title: Extended-spectrum beta-lactamase--producing enterobacteriaceae in the intensive care unit: acquisition does not mean cross-transmission.
abstract: BACKGROUND
  In intensive care unit (ICU), infection and colonization by resistant Gram-negative bacteria increase costs, length of stay and mortality. Extended-spectrum beta-lactamase--producing Enterobacteriaceae (ESBL-E) is a group of pathogens increasingly encountered in ICU setting. Conditions that promote ESBL-E acquisition are not completely understood. The increasing incidence of infections related to ESBL-E and the unsolved issues related to ESBL-E cross-transmission, prompted us to assess the rates of referred and acquired cases of ESBL-E in ICU and to assess patient-to-patient cross-transmission of ESBL-E using a multimodal microbiological analysis.
  
  
  METHODS
  During a 5-month period, all patients admitted to a medical ICU were tested for ESBL-E carriage. A rectal swab was performed at admission and then twice a week until discharge or death. ESBL-E strains were analyzed according to antibiotic susceptibility pattern, rep-PCR (repetitive-element Polymerase chain reaction) chromosomal analysis, and plasmid PCR (Polymerase chain reaction) analysis of ESBL genes. Patient-to-patient transmission was deemed likely when 2 identical strains were found in 2 patients hospitalized simultaneously in the ICU.
  
  
  RESULTS
  Among the 309 patients assessed for ESBL-E carriage on admission, 25 were found to carry ESBL-E (importation rate: 8%). During follow-up, acquisition was observed among 19 of them (acquisition rate: 6.5%). Using the multimodal microbiological approach, we found only one case of likely patient-to-patient ESBL-E transmission.
  
  
  CONCLUSIONS
  In unselected ICU patients, we found rather low rates of ESBL-E referred and acquired cases. Only 5% of acquisitions appeared to be related to patient-to-patient transmission. These data highlight the importance of jointly analyzing phenotypic profile and molecular data to discriminate strains of ESBL-E.
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.
authors.forename: Mikael
authors.initials: M
authors.lastname: Alves
authors.affiliation: Service de Microbiologie, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.
authors.forename: Astrid
authors.initials: A
authors.lastname: Lemire
authors.affiliation: Service de Microbiologie, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Decré
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Margetis
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.
authors.forename: Naïke
authors.initials: N
authors.lastname: Bigé
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.|Université Pierre et Marie Curie-Paris 6, Paris, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Pichereau
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.|Université Pierre et Marie Curie-Paris 6, Paris, France.
authors.forename: Hafid
authors.initials: H
authors.lastname: Ait-Oufella
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Baudel
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.|Université Pierre et Marie Curie-Paris 6, Paris, France.|Inserm-UPMC UMR S 1136, Paris, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Offenstadt
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.|Université Pierre et Marie Curie-Paris 6, Paris, France.|Inserm-UPMC UMR S 1136, Paris, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Guidet
authors.affiliation: Service de Microbiologie, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Barbut
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint-Antoine, Assistance Publique-Hôpitaux de Paris, 184 rue du Faubourg Saint-Antoine, 75012, Paris, France. eric.maury@aphp.fr.|Université Pierre et Marie Curie-Paris 6, Paris, France. eric.maury@aphp.fr.|Inserm-UPMC UMR S 1136, Paris, France. eric.maury@aphp.fr.
authors.forename: Eric
authors.initials: E
authors.lastname: Maury
mesh_terms: D000368:Aged; D003428:Cross Infection / Q000175:diagnosis; D004247:DNA / Q000032:analysis; D004755:Enterobacteriaceae / Q000201:enzymology / Q000302:isolation & purification*; D004756:Enterobacteriaceae Infections / Q000175:diagnosis* / Q000382:microbiology; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012007:Rectum / Q000382:microbiology; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D004247:DNA; D001618:beta-Lactamases
keywords: Anti-Bacterial Agents; Cross Infection; ESBL-E; Enterobacteriaceae; Polymerase chain reaction; beta-lactamase