A new probiotic strain and its potential effect on the recovery of immunity in malnourished mice

BARBIERI NP ; VILLENA J ; SALVA S ; HERRERA HM ; ALVAREZ S

Congreso; XXV Jornadas Cientificas de la Asociación de Biología de Tucumán; 2009

We reported that the oral administration of L. casei CRL 1505 (Lc05) to adult mice increases the resistance to Streptococcus pneumoniae (Sp) infection. The aim of this work was to study whether the administration of Lc05 improves the immunity against Sp in immunosuppressed mice. Swiss-albine mice were malnourished after they consumed a protein-free diet for 21d. Then repleted with a balanced conventional diet (BCD) for 7d, or BCD for 7d with Lc05 supplementation (108cell/mouse/d) on the last 5d. At the end of each treatment, these animals, well-nourished (WNC) and malnourished (MNC) controls were challenged with Sp (105cells/mouse). Lung colonization and bacteremia were higher in MNC than in WNC. Treatment with Lc05 significantly decreased pathogen numbers in lung and it was the only group with negative hemocultures. Lc05 treatment improved the number and the bactericidal activity of blood and bronchoalveolar (BAL) leukocytes. In the Lc05 group levels of serum and BAL anti-Sp IgG were higher than in MNC, whereas BAL anti-Sp IgA was higher than in WNC. Lc05 treatment has a beneficial influence on the recovery of malnourished mice, as it is able to improve innate and adaptive immune response in both the systemic and respiratory compartments