title: E. coli outbreak in a neonate intensive care unit in a general hospital in Mexico City.
abstract: Nosocomial infections are a major cause of morbidity and mortality among neonates admitted to neonatal intensive care units (NICUs). The aim of this paper was to describe an outbreak of Escherichia coli among infants admitted to the NICU of the General Hospital "Dr. Manuel Gea Gonzalez" in May of 2008. The isolated E. coli strains were identified using standard biochemical methods. The susceptibilities of these strains were analysed by determining their minimal inhibitory concentrations. Following this, their molecular relationships to each other were assessed by pulsed field gel electrophoresis (PFGE) analysis and corroborated by serology. Twelve E. coli strains were isolated from blood, urine, or indwelling catheter samples from five cases of preterm infants within a 3-day period. Patients were admitted to the NICU of the general hospital and, during the outbreak, developed sepsis caused by E. coli. For four of the patients, the average age was 23 days, while one patient was a 3-month-old infant. Prior to sepsis, the infants had received assisted ventilation and hyperalimentation through a central venous catheter. Two profiles were observed by PFGE; profile A was identified as the outbreak's cause and an outcome of cross-infection, while profile B showed genetic differences but serologically it was identified as part of the same serotype. We conclude that E. coli colonised the patients through horizontal transmission. A focal source of the microorganism in this outbreak was not identified, but cross-transmission through handling was the most probable route.
authors.affiliation: Departamento de Biología Molecular e Histocompatibilidad, Hospital General Dr. Manuel Gea González, Mexico, Mexico.
authors.forename: Erika Margarita
authors.initials: EM
authors.lastname: Carrillo-Casas
authors.forename: Zaydy
authors.initials: Z
authors.lastname: Suástegui-Urquijo
authors.forename: Sara
authors.initials: S
authors.lastname: Arroyo-Escalante
authors.forename: Rosario
authors.initials: R
authors.lastname: Morales-Espinosa
authors.forename: David
authors.initials: D
authors.lastname: Moncada-Barrón
authors.forename: Lorena
authors.initials: L
authors.lastname: Hernández-Delgado
authors.forename: José Luis
authors.initials: JL
authors.lastname: Méndez-Sánchez
authors.forename: Gabriela
authors.initials: G
authors.lastname: Delgado-Sapién
authors.forename: Armando
authors.initials: A
authors.lastname: Navarro-Ocaña
authors.forename: Ángel
authors.initials: Á
authors.lastname: Manjarrez-Hernández
authors.forename: Juan
authors.initials: J
authors.lastname: Xicohtencatl-Cortes
authors.forename: Rigoberto
authors.initials: R
authors.lastname: Hernández-Castro
mesh_terms: D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D004196:Disease Outbreaks; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000635:transmission; D005260:Female; D006769:Hospitals, General; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007363:Intensive Care Units, Neonatal; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D018805:Sepsis / Q000453:epidemiology* / Q000382:microbiology