Two consecutive outbreaks of Stenotrophomonas maltophilia (Xanthomonas maltophilia) in an intensive-care unit defined by restriction fragment-length polymorphism typing.
OBJECTIVE
To investigate and control consecutive outbreaks of Stenotrophomonas maltophilia infections in intensive-care-unit (ICU) patients.


METHODS
Epidemiological investigation; restriction fragment-length polymorphism typing by pulsed-field gel electrophoresis (PFGE) of genomic DNA of outbreak strains; institution of infection control measures to limit spread.


METHODS
The medical-surgical ICU in an 800-bed tertiary-care center in Calgary, Alberta, Canada.


RESULTS
S. maltophilia was recovered from 14 ICU patients (12 infected, 2 colonized) between February 1993 and February 1994. Ten of the 14 patient isolates and 1 environmental isolate were available for PFGE typing. Patient isolates from 6 of the first 10 patients were identical. Isolates from the next 3 of 4 patients and an isolate recovered from a ventilator being used by a patient not infected with S. maltophilia also were identical, but different from the first 6. The ventilator isolate was temporally associated with the latter 4 patients.


CONCLUSIONS
Molecular typing allowed us to determine that there were two separate consecutive S maltophilia outbreaks rather than a single protracted outbreak. Recovery of S. maltophilia from patient ventilators and an in-line suction catheter suggests that the organism may have been spread by cross-contamination from contaminated equipment or from an environmental source.
Alfieri
N
N
Calgary District Hospital Group, Alberta, Canada.
Ramotar
K
K
Armstrong
P
P
Spornitz
M E
ME
Ross
G
G
Winnick
J
J
Cook
D R
DR
D000368:Aged; D003428:Cross Infection / Q000453:epidemiology*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis; D004196:Disease Outbreaks; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology* / Q000235:genetics; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D014974:Xanthomonas / Q000235:genetics
D004269:DNA, Bacterial