterbird species are potential vectors of Vibrio cholerae

“…Fifty-three V . cholerae non-O1/O139 isolates were identified from Malaysian fish [54] and from ornamental fish originating in south-east Asian countries [55].…”