The emergence of KPC-2-producing K. pneumoniae in Greek hospitals creates an important challenge for clinicians and hospital epidemiologists, because it is added to the already high burden of antimicrobial resistance.

Carriers used for the local delivery of antibacterial agents may be classified as nonbiodegradable or biodegradable. A major representative of the former category are the polymethylmethacrylate (PMMA) beads often impregnated with gentamicin which have been commercially available for the last 2 decades. Examples of the latter category include the collagen-gentamicin sponge, apatite-wollastonite glass ceramic blocks, hydroxyapatite blocks, polylactide/polyglycolide implants and the polylactate polymers. All of the above systems release antibiotics at concentrations exceeding those of the minimum inhibitory concentrations (MICs) for the most common pathogens of chronic osteomyelitis without releasing any antibiotic in the systemic circulation and without producing adverse effects. The major disadvantage of the PMMA beads is the need for their surgical removal at the completion of antibiotic release, which usually takes place 4 weeks after their implantation. The biodegradable carriers do not require surgical removal, and of those listed, the collagen-gentamicin sponge has been applied successfully over the last decade for bone infections. Among the other biodegradable systems which are still in experimental stages, polylactate polymers carrying quinolones seem very promising, since they are characterised by prolonged duration of release at concentrations 100 to 1000 times the MICs of the causative bacteria implicated in bone infections; preliminary results have shown these carriers to be very effective in the management of experimental osteomyelitis caused by methicillin-resistant Staphylococcus aureus. Further development of such biodegradable systems will provide a novel approach in the future for the eradication of chronic osteomyelitis.

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IntroductionAlthough major changes of the immune system have been described in sepsis, it has never been studied whether these may differ in relation to the type of underlying infection or not. This was studied for the first time.MethodsThe statuses of the innate and adaptive immune systems were prospectively compared in 505 patients. Whole blood was sampled within less than 24 hours of advent of sepsis; white blood cells were stained with monoclonal antibodies and analyzed though a flow cytometer.ResultsExpression of HLA-DR was significantly decreased among patients with severe sepsis/shock due to acute pyelonephritis and intraabdominal infections compared with sepsis. The rate of apoptosis of natural killer (NK) cells differed significantly among patients with severe sepsis/shock due to ventilator-associated pneumonia (VAP) and hospital-acquired pneumonia (HAP) compared with sepsis. The rate of apoptosis of NKT cells differed significantly among patients with severe sepsis/shock due to acute pyelonephritis, primary bacteremia and VAP/HAP compared with sepsis. Regarding adaptive immunity, absolute counts of CD4-lymphocytes were significantly decreased among patients with severe sepsis/shock due to community-acquired pneumonia (CAP) and intraabdominal infections compared with sepsis. Absolute counts of B-lymphocytes were significantly decreased among patients with severe sepsis/shock due to CAP compared with sepsis.ConclusionsMajor differences of the early statuses of the innate and adaptive immune systems exist between sepsis and severe sepsis/shock in relation to the underlying type of infection. These results may have a major impact on therapeutics.

Synbiotics contained in the studied formula decrease significantly the risk for sepsis by bloodstream infections and the occurrence of VAP by A. baumannii. The mechanisms of action might involve direct immunomodulatory effect, prevention of bacterial translocation, or most likely a combination of both.