Chi-Chung Chen1, Chih-Cheng Lai2, Hui-Ling Huang3, Yu-Ting Su4, Yu-Hsin Chiu5, Han-Siong Toh6, Shyh-Ren Chiang7, Yin-Ching Chuang8, Ying-Chen Lu9, Hung-Jen Tang10. 1. Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan; Department of Food Science, National Chiayi University, Chiayi, Taiwan. Electronic address: ccomm2@yahoo.com.tw. 2. Department of Internal Medicine, Kaohsiung Veterans General Hospital Tainan Branch, Tainan, Taiwan. Electronic address: dtmed141@gmail.com. 3. Department of Health and Nutrition, Chia Nan University of Pharmacy and Science, Tainan, Taiwan. Electronic address: cherry85@mail.cnu.edu.tw. 4. Department of Health and Nutrition, Chia Nan University of Pharmacy and Science, Tainan, Taiwan. Electronic address: lovejj99forever@gmail.com. 5. Department of Internal Medicine, Chi Mei Medical Center, Liouying, Tainan, Taiwan. Electronic address: chiu0220@yahoo.com.tw. 6. Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan. Electronic address: kampungths@gmail.com. 7. Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan. Electronic address: crsmed@yahoo.com.tw. 8. Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan; Department of Internal Medicine, Chi Mei Medical Center, Liouying, Tainan, Taiwan. Electronic address: chuangkenneth@hotmail.com. 9. Department of Food Science, National Chiayi University, Chiayi, Taiwan. Electronic address: biolyc2016@gmail.com. 10. Department of Internal Medicine, Chi Mei Medical Center, Tainan, Taiwan. Electronic address: 8409d1@gmail.com.
Abstract
BACKGROUND: This study aims to investigate the antimicrobial ability and mechanism analysis of Lactobacillus species against carbapenemase-producing Enterobacteriaceae (CPE). METHODS: 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. RESULTS: 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. CONCLUSIONS: Lactobacillus strains exhibit potent anti-CPE activity, and lactic acid produced by Lactobacillus strains is the major antimicrobial mechanism.
BACKGROUND: This study aims to investigate the antimicrobial ability and mechanism analysis of Lactobacillus species against carbapenemase-producing Enterobacteriaceae (CPE). METHODS: 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. RESULTS: 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. CONCLUSIONS: Lactobacillus strains exhibit potent anti-CPE activity, and lactic acid produced by Lactobacillus strains is the major antimicrobial mechanism.
Authors: Ji Taek Hong; Min-Jung Lee; Sang Jun Yoon; Seok Pyo Shin; Chang Seok Bang; Gwang Ho Baik; Dong Joon Kim; Gi Soo Youn; Min Jea Shin; Young Lim Ham; Ki Tae Suk; Bong-Soo Kim Journal: J Ginseng Res Date: 2020-07-16 Impact factor: 6.060