1 research outputs found
Prevalence and serotyping of Listeria monocytogenes in Portuguese live bivalve molluscs sampled in various steps along the sanitary control process
The prevalence and contamination levels of Listeria
monocytogenes were investigated in live bivalve molluscs
for human consumption, collected in various
steps of the commercial and sanitary circuits in the
North of Portugal. Samples of di隆erent species were
collected per lot before and after depuration treatment
in two depuration units and further, when
placed in retail markets. Listeria monocytogenes was
isolated from 4% of the samples although with very
low contamination levels (less than 100MPNg 1).
None of the environmental (non-depurated) samples
were contaminated with the food-borne pathogen.
The positive samples involved depurated and commercialized
samples from two lots, one in each circuit.
Two serotypes (1/2a and 3b) were detected
among the isolated strains. This study demonstrated
the possibility of occurrence of L.monocytogenes contamination
of live bivalvemolluscs along the sanitary
control circuit, including at the retailmarket level. As
L. monocytogenes grows well at refrigerated temperatures
and in high salt matrixes such as seafood its
presence in these products should not be overlooked