Patterns of adherence of diarrheagenic Escherichia coli to... : The Pediatric Infectious Disease Journal (original) (raw)

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NATARO, JAMES P. MD, PHD; KAPER, JAMES B. PHD; ROBINS-BROWNE, ROY MBBCH, PHD; PRADO, VALERIA MD; VIAL, PABLO MD; LEVINE, MYRON M. MD DTPH

From the Division of Infectious Diseases and Tropical Pediatrics, Department of Pediatrics (JPN, PV, MML), The Department of Microbiology (JPN, JBK), The Division of Geographic Medicine, Department of Medicine (JPN, JBK, RRB, MML), and The Center for Vaccine Development (JPN, JBK, RRB, PV, MML), University of Maryland School of Medicine, Baltimore, MD and The Microbiology Unit, University of Chile Faculty of Medicine, Area Oriente, Santiago, Chile (VP).

Abstract

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 < 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 < 0.00001) from patients with diarrhea; in comparison only 20 of 134 probe-negative strains from controls were aggregative E. coli (P < 0.00001 us. probe-negative strains from diarrhea patients).