Virulence features of atypical enteropathogenic Escherichia coli identified by the eae(+) EAF-negative stx(-) genetic profile.
This study characterized 76 atypical enteropathogenic Escherichia coli (aEPEC) strains, previously classified by the eae(+) EAF-negative stx(-) genotype, isolated from children with diarrhea in Brazil. Presence of bfpA and bfpA/perA was detected in 2 and 6 strains, respectively. The expression of bundle-forming pilus (BFP), however, was observed by immunofluorescence in 1 bfpA and 3 bfpA/perA strains, classifying them as typical EPEC (tEPEC). The remaining 72 aEPEC strains were characterized by serotyping, intimin typing, adherence patterns to HEp-2 cells, capacity to induce actin aggregation (fluorescent actin staining test), and antimicrobial resistance. Our results show that aEPEC comprise a very heterogeneous group that does not present any prevalence or association regarding the studied characteristics. It also suggest that tEPEC and aEPEC must not be classified only by the reactivity with the EAF probe, and that the search of other markers present in pEAF, as well as the BFP expression, must be considered for this matter.
Laboratório de Bacteriologia, Instituto Butantan, 055030-900 São Paulo, Brazil.
Cecilia M
CM
Abe
Luiz R
LR
Trabulsi
Jorge
J
Blanco
Miguel
M
Blanco
Ghizlane
G
Dahbi
Jesús E
JE
Blanco
Azucena
A
Mora
Marcia R
MR
Franzolin
Carla R
CR
Taddei
Marina B
MB
Martinez
Roxane M F
RM
Piazza
Waldir P
WP
Elias
D018829:Adhesins, Bacterial / Q000235:genetics*; D001422:Bacterial Adhesion; D015373:Bacterial Typing Techniques; D001938:Brazil; D002460:Cell Line; D002648:Child; D003967:Diarrhea / Q000382:microbiology*; D054308:Enteropathogenic Escherichia coli / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics*; D036781:Fimbriae Proteins / Q000235:genetics; D005455:Fluorescent Antibody Technique / Q000379:methods; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D012097:Repressor Proteins / Q000235:genetics; D012703:Serotyping; D022621:Shiga Toxin / Q000235:genetics*; D014774:Virulence
D018829:Adhesins, Bacterial; C104901:BfpA protein, E coli; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; C120886:bfpT protein, E coli; C073819:eaeA protein, E coli; D036781:Fimbriae Proteins; D022621:Shiga Toxin