Gérôme P, Fabre M, Soler C-P, De Pina J J, Simon F
Service de biologie médicale, HIA Desgenettes, 108, boulevard Pinel, 69275 Lyon cedex 03, France.
Pathol Biol (Paris). 2009 Feb;57(1):44-50. doi: 10.1016/j.patbio.2008.05.007. Epub 2008 Jun 30.
The aim of this study was to compare the mycobacteria growth indicator tube and solid culture for recovery of complex tuberculosis mycobacteria from blood.
One hundred and twenty-five specimens from 67 Djiboutian patients with a positive serologic diagnosis of HIV and fever were collected in an Isolator tube. After centrifugation and washing with phosphate-buffer, smears were prepared from the pellet for auramin staining. The remaining sediment was suspended in 1 ml of buffer. One half was inoculated into two MGIT (incubation at 30 and 37 degrees C into Bactec 960) and the other onto two Loewenstein-Jensen and two Coletsos medium (incubation at 30 and 37 degrees C).
Eight cultures were contaminated: three on solid medium and MGIT simultaneously, five in MGIT only (three coagulase negative staphylococci, five enterobacteria). Fourteen strains of M. tuberculosis (six patients) and three M. canettii (two patients) (12 on solid media and MGIT, five in MGIT only) were recovered. The mean time to detection was 32.8 days for solid medium and 20.4 days for MGIT. Of a total of 25 patients with culture-proven tuberculosis, two patients had a positive blood culture only, six had blood and other specimens positive culture, 17 had a non blood specimens positive culture only.
MGIT processed into Bactec 960 is a viable tool for the detection of complexe tuberculosis mycobacteria from blood and the high-frequency of these mycobacteremia in HIV infected patients from country where the prevalence of tuberculosis is high is confirmed. However, the cost/benefit ratio of this bacteriologic diagnosis had to be evaluated in developping country.
本研究旨在比较分枝杆菌生长指示管和固体培养法从血液中分离复杂结核分枝杆菌的效果。
收集了吉布提67例血清学诊断HIV阳性且发热患者的125份标本，置于隔离管中。离心并用磷酸盐缓冲液洗涤后，取沉淀制备涂片进行金胺染色。将剩余沉淀悬浮于1 ml缓冲液中。一半接种到两支分枝杆菌生长指示管（在30℃和37℃下培养于Bactec 960中），另一半接种到两支罗-琴培养基和两支科莱索斯培养基（在30℃和37℃下培养）。
8份培养物被污染：3份在固体培养基和分枝杆菌生长指示管中同时被污染，5份仅在分枝杆菌生长指示管中被污染（3份凝固酶阴性葡萄球菌，5份肠杆菌）。共分离出14株结核分枝杆菌（6例患者）和3株堪氏分枝杆菌（2例患者）（12份在固体培养基和分枝杆菌生长指示管中分离到，5份仅在分枝杆菌生长指示管中分离到）。固体培养基检测的平均时间为32.8天，分枝杆菌生长指示管为20.4天。在25例经培养证实为结核病的患者中，2例仅血培养阳性，6例血培养和其他标本培养均阳性，17例仅非血标本培养阳性。
在Bactec 960中使用分枝杆菌生长指示管是从血液中检测复杂结核分枝杆菌的可行工具，且证实了在结核病高发国家的HIV感染患者中这些菌血症的高发生率。然而，这种细菌学诊断的成本效益比必须在发展中国家进行评估。
