Molecular and Phenotypic Characterization of Diarrheagenic Escherichia coli Strains Isolated from Bacteremic Children

Mercado, Erik; García Apac, Coralith Marlinda; García, Wilfredo; Riveros Ramirez, Maribel Denise; Durand Vara, David Percy; Ruiz, Joaquim; Ochoa Woodell, Theresa Jean

dc.contributor.author	Riveros Ramirez, Maribel Denise
dc.contributor.author	García, Wilfredo
dc.contributor.author	García Apac, Coralith Marlinda
dc.contributor.author	Durand Vara, David Percy
dc.contributor.author	Mercado, Erik
dc.contributor.author	Ruiz, Joaquim
dc.contributor.author	Ochoa Woodell, Theresa Jean
dc.date.accessioned	2019-01-25T15:28:06Z
dc.date.available	2019-01-25T15:28:06Z
dc.date.issued	2017
dc.identifier.uri	https://hdl.handle.net/20.500.12866/4704
dc.description.abstract	Escherichia coli is an important cause of Gram-negative bacteremia. The aim of this study was to characterize at the molecular and phenotypic levels E. coli strains belonging to different diarrheagenic pathotypes [diarrheagenic E. coli (DEC)] isolated from bacteremia in children younger than 5 years of age. Seventy bacteremia E. coli strains were collected in a prospective study in 12 hospitals in Lima, Peru. The presence of virulence genes associated with DEC [enterotoxigenic (lt and st), enteropathogenic (eaeA), shiga toxin-producing (stx1and stx2), enteroinvasive (ipaH), enteroaggregative (aggR), and diffusely adherent (daaD)] was determined by multiplex real-time polymerase chain reaction (PCR). Those positive E. coli strains were further analyzed for 18 additional virulence factors encoding genes and others phenotypic features. Virulence genes associated with DEC were identified in seven bacteremic children (10%), including: one aggR-positive [enteroaggregative E. coli (EAEC)], one eaeA-positive [enteropathogenic E. coli (EPEC)], one st-positive [enterotoxigenic E. coli (ETEC)], one daaD-positive [diffusely adherent E. coli (DAEC)], and three strain positive for aggR and daaD (EAEC/DAEC) at the same time. All strains, except EPEC, had the Ag43 adhesin, and all, except ETEC had the siderophore gene fyuA. The phylogenetic profile of these strains was variable, two (B2), two (D), two (A), and one (B1) strain. These isolates were susceptible to all tested antibacterial agents except to ampicillin and gentamicin. The three EAEC/DAEC strains showed biofilm formation and aggregative adhesion and had the same repetitive extragenic palindromic-PCR patterns. These findings suggest that some DEC strains, especially agg-R and daa-D positive, might cause bacteremia in children.	en_US
dc.language.iso	eng
dc.publisher	American Society of Tropical Medicine and Hygiene
dc.relation.ispartofseries	American Journal of Tropical Medicine and Hygiene (ASTMH Journal)
dc.rights	info:eu-repo/semantics/restrictedAccess
dc.subject	Adhesins, Bacterial/genetics/metabolism	en_US
dc.subject	Ampicillin/therapeutic use	en_US
dc.subject	Anti-Bacterial Agents/therapeutic use	en_US
dc.subject	Bacteremia/diagnosis/drug therapy/epidemiology	en_US
dc.subject	Child, Preschool	en_US
dc.subject	Diarrhea/drug therapy/epidemiology/microbiology	en_US
dc.subject	DNA, Bacterial/genetics	en_US
dc.subject	Drug Resistance, Multiple, Bacterial	en_US
dc.subject	Enteropathogenic Escherichia coli/drug effects/genetics/isolation & purification	en_US
dc.subject	Enterotoxigenic Escherichia coli/drug effects/genetics/isolation & purification	en_US
dc.subject	Humans	en_US
dc.subject	Infant	en_US
dc.subject	Infant, Newborn	en_US
dc.subject	Peru/epidemiology	en_US
dc.subject	Phylogeny	en_US
dc.subject	Prospective Studies	en_US
dc.subject	Real-Time Polymerase Chain Reaction	en_US
dc.title	Molecular and Phenotypic Characterization of Diarrheagenic Escherichia coli Strains Isolated from Bacteremic Children	en_US
dc.type	info:eu-repo/semantics/article
dc.identifier.doi	https://doi.org/10.4269/ajtmh.17-0066
dc.subject.ocde	https://purl.org/pe-repo/ocde/ford#3.03.06
dc.relation.issn	1476-1645