Genotyping, drug resistance and virulence factors of Candida species isolated from patients using long-term inhaled steroids.

Aims: In this study, it was aimed to determine the isolation frequency and species distribution of Candida species isolated from asthmatic patients using long-term inhaled steroids. It was also aimed to determine the drug resistance patterns and the frequency of erg11, HWP1, ALS1, INT1, SAP1 PLB1 genes in isolates.

Methods: Genotyping of Candida strains isolated from patients and healthy control group was performed by PCR-RFLP method. Drug resistance was investigated phenotypically, and the presence of erg11 resistance genes and HWP1, ALS1, INT1, SAP1 PLB1 virulence genes were investigated by PCR method.

Results: C albicans was the most isolated species in steroid-using patients and healthy control groups (patients: 44.2%; control group: 30.8%). C tropicalis and C glabrata were found to have the highest rates of non-albicans Candida in patients with 17.4% and 13.77%, respectively. Azole resistance was found to be significantly higher in isolates isolated from patients compared to the control group. Similarly, the presence of erg11 resistance gene was highest in C albicans (17.65%), C glabrata (12.5%) and C tropicalis (8.3%) strains in the control group, while C parapsilosis was highest in patients. (57.1%) and C glabrata (54.2%) strains. Compared to the control group, the virulence of Candida strains isolated from the patients was found to be higher. Presence of HWP1, ALS1, INT1, SAP1 and PLB1 genes in patients were determined as 72.1%, 63.9%, 68.9%, 57.38% and 54.5%, respectively. These rates were 29.4%, 35.3%, 25.5%, 17.7% and 23.5% in the healthy control group, respectively.

Conclusions: In asthma patients using long-term inhaled steroids, both Isolation rates of Candida species, drug resistance rates, presence of virulence genes were found to be significantly higher in patients than in the control group. We think that this may be due to the suppression of cellular immunity by long-term steroid use.