Application of multilocus enzyme electrophoresis to epidemiologic investigations of Xanthomonas maltophilia.

OBJECTIVE

To test the utility of a newly developed multilocus enzyme electrophoresis typing method for Xanthomonas maltophilia.

DESIGN

Isolates were first screened by slide agglutination, which served as the standard to characterize the outbreak strains. All isolates were then subjected to multilocus enzyme electrophoresis and the results analyzed based on epidemiological data.

SETTING

This outbreak occurred in a shock-trauma intensive care unit of a large general community hospital.

PATIENTS

Patients admitted to the shock-trauma intensive care unit who had X maltophilia isolated from any site greater than or equal to 24 hours after admission met the case definition. Specimens from patients who fit the case definition were characterized, as were specimens from other patients that were used as controls for nonoutbreak isolates. Environmental samples were also evaluated for X maltophilia.

RESULTS

Most of the 64 isolates received during this outbreak were serotype 10, and when they were subjected to multilocus enzyme electrophoresis, one electrophoretic type predominated and correlated to most outbreak isolates. Unrelated isolates of serotype 10 from other institutions all exhibited unique electrophoretic types.

CONCLUSION

Application of multilocus enzyme electrophoresis to X maltophilia outbreaks is a valuable addition to the characterization of suspected outbreak strains.