1. Department of Clinical Laboratory, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, Guangdong, China;
2. Department of Urology, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan People's Hospital, Guangdong, China;
3. Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China;
4. Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan;
5. Graduate Institute of Chinese Medical Science, China Medical University, Taichung, Taiwan;
6. Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan.
* These authors have contributed equally to this paper
Background: Pseudomonas aeruginosa can cause disease and also can be isolated from the skin of healthy people. Additionally, it exhibits certain antimicrobial effects against other microorganisms.
Methods: We collected 60 strains of P. aeruginosa and screened their antimicrobial effects against Staphylococcus aureus (ATCC 25923) using the filter paper-disk method, the cross-streaking method and the co-culture method and then evaluated the antimicrobial activity of the chloroform-isolated S. aureus extracts against methicillin-resistant S. aureus (MRSA, Gram-positive cocci), vancomycin intermediate-resistant S. aureus (VISA, Gram-positive cocci), Corynebacterium spp. (CS, Gram-positive bacilli), Acinetobacter baumannii (AB, Gram-negative bacilli), Moraxella catarrhalis (MC, Gram-negative diplococcus), Candida albicans (CA, fungi), Candida tropicalis (CT, fungi), Candida glabrata (CG, fungi) and Candida parapsilosis (CP, fungi).
Results: The PA06 and PA46 strains have strong antimicrobial effects. High-performance liquid chromatography (HPLC) analysis revealed that the major components of PA06 and PA46 that exhibit antimicrobial activity are functionally similar to phenazine-1-carboxylic acid (PCA) and pyocyanin. Preparative HPLC was performed to separate and isolate the 4 major potential antimicrobial components: PA06ER10, PA06ER16, PA06ER23 and PA06ER31. Further, the molecular masses of PA06ER10 (260.1), PA06ER16 (274.1), PA06ER23 (286.1) and PA06ER31 (318.2) were determined by electrospray ionization (ESI) mass spectrometry.
Conclusion: P. aeruginosa can produce small molecules with potential antimicrobial activities against MRSA, VISA, CS, MC, CA, CT, CG and CP but not against AB.
Keywords: Pseudomonas aeruginosa, Staphylococcus aureus, antimicrobial effects, PCA, pyocyanin.