Objective To reduce the turnaround time for laboratory diagnosis of bacteremia, the feasibility of rapid identification and susceptibility testing using samples taken directly from positive blood culture bottles was evaluated. Methods The growth of microorganisms in blood culture bottles was screened by the BACTEC 9000 blood culture system. 65 positive blood culture bottles containing gram-negative bacteria were adopted to test. Culture fluid was injected into BD SST vacutainer and centrifuged to pellet blood cells. After collecting required McFarland units, they were cultured on Phoenix 100 NMIC/ID-4(identification-gram-negative bacteria and susceptibility testing) cards using 0.25 McF and 0.5 McF methods respectively. They were also evaluated by the standard method, involving subculture tests from positive blood culture bottles. Results 63 of 65 gram-negative bacteria (96. 9% ) were correctly identified with 0. 25 McF method. 59 of 65 gram-negative bacteria(90.8% ) were correctly identified with 0.5 McF method. For antimicrobial susceptibility testing, the 0.25 McF direct method had an agreement rate more than 94% , the 0.5 McF method was more than 85.7% and direct blood sample KB method was more than 93.8% compared to the standard method. But the overall minor error rate in susceptibility testing of direct blood sample KB method is higher than other methods. Conclusion Applying 0. 25 McF and 0. 5 McF rapid identification and susceptibility test was practical. During to possessing more prominent advantages, laboratory put the 0. 25 McF direct method into practice had a timely, remarkable significance.

BACKGROUND: Talomerase activity inhibitor inhibits or kills renal carcinoma cells, and also affects stem cells that play importan roles in occurrence and development of renal carcinoma.OBJECTIVE: To observe renal carcinoma stem cell surface marker CD133 and telomerase activity expression in serum-free suspension culture, and to compare with renal carcinoma cells in serum suspension culture.DESIGN, TIME AND SETTING: The in vitro cytological study was performed at the Jiangsu University from June 2008 to Februar 2009.WIATERIALS: Fresh normal renal tissue surrounding renal carcinoma was obtained from Affiliated Hospital, Jiangsu University.Renal carcinoma stem cell line OS-RC-2 was supplied by Cell Bank, Chinese Academy of Sciences Shanghai Branch.METHODS: OS-RC-2 in logarithmic phase, digested by trypsin, and centrifuged. Supematant was removed. OS-RC-2 cell line in serum-free DMEM/F12 supplemented with epidermal growth factor and basic fibroblast growth factor was incubated at 2×105/L in 5% CO2 incubator at 37℃. Renal carcinoma cultured in serum and normal renal tissue served as controls.MAIN OUTCOME MEASURES: Cell growth was observed under an inverted microscope. Expression of CD133 and CD34 was detected using flow cytometry. Reel-time quantitative TRAP assay was applied to evaluate telomerase activity in renal carcinoma stem cells.RESULTS: After incubated in serum-free medium, renal carcinoma stem cells were round and suspended. Two days later, cell mass generated. Each cell mass contained 3-8 cells, with strong refraction. Seven days later, cell mass became more, presented big body that was regular, round or elliptical. CD133+CD34- rate in renal carcinoma stern cell mass was significantly greater in serum-free suspension culture compared with in serum suspension culture. CD133 and CD34 expression was not determined in normal renal tissue. There were significant differences among groups (F=328.25, P < 0.05). Telomerase activity was greater in renal carcinoma stem cells and renal carcinoma cells compared with normal renal ceils (F=-278.74, P < 0.05). No significant difference was detected between renal carcinoma stem cells and renal carcinoma cells.CONCLUSION: Compared with serum cultured renal carcinoma cells, serum-free cultured renal carcinoma cell surface marker CD133 presents high expression. Moreover, talomerase activity is high in renal carcinoma stem cells and renal carcinoma cells compared with normal renal tissue.