血培养阳性培养物直接药敏试验的评价

Evaluation of direct susceptibility testing for positive blood cultures

目的通过比对血培养阳性培养物直接药敏试验与标准药敏试验结果的一致性,探讨血培养直接药敏报告在临床血流感染诊治中的应用价值。方法选取西安交通大学第一附属医院2014年12月到2015年2月的血培养阳性标本,在进行标准药敏试验的同时,阳性报警后根据涂片染色结果按照革兰阳性菌和革兰阴性菌采用纸片扩散法进行直接药敏试验。统计直接药敏与标准药敏试验结果的符合率、严重错误率、重大错误率、微小错误率。结果该研究共包括血培养阳性菌株101株,药敏试验比对结果875个。革兰阳性菌标准符合率为94.3%,严重错误率为0.8%,重大错误率为0.4%,微小错误率为4.5%;革兰阴性菌标准符合率为94.1%,严重错误率为0.0%,重大错误率为3.7%,微小错误率为2.2%。革兰阳性菌中利奈唑胺、四环素、替考拉宁、万古霉素,革兰阴性菌中亚胺培南与美罗培南符合率为100.0%。氟喹诺酮类在革兰阳性菌与革兰阴性菌中均出现微小错误。革兰阳性菌中克林霉素出现严重错误。革兰阴性菌中头孢类抗菌药物符合率偏低,并易出现重大错误。结论利用血培养阳性物采用纸片扩散法进行直接药敏试验不仅能够快速、准确地为临床提供初步药敏结果,更易于在临床广泛使用。

Objective To explore the diagnostic value of direct susceptibility testing in blood stream infection by comparing the results of direct susceptibility test with standard susceptibility test of positive blood culture.Methods Positive blood culture specimens in the First Affiliated Hospital of Xi′an Jiaotong University were collected from December 2014 to February 2015,besides the standard susceptibility testing,according to the results of smear staining,disc diffusion susceptibility tests were carried out for the Gram-positive cocci and Gram-negative rods.Rates of consistency,very major errors,major errors and minor errors of direct susceptibility test compared to standard susceptibility test were analyzed.Results Altogether,101 isolates and 875organism/antibiotic combinations were evaluated.With regard to Gram-positive cocci,agreement between both methods was found in 94.3% of cases,with 0.8%very major,0.4% major and 4.5% minor errors.For Gram-negative rods,agreement was found in 94.1% of cases,with 0.0% very major,3.7% major and 2.2% minor errors.Agreement between both methods was 100.0%for linezolid,tetracycline,teicoplanin and vancomycin in Gram-positive cocci,imipenem and meropenem in Gram-negative rods.Minor errors occurred in fluoroquinolone for Gram-positive cocci and Gram-negative rods.Very major error occurred in clindamycin for Gram-positive cocci.Low consistent rate was found in cephalosporins antibiotics for Gramnegative rods,and major error occurred often.Conclusion Using positive blood culture for direct susceptibility test by disc diffusion susceptibility tests can not only provide rapid and accurate preliminary susceptibility results,but also save costs.Therefore,it can be widely used in clinical.