Antibiotic resistance profiles of Pseudomonas aeruginosa isolates isolated from clinical samples, and evaluation of biofilm formation and the presence of biofilm-related genes (pelA, pslD and algD)

Pseudomonas aeruginosa is identified as an opportunistic pathogen since it predominantly creates nosocomial infections in immune compromised people. The available knowledge about P. aeruginosa pathogenesis has primarily come from investigating clinical isolates; in this case there were a total of 100 samples obtained from a variety of locations in Baghdad hospitals and sorted into three groups: clinical (40) isolates from burns and (40) specimen from wounds and (30) from sputum, collected from October 2021 to the April 2022. Twenty isolates of P. aeruginosa were found of these samples and they cultured by specific and differential media, Using culture conditions, biochemical assays, and the VITEK-2 compact system, bacteria were identified. For all bacterial isolates, the antibiotic sensitivity test is valid according to the minimum inhibitory concentration (MICs). The maximum level of resistance was demonstrated to be against Tigecycline (8), followed by Cefazolin (64), while high sensitive was to Ciprofloxacin (0.25), followed by Levofloxacin (0.5) and Gentamicin (1), cefepime (1), Ceftazidime (2) and Imipenem (2), Amikacin (2) and Piperacillin /Tazobactum (8) respectively according to MICs results of each antibiotics. Biofilm production was detected using the micro titration plate technique, with the majority of strains (50%) producing moderate biofilms, 35% producing strong biofilms, and 15% producing weak biofilms. When it comes to virulence genes, In 20 isolates, three genes were identified, the algD gene was found in 17 isolates (85%), pelA was found in 17 isolates (85%), and pslD was found in 15 isolates (75%). The genes algD, pslD, and pelA were chosen as virulence factors, the genotypic algD/pslD/pelA – pattern, which is responsible for the phenotypic pattern of biofilm development. There were statistically significant variations in genotypic pattern predominance across biofilm forming isolates from various sources, Using Chi-square analysis, a very significant relationship between biofilm forming capability and genetic pattern (p value 0.764) was discovered. In this research we wanted to reveal if there was a linkage between the production of biofilms and the expression of biofilm-related genes (algD, pelA, pslD), and analyzing antibiotic resistance profiles in P. aeruginosa clinical samples isolated. Keywords: Biyofilm formation; Pseudomonas aeruginosa ; pelA; Polysacharide