Session Type: ePosters
Session Title: ePosters
Authors(s): J. Serrano-Lobo (1, 2), A. Gómez (1, 2), B. Rodríguez-Sánchez (1, 2), P. Muñoz (1, 2, 3, 4), P. Escribano (1, 2), J. Guinea (1, 2, 3)
Authors Affiliations(s): (1) Gregorio Marañon Hospital, Spain, (2) Instituto de Investigación Sanitaria, Hospital Gregorio Marañón, Spain, (3) CIBER Enfermedades Infecciosas-CIBERES (CB06/06/0058), Spain, (4) Medicine Department, Faculty of Medicine, Universidad Complutense de Madrid, Spain
Background:
Azole-containing agar allows conducting antifungal susceptibility testing against Aspergillus fumigatus routinely. We evaluated the impact of the kind of plastic trays used to prepare in-house agar plates on the performance of the procedure against A. fumigatus sensu stricto and cryptic species.
Methods:A. fumigatus sensu stricto [n=91] and cryptic species [n=52] were tested (EUCAST E.Def 9.3.2) and classified as susceptible or resistant (EUCAST breakpoints v10). In-house azole-containing agar plates were prepared according to EUCAST E.Def 10.1 procedure using three multi-dish plate kinds (Nunc® tissue-treated plates, Nunc® non-tissue-treated plates and Labclinics® tissue-treated plates). Sensitivity, specificity, and agreement values of the agar plates to screen for azole resistance were assessed.
Results:Overall, sensitivity/specificity agar plates containing itraconazole, voriconazole, or posaconazole to search for azole resistance against A. fumigatus sensu stricto were, respectively, 97.1/95.9, 78.9/95 and 31.3/99.4. Values against cryptic species were much lower. Sensitivity and specificity values were not impacted by the kind of trays used. Azole-containing agar method classified all isolates harbouring TR34-L98H substitutions as resistant to both itraconazole and voriconazole; however, false susceptibility (very major errors) to posaconazole was not uncommon and happened in isolates with posaconazole MICs of 0.25 mg/L. Isolates harbouring the G54R and TR46-Y121F-T289A substitutions were correctly classified by the agar method for the three drugs. False resistance (major errors) occurred in isolates showing tinny fungal growth. Finally, agreements between both procedures against the cryptic species were much lower.
Conclusions:Azole-containing agar plates proved to be an easy-to-use and reliable method to screen for azole resistance in A. fumigatus sensu stricto; the method was minimally impacted by the type of plastic tray used. The performance against cryptic species was rather poor.
Keyword(s): Aspergillus fumigatus, Azoles, ResistanceCOI Other: This work was supported by grants PI18/01155 from Fondo de Investigación Sanitaria (FIS. Instituto de Salud Carlos III. Plan Nacional de I+D+I 2013-2016). The study was co-funded by the European Regional Development Fund (FEDER) ‘A way of making Europe.’
Session Type: ePosters
Session Title: ePosters
Authors(s): J. Serrano-Lobo (1, 2), A. Gómez (1, 2), B. Rodríguez-Sánchez (1, 2), P. Muñoz (1, 2, 3, 4), P. Escribano (1, 2), J. Guinea (1, 2, 3)
Authors Affiliations(s): (1) Gregorio Marañon Hospital, Spain, (2) Instituto de Investigación Sanitaria, Hospital Gregorio Marañón, Spain, (3) CIBER Enfermedades Infecciosas-CIBERES (CB06/06/0058), Spain, (4) Medicine Department, Faculty of Medicine, Universidad Complutense de Madrid, Spain
Background:
Azole-containing agar allows conducting antifungal susceptibility testing against Aspergillus fumigatus routinely. We evaluated the impact of the kind of plastic trays used to prepare in-house agar plates on the performance of the procedure against A. fumigatus sensu stricto and cryptic species.
Methods:A. fumigatus sensu stricto [n=91] and cryptic species [n=52] were tested (EUCAST E.Def 9.3.2) and classified as susceptible or resistant (EUCAST breakpoints v10). In-house azole-containing agar plates were prepared according to EUCAST E.Def 10.1 procedure using three multi-dish plate kinds (Nunc® tissue-treated plates, Nunc® non-tissue-treated plates and Labclinics® tissue-treated plates). Sensitivity, specificity, and agreement values of the agar plates to screen for azole resistance were assessed.
Results:Overall, sensitivity/specificity agar plates containing itraconazole, voriconazole, or posaconazole to search for azole resistance against A. fumigatus sensu stricto were, respectively, 97.1/95.9, 78.9/95 and 31.3/99.4. Values against cryptic species were much lower. Sensitivity and specificity values were not impacted by the kind of trays used. Azole-containing agar method classified all isolates harbouring TR34-L98H substitutions as resistant to both itraconazole and voriconazole; however, false susceptibility (very major errors) to posaconazole was not uncommon and happened in isolates with posaconazole MICs of 0.25 mg/L. Isolates harbouring the G54R and TR46-Y121F-T289A substitutions were correctly classified by the agar method for the three drugs. False resistance (major errors) occurred in isolates showing tinny fungal growth. Finally, agreements between both procedures against the cryptic species were much lower.
Conclusions:Azole-containing agar plates proved to be an easy-to-use and reliable method to screen for azole resistance in A. fumigatus sensu stricto; the method was minimally impacted by the type of plastic tray used. The performance against cryptic species was rather poor.
Keyword(s): Aspergillus fumigatus, Azoles, ResistanceCOI Other: This work was supported by grants PI18/01155 from Fondo de Investigación Sanitaria (FIS. Instituto de Salud Carlos III. Plan Nacional de I+D+I 2013-2016). The study was co-funded by the European Regional Development Fund (FEDER) ‘A way of making Europe.’
