Roumaissaa Belkacem

Algeria

Antibacterial Potential of Some Probiotic Strains Isolated From Artisanal Dairy Products Against Multidrug Resistant Enterobacteriaceae.

Roumaissaa Belkacem1, Qada Benameur2 , Hajer Kilani 3
1. Department of Alimentary Sciences, University of Abdelhamid Ibn Badis Mostaganem, 27000 Mostaganem, Algeria.
2. Department of Agronomy, University of Abdelhamid Ibn Badis Mostaganem, 27000 Mostaganem, Algeria.
3. Department of Microbiology, University of Tunis El Manar, LR99ES09 Laboratory of Antibiotic Resistance, Tunis, Tunisia.

Abstract

Background

Infections caused by multidrug-resistant (MDR) Enterobacteriaceae are associated with increased morbidity and mortality than those caused by their susceptible counterparts. The development of new antimicrobial agents is urgent. The aim of the present study was to evaluate the antibacterial effect and synergistic effect of some probiotic strains, isolated from artisanal dairy products, against MDR Enterobactereaceae.

Methods

The probiotics strains were isolated from artisanal dairy products and characterized for their antimicrobial activity against Enterobactereaceae (MDR) clinical isolates including: Klebsiella pneumonia, Escherichia coli, Salmonella spp. and Enterobacter cloacae using agar disk diffusion and broth micro-dilution (BMD) methods. The synergistic effect of cell free supernatants (CFSs) of probiotic strains was determined by checkerboard assay.

Results

The result of the antagonistic effect showed that all probiotic isolates exhibited inhibitory effect against the selected Enterobactereaceae strains. The highest effect was observed against Escherichia coli (9.33±0.75 to 11.33±0.57 mm), followed by Salmonella spp. (8±00 to 10±0.57 mm), Enterobacter cloacae (9±00 to 10±00 mm) and Klebsiella pneumonia (8±1.14 to 9.5±0.70 mm).The strongest MIC values was observed against Escherichia coli (15.62 µl/mL), followed by Salmonella spp. (31.25 µl/mL), Klebsiella pneumonia (31.25 µl/mL) and Enterobacter cloacae (31.25 µl/mL). This finding showed a partial synergism between CFSs of some probiotic strains against Enterobacter cloaceae and Escherichia coli (0.5?FICI ?0.75).

Conclusions

This finding showed that the probiotic strains isolated from artisanal dairy products showed not only satisfactory antibacterial properties against MDR Enterobactereaceae isolates but also a synergistic effect between CFSs of some probiotic strains.