Clinical practice and needleless device type. Can J Infect Control 2008, 23:156-Clinical practice and needleless

Clinical practice and needleless device type. Can J Infect Control 2008, 23:156-
Clinical practice and needleless device type. Can J Infect Control 2008, 23:156-160, 162. 2. Tacconelli E, Smith G, Hieke K, Lafuma A, Bastide P: Epidemiology, medical outcomes and costs of catheterrelated bloodstream infections in intensive care units of four European countries: literature and registry based estimates. J Hosp Infect 2009, 72:97-103. 3. Mermel LA: Prevention of central venous catheter-related infections: what works other than impregnated or coated catheters? J Hosp Infect 2007, 65(Suppl 2):30-33. 4. Berenholtz SM, Pronovost PJ, Lipsett PA, et al.: Eliminating catheter-related bloodstream infections in the intensive care unit. Crit Care Med 2004, 32:2014-2020. 5. Anonymous: Reduction in central line-associated bloodstream infections among patients in intensive care units Pennsylvania, April 2001 March 2005. MMWR Recomm Rep 2005, 54:1013-1016. 6. Pronovost P, Needham D, Berenholtz S, et al.: An intervention to decrease catheter-related bloodstream infections in the ICU. N Engl J Med 2006, 355:2725-2732.Introduction Klebsiella species are opportunistic pathogens that can give rise to severe infections including pneumonia and sepsis. Typically, Klebsiella infections are nosocomial and mainly caused by Klebsiella pneumoniae, the medically most important species of the genus. Objective We set out to SCH 530348MedChemExpress Vorapaxar validate and extend our previous data using C3H/HeJ mice that PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/27766426 demonstrated an important role for TLR4 in K. pneumoniae pneumonia. Moreover, we were interested in the relative roles of cells from hematopoietic origin and parenchymal cells. Methods Using TLR2 and TLR4 single and TLR2x4 double knockout (KO) mice on a C57BL/6 background, the roles of TLR2 and TLR4 were investigated independently and together. We intranasally inoculated C57BL/6 wild-type (WT) and KO mice with K. pneumoniae (4 x 10? CFU per mouse) and studied host defense. Moreover, we performed bone marrow transplantation (BMT) experiments in which we transplanted KO bone marrow into irradiated WT mice and vice versa. Results Shortly after infection, both TLR4 and TLR2x4 KO mice demonstrated an attenuated proinflammatory response in the lungs. This was associated with higher bacterial counts 24 hours after infection in the lungs, liver and spleens of both TLR4 and TLR2x4 KO animals. Interestingly, although no differences in antibacterial host defense of TLR2 KO animals were observed, TLR2x4 KO animals were more susceptible to K. pneumoniae infection than the single TLR4 KO mice: after 44 hours of infection, 0/8 WT, 0/8 TLR2 KO mice, 5/8 TLR4 KO mice and 8/8 TLR2x4 KO mice had succumbed. Moreover, when infecting all strains with a high dose of K. pneumoniae (10? CFU), no differences in outgrowth were detected between WT, TLR2 and TLR4 KO animals, whereas double KO animals suffered from higher bacterial burdens in the lungs, liver, spleen and blood. BMT of WT bone marrow into irradiated TLR2x4 KO mice resulted in a reversed phenotype with similar bacterial growth compared with syngenic transplanted WT mice. Conclusions These data confirm our previous research that, during low-dose infections, TLR4 is of primary importance in host defense against K. pneumoniae. Nevertheless, when high numbers of bacteria are present, TLR2 acts together with TLR4 to orchestrate the immune response, a protective effect that is primarily mediated by hematopoietic cells.P24 Effect of the novel influenza A (H1N1) virus in the human immune systemA Antonopoulou, M Raftogiannis, F Baziaka, P Kout.