Bloodstream infection - the pathogenic research and clinical investigation / 中华传染病杂志

ABSTRACT

Objectives To identify the spectrum of pathogens causing bloodstream infection and their resistance profiles. Methods We examined records with positive blood culture from Jan. 1998 to Mar. 2003 in a teaching hospital in Shanghai. The contaminants were excluded according to the CDC definition of bloodstream infection. Bacteria were collected from April 1, 2002 to March 31, 2003 and MIC to the most commonly used antimicrobial agents was performed. Results 276 episodes occurred during the study period. Of all the BSI episodes, about 74.3% BSI were hospital-acquired and 37.3% were community-acquired. Gram-positive organisms accounted for 38% of isolates, while gram-negative for 44.2% and fungus for 13.8%. The commonest pathogens causing bloodstream infection in hospital-acquired BSI were coagulase-negative staphylococcus (16.9%) and Escherichia coli (16.6%), followed by Candida species (14.1%), Staphylococcus aureus (13.7%) and Klebsiella pneumoniae (13.2%). Streptococcus spp., Escherichia coli, coagulase-negative staphylococcus and Staphylococcus aureus are the leading pathogens causing community-acquired bloodstream infection, which accounted for 16.9%, 15.5%, 15.5%, 11.3% respectively. Susceptibility tests in vitro shows that methicillin resistance in S. aureus was 56%, while in coagulase-negative staphylococcus was 88%. Among the prevalent Gram-negative BSI isolates, resistance rates for most of the antimi-crobial agents were high. However, it is encouraging to note that the carbapenems retained potency against almost all the Enterobacteriaceae, including those resistant to the third-generation cephalosporins and extended-broad-spectrum penicillins. The crude mortality rate of BSI was 24.4%. Conclusion The rate of Coagulase-negative staphylococcus, Klebsiella pneumoniae and fungus in BSI have increased in the past years. Enterobacteriaceae, acinetobacter spp and fungus are more common in hospital-acquired BSI than community-acquired BSI.