Pathogenicity Island O-122 in enteropathogenic Escherichia coli strains is associated with diarrhea severity in children from Lima Peru.

EPEC is an attaching and effacing diarrheal pathogen that carries a large pathogenicity island, locus for enterocyte effacement (LEE). Recently, the pathogenicity island PAI O-122 was described among non-LEE effectors and found to be associated with diarrhea among atypical EPEC strains. It is unknown if incomplete PAI O-122 could be associated with diarrhea duration and severity. To identify these virulence determinants we analyzed 379 EPEC strains isolated from Peruvian children. EPEC was diagnosed by PCR(eae+, stx-) and classified as typical(t-EPEC) or atypical(a-EPEC). To characterize PAI O-122 we amplified three modules by PCR: Module 1(pagC), Module 2(senA, nleB and nleE) and Module 3(lifA/efa-1). To characterize the large ORF lifA/efa-1 we amplified the regions known as efa-N, efa-M and efa-C. Clinical information was obtained from the cohort study. A total of 379 EPEC strains were able to analyze PAI O-122 genes, 128 (10.4%) EPEC strains were isolated from 1235 diarrhea episodes and 251(9.2%) from 2734 healthy controls. t-EPEC strains were isolated from 14.8% (19/128) of children with diarrhea and 25/251(10.0%) from healthy controls. The most frequent PAI O-122 genes were nleE(37.7%), senA(34.6%) and nleB(37.5%), with similar prevalence among diarrhea and control samples. However, lifA/efa-1 was more common among diarrhea cases than healthy control cases (30.5% vs. 21.1%, p<0.05). The presence of complete PAI O-122 was associated with diarrhea episodes of higher severity among single pathogen infection (33.3% vs. 1.8%, p<0.05) mainly due to the presence of a complete lifA/efa-1 gene. In summary, the gene lifA/efa-1 is significantly associated with diarrheal episodes of higher severity, suggesting to be an important virulent factor.

Mercado EH ，Piscoche C ，Contreras C ，Durand D ，Riveros M ，Ruiz J ，Ochoa TJ ... -  《-》

Higher atypical enteropathogenic Escherichia coli (a-EPEC) bacterial loads in children with diarrhea are associated with PCR detection of the EHEC factor for adherence 1/lymphocyte inhibitory factor A (efa1/lifa) gene.

Slinger R ，Lau K ，Slinger M ，Moldovan I ，Chan F ... -  《Annals of Clinical Microbiology and Antimicrobials》

Prevalence and characteristics of the O122 pathogenicity island in typical and atypical enteropathogenic Escherichia coli strains.

Vieira MA ，Salvador FA ，Silva RM ，Irino K ，Vaz TM ，Rockstroh AC ，Guth BE ，Gomes TA ... -  《-》

Distribution of non-locus of enterocyte effacement pathogenic island-related genes in Escherichia coli carrying eae from patients with diarrhea and healthy individuals in Japan.

Narimatsu H ，Ogata K ，Makino Y ，Ito K ... -  《-》

Molecular characterization of virulence factors in diarrhoeagenic Escherichia coli isolates from children in Nairobi, Kenya.

Makobe CK ，Sang WK ，Kikuvi G ，Kariuki S ... -  《Journal of Infection in Developing Countries》