%0 Journal Article
%T Enterotoxigenic gene profiles of Bacillus cereus and Bacillus megaterium isolates recovered from honey B迆squeda de factores de virulencia en cepas de Bacillus cereus y de Bacillus megaterium aisladas de miel
%A A. C. L車pez
%A A. M. Alippi
%J Revista argentina de microbiologˋ-a
%D 2010
%I Asociaci車n Argentina de Microbiolog赤a
%X One hundred and thirty two Bacillus cereus and 52 Bacillus megaterium isolates from honeys were evaluated for the presence of genes encoding enterotoxin HBL, enterotoxin-T, cytotoxin K and the NHE complex, respectively. The relationship between hemolytic and coagulase activity and its correlation with the presence of the four mentioned enterotoxins was determined by principal component analysis (PCA). PCA in B. cereus revealed a positive correlation among free coagulase, hemolysis and the presence of genes hblA, hblB, hblC, hblD (HBL complex) and bceT (enterotoxin-T), but no correlation with the clumping factor (bound coagulase) and the presence of sequences of the NHE complex. On the other hand, PCA in B. megaterium showed a high positive correlation between coagulase (bound and free) and the haemolytic activity but no correlation in relation to the presence of genes of the HBL complex, cytotoxin K, enterotoxin T and the NHE complex. To our knowledge, this is the first report of the detection of cytotoxin K and of the NHE complex genes in B. megaterium. The relationship between the coagulase activity and the presence of virulence factors has not been described before in the genus Bacillus, being this work the first report of this correlation. Interestingly, the presence of the cytK gene was almost independent of the presence of the rest of virulence factors herein analyzed both in B. cereus and B. megaterium populations. Our results suggest that honey could be a possible vehicle for foodborne illness due to the presence of toxigenic B. cereus and B. megaterium strains containing different virulence factors. Se evaluaron 132 aislamientos de Bacillus cereus y 52 de Bacillus megaterium provenientes de mieles de distintos or赤genes geogr芍ficos para investigar la presencia de secuencias de ADN relacionadas con genes de virulencia y su posible correlaci車n con la actividad hemol赤tica y coagulasa. Con respecto a los genes de virulencia, se analizaron por PCR secuencias de ADN de los genes nhe (A, B y C), HBL (A, B, C, D), cytK y bceT. La relaci車n entre las variables fue evaluada mediante un an芍lisis de componentes principales, donde se encontr車 que los aislamientos de B. cereus mostraron una correlaci車n positiva entre actividad de coagulasa (coagulasa libre) y presencia de los genes del complejo HBL y bceT, mientras que en B. megaterium se hall車 una alta correlaci車n positiva entre actividad de coagulasa (libre y fija) y actividad hemol赤tica, pero no se observ車 correlaci車n significativa entre la presencia de genes de virulencia y dichas actividades. Este estudio
%K Bacillus cereus
%K Miel
%K Hem車lisis
%K Actividad de coagulasa
%K Enterotoxinas
%K Bacillus megaterium
%K Factores de virulencia
%K Bacillus cereus
%K Honey
%K Hemolysis
%K Coagulase activity
%K Enterotoxins
%K Bacillus megaterium
%K Virulence factors
%U http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0325-75412010000300014