Molecular epidemiology of zygomycosis and their related factors in tertiary referral centers in southern Iran

Abstract

Introduction: For the best management of the zygomycosis in immunocompromised patients, the present study aims to detect and identify the etiologic agents by DNA sequencing method and their related factors in clinical samples of patients.

Methodology: Clinical samples from 1,058 patients admitted in 11 university hospitals in Shiraz, Southern Iran were collected between July 2015 and July 2018. All samples (bronchoalveolar lavage, sputum, blood, tissue) were examined by routine microscopic and culture tests for zygomycetes. The etiologic agents were identified by the molecular method and sequencing.

Results: Direct microscopic examinations or pathology smear, culture, and PCR were positive in 61 (5.8%), 15 (1.4%), and 103 (9.7%) patients, respectively. According to EORTC/MSG criteria, the rates of proven, probable, and possible zygomycosis were 59.2% (61/103), 14.6% (15/103), and 26.2% (27/103 patients), respectively. The most prevalent etiologic agents according to sequencing were Rhizopus oryzae (44 cases), Rhizopus microsporus (31 cases), Rhizopus stolonifer (15 cases). Twenty-two patients (21.4%) with positive PCR died. There were significant relations between zygomycosis and the underlying disease (p = 0.043) and prior antifungal therapy (p = 0.023). White blood cell count was in the normal range in 14.1% of patients, and the means of erythrocyte sedimentation rate (ESR) and C reactive protein (CRP) were 65 mm/hour and 57 mg/L, respectively.

Conclusions: Molecular methods and sequencing may have considered as suitable tools to diagnose zygomycosis. Identification of the etiologic agents may be considered as the future antifungal therapy and management of the respective patients.