Bacterial culture results of 28 292 clinical blood specimens

Abstract:

ObjectiveTo investigate the distribution characteristics of pathogens isolated from clinical blood specimens from a hospital. MethodsBacteria isolated from 55 606 bottles of 28 292 blood specimens between 1999 and 2008 were cultured and identified by mimi VITAL Blood Culture Automation System and Bact/ALERT 3D System and VITEK 32 Automicrobic System,and the culture result was analysed statistically .ResultsIn aerobic and anaerobic culture of 28 292 blood specimens,5 837 showed positive culture results， the positive rate was 20.63%;The positive rate of aerobic and anaerobic bacteria was 83.50%(4 874/5 837) and 82.30%（4 804/5 837）respectively. A total of 5 837 strains of 117 species of 43 genus were detected, Salmonella paratyphi A accounted for 4 486 stains(76.85%).The distribution showed three peaks of bacterial detection were in the year of 2001 (1 263 strains) , 2004 (740 strains) and 2006 (713 strains). Grampositive cocci were the main isolated bacteria ,the ratio of grampositive cocci to gramnegative bacilli and fungi was 65.73∶25.30∶2.74. Coagulase negative Staphylococcus(CNS) accounted for 37.46%(493/1 316) of the detected bacteria except Salmonella spp., and had a tendency of increasing gradually(χ2=127.81,P＜0.01).The isolation rate of fungus was increasing gradually(χ2=29.77,P＜0.01). The obligate anaerobes accounted for 0.38%(22/5 837) of all isolated bacteria , and accounted for 1.67%(22/1 316) except Salmonella.Conclusion Performing both aerobic and anaerobic culture can enhance the positive detection rate. Constant detection of Salmonella paratyphi A and increasing tendency of opportunistic pathogens(CNS and fungus) should be paid much attention to .