Screening of Lactobacillus spp. for the prevention of Pseudomonas aeruginosa pulmonary infections

Abstract

BackgroundPseudomonas aeruginosa is an opportunistic pathogen that significantly increases morbidity and mortality in nosocomial infections and cystic fibrosis patients. Its pathogenicity especially relies on the production of virulence factors or resistances to many antibiotics. Since multiplication of antibiotic resistance can lead to therapeutic impasses, it becomes necessary to develop new tools for fighting P. aeruginosa infections. The use of probiotics is one of the ways currently being explored. Probiotics are microorganisms that exert a positive effect on the host’s health and some of them are known to possess antibacterial activities. Since most of their effects have been shown in the digestive tract, experimental data compatible with the respiratory environment are strongly needed. The main goal of this study was then to test the capacity of lactobacilli to inhibit major virulence factors (elastolytic activity and biofilm formation) associated with P. aeruginosa pathogenicity.ResultsSixty-seven lactobacilli were isolated from the oral cavities of healthy volunteers. These isolates together with 20 lactobacilli isolated from raw milks, were tested for their capacity to decrease biofilm formation and activity of the elastase produced by P. aeruginosa PAO1. Ten isolates, particularly efficient, were accurately identified using a polyphasic approach (API 50 CHL, mass-spectrometry and 16S/rpoA/pheS genes sequencing) and typed by pulsed-field gel electrophoresis (PFGE). The 8 remaining strains belonging to the L. fermentum (6), L. zeae (1) and L. paracasei (1) species were sensitive to all antibiotics tested with the exception of the intrinsic resistance to vancomycin. The strains were all able to grow in artificial saliva.ConclusionEight strains belonging to L. fermentum, L. zeae and L. paracasei species harbouring anti-elastase and anti-biofilm properties are potential probiotics for fighting P. aeruginosa pulmonary infections. However, further studies are needed in order to test their innocuity and their capacity to behave such as an oropharyngeal barrier against Pseudomonas aeruginosa colonisation in vivo.

Lactobacillus fermentum ATCC 23271 Displays In vitro Inhibitory Activities against Candida spp.

“…Members of the Lactobacillus genus have been proposed as probiotics as they can protect against infectious disease agents (Li et al, 2012; Ren et al, 2012; Zabihollahi et al, 2012; Alexandre et al, 2014). From those, some ( L. crispatus and L. acidophilus ) commonly colonize the female genital tract and have been studied as probiotics (Mastromarino et al, 2002; Antonio et al, 2009; Zhang et al, 2012; Kaewnopparat et al, 2013; Nami et al, 2014; Verdenelli et al, 2014).…”

Using Lactic Acid as an Antimicrobial Against Pseudomonas Aeroginosa and Validation of Its Test Method by Lc-MS/Ms.

“…Many authors could separate Lactic acid at retention times similar to that obtained in this study like 36 who get retention time of lactic acid at 5.02 min. Different retention time values were obtained by others studies like 34 who get retention time at 4 min.…”

The impact of Lactococcus lactis (probiotic nasal rinse) co‐culture on growth of patient‐derived strains of Pseudomonas aeruginosa

“…The pathogenicity of P. aeruginosa includes biofilm formation (decreasing the capability of antibiotic treatment to reach bacteria) and acquired antibiotic resistance, which complicates the strategy for eliminating infections and has encouraged the development of alternate treatment options . Alexandre et al . recently screened a variety of Lactobacilli cultures from milk and the oral cavity of healthy individuals and described 8 strains of the bacteria that were devoid of antibiotic resistance and able to decrease P. aeruginosa virulence factors (elastolytic activity and biofilm formation).…”