Patterns of adherence of diarrheagenic Escherichia coli to HEp-2 cells.
A total of 516 Escherichia coli strains randomly isolated from coprocultures of 154 Chilean children with diarrhea and 66 controls were examined with DNA probes and tested for adherence to HEp-2 cells. Three adherence patterns were distinguished, localized, true diffuse and "aggregative." Enteropathogenic E. coli (EPEC) were detected by EPEC adherence factor probe among 86 of the 372 isolates (23%) from patients with diarrhea vs. 14 of 144 (10%) strains from controls (P less than 0.0002). Of 95 strains that manifested localized adherence, 97% were EPEC adherence factor probe-positive; thus the HEp-2 assay may serve as an alternative to the probe in identifying EPEC adherence factor-positive EPEC. True diffuse adherence was not associated with diarrhea. In contrast the aggregative pattern appears to signify a new, distinct class of diarrheagenic E. coli (enteroadherent-aggregative E. coli). The aggregative pattern was found in only 3 of 27 enterotoxigenic, 0 of 4 enteroinvasive, 0 of 2 enterohemorrhagic and 2 of 86 EPEC strains but in 84 of 253 probe-negative strains (P less than 0.00001) from patients with diarrhea; in comparison only 20 of 134 probe-negative strains from controls were aggregative E. coli (P less than 0.00001 vs. probe-negative strains from diarrhea patients).
Nataro
J P
JP
Department of Pediatrics, University of Maryland School of Medicine, Baltimore.
Kaper
J B
JB
Robins-Browne
R
R
Prado
V
V
Vial
P
P
Levine
M M
MM
D001422:Bacterial Adhesion; D002460:Cell Line; D002675:Child, Preschool; D003967:Diarrhea / Q000382:microbiology*; D003968:Diarrhea, Infantile / Q000382:microbiology*; D004926:Escherichia coli / Q000502:physiology*; D006801:Humans; D007223:Infant