Antagonistic Activities of Cell-Free Supernatants of Lactobacilli Against Extended-Spectrum β-Lactamase Producing Klebsiella pneumoniae and Pseudomonas aeruginosa

Mohamed A El-Mokhtar; Khaled M Hassanein; Ahmed S Ahmed; Gamal Fm Gad; Mohamed M Amin; Osama Fe Hassanein

doi:10.2147/IDR.S235603

Antagonistic Activities of Cell-Free Supernatants of Lactobacilli Against Extended-Spectrum β-Lactamase Producing Klebsiella pneumoniae and Pseudomonas aeruginosa

Infect Drug Resist. 2020 Feb 17:13:543-552. doi: 10.2147/IDR.S235603. eCollection 2020.

Authors

Mohamed A El-Mokhtar¹, Khaled M Hassanein¹, Ahmed S Ahmed¹, Gamal Fm Gad², Mohamed M Amin³, Osama Fe Hassanein⁴

Affiliations

¹ Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut, Egypt.
² Department of Microbiology and Immunology, Faculty of Pharmacy, Minia University, Minia, Egypt.
³ Department of Microbiology and Immunology, Faculty of Medicine, Aswan University, Aswan, Egypt.
⁴ Drug Research Center, Assiut University, Assiut, Egypt.

Abstract

Aim: This study aimed to describe the inhibitory activity of cell-free supernatants (CFS) of lactobacilli against extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae (K pneumoniae) and Pseudomonas aeruginosa (P aeruginosa).

Material and methods: Pathogenic clinical strains of K pneumoniae and P aeruginosa were isolated from urine samples and selected for investigation. Anti-bacterial activities of the CFS of lactobacilli were assessed by agar well diffusion, MTT assay, as well as time-kill tests. In addition, the antibiofilm characteristics were analyzed by the microplate method against fresh and 24 h-old biofilms. The ability of CFS to interfere with bacterial invasion was analyzed by flow cytometry.

Results: Although all tested strains were ESBL producers and showed a multidrug-resistant phenotype, the CFS displayed a high anti-ESBL activity with inhibition zone diameters greater than 13 mm in the agar well diffusion assays against both pathogens. The growth kinetics of K pneumoniae and P aeruginosa were dramatically decreased in the presence of the CFS. The CFS not only inhibited the biofilm formation by these pathogens but also was able to remove the 24-h formed biofilms. The invasion abilities of FITC-labelled K pneumoniae decreased from 30.3%±7 to 15.4%±5 and invasion of FITC-labelled P aeruginosa was reduced from 36.9%±7 to 25.2%±5.

Conclusion: CFS of lactobacilli exhibit anti-ESBL activities, which suggests its potential application for controlling or preventing colonization of infections caused by ESBL-producing bacteria.

Keywords: ESBL; K pneumoniae; P aeruginosa; antibiofilm; lactobacilli.