Prevalence of Candida Infection at the Intensive Care Unit with Nested Polymerase Chain Reaction (PCR) Using Primer Mixes Specific to Candida DNA Topoisomerase II Genes

Abstract

Background: The occurrence of invasive Candida infections has increased during the past two decades as a result of increasing in the number of immunocompromised patients. Objectives: In this study (cross sectional design), during six months, the prevalence patterns of Candida species isolated from sterile body sites of patients admitted to the general hospital of Milad Intensive Care Units (ICUs) in Tehran (Iran), were determined. Methods: Candidal isolates were obtained from 50 patients admitted to Milad ICUs from April to September 2013. Identification of the isolates was performed using morphological and Polymerase Chain Reaction assay. For identification of Candida at the species level, degenerated and specific primers based on the genomic sequences of DNA topoisomerase II of Candida species were used and their specificities tested by PCR-based identifications. Results: A total of 67 Candida isolates were obtained from 50 patients. Out of 67 Candida isolates, 47.8% were C. glabrata, 28.3% were C. albicans, 7.5% were C. tropicalis, 7.5% were C. guilliermondii, 3% were C. krusei and 4.4% were C. dubliniensis. The main patient group affected by candidal infections was aged 50 to 70 years. Overall, 11.7% of patients had cancer while other diseases such as diabetes were less reported. The mean time of stay at the ICU before identification was 25.3 days (ranging from 2 to 120 days). Conclusions: Increase in the prevalence of non-C. albicans species in the recent years has become a problematic event amongst clinicians caring for ICU patients. Candida glabrata is the most common species isolated from ICU patients in comparison with other species in this study. These findings emphasized on the significance of organizing treatable prevention programs.