Nosocomial Candida glabrata colonization: an epidemiologic study

Abstract

Candida glabrata has emerged as an important nosocomial pathogen, yet little is known about its epidemiology. We prospectively followed 98 patients admitted to a medical intensive care unit and the bone marrow transplant unit of a university hospital. Samples from environmental surfaces and the hands of hospital personnel were also cultured. Patients with newly acquired C. glabrata strains were compared to controls who were culture negative for C. glabrata. C. glabrata was recovered from multiple sites from 24 patients and three environmental surfaces. Sixteen patients (17%) acquired C. glabrata after admission to the study units. Significant risk factors for the nosocomial acquisition of C. glabrata were prolonged duration of hospitalization in the unit and prior antimicrobial use. Strain delineation by restriction enzyme analysis revealed 28 different strains of C. glabrata; three strain types were common to nine patients. The environmental isolates were of the same strain type and common to five patients (four patients with newly acquired strains). These results suggest the possibility of exogenous nosocomial acquisition of C. glabrata, including the possible acquisition from the hospital environment. Transmission may be by indirect contact since identical strains of C. glabrata were recovered from patients who were geographically and temporally associated.

FIG. 1

Agarose gel electrophoresis of chromosomal DNA of C. glabrata with the restriction enzyme MspI. Lane O, bacteriophage lambda digested with EcoRI, used as a control; lanes A to G and J to N, clinical isolates from 12 separate patients; lanes H and I, environmental isolates; lane A, strain type 12; lanes B, D, F, G, H, and I, strain type 02; lane C, strain type 01; lane E, strain type 03; lanes J, K, L, and N, strain type 04; lane M, strain type 05.

FIG. 2

Schematic floor plan of the MICU and the BMTU. Circled numbers denote patients with newly acquired C. glabrata isolates. Squared numbers denote environmental samples culture positive for C. glabrata. The numbers 01 to 27 denote the separate strain types isolated from patients and the environment. The numbers 1 to 24 and 25 to 34 in the upper right-hand corner of each box denote patient room numbers.