Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan; Department of Food Science, National Chiayi University, Chiayi, Taiwan.
Department of Internal Medicine, Kaohsiung Veterans General Hospital Tainan Branch, Tainan, Taiwan.
J Microbiol Immunol Infect. 2021 Jun;54(3):447-456. doi: 10.1016/j.jmii.2020.01.005. Epub 2020 Feb 15.
This study aims to investigate the antimicrobial ability and mechanism analysis of Lactobacillus species against carbapenemase-producing Enterobacteriaceae (CPE).
Five Lactobacillus spp. strains and 18 CPE clinical isolates were collected. Their anti-CPE effects were assessed by agar well diffusion and broth microdilution assay, as well as time-kill test. Finally, the specific anti-CPE mechanism, especially for the effect of organic acids was determined using broth microdilution method.
All of five Lactobacilli isolates displayed the potent activity against most CPE isolates with mean zones of inhibition ranging 10.2-21.1 mm. The anti-CPE activity was not affected by heating, catalase, and proteinase treatment. Under the concentration of 50% LUC0180 cell-free supernatant (CFS), lactic acid, and mix acid could totally inhibit the growth of carbapenem-resistant Klebsiella pneumoniae (CPE0011), and acetic acid could inhibit 67.8%. In contrast, succinic acid and citric acid could not inhibit the growth of CPE0011. While we decreased the concentration to 25%, only lactic acid and mix acid displayed 100% inhibition. In contrast, succinic acid, citric acid and acetic acid did not show any inhibitory effect.
Lactobacillus strains exhibit potent anti-CPE activity, and lactic acid produced by Lactobacillus strains is the major antimicrobial mechanism.
本研究旨在探讨乳酸菌属对产碳青霉烯酶肠杆菌科（CPE）的抗菌能力和机制分析。
收集了 5 株乳酸菌和 18 株 CPE 临床分离株。通过琼脂孔扩散和肉汤微量稀释法以及时间杀伤试验评估它们对 CPE 的抑制作用。最后，使用肉汤微量稀释法确定特定的抗 CPE 机制，特别是有机酸的作用。
所有 5 株乳酸菌分离株对大多数 CPE 分离株均表现出强大的活性，平均抑菌环直径为 10.2-21.1mm。加热、过氧化氢酶和蛋白酶处理并不影响其抗 CPE 活性。在 50%LUC0180 无细胞上清液（CFS）、乳酸和混合酸浓度下，可完全抑制耐碳青霉烯类肺炎克雷伯菌（CPE0011）的生长，而乙酸可抑制 67.8%。相比之下，琥珀酸和柠檬酸不能抑制 CPE0011 的生长。当我们将浓度降低至 25%时，只有乳酸和混合酸显示出 100%的抑制作用。相比之下，琥珀酸、柠檬酸和乙酸没有显示出任何抑制作用。
乳酸菌株具有强大的抗 CPE 活性，而乳酸菌株产生的乳酸是主要的抗菌机制。
