title: Longer intestinal persistence of Enterococcus faecalis compared to Enterococcus faecium clones in intensive-care-unit patients.
abstract: The dynamics of intestinal colonization with enterococcal clones in intensive-care-unit (ICU) patients was evaluated. Eight patients admitted directly to the neurosurgical ICU at the Ramón y Cajal University Hospital (Madrid, Spain) from the community and with no overlapping stay during a 10-month period in 2006 were studied. Rectal swab specimens were collected on admission and daily until the patients were discharged. Clonality was determined by pulsed-field gel electrophoresis and multilocus sequence typing. Clonal colonization dynamics were estimated by using two new parameters: the clonal diversity per patient per day (CDPD) and the clonal persistence ratio (CPR). Enterococcus faecalis isolates (n = 123) and Enterococcus faecium isolates (n = 66) were resolved into 13 and 15 clones, respectively. The CDPD of E. faecalis steadily increased during admission, and E. faecalis showed a higher (P = 0.001) CPR value than E. faecium (0.86 and 0.42, respectively). E. faecium, with the exception of an ampicillin-resistant clone belonging to clonal complex 17, frequently appeared as a short-term colonizer, even though the E. faecalis clones had significantly (P = 0.03) more days under antibiotic exposure than E. faecium (77.5 and 65 days/100 colonization days, respectively). E. faecalis had a longer persistence than E. faecium, except for the CC17 ampicillin-resistant clone, and E. faecalis showed a cumulative increase in CDPD, whereas E. faecium did not. CDPD and CPR were useful for measuring the dynamics of intestinal colonization with enterococcal clones.
authors.affiliation: Servicio de Microbiología, Hospital Universitario Ramón y Cajal, Madrid, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Ruiz-Garbajosa
authors.forename: Rosa
authors.initials: R
authors.lastname: del Campo
authors.forename: Teresa M
authors.initials: TM
authors.lastname: Coque
authors.forename: Angel
authors.initials: A
authors.lastname: Asensio
authors.forename: Marc
authors.initials: M
authors.lastname: Bonten
authors.forename: Rob
authors.initials: R
authors.lastname: Willems
authors.forename: Fernando
authors.initials: F
authors.lastname: Baquero
authors.forename: Rafael
authors.initials: R
authors.lastname: Cantón
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000668:Ampicillin Resistance; D015373:Bacterial Typing Techniques; D002353:Carrier State / Q000382:microbiology*; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D013293:Enterococcus faecalis / Q000302:isolation & purification*; D016984:Enterococcus faecium / Q000302:isolation & purification*; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology*; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D012007:Rectum / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013030:Spain
chemical_list: D004269:DNA, Bacterial