Background: Owing to problems in accurate species identification of the diverse genus clostridium, the epidemiology and pathogenicity of many species are not fully understood. Moreover, previous studies on clostridium bacteraemia have been limited and relied only on phenotypic species identification. Aims: To characterise the epidemiology, disease spectrum, and outcome of clostridium bacteraemia using 16S ribosomal RNA (rRNA) gene sequencing. Method: During a four year period (1998)(1999)(2000)(2001), all cases of clostridium bacteraemia were prospectively studied and all ''non-perfringens'' clostridium isolates identified to the species level by 16S rRNA gene sequencing. Results: Fifty one blood culture isolates were identified as Clostridium perfringens and 17 belonged to 11 other clostridium species. The first case of C disporicum infection and two cases of clostridium bacteraemia in children with intussusception were also described. Of the 68 clostridium isolates from 68 different patients, 38 were associated with clinically relevant bacteraemia. The gastrointestinal and hepatobiliary tracts were common sites of both underlying disease and portal of entry in these patients. Clostridium perfringens accounted for 79% of all clinically relevant bacteraemia, with the remainder caused by a diversity of species. The attributable mortality rate of clinically relevant clostridium bacteraemia was 29%. Younger age and underlying gastrointestinal/hepatobiliary tract disease were associated with mortality (p , 0.05). Conclusions: Patients with clinically relevant clostridium bacteraemia should be investigated for the presence of underlying disease processes in the gastrointestinal or hepatobiliary tracts. 16S rRNA gene analysis will continue to be useful in further understanding the pathogenicity of various clostridium species.

In power markets, operating reserve procurement is usually centrally handled according to certain reliability rules and aiming at minimization of total cost for reserve procurement. In this approach, there are no customers' choices, no incentives for IS0 to minimize the total cost or for reserve suppliers to commit promised reserve capacity. It may leads to severe inefficiency. In this paper, we propose a decentralized approach for operating reserve procurement and in the meantime, to discover the market price for it. In the approach, each participant selects the optimal decision to maximize his or her own interests. Insurance theory is applied; which allows consumers to transfer their risk for financial loss of outage to the ISO, and induces incentive for the IS0 to manage the entire amount of reserve capacity in an efficient manner. A penalty system is introduced, which improves the liability for the genco to provide operating reserve. Detailed math model and solution procedure are presented. It is also shown that with properly defined reserve market's structure, the decentralized approach can yield same optimal solution as its centralized counterpart. Numerical example results illustrate the effectiveness of the suggested approach.