Dematiaceous fungal pathogens: analysis of ribosomal DNA gene polymorphism by polymerase chain reaction–restriction fragment length polymorphism

Abstract

Restriction fragment length polymorphisms (RFLP) of ribosomal gene small subunit (SSU rDNA) and internal transcribed spacer (ITS) regions was examined in 12 isolates of dematiaceous agents of chromoblastomycosis and phaeohyphomycosis. The amplicon length of the fragment ITS1-ITS4, comprising the 5.8 rDNA and ITS1-ITS2 spacers, ranged in size from 620 to 690 bp. This result indicated a polymorphism of size in this region. Additionally the RFLP profiles showed a high degree of inter- and intra-specific variability. In contrast, the SSU rDNA amplification, using NS1-NS2 primers, originated a fragment of approximately 570 bp and its restriction profile proved to be well conserved among the species studied and was clustered into only two genetically heterogeneous groups, the first one formed by Fonsecaea pedrosoi and Fonsecaea compacta and the second one formed by Cladophialophora (Cladosporium) carrionii, Cladophialophora (Xylohypha) bantiana, Phialophora verrucosa and Rhinocladiella species.

Synthetic Consolidants Attacked by Melanin-Producing Fungi: Case Study of the Biodeterioration of Milan (Italy) Cathedral Marble Treated with Acrylics

“…In the case of meristematic fungi, the main drawbacks of culture are the length of time (at least 1 month) that is necessary for growth and their morphological plasticity, which greatly prevents direct microscopic identification. As a consequence, DNA-based methods have been successfully applied to studies of dematiaceous fungus colonization on different kinds of sample environments; these methods include restriction fragment length polymorphism analysis (3,10,30,31), random amplified polymorphic DNA analysis (34), and partial or complete 18S rRNA gene sequencing (2,16,25). For this reason we employed sequencing of DGGE bands to detect fungi independently from cultivation.…”

Specific Oligonucleotide Primers for Identification ofCladophialophora carrionii, a Causative Agent of Chromoblastomycosis

“…Because C. carrionii and C. bantiana are morphologically very similar, differentiation according to morphological characteristics is difficult. Analysis of ribosomal DNAs by restriction fragment length polymorphisms revealed that C. carrionii and C. bantiana have DNA restriction patterns that are identical to those of most enzymes (6). Our PCR assay offers a reliable method to discriminate these species.…”

Rapid Identification of the Genus Fonsecaea by PCR with Specific Oligonucleotide Primers

“…F. compacta has been reported to be a dysplastic variety of F. pedrosoi (5). In addition, 18S and ITS restriction fragment length polymorphism patterns for this species identical to those for F. pedrosoi have been demonstrated by the use of several restriction enzymes (2,6). However, the two species show distinct morphological characteristics; F. pedrosoi produces slender conidia generated by loosely branched conidiogenous cells, whereas F. compacta produces spherical conidia generated by densely clustered conidiogenous cells (8).…”