Résumé:
Lactic acid bacteria are widely used in the agri-food industry due to their essential role in food
fermentation and preservation processes. Among them, the genera Lactobacillus, Streptococcus,
and Bifidobacterium are particularly known for their antimicrobial properties and beneficial effects
on human health.
In this context, the present study focused on five local strains of lactic acid bacteria, all Grampositive
and catalase-negative, in order to evaluate their antimicrobial potential against
uropathogens. The collection studied includes five strains belonging to the Lactobacillus genus:
Lactobacillus acidophilus LB13, Limosilactobacillus fermentum LB25b, Lactobacillus brevis
LB31, Limosilactobacillus fermentum LB02, and Lactobacillus acidophilus LB32.
Urinary tract infections (UTIs) encompass a range of conditions caused by the colonization of the
urinary tract by pathogenic bacteria, referred to as uropathogens. These infections can affect the
urethra, bladder (cystitis), ureters, or kidneys (pyelonephritis). They are mostly caused by
Enterobacteriaceae, particularly Escherichia coli, which accounts for over 80% of cases, as well
as other pathogens such as Proteus spp. and Klebsiella. Their high prevalence, especially among
women, makes them a major public health concern.
To assess the antimicrobial activity of the lactic acid strains, the well diffusion method was
employed. This approach allowed the evaluation of the inhibitory effects of antimicrobial
substances produced by the lactic acid bacteria on four reference pathogenic strains: Escherichia
coli, Klebsiella pneumoniae, Proteus mirabilis, and Proteus vulgaris. The results showed
significant inhibition of these pathogens' growth, with inhibition zones ranging from 11 to 21 mm,
depending on the strain tested.
The main objective of this study was to demonstrate the antagonistic effect of lactic acid bacteria
on uropathogens, with the aim of identifying strains with the highest antimicrobial potential for
future therapeutic or probiotic applications.
