title: Lactobacillus casei administration reduces lung injuries in a Streptococcus pneumoniae infection in mice.
abstract: The effect of the oral administration of Lactobacillus casei on the prevention of a Streptococcus pneumoniae lung infection in a mouse experimental model was studied, analyzing the innate and specific immune response. Adult Swiss albino mice were treated with L. casei (10(9)CFU/day) for 2, 5 and 7 d. Mice were infected intranasally with S. pneumoniae (10(6)CFU/mouse) after each treatment and the microbiological, histopathological and host responses were determined for 15 d after infection. Feeding L. casei for 2 d induced a faster clearance of S. pneumoniae, with a lower number of pneumococci in lung and a shorter period of septicemia than in the control group. L. casei administration induced activation of phagocytes as evidenced by the strong myeloperoxidase activity and the nitro blue tetrazolium assay in lung. Mice given L. casei for 2 d showed higher levels of anti-pneumococcal serum IgG and bronchoalveolar lavage IgA than the control mice. The group fed L. casei for 2 d could beneficially regulate the balance between tumor necrosis factor alpha and interleukin 10, allowing a more effective immune response against infection and modulating the inflammatory response, with less damage to the lung.
authors.affiliation: Laboratorio de Bioquímica Clínica Experimental, Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, 4000 San Miguel de Tucumán, Tucumán, Argentina.
authors.forename: Silvia
authors.initials: S
authors.lastname: Racedo
authors.forename: Julio
authors.initials: J
authors.lastname: Villena
authors.forename: Marcela
authors.initials: M
authors.lastname: Medina
authors.forename: Graciela
authors.initials: G
authors.lastname: Agüero
authors.forename: Virginia
authors.initials: V
authors.lastname: Rodríguez
authors.forename: Susana
authors.initials: S
authors.lastname: Alvarez
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology; D007780:Lacticaseibacillus casei; D007958:Leukocyte Count; D008168:Lung / Q000201:enzymology / Q000382:microbiology / Q000473:pathology; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology; D051379:Mice; D009580:Nitroblue Tetrazolium / Q000032:analysis; D009195:Peroxidase / Q000378:metabolism; D011018:Pneumonia, Pneumococcal / Q000097:blood / Q000276:immunology / Q000382:microbiology* / Q000517:prevention & control*; D012128:Respiratory Distress Syndrome / Q000276:immunology / Q000382:microbiology* / Q000473:pathology / Q000517:prevention & control*; D013296:Streptococcus pneumoniae / Q000254:growth & development*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D009580:Nitroblue Tetrazolium; D009195:Peroxidase