Molecular Characterization of Stenotrophomonas maltophilia isolates from cystic fibrosis patients and the hospital environment.
OBJECTIVE
To ascertain whether cystic fibrosis (CF) patients are colonized or infected with unique or multiple strains of Stenotrophomonas maltophilia; to understand whether some strains colonize or infect more than 1 patient, indicating clonal spread; and to explore the molecular heterogeneity of hospital water isolates and their correlation with clinical isolates.


METHODS
The regional CF center of Policlinico "Umberto I" of Rome, Italy.


METHODS
The study was carried out on a random sample of S. maltophilia isolates (n = 110) collected from CF patients (n = 50) during the period 2002-2005 and on 24 water isolates obtained during a monitoring program in the first 6 months of 2005. Home environmental samplings were not performed. All isolates, which were recovered from cultures of specimens obtained in both inpatient and outpatient settings, were genotyped with DNA macrorestriction analysis with the restriction enzyme XbaI and pulsed-field gel electrophoresis.


RESULTS
One-third of the patients with repeated episodes of S. maltophilia infection or colonization hosted more than 1 strain. A potential transmission, defined as the isolation of the same strain in 2 or more patients, occurred 5 times, showing a frequency of potential transmission episodes slightly higher than previously reported. Water, taps, and sinks of the different rooms of the CF center tended to be persistently colonized with the same strain of S. maltophilia, with no correlation between clinical and water-associated isolates.


CONCLUSIONS
The study does not provide sufficient data to conclude definitively that isolation of colonized or infected CF patients and control of hospital water systems contamination would be beneficial infection control measures. Epidemiologic analytical studies that correlate the presence of S. maltophilia with clinical outcomes are strongly needed.
Marzuillo
Carolina
C
Department of Experimental Medicine, Sapienza University of Rome, Italy.
De Giusti
Maria
M
Tufi
Daniela
D
Giordano
Alessandra
A
Del Cimmuto
Angela
A
Quattrucci
Serena
S
Mancini
Carlo
C
Villari
Paolo
P
D000293:Adolescent; D015373:Bacterial Typing Techniques; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D003550:Cystic Fibrosis / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004866:Equipment Contamination; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D006761:Hospitals; D006801:Humans; D017053:Infection Control; D008297:Male; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D012307:Risk Factors; D020615:Stenotrophomonas maltophilia / Q000145:classification* / Q000302:isolation & purification; D014871:Water Microbiology
D004269:DNA, Bacterial