Session Type: ePosters
Session Title: ePosters
Authors(s): J. Serrano-Lobo (1, 2), A. Gómez (1, 2), B. Rodríguez-Sánchez (1, 2), P. Muñoz (1, 2, 3, 4), P. Escribano (1, 2), J. Guinea (1, 2, 3)
Authors Affiliations(s): (1) Gregorio Marañon Hospital, Spain, (2) Instituto de Investigación Sanitaria, Hospital Gregorio Marañón, Spain, (3) CIBER Enfermedades Infecciosas-CIBERES (CB06/06/0058), Spain, (4) Medicine Department, Faculty of Medicine, Universidad Complutense de Madrid, Spain
Background:
Azole-containing agar allows conducting antifungal susceptibility testing against Aspergillus fumigatus routinely. We evaluated the impact of the kind of plastic trays used to prepare in-house agar plates on the performance of the procedure against A. fumigatus sensu stricto and cryptic species.
Methods:A. fumigatus sensu stricto [n=91] and cryptic species [n=52] were tested (EUCAST E.Def 9.3.2) and classified as susceptible or resistant (EUCAST breakpoints v10). In-house azole-containing agar plates were prepared according to EUCAST E.Def 10.1 procedure using three multi-dish plate kinds (Nunc® tissue-treated plates, Nunc® non-tissue-treated plates and Labclinics® tissue-treated plates). Sensitivity, specificity, and agreement values of the agar plates to screen for azole resistance were assessed.
Results:Overall, sensitivity/specificity agar plates containing itraconazole, voriconazole, or posaconazole to search for azole resistance against A. fumigatus sensu stricto were, respectively, 97.1/95.9, 78.9/95 and 31.3/99.4. Values against cryptic species were much lower. Sensitivity and specificity values were not impacted by the kind of trays used. Azole-containing agar method classified all isolates harbouring TR34-L98H substitutions as resistant to both itraconazole and voriconazole; however, false susceptibility (very major errors) to posaconazole was not uncommon and happened in isolates with posaconazole MICs of 0.25 mg/L. Isolates harbouring the G54R and TR46-Y121F-T289A substitutions were correctly classified by the agar method for the three drugs. False resistance (major errors) occurred in isolates showing tinny fungal growth. Finally, agreements between both procedures against the cryptic species were much lower.
Conclusions:Azole-containing agar plates proved to be an easy-to-use and reliable method to screen for azole resistance in A. fumigatus sensu stricto; the method was minimally impacted by the type of plastic tray used. The performance against cryptic species was rather poor.
Keyword(s): Aspergillus fumigatus, Azoles, ResistanceCOI Other: This work was supported by grants PI18/01155 from Fondo de Investigación Sanitaria (FIS. Instituto de Salud Carlos III. Plan Nacional de I+D+I 2013-2016). The study was co-funded by the European Regional Development Fund (FEDER) ‘A way of making Europe.’
Session Type: ePosters
Session Title: ePosters
Authors(s): J. Serrano-Lobo (1, 2), A. Gómez (1, 2), B. Rodríguez-Sánchez (1, 2), P. Muñoz (1, 2, 3, 4), P. Escribano (1, 2), J. Guinea (1, 2, 3)
Authors Affiliations(s): (1) Gregorio Marañon Hospital, Spain, (2) Instituto de Investigación Sanitaria, Hospital Gregorio Marañón, Spain, (3) CIBER Enfermedades Infecciosas-CIBERES (CB06/06/0058), Spain, (4) Medicine Department, Faculty of Medicine, Universidad Complutense de Madrid, Spain
Background:
Azole-containing agar allows conducting antifungal susceptibility testing against Aspergillus fumigatus routinely. We evaluated the impact of the kind of plastic trays used to prepare in-house agar plates on the performance of the procedure against A. fumigatus sensu stricto and cryptic species.
Methods:A. fumigatus sensu stricto [n=91] and cryptic species [n=52] were tested (EUCAST E.Def 9.3.2) and classified as susceptible or resistant (EUCAST breakpoints v10). In-house azole-containing agar plates were prepared according to EUCAST E.Def 10.1 procedure using three multi-dish plate kinds (Nunc® tissue-treated plates, Nunc® non-tissue-treated plates and Labclinics® tissue-treated plates). Sensitivity, specificity, and agreement values of the agar plates to screen for azole resistance were assessed.
Results:Overall, sensitivity/specificity agar plates containing itraconazole, voriconazole, or posaconazole to search for azole resistance against A. fumigatus sensu stricto were, respectively, 97.1/95.9, 78.9/95 and 31.3/99.4. Values against cryptic species were much lower. Sensitivity and specificity values were not impacted by the kind of trays used. Azole-containing agar method classified all isolates harbouring TR34-L98H substitutions as resistant to both itraconazole and voriconazole; however, false susceptibility (very major errors) to posaconazole was not uncommon and happened in isolates with posaconazole MICs of 0.25 mg/L. Isolates harbouring the G54R and TR46-Y121F-T289A substitutions were correctly classified by the agar method for the three drugs. False resistance (major errors) occurred in isolates showing tinny fungal growth. Finally, agreements between both procedures against the cryptic species were much lower.
Conclusions:Azole-containing agar plates proved to be an easy-to-use and reliable method to screen for azole resistance in A. fumigatus sensu stricto; the method was minimally impacted by the type of plastic tray used. The performance against cryptic species was rather poor.
Keyword(s): Aspergillus fumigatus, Azoles, ResistanceCOI Other: This work was supported by grants PI18/01155 from Fondo de Investigación Sanitaria (FIS. Instituto de Salud Carlos III. Plan Nacional de I+D+I 2013-2016). The study was co-funded by the European Regional Development Fund (FEDER) ‘A way of making Europe.’