Priming with intranasal lactobacilli prevents Pseudomonas aeruginosa acute pneumonia in mice

BMC Microbiology

article

Fangous, Marie-Sarah¹  Gosset, Philippe³  Galakhoff, Nicolas²  Gouriou, Stéphanie²  Guilloux, Charles-Antoine²  Payan, Christopher²  Vallet, Sophie²  Héry-Arnaud, Geneviève²  Le Berre, Rozenn² 

[1] Laboratoire de biologie médicale, Centre Hospitalier de Cornouaille;Univ Brest, Inserm, EFS;University of Lille, Institut Pasteur de Lille, CIIL - Center for Infection and Immunity of Lille- OpInfIELD;Département de Bactériologie-Virologie, Hygiène hospitalière et Parasitologie-Mycologie;Département de Médecine Interne et Pneumologie

关键词: Lactobacillus;    Probiotics;    Intranasal administration;    Pseudomonas aeruginosa;    Respiratory tract infection;    Mice;   

DOI  :  10.1186/s12866-021-02254-7

学科分类：放射科、核医学、医学影像

来源: BioMed Central

【 摘 要 】

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

【 授权许可】

CC BY|CC0