Biotype stability of Candida albicans isolates after culture storage determined by randomly amplified polymorphic DNA and phenotypical methods.
Typing methods to evaluate isolates in relation to their phenotypical and molecular characteristics are essential in epidemiological studies. In this study, Candida albicans biotypes were determined before and after storage in order to verify their stability. Twenty C. albicans isolates were typed by Randomly Amplified Polymorphic DNA (RAPD), production of phospholipase and proteinase exoenzymes (enzymotyping) and morphotyping before and after 180 days of storage in Sabouraud dextrose agar (SDA) and sterilised distilled water. Before the storage, 19 RAPD patterns, two enzymotypes and eight morphotypes were identified. The fragment patterns obtained by RAPD, on the one hand, were not significantly altered after storage. On the other hand, the majority of the isolates changed their enzymotype and morphotype after storage. RAPD typing provided the better discriminatory index (DI) among isolates (DI = 0.995) and maintained the profile identified, thereby confirming its utility in epidemiological surveys. Based on the low reproducibility observed after storage in SDA and distilled water by morphotyping (DI = 0.853) and enzymotyping (DI = 0.521), the use of these techniques is not recommended on stored isolates.
Bacelo
Katia Leston
KL
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil. katialbacelo@gmail.com
da Costa
Karen Regina Carim
KR
Ferreira
Joseane Cristina
JC
Candido
Regina Celia
RC
D002176:Candida albicans / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D004271:DNA, Fungal / Q000235:genetics; D005656:Fungal Proteins / Q000378:metabolism; D042822:Genomic Instability; D005838:Genotype; D006801:Humans; D016533:Mycological Typing Techniques; D009172:Mycology / Q000379:methods*; D010447:Peptide Hydrolases / Q000378:metabolism; D010641:Phenotype; D010740:Phospholipases / Q000378:metabolism; D011309:Preservation, Biological; D019105:Random Amplified Polymorphic DNA Technique; D013048:Specimen Handling / Q000379:methods*
D004271:DNA, Fungal; D005656:Fungal Proteins; D010740:Phospholipases; D010447:Peptide Hydrolases