, 2008; Veelders et al., 2010). A number of other social phenomena such as cross-feeding, resistance and QS might also be involved in the biofilm dynamics of S. cerevisiae. Danish Agency for Science Technology and Innovation is acknowledged for financial support (FTP 10-084027) MLN0128 purchase “
“Neonates and infants, due to the immaturity in their adaptive immunity, are thought to depend largely on the innate immune system for protection

against bacterial infection. However, the innate immunity-mediated antimicrobial response in neonates and infants is incompletely characterized. Here, we report that infant mice were more susceptible to microbial sepsis than adult mice, with significantly reduced bacterial clearance from the circulation and visceral organs. Infant PMNs exhibited less constitutive expression of the chemokine receptor

CXCR2, and bacterial infection caused further reduction of PMN CXCR2 in infant mice compared with adult mice. This correlates with diminished in vitro chemotaxis of infant PMNs toward the chemoattractant CXCL2 and impaired in vivo recruitment of infant PMNs into the infectious site. Furthermore, consistent with the reduced antimicrobial response in vivo, infant macrophages displayed an impaired bactericidal activity with a defect in phagosome maturation after ingestion of either gram-positive or gram-negative bacteria. Thus, infant mice exhibit an increased vulnerability to microbial Adenosine XL765 purchase infection with delayed bacterial clearance, which is associated with the inefficiency in their innate phagocyte-associated antimicrobial functions characterized by defects in PMN recruitment and macrophage phagosome maturation during microbial sepsis. Despite advances in medicine and the best available supportive care, death associated with neonatal and infant sepsis has remained largely unchanged over the last two decades and approximately four million children under the age of 6 months die from infections

each year worldwide [1-4]. Mortality rates from microbial sepsis in premature-birth and very low-birth-weight infants continue to increase and the incidence could be as high as 50% [5, 6]. Even in infants born in term, the inefficient response of their immune system to a variety of pathogens not only pre-disposes but makes them more vulnerable to microbial infection [4, 7]. Furthermore, neonates and infants who survive severe sepsis may suffer from developmental and growth impairment, which undoubtedly leads to long-term social and economic consequences [8-10]. Neonates and infants are generally more susceptible to a wider range of microbial infection than adults and are especially vulnerable to intracellular pathogen-associated infection [11-13].