Listeria monocytogenesin Ready-to-Eat Seafood and Potential Hazards for the Consumers

Abstract

<jats:p>The risk of exposure to<jats:italic>Listeria monocytogenes</jats:italic>(<jats:italic>L. monocytogenes</jats:italic>) when consuming Ready-to-Eat (RTE) seafood was assessed in the Veneto Region (Italy). Thirty-eight samples were analyzed, each sample consisted of three subunits belonging to the same batches. The first of the three units was examined immediately, the second was stored at +4°C (for all of its shelf-life) and the third at +10°C (for the latter third of its<jats:italic>shelf-life</jats:italic>) before the analysis. Chemical-physical and microbiological parameters were tested simultaneously. Culture results showed the presence of viable<jats:italic>L. monocytogenes</jats:italic>in 9 (23,68%) of the 38 samples analysed, 3 (33,33%) of which with a concentration &gt;100 cfu/g. PCR tests yielded 12<jats:italic>L. monocytogenes</jats:italic>positive samples. Semipreserves with aw (water activity) and pH values that favour<jats:italic>L. monocytogenes</jats:italic>growth were the only ones to result positive to microbiological and PCR tests. Temperature proved to be an important factor as it limits the growth of<jats:italic>L. monocytogenes</jats:italic>, including products with potentially high competitive microbial charges. Four different serotypes were recovered and ribotyping has helped to highlight the genomic variability of<jats:italic>L. monocytogenes</jats:italic>strains in food. This supports the hypothesis that<jats:italic>L. monocytogenes</jats:italic>continues to evolve genetically to the detriment of phenotypic conservation.</jats:p>

Antimicrobial activity of cauliflower (Brassica oleracea var. Botrytis) by-product against Listeria monocytogenes

“…The incidence of listeriosis mainly affects young and elderly people (over 65 years), pregnant women and immune-compromised people (Adzitey et al, 2010;Gambarin et al, 2012), with high morbidity and mortality rates associated with L. monocytogenes (about 30%). Nowadays, L. monocytogenes is one of the most worrying foodborne pathogens, with one of the highest hospitalization rates (91%) and long-term sequels in affected patients (Denny & McLauchlin, 2008).…”

Listeria monocytogenes: A Dangerous and Insidious Pathogen in Seafood

“…The growth of L. monocytogenes has demonstrated to be sensitive to changes in pH, refrigeration temperature and a w ; so the microorganism is present in the cultivable and detectable form only at certain environmental conditions. Differently from classical microbiology methods, the molecular methods can detect its presence even under conditions that do not encourage it to grow (Gambarin et al 2012). For this reason, lately, new molecular identification techniques have arisen (Gambarin et al 2012;Kérouanton et al 2010) along with analytical techniques as MALDI-TOF MS (matrix-assisted laser desorption/ ionisation time-of-flight mass spectrometry) (Jadhav et al 2012).…”

“…Differently from classical microbiology methods, the molecular methods can detect its presence even under conditions that do not encourage it to grow (Gambarin et al 2012). For this reason, lately, new molecular identification techniques have arisen (Gambarin et al 2012;Kérouanton et al 2010) along with analytical techniques as MALDI-TOF MS (matrix-assisted laser desorption/ ionisation time-of-flight mass spectrometry) (Jadhav et al 2012). To assess the potential virulence of L. monocytogenes strains, the following typing methods can be used: ribotyping (Pagadala et al 2012), PFGE typing (Jensen et al 2010) or multilocus sequence typing (MLST) (Jadhav et al 2012).…”

A sensitive impedance biosensor based on immunomagnetic separation and urease catalysis for rapid detection of Listeria monocytogenes using an immobilization-free interdigitated array microelectrode

“…It can survive at temperatures as low as 4 °C, at pH as low as 4.4, and at salt concentrations of up to 14% (Cole et al, 1990). The infection sources of L. monocytogenes can be meal (Aureli et al, 2000), egg (Rivoal et al, 2013), poultry (Meyer et al, 2012), seafood (Gambarin et al, 2012), dairy product (El Marnissi et al, 2013) and vegetable (Sant'Ana et al, 2012), etc. Infection of L. monocytogenes may lead to listeriosis, which is one of the leading causes of death for foodborne illness, and the mortality rate is approximately 30% in high risk groups (Silk et al, 2014;Swaminathan and Gerner-Smidt., 2007).…”