Identification of Acinetobacter baumannii biofilms in cystic fibrosis patients using molecular methods in Urmia, Iran, 2024
Identification of Acinetobacter baumannii biofilms in cystic fibrosis patients using molecular methods in Urmia, Iran, 2024
Farzin Samadi,1,*Samira Mohammadi,2Sara Didar,3Toran Ebrahimi,4Hadis Abbaszadeh,5Soleiman Moradi Darmanderik,6
1. Department of Microbiology and Parasitology, Kia Tashkhis Ayaz laboratory, Urmia, Iran 2. Department of Microbiology and Parasitology, Kia Tashkhis Ayaz laboratory, Urmia, Iran 3. Department of Microbiology and Parasitology, Kia Tashkhis Ayaz laboratory, Urmia, Iran 4. Department of Microbiology and Parasitology, Kia Tashkhis Ayaz laboratory, Urmia, Iran 5. Department of Microbiology and Parasitology, Kia Tashkhis Ayaz laboratory, Urmia, Iran 6. Department of Microbiology and Parasitology, Kia Tashkhis Ayaz laboratory, Urmia, Iran
Introduction: Biofilm formation is an endless cycle, in which organized bacterial communities are housed in a matrix of extracellular polymeric materials (EPS) that bind microbial cells to a surface. The persistence of chronic Acinetobacter baumannii lung infections in cystic fibrosis (CF) patients is due to biofilm-growing mucoid (alginate-producing). The purpose of this study is to investigate the effect of antibiotic treatment in preventing the formation of biofilm caused by Acinetobacter baumannii.
Methods: Laboratory identification of Acinetobacter baumannii isolates by standard microbiological and biochemical methods. The susceptibility of the isolates to different antibiotics was determined using the disk diffusion method on cation-adjusted Müller-Hinton agar. Antibiotic discs tested with ceftazidime, piperacillin/tazobactam, ciprofloxacin, and levofloxacin, Were treated with gentamicin, amikacin, tobramycin, imipenem and meropenem. The adhesive biofilms were fixed with 100% methanol for 15 minutes, the solutions were removed and the plate dried. The biofilms were stained with 200 μl of 0.1% crystalline violet for 10 minutes at room temperature and then washed with water and dried. Biofilm was obtained in each well by treatment with 200 μl of 96% ethanol for 30 minutes. All Acinetobacter baumannii isolates for the three genes encoding biofilm, algD, and pslD using the polymerase chain reaction (PCR) method, using specific primers.
Results: 18.36% produce strong biofilms. 30.15% produced average biofilm. 31.75% produced poor biofilm, while 19.74% of isolates did not produce as film-free. Acinetobacter baumannii's development of resistance to many antimicrobial agents is a major challenge in controlling its infections.
Conclusion: Acinetobacter baumannii infections typically progress from the acquisition of a single environmental strain to an extensive genetic and phenotypic adaptation to the lung environment. Chronic infections are commonly caused by a single Acinetobacter baumannii lineage. However, different lineages have been found in isolates from the same sputum sample or obtained longitudinally from the same patient. Given the high intraspecific diversity of Acinetobacter baumannii in the CF lung, caution is warranted when assuming that one or more isolates are the cause of infection in a CF patient. CF patients, especially at a young age, should be checked for this infection every month.