title: Massive increase, spread, and exchange of extended spectrum β-lactamase-encoding genes among intestinal Enterobacteriaceae in hospitalized children with severe acute malnutrition in Niger.
abstract: BACKGROUND
  From the time of CTX-M emergence, extended-spectrum β-lactamase-producing enterobacteria (ESBL-E) have spread worldwide in community settings as well as in hospitals, particularly in developing countries. Although their dissemination appears linked to Escherichia coli intestinal carriage, precise paths of this dynamic are largely unknown.
  
  
  METHODS
  Children from a pediatric renutrition center were prospectively enrolled in a fecal carriage study. Antibiotic exposure was recorded. ESBL-E strains were isolated using selective media from fecal samples obtained at admission and, when negative, also at discharge. ESBL-encoding genes were identified, their environments and plasmids were characterized, and clonality was assessed with polymerase chain reaction-based methods and pulsed-field gel electrophoresis for E. coli and Klebsiella pneumoniae. E. coli strains were subjected to multilocus sequence typing.
  
  
  RESULTS
  The ESBL-E carriage rate was 31% at admission in the 55 children enrolled. All children enrolled received antibiotics during hospitalization. Among the ESBL-E-negative children, 16 were resampled at discharge, and the acquisition rate was 94%. The bla(CTX-M-15) gene was found in >90% of the carriers. Genetic environments and plasmid characterization evidenced the roles of a worldwide, previously described, multidrug-resistant region and of IncF plasmids in CTX-M-15 E. coli dissemination. Diversity of CTX-M-15-carrying genetic structures and clonality of acquired ESBL E. coli suggested horizontal genetic transfer and underlined the potential of some ST types for nosocomial cross-transmission.
  
  
  CONCLUSIONS
  Cross-transmission and high selective pressure lead to very high acquisition of ESBL-E carriage, contributing to dissemination in the community. Strict hygiene measures as well as careful balancing of benefit-risk ratio of current antibiotic policies need to be reevaluated.
authors: French National Reference Center for Bacterial Resistance in Commensal Flora, Laboratory of Bacteriology, Bichat-Claude Bernard Hospital, Assistance Publique-Hôpitaux de Paris. paullouis.woerther@bch.aphp.fr
authors: Paul-Louis
authors: PL
authors: Woerther
authors: Cécile
authors: C
authors: Angebault
authors: Hervé
authors: H
authors: Jacquier
authors: Henri-Charles
authors: HC
authors: Hugede
authors: Ann-Carole
authors: AC
authors: Janssens
authors: Sani
authors: S
authors: Sayadi
authors: Assiya
authors: A
authors: El Mniai
authors: Laurence
authors: L
authors: Armand-Lefèvre
authors: Etienne
authors: E
authors: Ruppé
authors: François
authors: F
authors: Barbier
authors: Laurent
authors: L
authors: Raskine
authors: Anne-Laure
authors: AL
authors: Page
authors: Nathalie
authors: N
authors: de Rekeneire
authors: Antoine
authors: A
authors: Andremont
mesh_terms: D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology; D002673:Child, Hospitalized; D002675:Child, Preschool; D016521:Electrophoresis, Gel, Pulsed-Field; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology*; D004926:Escherichia coli / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D022761:Gene Transfer, Horizontal; D006801:Humans; D007223:Infant; D007711:Klebsiella pneumoniae / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D008297:Male; D044342:Malnutrition / Q000150:complications*; D058889:Molecular Typing; D009548:Niger / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D001618:beta-Lactamases