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Updated: Dec 28, 2025
Detection of Invasive Pulmonary Aspergillosis in Haematological Malignancy Patients by using Lateral-flow Technology
Published on: March 22, 2012
Prospective multicentre study on azole resistance in Aspergillus isolates from surveillance cultures in
A Prigitano1, M C Esposto1, A Grancini2
1Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy.
Objectives:
This study was conducted to assess the prevalence of azole resistance in Aspergillus isolates from patients with haematological malignancies or who were undergoing haematopoietic stem cell transplantation and to identify the molecular mechanism of resistance.
Methods:
In this 28-month prospective study involving 18 Italian centres, Aspergillus isolates from surveillance cultures were collected and screened for azole resistance, and mutations in the cyp51A gene were identified. Resistant isolates were genotyped by microsatellite analysis, and the allelic profiles were compared with those of resistant environmental and clinical isolates from the same geographical area that had been previously genotyped.
Results:
There were 292 Aspergillus isolates collected from 228 patients. The isolates belonged mainly to the section Fumigati (45.9%), Nigri (20.9%), Flavi (16.8%) and Terrei (4.8%). Three isolates showed itraconazole resistance: Aspergillus fumigatus sensu stricto, Aspergillus lentulus (section Fumigati) and Aspergillus awamori (section Nigri). The itraconazole resistance rates were 1% and 1.48% considering all Aspergillus spp. isolates and the Aspergillus section Fumigati, respectively. The prevalence of azole resistance among all the patients was 1.3%. Among patients harbouring A. fumigatus sensu stricto isolates, the resistance rate was 0.79%. The A. fumigatus isolate, with the TR34/L98H mutation, was genotypically distant from the environmental and clinical strains previously genotyped.
Conclusions:
In this study, the Aspergillus azole resistance rate was 1% (3/292). In addition to A. fumigatus sensu stricto, A. lentulus and A. awamori azole-resistant isolates were identified. Therefore, it is important have a correct identification at the species level to address a rapid therapy better, quickly understand the shift towards cryptic species and have an updated knowledge of the local epidemiology.
Insights
Azole resistance in Aspergillus is a concern, with a 1% prevalence found in immunocompromised patients. This study identified resistance in Aspergillus fumigatus, Aspergillus lentulus, and Aspergillus awamori, highlighting the need for accurate species identification.
Area of Science:
- Medical Mycology
- Antifungal Resistance
- Clinical Microbiology
Background:
- Azole antifungals are crucial for treating invasive Aspergillus infections, particularly in immunocompromised patients.
- Emergence of azole resistance in Aspergillus poses a significant threat to patient outcomes.
- Patients with haematological malignancies and those undergoing stem cell transplantation are at high risk for invasive aspergillosis.
Purpose of the Study:
- To determine the prevalence of azole resistance in Aspergillus isolates from high-risk patient populations.
- To investigate the molecular mechanisms underlying azole resistance in these isolates.
- To assess the epidemiological impact of azole resistance in a multicenter Italian study.
Main Methods:
- Prospective collection of Aspergillus isolates from surveillance cultures across 18 Italian centers over 28 months.
- Screening of isolates for resistance to azole antifungals.
- Identification of mutations in the cyp51A gene and molecular genotyping of resistant strains using microsatellite analysis.
Main Results:
- A total of 292 Aspergillus isolates were collected from 228 patients, predominantly from the section Fumigati (45.9%).
- Three isolates exhibited itraconazole resistance: Aspergillus fumigatus sensu stricto, Aspergillus lentulus, and Aspergillus awamori, resulting in an overall azole resistance rate of 1% (3/292).
- The single azole-resistant Aspergillus fumigatus isolate harbored the TR34/L98H mutation and was genotypically distinct from previously characterized strains.
Conclusions:
- The study identified a 1% prevalence of azole resistance in Aspergillus isolates from immunocompromised patients, including non-fumigatus species.
- Accurate species-level identification is critical for effective and timely antifungal therapy.
- Monitoring local epidemiology and understanding the emergence of cryptic species are essential for managing azole resistance.
