Investigation of the Flagellar Genes FleN and FlgE in Clinical Pseudomonas aeruginosa Isolates

Abstract Background: Pseudomonas aeruginosa is one of the most prevalent etiological agents that cause mortality and morbidity in hospitalized patients. Its sophisticated macromolecular appendage, known as the flagellum, plays important roles in bacterial movement, the infection cycle, and antibiotic resistance. P. aeruginosa possesses one or more polar flagella, and the number of these macromolecules is determined by the FleN gene, which also affects other flagellar regulatory genes, bacterial motility, and, consequently, virulence. Meanwhile, the FlgE gene encodes the hook portion of flagella and has an impact on the synthesis of intact flagella and their motility. Therefore, these genes play pivotal roles in P. aeruginosa virulence, and confirming their presence in clinical isolates is of utmost importance for assessing the intensity of virulence and pathogenicity. Objectives: The current study aimed to detect the presence of the flagellar genes FleN and FlgE in clinical P. aeruginosa isolates, and this study is considered the first of its kind to explore that. Materials and Methods: About 102 specimens from various clinical sources, such as burn, mid-stream urine, wound, ear, and sputum, were collected from patients referred to Baghdad Medical City, Imam Ali, and Shahid Al-Sadr Hospitals in Baghdad, Iraq. All isolates were identified based on phenotypic characteristics, biochemical tests, and confirmation by the Vitek 2 compact system. Conventional PCR was employed to detect flagellar genes. Results: Out of 102 specimens, 33 P. aeruginosa isolates were identified. The finding of conventional PCR indicated the presence of the FleN gene in 26 (78.8%) of these isolates, with the highest percentage found in burn isolates, followed by wound, urine, ear, and sputum isolates. Meanwhile, the FlgE gene was detected in 20 (60.6%) of the isolates, with the highest percentage observed in burn isolates, followed by wound and ear isolates, and the lowest percentage in urine and sputum isolates. Conclusion: The pathogenic bacterium P. aeruginosa is widely distributed in clinical sites, and the majority of them carry the flagellar genes FleN and FlgE .