[9] The genus Lichtheimia contains four species, of which L. corymbifera and L. ramosa have been reported from human infections.[10] Reviews describing the less common members of Mucorales causing the remaining 20–30% of mucormycosis cases mostly include Actinomucor, Apophysomyces, Cokeromyces, Cunninghamella, Rhizomucor, Saksenaea and Syncephalastrum.[3, 11] The prognosis of invasive mucormycosis remains poor, with recently reported mortality Bortezomib cell line rates varying between 45% and 64%, and in some report 85%,[12] depending on the underlying disease.[13, 14] Early recognition of the source of infection is among the key elements in successful management of infection.[15] Conventional
diagnosis is difficult because symptoms, signs, radiographic manifestations and histopathology of mucormycosis are non-specific,[6] and culture of sputum, paranasal sinus secretions or bronchoalveolar lavage fluid is frequently unsuccessful. In general conventional diagnostics are slow, unsuited for screening purposes and may have limited specificity. selleck chemicals Mucoralean fungi are particularly suitable for molecular techniques because interspecific distances tend to be large and intraspecific variability is relatively low.[11] The most common molecular method in clinics so far is sequencing of the ITS and D1/D2 ribosomal
DNA (rDNA) regions and Blast comparison in available databases. Rolling circle amplification (RCA) is an isothermal amplification method which has been proved to be rapid, cost-effective and specific for molecular identification of pathogenic fungi.[16-18] In this paper, we propose seven padlock probes on the basis of the rDNA ITS region to identify the most clinical relevant taxa of Mucorales, viz. R. microsporus, R. arrhizus var. arrhizus, R. arrhizus var. delemar, M. irregularis (formerly Rhizomucor variabilis), M. circinelloides, L. ramosa and L. corymbifera. In total 42 strains from reference
collection of the Centraalbureau voor Schimmelcultures (CBS-KNAW Fungal Biodiversity Centre, Utrecht, the Netherlands), were used in this study and are listed in Table 1. Dichloromethane dehalogenase The set included six strains each of R. microsporus, R. arrhizus var. arrhizus, R. arrhizus var. delemar, M. irregularis, M. circinelloides, L. ramosa and L. corymbifera, including strains tested as negative controls. Isolates were identified with different genetic markers prior this study and there is no conflict about their taxonomic identification.[8, 11, 19] Lyophilised strains were grown on 5% Malt Extract Agar (MEA; Oxoid, Basingstoke, UK) in 8 cm culture plates incubated at 30 °C for 3 days. DNA was extracted using a CTAB method as described previously.[19] ITS amplicons were generated with primers V9G and LS266. The ITS amplicons were used as targets for RCA reactions. ITS sequences of all strains were aligned and adjusted manually using BioNumerics v. 4.