ANTIMICROBIAL ACTIVITY OF COPAIFERA SPP. AGAINST BACTERIA ISOLATED FROM MILK OF COWS WITH MASTITIS

Abstract The antimicrobial activities of the oleoresin (OR) and the essential oil (EO) of Copaifera spp. were checked against microorganisms isolated from milk samples of cows diagnosed with grade III subclinical mastitis. The OR had good antimicrobial activity (MIC ≤ 100 µg/mL) against samples of coagulase-positive Staphylococcus, coagulase-negative Staphylococcus, Streptococcus of groups C, F, and G, and Corynebacterium spp. Meanwhile, the EO had good antimicrobial activity (MIC≤100 µg/mL) against coagulase-negative Staphylococcus and Corynebacterium spp. The OR and the EO were inactive and weak to inactive, respectively, against Escherichia coli. Overall, the OR had better antimicrobial activity than the essential oil against the 55 bacterial isolates (p<0.0001). The GC/MS analysis identified sesquiterpenes in EO and by the ESI FT-ICR MS method, the identification of diterpenic acids in OR was possible. Therefore, this raw plant material is promising for the development of phytotherapeutic drugs against bovine mastitis.

摘要 本研究检测了 Copaifera属（Copaifera spp.）植物的油树脂（oleoresin, OR）与精油（essential oil, EO）对从确诊为三级亚临床乳腺炎的奶牛乳汁样本中分离得到的微生物的抗菌活性。结果显示，油树脂对凝固酶阳性葡萄球菌（coagulase-positive Staphylococcus）、凝固酶阴性葡萄球菌（coagulase-negative Staphylococcus）、C、F、G群链球菌（Streptococcus of groups C, F, and G）以及棒杆菌属（Corynebacterium spp.）菌株均展现出良好的抗菌活性（最低抑菌浓度≤100 µg/mL，Minimum Inhibitory Concentration, MIC）。与此同时，精油仅对凝固酶阴性葡萄球菌与棒杆菌属菌株表现出良好的抗菌活性（最低抑菌浓度≤100 µg/mL）。针对大肠杆菌（Escherichia coli），油树脂与精油分别表现为无抗菌活性与弱抗菌活性。在针对55株细菌分离株的整体抗菌活性比较中，油树脂的抗菌效果显著优于精油（p<0.0001）。通过气相色谱-质谱联用分析（Gas Chromatography-Mass Spectrometry, GC/MS），在精油中鉴定出倍半萜类（sesquiterpenes）成分；借助电喷雾电离傅里叶变换离子回旋共振质谱法（Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, ESI FT-ICR MS），成功在油树脂中鉴定出二萜酸类（diterpenic acids）成分。综上，该植物原料在开发针对牛乳腺炎的植物治疗药物方面具有良好应用前景。