Priming with intranasal lactobacilli prevents Pseudomonas aeruginosa acute pneumonia in mice

• DOI: 10.1186/s12866-021-02254-7
• Publication Date: 2021-06-28T13:03:17Z
• Authors: Marie-Sarah Fangous; Philippe Gosset; Nicolas Galakhoff; Stéphanie Gouriou; Charles-Antoine G...; Christopher Payan; Sophie Vallet; Geneviève Héry-Ar...; Rozenn Le Berre
• Keywords: Proinflammatory cytokine

Increasing resistance to antibiotics of Pseudomonas aeruginosa leads therapeutic deadlock and alternative therapies are needed. We aimed evaluate the effects Lactobacillus clinical isolates in vivo, through intranasal administration on a murine model pneumonia.We screened vitro 50 pulmonary for their ability decrease synthesis two QS dependent-virulence factors (elastase pyocyanin) produced by strain PAO1. Two blends three were then tested vivo: one with highly effective anti-PAO1 virulence properties (blend named L.rff L. rhamnosus, fermentum strains), second no L.psb, paracasei, salivarius brevis). Each blend was administered intranasally mice 18 h prior PAO1 infection. Animal survival, bacterial loads, cytological analysis, cytokines secretion lungs evaluated at 6 or 24 post infection Intranasal priming both lactobacilli significantly improved 7-day survival from 12% control group 71 100% groups receiving L.psb respectively. No mortality observed either L.psb. Additionally, lung clearance enhanced h. A 2-log 4-log reduction + respectively, compared group. Significant reductions neutrophil recruitment proinflammatory cytokine chemokine after saline solution, whereas IL-10 production increased.These results demonstrate that acts as prophylaxis, avoids fatal complications caused pneumonia mice. These independent anti-Pseudomonas activity QS-dependent factors. Further experiments required identify immune mechanism before initiating trials.