Evaluation of Biocides Susceptibility and Expression of Qace-Δ1 And Suge1 Genes of Pseudomonas Aeruginosa in Exposure to Biocides and Meropenem

Pseudomonas aeruginosa is a species of medical significance that plays a role in nosocomial infections, particularly those resulting from burns and wounds. Bacterial antibiotic resistance may have developed as a result of the abuse of biocides in hospitals. This study aimed to determine the minimum inhibitory concentrations (MICs) of carbapenem-resistant P. aeruginosa isolates in relation to ethylenediaminetetraacetic acid (EDTA), chlorohexidine (CHX), and resazurin dye using a microtiter plate assay. Additionally, it evaluated the expression of the efflux pump genes (qacE-Δ1 and sugE1) at sub-inhibitory concentrations of the biocides using RT-qPCR (delta delta Ct method) to improve their efflux pump system. The MICs of 24 P. aeruginosa isolates (14 isolates were resist to carbapenems and 10 isolates sensitive to carbapenems) against Chloroxylenol (Dettol) revealed that the range of MICs were (0. 125-2%). The results of MICs of Chlorohexidine (CHX) revealed that the range of inhibitory activity was (0.8-102.4 µg/ml), also the findings of MICs of EDTA demonstrated that the range of inhibitory activity was (125-2000 µg/ml). The genes involved in efflux pump (qacE -Δ1 and sugE1) were found to be significantly up-regulated in the local isolates, according to our findings.. The four isolates' sugE1 gene expression folds ranged from 1.81 to 5.39; this result was more than the fold of the control (the fold change is 1), with the meropenem isolate having the highest fold value (5.39) and sub-MIC value (8 µg/ml). Furthermore, the four isolates' qacE-Δ1 gene expression folds ranged from 2.11 to 5.01, which was higher than the fold of the control, where the highest fold value was recorded for the EDTA (5.01) with the sub-MIC value (125-500 µg/ml). Also, a high value of upregulation of the gene qacE –Δ1, during the treatment with dettol with sub-MIC (0.25-0.5%), and the fold change was 4.19. In conclusion, the present findings indicated to the significant relationship between the treatments with meropenem and the high values of gene expression of the gene sugE1 in comparison with the control and other agents, Furthermore, compared to the antibiotic and control, there was a strong correlation found between the high fold changes of the gene qacE -Δ1 with the presence of dettol and EDTA.