**Abstract**

Cystic fibrosis (CF) is a multisystem genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Microbial infection is the defined characteristics of cystic fibrosis airway disease. This infection is caused by bacteria, fungi, and viruses which increase complications leading to patient death. Additionally, bacterial pathogens including *Haemophilus influenza*, *Staphylococcus aureus*, *Pseudomonas aeruginosa*, nontuberculous mycobacterium (NTM) species, and MRSA are attributed to pulmonary infections. Subsequently, fungal pathogens such as *Candida* sp. and filamentous fungi such as *Aspergillus fumigatus* can also lead to pulmonary infections. On the other hand, *Pseudomonas aeruginosa* is the most common bacterial pathogen leading to complications in CF distal airways disease. Also, *Aspergillus fumigatus* can lead to aspergillus lung diseases including allergic bronchopulmonary aspergillosis and aspergilloma formation. Control of pathogenic microorganisms associated with cystic fibrosis may prevent pulmonary complications and has the potential to improve the prognosis of this life-limiting disease.

**Keywords:** cystic fibrosis, *Pseudomonas aeruginosa*, *Aspergillus fumigatus*, *Haemophilus influenzae*, MRSA, CFTR, NTM, microbial infection, respiratory diseases
