Biofilm Production by Candida Species and Inadequate Antifungal Therapy as Predictors of Mortality for Patients with Candidemia

• Published in: Journal of Clinical Microbiology 2007-06, Vol.45 (6), p.1843-1850
• Main Authors: Tumbarello, Mario, Posteraro, Brunella, Trecarichi, Enrico Maria, Fiori, Barbara, Rossi, Marianna, Porta, Rosaria, de Gaetano Donati, Katleen, La Sorda, Marilena, Spanu, Teresa, Fadda, Giovanni, Cauda, Roberto, Sanguinetti, Maurizio
• Format: Article
• Language: English
• Subjects: Aged; Antifungal Agents - pharmacology; Antifungal Agents - therapeutic use; Biofilms - drug effects; Biofilms - growth & development; Biological and medical sciences; Candida - classification; Candida - drug effects; Candida - growth & development; Candida albicans; Candida glabrata; Candida parapsilosis; Candida tropicalis; Candidiasis - drug therapy; Candidiasis - epidemiology; Candidiasis - microbiology; Candidiasis - mortality; Female; Fundamental and applied biological sciences. Psychology; Fungemia - drug therapy; Fungemia - epidemiology; Fungemia - microbiology; Fungemia - mortality; Hospitals, University; Humans; Infectious diseases; Italy - epidemiology; Male; Medical sciences; Microbial Sensitivity Tests; Microbiology; Middle Aged; Miscellaneous; Mycology; Predictive Value of Tests; Risk Factors
• ISSN: 0095-1137; 1098-660X; 1098-5530
• DOI: 10.1128/JCM.00131-07

Nosocomial Candida bloodstream infections rank among infections with highest mortality rates. A retrospective cohort analysis was conducted at Catholic University Hospital to estimate the risk factors for mortality of patients with candidemia. We reviewed records for patients with a Candida bloodstream infection over a 5-year period (January 2000 through December 2004). Two hundred ninety-four patients (42.1% male; mean age ± standard deviation, 65 ± 12 years) were studied. Patients most commonly were admitted with a surgical diagnosis (162 patients [55.1%]), had a central venous catheter (213 [72.4%]), cancer (118 [40.1%]), or diabetes (58 [19.7%]). One hundred fifty-four (52.3%) patients died within 30 days. Of 294 patients, 168 (57.1%) were infected by Candida albicans, 64 (21.7%) by Candida parapsilosis, 28 (9.5%) by Candida tropicalis, and 26 (8.8%) by Candida glabrata. When fungal isolates were tested for biofilm formation capacity, biofilm production was most commonly observed for isolates of C. tropicalis (20 of 28 patients [71.4%]), followed by C. glabrata (6 of 26 [23.1%]), C. albicans (38 of 168 [22.6%]), and C. parapsilosis (14 of 64 [21.8%]). Multivariable analysis identified inadequate antifungal therapy (odds ratio [OR], 2.35; 95% confidence interval [95% CI], 1.09 to 5.10; P = 0.03), infection with overall biofilm-forming Candida species (OR, 2.33; 95% CI, 1.26 to 4.30; P = 0.007), and Acute Physiology and Chronic Health Evaluation III scores (OR, 1.03; 95% CI, 1.01 to 1.15; P < 0.001) as independent predictors of mortality. Notably, if mortality was analyzed according to the different biofilm-forming Candida species studied, only infections caused by C. albicans (P < 0.001) and C. parapsilosis (P = 0.003) correlated with increased mortality. Together with well-established factors, Candida biofilm production was therefore shown to be associated with greater mortality of patients with candidemia, probably by preventing complete organism eradication from the blood.