Characterization of Listeria monocytogenes isolates of food and human origins from Brazil using molecular typing procedures and in vitro cell culture assays.
The spreading of diseases through foods is a worldwide concern. Here, molecular and in vitro cell-culture assays were employed to characterize 63 Brazilian Listeria monocytogenes isolates (food, 47; clinical, 16). Serotype 4b was the most predominant (49%) followed by (1/2)b (30%), (1/2)a (10%), (1/2)c (6%), 3c (3%) and 3b (2%). Ribotyping yielded 17 ribopatterns, which were grouped into four phylogenetic clusters. Cluster A comprised of 39/63 isolates primarily of food origin, and clusters B, C and D contained both food and clinical isolates. Isolates were positive for virulence determinants prfA, hlyA and inlA: clinical isolates were more invasive to Caco-2 cells and expressed high levels of inlA transcripts than the food isolates. Highly invasive isolates also provoked more Ped-2E9 cells to die by apoptosis than the weakly-invasive strains. These data demonstrate a strong genetic relatedness among clinical and food isolates and suggest transmission of a subset of L. monocytogenes strains from food to humans.
Bueno
Valter F
VF
Department of Veterinary Medicine, Federal University of Goiás, Goiânia, Brazil.
Banerjee
Pratik
P
Banada
Padmapriya P
PP
José de Mesquita
Albenones
A
Lemes-Marques
Eneida G
EG
Bhunia
Arun K
AK
D001938:Brazil; D018938:Caco-2 Cells; D018929:Cell Culture Techniques; D005516:Food Microbiology; D006801:Humans; D008089:Listeria monocytogenes / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification* / Q000472:pathogenicity; D008088:Listeriosis / Q000453:epidemiology / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D021521:Ribotyping; D012703:Serotyping; D014774:Virulence