The Expression Response of lasI Quorum Sensing Gene Upon Exposure to Some Microbicides in Pseudomonas aeruginosa Isolated from Local Clinical Specimens

Abstract

Microbicides are frequently used to manage surface bacterial contamination in a variety of settings and to prohibit infections from spreading to individuals as nosocomial infections. Due of its numerous virulence factors, which are controlled by the crucial quorum-sensing (QS) network, Pseudomonas aeruginosa can withstand hostile environments. This work aims to determine the minimum inhibitory concentration (MIC) of microbicide agents and explore the role of the lasI gene in P. aeruginosa biofilm development in order to gain a better understanding of how these bacteria may survive in such a kind of environment.As well as measure the target gene expression before and after using microbicides.One hundred clinical sampleswere collected during the period from June 2023 until November 2023 from patients attending Baghdad hospitals. The VITEK-2 compact system was used to confirm the isolates of P. aeruginosa. Micro titer plate technique was employed to assess the isolates' capacity to produce biofilms in vitro. Out of collected samples, 38 (38%) P. aeruginosa isolates were identified. The highest percentages (47.37% and 23.68%) were assigned to burn and wound infections, while the lowest frequency (10.53% and 18.42%) was assigned to ear and UTI infections. The results indicated that the biofilm formation was strong in (79.41%), moderate in (14.17%) and weak in (5.88%). The antibiotics test showed the highest resistance to the fluoroquinolonesabout 80%.The QSgene was detected in 34 (89.47%) of the isolates.In conclusion, the expression level of lasI gene showed down regulation of concentrations of microbicides treatment average (32-64 µg/ml).Significant correlations were found between the lasI gene and the use of microbicides and biofilm development.