Diversity and frequency of yeasts in the lower respiratory tract of TICU patients
Lackner M., Rainer J., Mayr A., Koller W., Pedross F. & Pöder R. (2010) Diversity and frequency of yeasts in the lower respiratory tract of TICU patients
Sydowia 62 (1): 57–66
Preceding yeast colonisation is known to be a major risk factor for candidemia in special patient groups. Some yeasts are resistant to routinely used antifungals, biodiversity of the colonising strains is a critical point for therapy and the course of a possible infection. Diversity and frequency of yeasts in the respiratory tract of Trauma-Intensive-Care-Unit (TICU) patients without preventive antimycotic treatment were analysed in view of TICU stay duration and age groups. Two-hundred respiratory-tract-secretion samples (RTSS: sputum, tracheal and bronchial secretions, broncho-alveolar lavages) were serially taken from all TICU-patients stationed during a period of four months. RTSS were inoculated on a new semi-selective medium (SceSel+). Pure cultures (n = 493) from RTSS were identified by morphological and physiological means. Statistical analyses were conducted to determine correlations between patient age, duration of TICU stay, and patterns of colonising microorganisms. Of the RTSS, 108 were yeast-positive (54.0 %). Yeasts identified as Candida albicans occurred in 46.0 % of all RTSS, C. glabrata (10.0 %), C. lusitaniae (4.5 %), C. tropicalis (4.0 %), C. dubliniensis (2.5 %), Rhodotorula sp. (1.0 %), C. famata, and C. kefyr (0.5 %). In 84 samples (42.0 %), only strains of one species were isolated, 9.5 % contained two, while three or more were identified in 2.5 % of the samples. Colonisation by C. glabrata positively correlated with duration of the TICU stay. Duration of the TICU stay and patients’ age are considered as main risk factors for multiple yeast colonisations shifting to therapy refractory yeasts. Yeast diversity increased significantly with age and duration of TICU stay. More than 50 % of patients younger than 30 years were almost exclusively colonised by C. albicans (22 out of 42 patients).
Keywords: epidemiology, Candida spp., intensive care, yeast consortia, risk factors