title: Control of Klebsiella pneumoniae pulmonary infection and immunomodulation by oral treatment with the commensal probiotic Bifidobacterium longum 5(1A).
abstract: Klebsiella pneumoniae (Kp) a common cause of pneumonia leads to intense lung injury and mortality that are correlated with infective exacerbations. Probiotics are a class of microorganisms that have immunomodulatory effects to benefit health. We investigated whether the probiotic Bifidobacterium longum 5(1A) induces protection in mice against lung infection induced by Kp and the potential involved mechanisms. Kp infection induced secretion of pro-inflammatory cytokines, neutrophil recruitment, significant bacterial load in the lung and 50% lethality. However, treatment with live B. longum 5(1A) induced faster resolution of inflammation associated with an increased production of IL-10, decreased lung damage with significantly reduction of bacterial burden that contributed to rescue 100% of mice from death. We found that these effects could be attributed, at least in part, to activation of the Toll-like receptor (TLR) adapter protein Mal, since B. longum 5(1A) treatment in Mal-deficient infected mice did not show the protection observed in wild type infected mice. Thus, we propose that live B. longum 5(1A) activates TLR-signaling pathway that results in ROS production and protects the host against pneumonia-induced death by finely tuning the inflammatory response and contributing to faster return to lung homeostasis.
authors.affiliation: Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil. Electronic address: angelicathomaz@gmail.com.
authors.forename: Angélica T
authors.initials: AT
authors.lastname: Vieira
authors.affiliation: Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
authors.forename: Victor M
authors.initials: VM
authors.lastname: Rocha
authors.affiliation: Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Tavares
authors.affiliation: Laboratório de Vírus Respiratórios e do Sarampo, Instituto Oswaldo Cruz/FIOCRUZ-Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Cristiana C
authors.initials: CC
authors.lastname: Garcia
authors.affiliation: Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
authors.forename: Mauro M
authors.initials: MM
authors.lastname: Teixeira
authors.affiliation: Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
authors.forename: Sérgio C
authors.initials: SC
authors.lastname: Oliveira
authors.affiliation: Department of General Pathology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
authors.forename: Geovanni D
authors.initials: GD
authors.lastname: Cassali
authors.affiliation: Department of General Pathology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
authors.forename: Conrado
authors.initials: C
authors.lastname: Gamba
authors.affiliation: Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil.
authors.forename: Flaviano S
authors.initials: FS
authors.lastname: Martins
authors.affiliation: Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil. Electronic address: jnicoli@icb.ufmg.br.
authors.forename: Jacques R
authors.initials: JR
authors.lastname: Nicoli
mesh_terms: D000818:Animals; D058491:Bacterial Load; D001644:Bifidobacterium / Q000276:immunology*; D002648:Child; D004195:Disease Models, Animal; D006801:Humans; D056747:Immunomodulation; D007710:Klebsiella Infections / Q000628:therapy*; D007711:Klebsiella pneumoniae / Q000276:immunology*; D008810:Mice, Inbred C57BL; D018410:Pneumonia, Bacterial / Q000628:therapy*; D019936:Probiotics / Q000008:administration & dosage*; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Bifidobacterium longum 5(1A); Inflammation; Klebsiella pneumoniae; Mal/TIRAP; Microbiota; Probiotic