ORIGINAL ARTICLE Molecular typing of clinical Candida strains using random amplified polymorphic DNA and contour-clamped homogenous electric fields electrophoresis E. Noumi 1,2 , M. Snoussi 1 , F. Saghrouni 3 , M. Ben Said 3 , L. Del Castillo 2 , E. Valentin 2 and A. Bakhrouf 1 1 Laboratoire d’Analyse, Traitement et Valorisation des Polluants de l’Environnement et des Produits, De ´ partement de Microbiologie, Faculte ´ de Pharmacie, Monastir, Tunisie 2 Departamento de Microbiologia y Ecologı´a, Facultad de Farmacia, Universidad de Valencia, Burjassot, Valencia, Spain 3 Laboratoire de Parasitologie, Ho ˆ pital Farhat Hached de Sousse, Sousse, Tunisie Introduction The origin of candidiasis can be either endogenous or exogenous. Knowing the source of infection can help with the prevention of clonal spread of pathogenic fungi, the prevention of clinical infection and selection of antifungal treatment (Edwards 2000). Candida species are opportu- nistic pathogens. They occur as normal commensals in a large proportion of healthy individuals (Pei et al. 2007). Candida albicans, and a lesser extent Candida glabrata, are the most commonly involved species. On the other hand, C. albicans is frequently isolated from stomatitis in denture wearing. Vulvovaginal candidiasis is a common problem in women in many health care clinics (Nyirjesy et al. 2006). It was estimated that 75% of women have at least one episode of vaginitis during their lifetime (Lanchares and Hernandez 2000), whereas vulvovaginal candidiasis affects 5% of women of childbearing age (Ringdahl 2006). However, denture stomatitis is a common inflammatory condition that affects denture wearers especially caused by C. albicans. Pathogenic yeast species live as normal commensals of the oral cavity in 30–60% of healthy individuals (Haberland-Carrodeguas et al. 2002). Several virulence factors in Candida species, especially C. albicans, such as production of hydrolytic enzymes and biofilm formation on surfaces and cells can contribute to their pathogenicity (Ghannoum 2000). An investigation of the genetic relatedness between clinical Candida strains may be of great importance in clinical diagnosis, Keywords Candida albicans, Candida glabrata, CHEF electrophoresis, DNA fingerprinting, RAPD, stomatitis, vaginitis. Correspondence Emira Noumi, Laboratoire d’Analyse, Traitement et Valorisation des Polluants de l’Environnement et des Produits, De ´ partement de Microbiologie, Faculte ´ de Pharmacie, Monastir, Tunisie. E-mail: emira_noumi@yahoo.fr 2008 ⁄ 2066: received 2 December 2008, revised 29 April 2009 and accepted 30 April 2009 doi:10.1111/j.1365-2672.2009.04384.x Abstract Aims: This report describes an investigation into the genetic profiles of 38 Candida albicans and 19 Candida glabrata strains collected from a dental hospital of Monastir (Tunisia) and the Laboratory of Parasitology, Farhat Hached Hospi- tal of Sousse (Tunisia), using two typing methods: random amplified polymor- phic DNA (RAPD) and contour-clamped homogenous electric fields (CHEF). Methods and Results: The two methods (RAPD and CHEF electrophoresis) were able to identify clonal-related isolates from different patients. RAPD method using two primers (CA1 and CA2) exhibited the highest discriminatory power by discriminating 22 genotypes for C. albicans with CA1 oligonucleo- tides and 19 genotypes with CA2 primer. For C. glabrata, 17 genotypes were obtained when both primers CA1 and CA2 were combined. The CHEF karyo- typing of C. albicans has discriminated only 17 different karyotypes. Conclusion: The genotype of each isolate and genotypic difference among C. albicans and C. glabrata isolates were patient specific and not associated with the site of infection, geographic origin or date of isolation. Significance and Impact of the Study: Identification of relatedness between Candida species using molecular approaches with high discriminatory power is important in determining adequate measures for interruption of transmission of this yeast. Journal of Applied Microbiology ISSN 1364-5072 ª 2009 The Authors Journal compilation ª 2009 The Society for Applied Microbiology, Journal of Applied Microbiology 107 (2009) 1991–2000 1991