Sepsis Research Today is a free monthly online journal that collates and summarizes the latest research about Sepsis, including details on septicemia, diagnosis, symptoms, treatment.

Characterisation of the host inflammatory response to Staphylococcus epidermidis in neonatal whole blood.

Härtel C, Osthues I, Rupp J, Haase B, Röder K, Göpel W, Herting E, Schultz C

Department of Paediatrics, University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany. haertel@paedia.ukl.mu-luebeck.de

BACKGROUND: Coagulase-negative staphylococci (CoNS) are the most prevalent pathogens causing late-onset sepsis, and gestational age is the most important risk factor for these infections. OBJECTIVE: To characterise innate immune responses to S epidermidis by assessment of whole blood in vitro cytokine production in a large group of preterm and term infants. RESULTS: The S epidermidis-induced in vitro production of proinflammatory cytokines such as intracytoplasmic interleukin (IL) 6 and tumour necrosis factor alpha in cord blood samples was found to be dependent on gestational age (R = 0.279, 95% CI 0.10 to 0.44, p = 0.002; R = 0.251, 95% CI 0.07 to 0.41, p = 0.005, respectively; n = 121). In contrast, the production of anti-inflammatory cytokines such as IL10 and transforming growth factor beta was not associated with gestational age. When different stimulation strategies were compared, a strong correlation was noted for cytokine responses after lipopolysaccharide and S epidermidis exposure--that is, IL6 (R = 0.431, 95% CI 0.29 to 0.55, p<0.001, n = 161) and IL10 (R = 0.332, 95% CI 0.18 to 0.47, p<0.001, n = 161). In addition, a lower IL6 production was found in supernatants of whole blood cultures infected with a clinically isolated IcaABD-positive (biofilm production) strain compared with a control IcaABD-negative ATCC strain (p = 0.009). CONCLUSIONS: These in vitro data suggest that proinflammatory responses to S epidermidis are dependent on gestational age in preterm infants, whereas the counteracting anti-inflammatory response to S epidermidis may not be directly related to gestational age. Individual host factors may have a role as well as bacterial determinants, such as biofilm production. Further studies are encouraged to investigate the different aspects of innate immune responses to CoNS in vivo.

Published 25 February 2008 in Arch Dis Child Fetal Neonatal Ed, 93(2): F140-5.
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