It seems clear now that the majority of commensal and infecting populations of C. albicans from the same individuals are clonal in origin but subsequently undergo microevolution

at the site of colonization and through recurrent episodes of infection [5, 10, 11]. The microevolution of the strains is a frequent process in recurrent infections and it takes place in response to adaptive changes [9, 12]. A recent work which examined the “in vitro” dynamics of C. albicans populations Temsirolimus clinical trial in the presence or absence of fluconazole has shown that mutations that lead to increased drug resistance appear frequently [13]. Others authors suggest that natural C. albicans populations comprise a mixture of closely related strain types [6]. Typing methods have been described as useful tools for the differentiation between

strains isolated only once and those able to cause recurrent infections. Although several typing methods have been described for C. albicans (AFLP, RFLP-PCR or MLST), one of the most suitable is the fragment length PFT�� datasheet analysis of microsatellites called Microsatellite Length Polymorphism (MLP). This technique has a high discriminatory power and reproducibility. MLP analysis has proved its efficacy and reproducibility in a large number of epidemiological studies [9, 14–19]; however, this technique is not easy to use and the estimated cost per isolate remains high. The High Resolution selleck inhibitor Melting (HRM) provides a faster and cheaper method for microsatellite fragment analysis. This technique uses fluorescent DNA binding dyes with improved saturation properties allowing a precise assessment of sequence variation based on DNA melting curves analysis [20, 21]. The suitability of HRM to discriminate PCR products based on one nucleotide change has also been described. Some recent articles, focusing on the capacity of HRM to identify and genotype fungi, have been reported

[15, 22]. In this work, we developed a method based on HRM to assess the relatedness of strains in a clinical case of recurrent candiduria. The results were compared with the conventional MLP genotyping techniques. The isolates, recovered over a period of five years, many additionally showed significant differences in their susceptibility to antifungal agents. Antifungal susceptibility test and selection of resistant population was performed. Methods Origin of the strains and clinical data from the patient The strains were isolated from a 62 year old male with medullary sponge right kidney (Carchi-Ricci disease) and recurrent reno-urethral lithiasis subjected to several lithotripsies. The patient was admitted in a Tertiary General Hospital (Hospital Virgen de la Concha, Zamora, Spain) diagnosed with right pyelonephritis caused by obstructive kidney stones. C. albicans was isolated in blood cultures and urocultures.