The rise of Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious global health threat and reduces the efficacy of current treatments. The present study investigates the antibacterial and antibiofilm properties of exoproducts from Pseudomonas aeruginosa against MRSA. The confirmation of the identities of P.aeruginosa and S.aureus was achieved through the sequencing of the 16S rRNA gene. Using the agar diffusion assay, the cell-free supernatants (PA-CFS) derived from both the extensively drug-resistant (XDR) P. aeruginosa strain and the reference strain ATCC 27853 demonstrated notable antibacterial activity against MRSA, exhibiting inhibition zones ranging from 28.67 ± 0.33 to 33.33 ± 0.33 mm and 26.67 ± 0.33 to 28.66 ± 0.33 mm, respectively. The minimum inhibitory concentration (MIC) assays demonstrated the capability of PA-CFS (XDR) and PA-CFS (ATCC 27853) to suppress MRSA growth at a concentration of 1 × 107 CFU/mL, with stability noted across varied pH and temperature conditions. Biofilm quantification revealed that a 1/2 × MIC of PA-CFS significantly hindered biofilm formation, achieving inhibition rates of 22.301% and 23.886% for PA-CFS (ATCC 27853) and PA-CFS (XDR), respectively. The staphylolytic activity indicated a substantial lysis of MRSA populations influenced by PA-CFS. PCR analysis validated the existence of the lasA virulence gene in the two strains of P. aeruginosa. GC–MS investigation of ethyl acetate extracts from PA-CFS indicated the presence of 22 distinct peaks for the PA-CFS (ATCC 27853) strain and 8 peaks for the PA-CFS (XDR) strain. These findings indicate that P. aeruginosa exoproducts significantly contribute to microbial competition by overcoming challenges posed by MRSA.
Sirwan Muhammed Ameen (Wed,) studied this question.