Molecular and Microscopic Diagnosis of Pathogenic Fungi from Patients with Respiratory Disease in Baghdad

Abstract

This study aimed to isolate and identify fungal species from patients exhibiting symptoms of asthma, bronchial allergy, and chronic respiratory diseases. Samples were collected from patients attending several hospitals in Baghdad-Baghdad Teaching Hospital (Medical City), Al-Kadhimiya Teaching Hospital, Al-Furat Teaching Hospital, and Al-Yarmouk Hospital-between February and May 2024. A total of 203 samples were obtained from patients diagnosed with respiratory conditions by specialized physicians. Twenty-two fungal isolates were identified, including 15 from blood samples and 7 from sputum samples. The patients included 16 males and 13 females, aged between 24 and 70 years, Fungal identification was initially conducted using light microscopy and biochemical tests based on standard taxonomic keys. Further confirmation was achieved through molecular diagnosis using PCR. Seven fungal isolates were selected for molecular analysis, revealing four isolates of Penicillium chrysogenum, one Aspergillus ochraceus, one Penicillium consobrinum, and one Alternaria alternata. PCR amplification targeting the 18S rRNA gene produced specific bands at 476 bp, 612 bp, and 720 bp, confirming the identification. DNA sequencing of the PCR products showed 100% similarity to reference strains in the NCBI BLAST database, confirming the accuracy of the fungal identification.