Lee Eon-Bee, Lee Kyubae
Laboratory of Veterinary Pharmacokinetics and Pharmacodynamics, College of Veterinary Medicine, Kyungpook National University, Daegu, 41566, Republic of Korea.
Veterinary Drugs and Biologics Division, Animal and Plant Quarantine Agency, Gimcheon, 39660, Republic of Korea.
AMB Express. 2024 Jul 4;14(1):79. doi: 10.1186/s13568-024-01736-x.
This study investigated the antibacterial properties of Coptis rhizome, a plant traditionally used for respiratory infections, against Streptoccus pneumonia (S. pneumoniae), for which there has been minimal empirical evidence of effectiveness. The study particularly examined autolysis, indirectly associated with antibacterial resistance, when using Coptis rhizome for bacterial infections. In our methodology, Coptis rhizome was processed with ethanol and distilled water to produce four different extracts: CRET30, CRET50, CRET70, and CRDW. The antibacterial activity of these extracts were tested through Minimum Inhibitory Concentration (MIC) assays, disk diffusion tests, and time-kill assays, targeting both standard (ATCC 49619) and resistant (ATCC 70067) strains. The study also evaluated the extracts' biofilm inhibition properties and monitored the expression of the lyt gene, integral to autolysis. The results prominently showed that the CRET70 extract demonstrated remarkable antibacterial strength. It achieved an MIC of 0.125 µg/mL against both tested S. pneumoniae strains. The disk diffusion assay recorded inhibition zones of 22.17 mm for ATCC 49619 and 17.20 mm for ATCC 70067. Impressively, CRET70 resulted in a 2-log decrease in bacterial numbers for both strains, showcasing its potent bactericidal capacity. The extract was also effective in inhibiting 77.40% of biofilm formation. Additionally, the significant overexpression of the lytA gene in the presence of CRET70 pointed to a potential mechanism of action for its antibacterial effects. The outcomes provided new perspectives on the use of Coptis rhizome in combating S. pneumoniae, especially significant in an era of escalating antibiotic resistance.
本研究调查了黄连（一种传统上用于治疗呼吸道感染的植物）对肺炎链球菌的抗菌特性，此前针对其有效性的实证证据极少。该研究特别考察了使用黄连治疗细菌感染时与抗菌耐药性间接相关的自溶作用。在我们的方法中，黄连用乙醇和蒸馏水进行处理，以制备四种不同的提取物：CRET30、CRET50、CRET70和CRDW。通过最低抑菌浓度（MIC）测定、纸片扩散试验和时间杀菌试验，针对标准菌株（ATCC 49619）和耐药菌株（ATCC 70067）测试了这些提取物的抗菌活性。该研究还评估了提取物的生物膜抑制特性，并监测了自溶作用所必需的lyt基因的表达。结果显著表明，CRET70提取物表现出显著的抗菌强度。它对两种受试肺炎链球菌菌株的MIC均达到0.125μg/mL。纸片扩散试验记录到，针对ATCC 49619的抑菌圈为22.17mm，针对ATCC 70067的抑菌圈为17.20mm。令人印象深刻的是，CRET70使两种菌株的细菌数量均减少了2个对数，显示出其强大的杀菌能力。该提取物还能有效抑制77.40%的生物膜形成。此外，在CRET70存在的情况下lytA基因的显著过表达指出了其抗菌作用的潜在作用机制。这些结果为黄连在对抗肺炎链球菌方面的应用提供了新的视角，在抗生素耐药性不断升级的时代尤为重要。
