HeLa-cell adherence patterns and actin aggregation of enteropathogenic Escherichia coli (EPEC) and Shiga-toxin-producing E. coli (STEC) strains carrying different eae and tir alleles.
A collection of 69 eae-positive strains expressing 29 different intimin types and eight tir alleles was characterized with respect to their adherence patterns to HeLa cells, ability to promote actin accumulation in vitro, the presence of bfpA alleles in positive strains, and bundle-forming pilus (BFP) expression. All of the nine typical enteropathogenic Escherichia coli (tEPEC) studied harbored the enteropathogenic E. coli adherence factor (EAF) plasmid, as shown by PCR and/or EAF probe results. In addition, they were positive for bfpA, as shown by PCR, and BFP expression, as confirmed by immunofluorescence (IFL) and/or immunoblotting (IBL) assays. Localized adherence (LA) was exclusively displayed by those nine tEPEC, while localized-adherence-like (LAL) was the most frequent pattern among atypical EPEC (aEPEC) and Shiga-toxinproducing E. coli (STEC). All LA and LAL strains were able to cause attaching and effacing (AE) lesions, as established by means of the FAS test. There was a significant association between the presence of tir allele alpha1 and bfpA-positive strains, and consequently, with the LA pattern. However, intimin type or bfpA was not associated with the adherence pattern displayed in HeLa cells. Among the eight bfpA alleles detected, a new type (beta10; accession number FN391178) was identified in a strain of serotype O157:H45, and a truncated variant (beta3.2-t; accession number FN 391181) in four strains belonging to different pathotypes.
Mora
Azucena
A
Department of Microbiology and Parasitology, Faculty of Veterinary Science, University of Santiago de Compostela, Lugo, Spain.
Blanco
Miguel
M
Yamamoto
Denise
D
Dahbi
Ghizlane
G
Blanco
Jesús E
JE
López
Cecilia
C
Alonso
María P
MP
Vieira
Mônica A M
MA
Hernandes
Rodrigo T
RT
Abe
Cecilia M
CM
Piazza
Roxane M F
RM
Lacher
David W
DW
Elias
Waldir P
WP
Gomes
Tania A T
TA
Blanco
Jorge
J
D000199:Actins / Q000378:metabolism*; D018829:Adhesins, Bacterial / Q000235:genetics*; D000483:Alleles; D001422:Bacterial Adhesion; D004269:DNA, Bacterial / Q000235:genetics; D054308:Enteropathogenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000235:genetics*; D036781:Fimbriae Proteins / Q000235:genetics; D010861:Fimbriae, Bacterial / Q000502:physiology; D005838:Genotype; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011956:Receptors, Cell Surface / Q000235:genetics*; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity*; D037521:Virulence Factors / Q000235:genetics*
D000199:Actins; D018829:Adhesins, Bacterial; C104901:BfpA protein, E coli; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D011956:Receptors, Cell Surface; C109287:Tir protein, E coli; D037521:Virulence Factors; C073819:eaeA protein, E coli; D036781:Fimbriae Proteins