Hemodialysis and Kidney Transplantation as Predisposing Conditions to Onychomycosis.

BACKGROUND/AIM: Onychomycosis (OM) is one of the commonest superficial fungal infections. Patients undergoing hemodialysis (HD) treatment and kidney transplant recipients (KTR) are considered at risk of contracting fungal infections, but the few published data do not reach the conclusion of whether they are predisposed to OM. This study aimed to determine the prevalence and etiology of OM in these patients and to determine the antifungal susceptibility profile of the isolated fungal species. METHODS: We recruited 149 HD patients, 187 KTR, and a control group comprising 174 patients attending an internal medicine service with other diseases than renal diseases. All patients underwent an examination of all toenails to check for the presence of OM. Antifungal susceptibility tests were performed following the Clinical and Laboratory Standards Institute (CLSI) recommendations. RESULTS: The prevalence rates of OM in HD patients (23.4%) and KTR (23.0%) were significantly higher than those in age- and sex-matched control groups (13.2%). In HD patients, OM was associated with diabetes but not with the duration of dialysis. In KTR, OM was more prevalent in those without diabetes and likely also in those using mycophenolate mofetil or azathioprine but was not associated with the duration of transplantation. Trichophyton rubrum was the most prevalent species (45.9%) followed by T. mentagrophytes (24.5%) and Candida parapsilosis (18.0%). Fluconazole, itraconazole, voriconazole, and terbinafine were all efficient against the isolates of dermatophyte, with terbinafine showing the lowest and fluconazole the highest minimal inhibitory concentrations. All isolates of C. parapsilosis were sensitive to the antifungals according to the CLSI criteria. CONCLUSION: We found a high prevalence of OM in HD and KTR patients and suggest that these conditions should be considered a risk factor of OM. All 4 antifungals evaluated in the study showed good in vitro activity against the etiologic agents.

The use of nested Polymerase Chain Reaction (nested PCR) for the early diagnosis of Histoplasma capsulatum infection in serum and whole blood of HIV-positive patients.

The aim of the study was to detect the rDNA sequences and their regions in Histoplasma capsulatum, which could be considered species-specific and used as a molecular method for this diagnosis by the technique of nested polymerase chain reaction (nested PCR), employing specific sequences (primers) for H. capsulatum: 18S rDNA region (HC18), 100 kDa (HC100) and the sequence 5.8 S-ITS rDNA (HC5.8). The PCR sequences HC18, HC100 and HC5.8 resulted in a specificity of 100%. The molecular assays may increase the specificity, sensitivity and speed in the diagnosis of Histoplasmosis.

The use of nested Polymerase Chain Reaction (nested PCR) for the early diagnosis of Histoplasma capsulatum infection in serum and whole blood of HIV-positive patients* / Uso da Reação em Cadeia da Polimerase aninhada (PCR aninhada) para o diagnóstico precoce da infecção pelo Histoplasma capsulatum no soro e no sangue total de pacientes HIV positivos

The aim of the study was to detect the rDNA sequences and their regions in Histoplasma capsulatum, which could be considered species-specific and used as a molecular method for this diagnosis by the technique of nested polymerase chain reaction (nested PCR), employing specific sequences (primers) for H. capsulatum: 18S rDNA region (HC18), 100 kDa (HC100) and the sequence 5.8 S-ITS rDNA (HC5.8). The PCR sequences HC18, HC100 and HC5.8 resulted in a specificity of 100%. The molecular assays may increase the specificity, sensitivity and speed in the diagnosis of Histoplasmosis.

O objetivo do estudo consistiu em detectar seqüências no ADNr e as suas regiões no Histoplasma capsulatum, que pudessem ser consideradas espécie-específicas e usadas como método molecular para o diagnóstico pela técnica da reação em cadeia da polimerase aninhada ("nested PCR") com seqüências específicas ("primers") para H. capsulatum: regiões 18S ADNr (HC18), 100kDa (HC100) e a seqüência 5.8 S ADNr-ITS (HC5.8). A "nested PCR" com as seqüências HC18, HC100 e HC5.8 resultaram em 100% de especificidade. Os ensaios moleculares podem aumentar a especificidade, sensibilidade e rapidez na diagnose da Histoplasmose.

Phylogeography of the fungal pathogen Histoplasma capsulatum.

Until recently, Histoplasma capsulatum was believed to harbour three varieties, var. capsulatum (chiefly a New World human pathogen), var. duboisii (an African human pathogen) and var. farciminosum (an Old World horse pathogen), which varied in clinical manifestations and geographical distribution. We analysed the phylogenetic relationships of 137 individuals representing the three varieties from six continents using DNA sequence variation in four independent protein-coding genes. At least eight clades were idengified: (i) North American class 1 clade; (ii) North American class 2 clade; (iii) Latin American group A clade; (iv) Latin American group B clade; (v) Australian clade; (vi) Netherlands (Indonesian?) clade; (vii) Eurasian clade and (viii) African clade. Seven of eight clades represented genetically isolated groups that may be recognized as phylogenetic species. The sole exception was the Eurasian clade which originated from within the Latin American group A clade. The phylogenetic relationships among the clades made a star phylogeny. Histoplasma capsulatum var. capsulatum individuals were found in all eight clades. The African clade included all of the H. capsulatum var. duboisii individuals as well as individuals of the other two varieties. The 13 individuals of var. farciminosum were distributed among three phylogenetic species. These findings suggest that the three varieties of Histoplasma are phylogenetically meaningless. Instead we have to recognize the existence of genetically distinct geographical populations or phylogenetic species. Combining DNA substitution rates of protein-coding genes with the phylogeny suggests that the radiation of Histoplasma started between 3 and 13 million years ago in Latin America.