Antibacterial and Antibiofilm Effects of Lactobacilli Strains against Clinical Isolates of Pseudomonas aeruginosa under Conditions Relevant to Cystic Fibrosis

Abstract

Therapy of lung infections sustained by Pseudomonas aeruginosa in cystic fibrosis (CF) patients is challenging due to the presence of a sticky mucus in the airways and the ability of the bacterium to form biofilm, which exhibits increased antibiotic tolerance. A lung-directed bacteriotherapy through the airway administration of probiotics could represent an alternative approach to probiotic diet supplementation to improve the benefits and clinical outcomes of this kind of intervention in CF patients. This study aims to evaluate the ability of probiotic strains to grow in artificial sputum medium (ASM), mimicking the CF lung microenvironment, and to affect the planktonic and biofilm growth of CF clinical strains of P. aeruginosa in the same conditions. The results demonstrate that Lacticaseibacillus rhamnosus and Lactiplantibacillus plantarum (LP) can grow in ASM. LP inhibited the planktonic growth of P. aeruginosa, while both lactobacilli reduced the pre-formed biofilm of P. aeruginosa. Interestingly, LP was demonstrated to reduce the amount of polysaccharides in the extracellular matrix of P. aeruginosa biofilms and to potentiate the antibiofilm effects of tobramycin. Overall, the results indicated that LP is a promising candidate as an adjuvant in the antimicrobial therapy of P. aeruginosa infections in CF patients.

Antagonistic Effects of Corynebacterium pseudodiphtheriticum 090104 on Respiratory Pathogens

“…L. plantarum MBS17 [61] and L. fermentum LP10 [62] have been described to coaggregate with pathogenic strains of K. pneumoniae, while L. brevis gp104 can coaggregate with S. aureus [63]. This phenomenon has also been reported with pathogenic strains of P. aeruginosa isolated from sputum samples of cystic fibrosis patients, which can coaggregate with lactobacilli and bifidobacteria strains [64,65]. On the other hand, it was documented that B. subtilis KATMIRA1933 and B. amyloliquefaciens B-1895 are capable of coaggregating with various Acinetobacter spp.…”

Anti-Staphylococcal Biofilm Effects of a Liposome-Based Formulation Containing Citrus Polyphenols

“…Briefly, biofilms were detached from wells by scraping with a sterile tip and transferred to 1 mL of PBS. Suspensions were vigorously vortexed for 30 s (s), sonicated for 30 s using a water bath sonicator (Ultrasonic cleaner, VWR), and vortexed for an additional 30 s. After being diluted in PBS, aliquots were seeded on agar plates for CFU counts [57].…”

Strong Activity and No Resistance Induction Exerted by Cell-Free Supernatants from Lacticaseibacillus rhamnosus against Mono-Species and Dual-Species Biofilms of Wound Pathogens in In Vivo-like Conditions

“…Such proteinaceous components include bacteriocins whose main mechanisms of action involve pore formation in bacterial membranes [14]. Interestingly, the ability to reduce biofilm formation or even disrupt biofilms has been reported for lactic acid bacteria and their supernatants due to several, and not yet fully elucidated, mechanisms, which include the inhibition of quorum sensing and virulence factor expression, inhibition of motility, extracellular DNase activity, reduction in the amount of the biofilm extracellular matrix, and modification of the bacterial cell surface, among others [14,21,22].…”