Molecular identification, phylogenetic analysis and antifungal susceptibility patterns of Aspergillusnidulans complex and Aspergillusterreus complex isolated from clinical specimens

OBJECTIVE

Aspergillus sections Terrei and Nidulantes are the less common causes of invasive aspergillosis and pulmonary aspergillosis (PA) in immunocompromised patients when compared to A. fumigatus and A. flavus. Identifying these fungi as the infectious agent is crucial because of the resistance to amphotericin B (AMB) and increased lethality. The aim of this study was to identify the molecular status, evaluate the genetic diversity and examine the antifungal susceptibility profile of the uncommon Aspergillus species. Forty-five uncommon Aspergillus species were identified based on the microscopic and macroscopic criteria. Then, the molecular identification was performed using the sequencing beta tubulin (benA) gene. In vitro antifungal susceptibility to amphotericin B (AMB), itraconazole (ITC), ravuconazole (RAV), voriconazole (VRC), caspofungin (CFG) isavuconazole (ISA) and posaconazole (POS) test was performed according to the CLSI M38-A2 guidelines.

RESULTS

A. terreus was the most species detected, followed by A. nidulans, A. latus, A.ochraceus, and A. citrinoterreus, respectively. The analysis of the benA gene showed the presence of 12 distinct genotypes among the A. terreus isolates. The other species did not show any intraspecies variation. CFG exhibited the lowest MEC₅₀/MIC₅₀ (0.007μg/mL), followed by POS (0.125μg/mL), VRC, ITC, ISA (0.25μg/mL), RAV (0.5μg/mL), and AMB (8μg/mL). Among all the isolates, only 15.5% (7/45) were susceptible to AMB.

CONCLUSION

Antifungal susceptibility pattern of the uncommon Aspergillus species is useful to improve patient management and increase knowledge concerning the local epidemiology. Moreover, this information is necessary when an outbreak dealing with drug-resistant infections occurs.

Prevalence of allergic bronchopulmonary aspergillosis in cystic fibrosis patients using two different diagnostic criteria

Summary

Objective.There are different diagnostic criteria for the diagnosis of Allergic bronchopulmonary aspergillosis (ABPA) in CF patients. In this present study we evaluated the prevalence of ABPA in Iranian CF patients by two more usual diagnostic criteria as ISHAM working criteria (A) and CF Foundation Consensus Conference criteria (B). Methods.Eighty-six CF patients were included in the study. All CF patients underwent for Aspergillus skin prick test (AST), Aspergillus-specific IgE (sIgEAf) and Aspergillus-specific IgG (sIgGAf), total IgE. The ABPA prevalence was estimated by two diagnostic criteria, (A) and (B) and compared. Results. The frequency of positive AST, total IgE, sIgEAf and sIgGAf were 47 (54.6%), 9 (10.5%), 42 (48.8%) and 67 (77.9%), respectively. The obtained rate of ABPA prevalence (10.5%) was identical in two diagnostic criteria A and B (kappa value of 1.000). Conclusions.The applied diagnostic criteria had no significant effect on the reported rate of ABPA prevalence.