Introduction: Listeria monocytogenes
is a pathogen acquired through the consumption of contaminated foods.
Thirteen serotypes have been reported, of which 1/2a, 1/2b, and 4b are responsible for 98% of human listeriosis cases.
This study examines the association between serotypes and virulent clones, offering greater information and providing
tools to prevent and control diseases caused by L. monocytogenes
To identify the serotypes from L. monocytogene
strains isolated from different samples by performing
the molecular subtyping technique; to determine the 85M fragment that codifies for epidemic clone I.
108 strains of L. monocytogenes
were used, isolated from samples of animals, body fluids, foods, and food
processing plant equipment and spaces. The samples were identified by following the Bacteriological Analytical
Manual protocol described by the Food and Drug Administration (FDA). The strains were identified by Polymerase
Chain Reaction (PCR) using primers and a standardized protocol from a previous research project. Serotype
identification was performed by multiplex PCR. The determination of the 85M fragment of the SSCS cassette was done
by following the protocol by Yildrim et al.
Of the 108 L. monocytogenes
strains analyzed, 60.2% (65 strains) belonged to the 4b-4d-4e serotype, 17.6%
(19 strains) were identified as 1/2a-3a serotype, 14.8% (16 strains) were 4a-4c serotype, 3.7% (4 strains) belonged to
the 1/2c-3c serotype, and (3.7%) corresponded to the 1/2b-3b-7 serotype. It was determined that the L. monocytogenes
strains serotype 4b-4d-4e and 1/2a-3b have the 85M fragment of the SSCS cassette.
This study reports the predominant existence of L. monocytogenes
strains serotype 4b-4d-4e in food,
environmental, and clinical samples. The presence of an epidemic clone I region was also found in L. monocytogenes