Nazarowec-White M, Farber J M
Bureau of Microbial Hazards, Food Directorate, Health Canada, Postal Locator 2204A2, Ottawa, Ontario, Canada K1A 0L2.
J Med Microbiol. 1999 Jun;48(6):559-567. doi: 10.1099/00222615-48-6-559.
Enterobacter sakazakii, designated a unique species in 1980, has been implicated as the causative organism in a rare but severe form of neonatal meningitis. Dried infant formula milk has been identified as a potential source of the organism. E. sakazakii isolates from dried infant formula available in Canada and clinical isolates obtained from Canadian hospital culture collections were characterised by phenotypic (biotype and antibiograms) and genotypic (ribotyping, random amplification of polymorphic DNA and pulsed-field gel electrophoresis) methods. Three biotypes and four antibiogram patterns were observed in the 18 isolates examined. Ribotyping with the Dupont Riboprinter microbial identification system divided the 18 isolates into 10 ribotypes. Three isolates from the same hospital had indistinguishable ribotyping patterns although each was isolated in a different year, as did three food isolates from one company. Pulsed-field gel electrophoresis (PFGE) and random amplification of polymorphic DNA (RAPD) profiles indicated minor differences between the isolates that were indistinguishable by ribotyping. PFGE (with the restriction endonucleases Xba1 and Spe1) and RAPD gave discrete patterns that enabled easy comparison of E. sakazakii isolates, with a high degree of discrimination. The discriminatory index showed RAPD and PFGE were shown to be the most discriminatory typing schemes for E. sakazakii, followed by ribotyping, biotyping and antibiograms.
阪崎肠杆菌于1980年被认定为一个独特的菌种，它被认为是一种罕见但严重的新生儿脑膜炎的致病微生物。干燥婴儿配方奶粉已被确定为该微生物的一个潜在来源。对加拿大市售干燥婴儿配方奶粉中的阪崎肠杆菌分离株以及从加拿大医院培养物保藏中心获得的临床分离株，采用表型（生物型和抗菌谱）和基因型（核糖体分型、随机扩增多态性DNA和脉冲场凝胶电泳）方法进行了鉴定。在所检测的18株分离株中观察到了三种生物型和四种抗菌谱模式。使用杜邦核糖体指纹图谱微生物鉴定系统进行核糖体分型，将18株分离株分为10个核糖体型。来自同一家医院的三株分离株尽管是在不同年份分离得到的，但其核糖体分型模式却无法区分，来自一家公司的三株食品分离株也是如此。脉冲场凝胶电泳（PFGE）和随机扩增多态性DNA（RAPD）图谱表明，核糖体分型无法区分的分离株之间存在细微差异。PFGE（使用限制性内切酶Xba1和Spe1）和RAPD产生了离散的图谱，便于对阪崎肠杆菌分离株进行比较，且具有高度的鉴别力。鉴别指数表明，RAPD和PFGE是阪崎肠杆菌最具鉴别力的分型方法，其次是核糖体分型、生物分型和抗菌谱。
