Aspergillus flavus: epidemiological study and molecular typing in invasive aspergillosis patients

I.Hadrich 1; F. Makni1, S. Neji1, F. Cheikhrouhou1, A. Sellami1, H. Sellami1, M. Elloumi 2, A. Ayadi1

Author address: 

1Laboratory of Parasitology- Mycology, HU Habib Bourguiba Sfax, Tunisia 2HU Hedi-Chaker Sfax, Tunisia


Invasive aspergillosis (IA) is a major opportunistic infection in haematology patients. Preventive measures are important to control IA because diagnosis is difficult and the outcome of treatment is poor. Objectives: We prospectively and evaluate the prevalence of invasive aspergillosis in the protect unit of haematology and examined the environmental contamination by Aspergillus. We describe a new panel of microsatellites for typing A. flavus isolates. Materials and methods: Three year prospective study (September 2004 September 2007) were carried out in the haematology ward of Hedi Chaker Hospital. Suspected Invasive aspergillosis cases were classified using the EORTC criteria. We collected weekly environmental samples (patient’s rooms, tables and acclimatisers) and clinical samples from each patient (nasal, expectoration and auricular). A total of 7 microsatellites markers were selected. Primers were designed with the software Primer 3, and their specificity was verified by BLASTn. Results: 163 neutropenic patients were hospitalized. 1 proven, 31 probable and 15 possible IA were diagnosed. Clinical sampling revealed that A. flavus was the most frequent species (79.2%). From 690 environnemental samples, A. flavus was isolated in the forth rang after Penicillium, Cladosporium and Alternaria. The molecular study of 48 A. flavus isolates detected from clinical and environmental samples confirmed the mycological identification. For the typing of A. flavus isolates, we found a variation from 2 to 7 alleles for each marker. The combination of five markers yielded a Simpson's diversity index of 0.952 and using 12 microsatellites this index was 0.97. Conclusion: Our findings underline the importance of environmental surveillance and strict application of preventive measures. The microsatellites approach is very suitable tool for large scale epidemiological studies.

abstract No: 


Full conference title: 

4th Trends in Medical Mycology
    • TIMM 4th (2012)