Comparative Characteristics of the Spleen White Pulp in Experimental Models of Sepsis Caused by Different Strains of Pseudomonas aeruginosa.

We describe reactive changes in the spleen white pulp in male C57BL/6 mice with experimental sepsis induced by intraperitoneal administration of Pseudomonas aeruginosa 1840 (Pa1840) with exotoxin U gene or Pseudomonas aeruginosa 1623 (Pa1623) with exotoxin S gene. Histological analysis and morphometry revealed hypoplasia of the spleen white pulp in mice with sepsis induced by Pa1840, while sepsis caused by Pa1623 was associated with its hyperplasia; with apoptosis of white pulp cells was observed in both cases. The results attest to ambiguous nature of the reactive changes in the white pulp of the spleen in experimental sepsis models initiated by Pa1840 and Pa1623 stains.