Downloaded from www.microbiologyresearch.org by IP: 54.70.40.11 On: Thu, 25 Oct 2018 20:56:53 Multilocus sequence typing of Candida albicans isolates from a burn intensive care unit in Iran Mohammad H. Afsarian, 1,2 Hamid Badali, 1 Teun Boekhout, 3 Tahereh Shokohi 1 and Farzad Katiraee 4 Correspondence Tahereh Shokohi shokohi.tahereh@gmail.com Received 2 December 2014 Accepted 22 December 2014 1 Department of Medical Mycology and Parasitology/Invasive Fungi Research Center (IFRC), School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran 2 Department of Microbiology, Fasa University of Medical Sciences, Fasa, Iran 3 CBS Fungal Biodiversity Centre (CBS-KNAW), Utrecht, The Netherlands 4 Department of Pathobiology, Division of Mycology, School of Veterinary Medicine, University of Tabriz, Tabriz, Iran Burn intensive care unit (BICU) patients are specifically exposed to deep-seated nosocomial infections due to Candida albicans. Superficial carriage of C. albicans is a potential source of infection and dissemination, and typing methods could be useful to trace the different isolates. Multilocus sequence typing is a powerful genotyping method for pathogenic micro-organisms, including Candida albicans. Thirty clinical isolates of C. albicans obtained from 22 patients that were admitted to the BICU from a burn hospital at Sari, Mazandaran state, Iran, were studied epidemiologically by multilocus sequence typing (MLST). Seventy-five variable nucleotide sites were found. Sixty-two alleles were identified among the seven loci of the C. albicans isolates and one new allele was obtained. Eighteen diploid sequence types (DSTs) were identified, and among those 10 were new. These isolates belonged to nine clonal clusters (CCs) while two isolates occurred as singletons. Eleven (36.7 %) isolates belonged to CC 124 after eBURST analysis and 13 isolates (43.3 %) were assigned to clade 4. Approximately 17 % of the 30 isolates belonged to clade 1 (CC 69 and CC 766). Isolates from several patients with burns were found to be related genetically. Some patients yielded multiple isolates with identical DSTs, suggesting colonization or infection caused by cross-contamination between patients. Isolates that show identical or similar allelic profiles are presumed to be identical or closely related and may be used to evaluate the genetic relationships between isolates from a specific environment such as the BICU. INTRODUCTION Fungal infections due to Candida species have increased during recent decades as these yeasts have emerged as an important opportunistic fungal pathogen. Candida species can cause various clinical manifestations ranging from superficial to systemic candidiasis in either immunocom- petent or immunocompromised hosts (Garcia-Hermoso et al., 2007; Odds et al., 2007; Pfaller & Diekema 2007; Fesharaki et al., 2013). Infections due to C. albicans are an important cause of morbidity and mortality among hospitalized patients who have been admitted to inten- sive care units (ICUs) and in oncology wards worldwide (Bougnoux et al., 2006, 2008; Horn et al., 2009; Tortorano et al., 2012; Sardi et al., 2013). Burn patients are especially susceptible to Candida infections because they have most of the risk factors for hospital-acquired fungal infections, i.e. cutaneous and vascular portals of entry (inhabiting catheters, parenteral nutrition) and broad-spectrum anti- microbial therapy. In most cases, colonization by C. albicans of the skin or mucosa occurs before invasion and systemic infection, and colonization may be a major reservoir for cross-contamination. Therefore, identification of the source of colonization and the transmission route of infection will contribute to the prevention of nosocomial infections due to C. albicans among burn patients (Bougnoux et al., 2004; Lee et al., 2013). Nosocomial candidiasis caused by C. albicans requires a precise understanding of the epidemiology in different geographical regions using a reliable typing system. Recently, several molecular typing techniques have been used to study epidemiological relationships of C. albicans isolates such as randomly amplified polymorphic DNA (Robert et al., 1995), RFLP (Vazquez et al., 1993), Southern blot hybridization with discriminating probes (Myoung et al., 2011), amplified fragment length polymorphism analysis (Borst et al., 2003) and microsatellites length Abbreviations: BICU, burn intensive care unit; CC, clonal cluster; DST, diploid sequence type; MLST, multilocus sequence typing. Journal of Medical Microbiology (2015), 64, 248–253 DOI 10.1099/jmm.0.000015 248 000015 G 2015 The Authors Printed in Great Britain