Parity among interpretation methods of MLEE patterns and disparity among clustering methods in epidemiological typing of Candida albicans Marcelo Fabiano Gomes Boriollo a, * , Edvaldo Antonio Ribeiro Rosa b , Reginaldo Bruno Gonc ¸alves a , Jose ´ Francisco Ho ¨ fling a a Microbiology and Immunology Laboratory, Dental School of Piracicaba, State University of Campinas, Piracicaba, Brazil b Stomatology Laboratory, Center of Biological and Health Sciences, Pontifical Catholic University of Parana ´, Curitiba, Brazil Received 25 May 2004; received in revised form 17 May 2005; accepted 24 May 2005 Available online 11 July 2005 Abstract The typing of C. albicans by MLEE (multilocus enzyme electrophoresis) is dependent on the interpretation of enzyme electrophoretic patterns, and the study of the epidemiological relationships of these yeasts can be conducted by cluster analysis. Therefore, the aims of the present study were to first determine the discriminatory power of genetic interpretation (deduction of the allelic composition of diploid organisms) and numerical interpretation (mere determination of the presence and absence of bands) of MLEE patterns, and then to determine the concordance (Pearson product-moment correlation coefficient) and similarity (Jaccard similarity coefficient) of the groups of strains generated by three cluster analysis models, and the discriminatory power of such models as well [model A: genetic interpretation, genetic distance matrix of Nei (d ij ) and UPGMA dendrogram; model B: genetic interpretation, Dice similarity matrix (S D1 ) and UPGMA dendrogram; model C: numerical interpretation, Dice similarity matrix (S D2 ) and UPGMA dendrogram]. MLEE was found to be a powerful and reliable tool for the typing of C. albicans due to its high discriminatory power (N 0.9). Discriminatory power indicated that numerical interpretation is a method capable of discriminating a greater number of strains (47 versus 43 subtypes), but also pointed to model B as a method capable of providing a greater number of groups, suggesting its use for the typing of C. albicans by MLEE and cluster analysis. Very good agreement was only observed between the elements of the matrices S D1 and S D2 , but a large majority of the groups generated in the three UPGMA dendrograms showed similarity S J between 4.8% and 75%, suggesting disparities in the conclusions obtained by the cluster assays. D 2005 Elsevier B.V. All rights reserved. Keywords: Candida albicans ; MLEE patterns; Interpretation methods; Cluster analysis 0167-7012/$ - see front matter D 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.mimet.2005.05.012 * Corresponding author. Laboratatory of Microbiology and Immunology, Department of Oral Diagnostic, Dental School of Piracicaba, State University of Campinas, Av. Limeira 901, CEP13414-903 CP052, Piracicaba, SP, Brazil. Tel.: +55 19 3412 5321; fax: +55 19 3412 5218. E-mail address: marcelofgb@yahoo.com.br (M.F.G. Boriollo). Journal of Microbiological Methods 64 (2006) 346 – 365 www.elsevier.com/locate/jmicmeth