Purpose: Invasive aspergillosis is the most threatening disease affecting the patients suffering from immune system defects which causes iatrogenic fungal diseases and high mortality in them. One of the main factors influencing the pathogenesis of this fungus is its capacity to produce and secrete B group phospholipases which causes tissue damages and destruction of cytoplasmic membranes of invaded cells. A survey of molecules has demonstrated that the main resistance against the azole antifungals in Aspergillus fumigatus is related to substitution of amino acid in CYP51A gene.
Materials and Methods: Extraction of DNA from Aspergillus fumigatus was performed by use of cTAB method, identification of molecules by use of primers for CYP51A gene, and the primer of B1 Phospholipase by utilizing the PCR technique. After determination of the sequence, Aspergillus fumigatus was separated and the results were compared with the similar species in the gene bank. Afterwards, the test of drug sensitivity to itraconazole via micro-dilution method and by use of the NLCCLS guideline was performed and its MIC rate was surveyed after incubation for 72 hours.
Results: Both CYP51A and PLb1 gene segments were matched after identifying the sequences; and several mutations were observed in the various nucleotide sequences of their promoter region which demonstrated the sensitivity and resistance to itraconazole.
Conclusion: The Aspergillus fumigatus species may have several mutations in CYP51A gene which causes resistance and sensitivity to itraconazole. Aspergillus fumigatus species examined were extracted from the ICU air and the presence of the wild type of Aspergillus fumigatus is likely. The mutations happened in the survey of Phospholipase B1 is indicative of high virulence of Iranian Aspergillus fumigatus and its resistance to itraconazole.
Full conference title:
- AAA 8th (2018)