OBJECTIVES: The aim of this study was: (i) to study the prevalence of triazole-resistant Aspergillus fumigatus isolates in the Netherlands; and (ii) to design rapid real-time PCR methods to identify such isolates. METHODS: A novel mixed-format real-time PCR assay is described for the detection of mutations leading to triazole resistance in A. fumigatus. One set of PCR primers and a probe carrying a single fluorescent label in combination with a double-stranded DNA fluorescent dye allow simultaneous detection of (a) specific mutation(s) as well as of the amplified product that serves as an internal amplification control. The method was applied to a random collection of 209 clinical isolates from throughout the Netherlands and was compared with phenotypic susceptibility testing. RESULTS: A total of four triazole-resistant isolates were identified, resulting in a prevalence of resistant isolates of <2%. All four isolates contained an identical combination of mutations leading to multi-triazole resistance, as reported before by others. Molecular testing results were 100% concordant with phenotypic susceptibility testing. CONCLUSIONS: Although in specific patient populations the prevalence of resistance in A. fumigatus may be an emerging problem, in the general population it is still relatively low. The novel real-time PCR format allows rapid and reliable identification of such isolates.
OBJECTIVES: The aim of this study was: (i) to study the prevalence of triazole-resistant Aspergillus fumigatus isolates in the Netherlands; and (ii) to design rapid real-time PCR methods to identify such isolates. METHODS: A novel mixed-format real-time PCR assay is described for the detection of mutations leading to triazole resistance in A. fumigatus. One set of PCR primers and a probe carrying a single fluorescent label in combination with a double-stranded DNA fluorescent dye allow simultaneous detection of (a) specific mutation(s) as well as of the amplified product that serves as an internal amplification control. The method was applied to a random collection of 209 clinical isolates from throughout the Netherlands and was compared with phenotypic susceptibility testing. RESULTS: A total of four triazole-resistant isolates were identified, resulting in a prevalence of resistant isolates of <2%. All four isolates contained an identical combination of mutations leading to multi-triazole resistance, as reported before by others. Molecular testing results were 100% concordant with phenotypic susceptibility testing. CONCLUSIONS: Although in specific patient populations the prevalence of resistance in A. fumigatus may be an emerging problem, in the general population it is still relatively low. The novel real-time PCR format allows rapid and reliable identification of such isolates.
Authors: A Arastehfar; A Carvalho; J Houbraken; L Lombardi; R Garcia-Rubio; J D Jenks; O Rivero-Menendez; R Aljohani; I D Jacobsen; J Berman; N Osherov; M T Hedayati; M Ilkit; D James-Armstrong; T Gabaldón; J Meletiadis; M Kostrzewa; W Pan; C Lass-Flörl; D S Perlin; M Hoenigl Journal: Stud Mycol Date: 2021-05-10 Impact factor: 16.097
Authors: A Espinel-Ingroff; A Chowdhary; G M Gonzalez; C Lass-Flörl; E Martin-Mazuelos; J Meis; T Peláez; M A Pfaller; J Turnidge Journal: Antimicrob Agents Chemother Date: 2013-05-28 Impact factor: 5.191
Authors: Clara E Negri; Sarah S Gonçalves; Ana Cristina P Sousa; Maria Daniela Bergamasco; Marinês D V Martino; Flavio Queiroz-Telles; Valerio Rodrigues Aquino; Paulo de Tarso O Castro; Ferry Hagen; Jacques F Meis; Arnaldo L Colombo Journal: Antimicrob Agents Chemother Date: 2017-10-24 Impact factor: 5.191