緑膿菌に対するオウレンの抗菌活性及び病原因子の産生に与える影響

抄録

Although carbapenem antibiotics are effective therapeutic agents against Gram-negative bacteria, the recent emergence of carbapenem- and multidrug-resistant Pseudomonas aeruginosa (MDRP) has become a problem. In the present study, we investigated the antimicrobial activity of Coptidis rhizoma against P. aeruginosa and the pathogenic factors it produces. The bacterial strains used include an MDRP strain, as well as reference strains PAO 1 and ATCC 27853. Drug sensitivity testing was performed in accordance with the Clinical Laboratory Standards Institute guidelines and the microdilution method was used. We compared the antimicrobial effects of the herbal medicine Coptidis rhizoma with imipenem, amikacin, and ciprofloxacin, and investigated the combined use of Coptidis rhizoma and antibiotics using a checkerboard method. The effects of Coptidis rhizoma on swarming motility were also investigated. Biofilm formation was measured using the crystal violet method, and protease production by P. aeruginosa was measured using a skim milk agar assay. The antibacterial activity of combined use of Coptidis rhizoma and aminoglycoside drugs was confirmed. The use of Coptidis rhizoma in combination with antibiotics suppressed swarming motility and inhibited biofilm formation. Protease production by P. aeruginosa was also suppressed, indicating that the activity of aminoglycoside antibiotics was restored. These results reveal the potential of Coptidis rhizoma against P. aeruginosa-associated pathogenesis.