Vol.58 No.5 September 2010
Prognostic factors and the role of interleukin-1 in bacteremia caused by Pseudomonas aeruginosa
Department of Infectious Disease and Infection Control, Jikei University School of Medicine, 3-25-8 Nishi-shimbashi, Minato-ku, Tokyo, Japan
Abstract
Pseudomonas aeruginosa, which makes up 3-7% in all bacteremia, sometimes causes severe infectious diseases especially in immunocompromised host. Furthermore, P. aeruginosa is also one of the most important pathogens in nosocomial infections, because P. aeruginosa infections are sometimes persistent due to its drug-resistance. Among 89 patients with P. aeruginosa bacteremia at Jikei University Affiliated Hospital between April 2003 and December 2007, their nosocomial acquisition and immunosuppressive conditions, such as acute leukemia and chronic renal diseases, were accounted in 91.0% and 85.4%, respectively. The 30-day mortality rate of all patients with P. aeruginosa bacteremia was 24.7% without depending on administered anti-pseudomonal antimicrobials, suggesting that possible prognostic factors were thrombocytopenia, hypoalbuminemia and polymicrobial bacteremia. Interleukin-1(IL-1) is one of the typical inflammatory cytokines in P. aeruginosa bacteremia. In order to elucidate the role of IL-1 in P. aeruginosa bacteremia, the susceptibility of IL-1-deficient mice to P. aeruginosa was compared to that of wild-type mice. In gut-derived sepsis model, IL-1-deficient mice were more susceptible to P. aeruginosa than wild-type mice. On the other hand, the susceptibilities to P. aeruginosa of IL-1 deficient mice and wild-type mice are similar in intravenous injecting sepsis model. However, when the mice were pretreated with cyclophosphamide, the susceptibility of IL-1-deficient mice to P. aeruginosa was also higher than that of wild-type mice, significantly. These results suggested that the role of IL-1 during P. aeruginosa bacteremia was enhanced under the immunosuppressive condition. To date, the mortality rates of P. aeruginosa bacteremia is still high, whereas many anti-pseudomonal antimicrobials had been introduced. Therefore, we need further studies on the prognostic factors and antimicrobial therapy in P. aeruginosa infections.
Key word
Pseudomonas aeruginosa, bacteremia, prognostic factor, interleukin-1 （IL-1）
Received
July 31, 2010
Accepted
August 10, 2010
Jpn. J. Chemother. 58 (5): 547-554, 2010
