Antimicrobial Activity of Lactobacillus Species Against Carbapenem-Resistant Enterobacteriaceae

Abstract

Objective This study aims to identify suitable lactobacilli that have anti-carbapenem-resistant Enterobacteriaceae (CRE) activity with in vitro tolerance to pepsin and bile salts. Methods Fifty-seven Lactobacillus spp. strains encompassing nine species were collected for investigation. Their viabilities in the presence of pepsin and bile salts were tested using tolerance tests. Their anti-CRE effects were assessed by agar well diffusion and broth microdilution assay, as well as time-kill test. Results Of the 57 Lactobacillus isolates collected, 31 had a less than 2-log reduction in their viability in both pepsin and bile salt tolerance tests. Of these 31 isolates, 5 (LUC0180, LUC0219, LYC0289, LYC0413, and LYC1031) displayed the greatest anti-CRE activity with a CRE zone of inhibition greater than 15 mm in agar well diffusion assays. The minimal inhibitory percentages of supernatants from these five strains against CREs ranged from 10 to 30%. With the exception of LUC0180, which had a minimal bactericidal percentage ≥ 40%, the bactericidal percentage of all the strains ranged from 20 to 40%. The inhibitory effect of the cell-free culture supernatants from these Lactobacillus strains did not change after heating but was abolished as the pH changed to 7.0. After a 24-h incubation, five of the Lactobacillus strains at a concentration of 10 8 CFU/ml totally inhibited the growth of carbapenem-resistant Escherichia coli (CRE316) and Klebsiella pneumoniae (CRE632). After a 48-h incubation, the growth of CRE316 was completely inhibited under each concentration of lactobacilli based on time-kill test. Furthermore, when the concentration of lactobacilli was at 10 8 CFU/ml, the decline in pH was faster than at other concentrations. Conclusion Some Lactobacillus strains exhibit anti-CRE activity, which suggests potential applications for controlling or preventing CRE colonization or infection.

<p>Antagonistic Activities of Cell-Free Supernatants of Lactobacilli Against Extended-Spectrum β-Lactamase Producing <em>Klebsiella pneumoniae</em> and <em>Pseudomonas aeruginosa</em></p>

“…Given the fact that all tested K pneumoniae and P aeruginosa strains were ESBL producers, it could be concluded that CFS is an excellent strategy to get rid of these difficult-to-treat pathogens. Similar to our results, Chen et al 10 showed that some Lactobacillus strains are able to inhibit carbapenem-resistant Enterobacteriaceae.…”

“…The inhibitory compounds produced by lactobacilli include organic acids such as lactic acid, acetic acid, and formic acid or bacteriocins. 8,9 Through these antimicrobial mechanisms, lactobacilli have demonstrated antagonistic activates against different pathogenic bacteria, including carbapenem-resistant Enterobacteriaceae, 10 Escherichia coli, 11 Helicobacter pylori, 12 Salmonella, 13 Shigella, 14 P aeruginosa, 15 and Staphylococcus aureus. 16 However, no previous studies have assessed the antimicrobial activity of lactobacillus against ESBL-producing K pneumoniae or P aeruginosa.…”

Probiotic and Antioxidant Potential of Lactobacillus reuteriLR12 and Lactobacillus lactisLL10 Isolated from Pineapple Puree and Quality Analysis of Pineapple-Flavored Goat Milk Yoghurt during Storage

“…The culture was centrifuged at 10,000 rpm for 20 min at 4 °C. The supernatant was filter sterilized using a 0.22 μm filter, as described earlier [ 19 ].…”

Comparative Genomics of the Transport Proteins of Ten Lactobacillus Strains

“…are considered to be efficient probiotic organisms in the GIT of humans [ 9 ]. The ability of these organisms to produce lactic acid and other metabolites helps to kill pathogenic microbes [ 10 ]. Among these metabolites there are antimicrobial proteins called bacteriocins; these are small proteins or peptides that are ribosomally synthesized and are effective at killing pathogenic microbes [ 11 ].…”