High acquisition and environmental contamination rates of CC17 ampicillin-resistant Enterococcus faecium in a Dutch hospital.
BACKGROUND
Enterococcus faecium has rapidly emerged as a nosocomial pathogen worldwide, and the majority of these isolates belong to clonal complex-17 (CC17). In Europe, CC17 isolates are usually ampicillin-resistant, but most are still vancomycin-sensitive. We aimed to study ampicillin-resistant E. faecium (ARE) epidemiology in our hospital.


METHODS
In a 3 month study, 210 of 358 admissions (59%) to haematology and gastroenterology/nephrology were screened for rectal ARE colonization on admission (<48 h) and 148 of 210 (70%) also at discharge (<72 h). In a second (3 month) study, environmental swabs from eight predetermined sites were obtained from ARE-colonized haematology patients once weekly. All ARE isolates were genotyped by multiple-locus variable-number tandem repeat analysis (MLVA).


RESULTS
ARE admission prevalence was 10% and 16% and acquisition rates were 39% and 15% in haematology and gastroenterology/nephrology, respectively. Carriage on admission was associated with previous admission <1 year (OR 5.0, 95% CI 1.8-14.0) and acquisition with beta-lactam (OR 2.7, 95% CI 1.1-6.7) and quinolone use (OR 3.1, 95% CI 1.1-8.2). Five of the 57 (9%) colonized patients developed invasive ARE infections. Genotyping revealed 12 genotypes (all CC17) with two MLVA types responsible for 94% of acquisitions. In 18 of the 19 colonized patients, the environment was contaminated with ARE. Sites most often contaminated were the toilet seat (43%), over-bed table (34%) and television remote control (28%).


CONCLUSIONS
CC17 ARE epidemiology is characterized by high admission (10% to 16%), acquisition (15% to 39%) and environmental contamination (22%) rates, resulting from cross-transmission, readmission and antibiotic pressure. A multifaceted infection control approach will be needed to curtail further spread.
de Regt
Marieke J A
MJ
Department of Medical Microbiology, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
van der Wagen
Lotte E
LE
Top
Janetta
J
Blok
Hetty E M
HE
Hopmans
Titia E M
TE
Dekker
Adriaan W
AW
Hené
Ronald J
RJ
Siersema
Peter D
PD
Willems
Rob J L
RJ
Bonten
Marc J M
MJ
D000668:Ampicillin Resistance; D015373:Bacterial Typing Techniques; D002353:Carrier State / Q000382:microbiology; D016000:Cluster Analysis; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D016984:Enterococcus faecium / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification*; D004783:Environmental Microbiology; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology*; D006761:Hospitals; D006801:Humans; D018598:Minisatellite Repeats; D009426:Netherlands / Q000453:epidemiology; D012007:Rectum / Q000382:microbiology
D004269:DNA, Bacterial