| 摘要: | 1928年弗萊明開啟了抗生素時代，隨後即開創20多年抗生素的蓬勃發展，但在1990年代新穎的感染症迅速產生，抗生素的發展卻慢了下來，抗藥性菌株則逐?增加，使得治療更加困難；美國「戰勝抗藥菌之國家策略」白皮書將抗碳青黴烯類抗生素腸內菌（carbapenem-resistant Enterobacteriaceae, CRE）列為需急迫解決的抗藥菌，產廣效性乙內醯胺?（Extended-spectrum β-lactamases, ESBL）菌株快速繁衍，導致carbapenem 類藥物廣泛的被使用，部分抗藥基因藉由質體的傳遞，使得抗藥性在菌株間散播，導致抗藥性急遽增加甚至無藥可用，因此尋找天然健康的治療方式，來協助抗生素的使用已成為新的趨勢。本研究目的即在探討乳酸桿菌對CRE菌之抑制能力，利用瓊脂挖洞擴散法、微量肉湯稀釋法及殺菌時間曲線試驗測試57株乳酸桿菌對不同脈衝式電泳（pulse-field gel electrophoresis, PFGE）分型抗carbapenem之臨床大腸桿菌（carbapenem-resistant E. coli, CREC）及肺炎克雷伯氏菌（Klebseilla peumoniae）之抑菌能力進行評估。實驗結果顯示部分乳酸桿菌的體外試驗對CREC具有極佳的抑制效果，其中LUC180、LUC192、LUC197、LUC219、LUC289、LUC413、LYC1031抑制效果最為顯著，抑制效果最佳的菌種有副乾酪乳桿菌及植物乳桿菌，當乳酸桿菌上清液pH值越低，抑制效果越好，但若要把它開發運用於人體，仍需進一步考慮胃酸之pH值、消化道蛋白?及乳酸桿菌定殖於腸道中的貼附能力，並進一步測試在活體內之效果。
Penicillin was discovered in 1928 by Alexander Fleming, which started the dawning of the antibiotic era. The rise of antibiotic-resistant bacterial strains that didn’t respond to the drugs developed to kill or inhibit them, threaten us when simple infections were often fatal. Carbapenem-resistant Enterobacteriaceae (CRE) was a critical resistant pathogen with urgent threats, the priority was identified by the white paper on “National Strategy to Combating Antibiotic-Resistant Bacteria” in the USA. The increasing use of carbapenems for therapy of infectious diseases had led to a rapid dissemination of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, notably Escherichia coli and Klebsiella pneumonia. Nowadays, the most important thing is to find new treatment strategies to replace or reduce the use of antibiotics for slowing the rise of antibiotics resistance. The aim of this study was to investigate the antibacterial properties of 57 selected strains of Lactobacillus spp. against carbapenem-resistant E. coli (CREC) and carbapenem-resistant Klebseilla peumoniae (CRKP). All strains of CREC and CRKP with different molecular typing were identified by pulse-field gel electrophoresis (PFGE) methods. The well-diffusion assays, broth microdilution assays and time killing tests were used to evaluate the antimicrobial activities of Lactobacillus spp. in vitro. Our results indicated that seven strains of Lactobacillus spp. had significant antimicrobial effects against CREC, including LUC180, LUC192, LUC197, LUC219, LUC289, LUC413, LYC1031. Both of Lactobacillus paracasei and Lactobacillus plantarum strains showed strong antimicrobial activities against pathogens. The results of this in vitro study indicated that antimicrobial properties of Lactobacillus spp. were strain-related. Moreover, the metabolic processes of Lactobacillus spp. strains reduced the pH of environment, and displayed a significantly higher bactericidal effect at a lower pH. We suggest that the mechanism of inhibitory activities of Lactobacillus spp. strains appeared to be due to the production of organic acids. However, the in vivo antimicrobial activities of Lactobacillus spp. strains are linked to acid resistance, protease tolerance, survival and gut colonization, etc., and the further studies are still needed. |
