Archibald L K, McDonald L C, Addison R M, McKnight C, Byrne T, Dobbie H, Nwanyanwu O, Kazembe P, Reller L B, Jarvis W R
Hospital Infections Program, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
J Clin Microbiol. 2000 Aug;38(8):2994-7. doi: 10.1128/JCM.38.8.2994-2997.2000.
In less-developed countries, studies of bloodstream infections (BSI) have been hindered because of the difficulty and costs of culturing blood for bacteria, mycobacteria, and fungi. During two study periods (study period I [1997] and study period II [1998]), we cultured blood from patients in Malawi by using the BACTEC MYCO/F LYTIC (MFL), ISOLATOR 10 (Isolator), Septi-Chek AFB (SC-AFB), and Septi-Chek bacterial (SC-B) systems. During study period I, blood was inoculated at 5 ml into an MFL bottle, 10 ml into an Isolator tube for lysis and centrifugation, and 10 ml into an SC-B bottle. Next, 0.5-ml aliquots of Isolator concentrate were inoculated into an SC-AFB bottle and onto Middlebrook 7H11 agar slants, chocolate agar slants, and Inhibitory Mold Agar (IMA) slants. During study period II, the SC-B and chocolate agar cultures were discontinued. MFL growth was detected by fluorescence caused by shining UV light (lambda = 365 nm) onto the indicator on the bottom of the bottle. During study period I, 251 blood cultures yielded 44 bacterial isolates. For bacteremia, the MFL was similar to the Isolator concentrate on chocolate agar (34 of 44 versus 27 of 44; P, not significant [NS]), but more sensitive than the SC-B bottle (34 of 44 versus 24 of 44; P = 0.05). For both study periods combined, 486 blood cultures yielded 37 mycobacterial and 13 fungal isolates. For mycobacteremia, the sensitivities of the MFL and Isolator concentrate in the SC-AFB bottle were similar (30 of 37 versus 29 of 37; P, NS); the MFL bottle was more sensitive than the concentrate on Middlebrook agar (30 of 37 versus 15 of 37; P = 0.002). For fungemia, the MFL bottle was as sensitive as the SC-B bottle or Isolator concentrate on chocolate agar or IMA slants. We conclude that the MFL bottle, inoculated with just 5 ml of blood and examined under UV light, provides a sensitive and uncomplicated method for comprehensive detection of BSI in less-developed countries.
在欠发达国家，由于对血液进行细菌、分枝杆菌和真菌培养存在困难且成本高昂，血流感染（BSI）的研究受到了阻碍。在两个研究阶段（研究阶段I[1997年]和研究阶段II[1998年]），我们使用BACTEC MYCO/F LYTIC（MFL）、ISOLATOR 10（Isolator）、Septi-Chek AFB（SC-AFB）和Septi-Chek细菌（SC-B）系统对马拉维患者的血液进行培养。在研究阶段I，将5毫升血液接种到一个MFL瓶中，10毫升血液接种到一个用于裂解和离心的Isolator管中，10毫升血液接种到一个SC-B瓶中。接下来，将0.5毫升的Isolator浓缩液接种到一个SC-AFB瓶以及Middlebrook 7H11琼脂斜面、巧克力琼脂斜面和抑制性霉菌琼脂（IMA）斜面上。在研究阶段II，停止了SC-B和巧克力琼脂培养。通过将紫外线（波长λ = 365纳米）照射到瓶底的指示剂上产生的荧光来检测MFL培养物的生长情况。在研究阶段I，251份血培养产生了44株细菌分离株。对于菌血症，MFL与巧克力琼脂上的Isolator浓缩液相似（44株中的34株对44株中的27株；P，无显著差异[NS]），但比SC-B瓶更敏感（44株中的34株对44株中的24株；P = 0.05）。对于两个研究阶段合并的数据，486份血培养产生了37株分枝杆菌和13株真菌分离株。对于分枝杆菌血症，MFL和SC-AFB瓶中的Isolator浓缩液的敏感性相似（37株中的30株对37株中的29株；P，无显著差异）；MFL瓶比Middlebrook琼脂上的浓缩液更敏感（37株中的30株对37株中的15株；P = 0.002）。对于真菌血症，MFL瓶与SC-B瓶或巧克力琼脂或IMA斜面上的Isolator浓缩液的敏感性相同。我们得出结论，仅接种5毫升血液并在紫外线照射下检查的MFL瓶，为欠发达国家全面检测BSI提供了一种敏感且简便的方法。
