Phenotypic and genotypic characteristics of Escherichia coli strains of non-enteropathogenic E. coli (EPEC) serogroups that carry EAE and lack the EPEC adherence factor and Shiga toxin DNA probe sequences.
This study was conducted to characterize the virulence potential of 59 Escherichia coli strains carrying EAE and lacking the enteropathogenic E. coli adherence factor and Shiga toxin probe sequences. In hybridization studies, all strains carried the locus of enterocyte effacement (LEE)-associated DNA sequences. Of the other 15 virulence DNA sequences tested, HLY was the most frequent (44.1%); 17 combinations of these sequences were found, but strains carrying EAE only (EAE profile) were the most frequent (35.6%). Except for 1 cytodetaching strain, all others adhered to HeLa and Caco-2 cells, most of which (approximately 75.0%) showed variations of the localized adherence pattern. Actin accumulation was detected in 75.9% of the nondetaching strains. Most strains had LEE, probably inserted in pheU (49.2%), and presented a nontypeable intimin (83.1%). Translocated intimin receptor-derived DNA sequences correlated with enteropathogenic and enterohemorrhagic E. coli in 61.0% and 32.0% of the strains, respectively. Thirty-five different serotypes were found. Only strains with the EAE profile were associated with diarrhea (P=.039).
Vieira
M A
MA
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu, 862-3* andar, São Paulo, SP, Brazil, CEP 04023-062.
Andrade
J R
JR
Trabulsi
L R
LR
Rosa
A C
AC
Dias
A M
AM
Ramos
S R
SR
Frankel
G
G
Gomes
T A
TA
D000199:Actins / Q000378:metabolism; D018829:Adhesins, Bacterial; D001422:Bacterial Adhesion / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001483:Base Sequence; D015153:Blotting, Western; D018938:Caco-2 Cells; D002352:Carrier Proteins; D016022:Case-Control Studies; D002478:Cells, Cultured; D015342:DNA Probes / Q000737:chemistry; D004269:DNA, Bacterial / Q000032:analysis*; D003967:Diarrhea / Q000382:microbiology; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins; D005838:Genotype; D006367:HeLa Cells; D006801:Humans; D006824:Hybridization, Genetic; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011956:Receptors, Cell Surface / Q000235:genetics; D012703:Serotyping; D022621:Shiga Toxin / Q000235:genetics; D014178:Translocation, Genetic; D014774:Virulence
D000199:Actins; D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D015342:DNA Probes; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D011956:Receptors, Cell Surface; C109287:Tir protein, E coli; C073819:eaeA protein, E coli; D022621:Shiga Toxin