血培养联合PCR对HIV感染者和AIDS患者分枝杆菌血症诊断的分析

摘要

目的 评价应用BACTEC Myco/F Lytic(MFL)培养基血培养联合聚合酶链反应(PCR)对人类免疫缺陷病毒(HIV)感染者和获得性免疫缺陷综合征(AIDS)患者合并分枝杆菌(MB)感染诊断的效果.方法 用MFL配合BACTEC 9120血培养仪对55例可疑合并MB感染的HIV/AIDS患者血标本进行培养,联合抗酸染色和PCR对阳性标本进行菌种鉴定.结果 55例患者血培养分析显示,MFL血培养的总报阳率为32.7%(18/55),其中7例(12.7%)报阳标本经证实为MB生长,8例(14.5%)报阳标本中未检出任何微生物,暂定为假报警,3例(5.4%)检出污染菌.其中MB的平均培养周期为746.79 h,约31.1 d.7例MB培养阳性标本经PCR鉴定,5例(71.4%)为结核分枝杆菌(TB),2例(28.6%)为鸟分枝杆菌复合体(MAC).结论 MFL血培养能协助临床诊断MB血症,该法操作简单、安全性高,但培养周期较长,且存在假报警及某些需氧菌污染的情况.故宜联合其他检测手段对MB血症进行检测.%Objective To evaluate the diagnosis value of BACTEC Myco/F Lytic (MFL) medium on blood culture combined with polymerase chain reaction(PCR) for detection of Mycobacterium (MB) in human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS) patients. Methods A total of 55 blood specimens from HIV/AIDS patients were inoculated in MFL medium, and then were placed in BACTEC 9120 blood culture system. Acid fast stain and PCR were used for the MB identification of all positive samples. Results The 18 (32.7％) samples out of 55 were reported as positive by the BACTEC 9120 blood culture system, including 7 ( 12.7％ ) samples were found as MB [5(71.4％) MB tuberculosis (TB) and 2 (28.6％) MB avium complex (MAC) identified by PCR], 8( 14.5％)samples were temporarily considered as false positive, and 3 (5.4％) samples were found as contaminated bacteria. The average time for the detection of MB was 746.79 h, about 31.1 d. Conclusions Although blood culture with MFL medium is a simple and safe diagnostic method for the detection of MB, the long turnaround time, possible false positive report and aerobic bacterial contamination make it of limited usefulness. MFL medium blood culture should combine with other assays for the MB detection.