Clark N C, Hill B C, O'Hara C M, Steingrimsson O, Cooksey R C
Antimicrobics Investigations Branch, Center for Infectious Diseases, U.S. Public Health Service, Atlanta, Georgia 30333.
Diagn Microbiol Infect Dis. 1990 Nov-Dec;13(6):467-72. doi: 10.1016/0732-8893(90)90078-a.
Two unrelated hospital outbreaks of Enterobacter sakazakii, involving meningitis, bacteremia, and colonization of neonates, were investigated. In each of these outbreaks, E. sakazakii was isolated from both patients and dried infant formula. In previous outbreaks, the source and mode of transmission of E. sakazakii in neonatal infections was not determined. In this study, we used a combination of typing methods (plasmid analysis, antibiograms, chromosomal restriction endonuclease analysis, ribotyping, and multilocus enzyme electrophoresis) to evaluate the isolates from each outbreak as to their relatedness. The typing results differed among outbreaks, but in each one, patient and formula isolates shared the same typing pattern. The only exceptions were disk antibiograms, which often varied among colonies selected from each of the isolates. Plasmid analysis, chromosomal restriction endonuclease analysis, ribotyping, and multilocus enzyme electrophoresis all were effective as epidemiological typing methods for E. sakazakii, especially when used in combination. By using this typing scheme, we have confirmed that E. sakazakii from intrinsically contaminated dried infant formula was the source of neonatal infection.
对两起与阪崎肠杆菌有关的医院感染暴发事件进行了调查，这两起事件均涉及新生儿脑膜炎、菌血症及定植。在每起暴发事件中，均从患者和干燥婴儿配方奶粉中分离出了阪崎肠杆菌。在以往的暴发事件中，新生儿感染中阪崎肠杆菌的来源及传播方式尚未确定。在本研究中，我们联合使用了多种分型方法（质粒分析、抗菌谱分析、染色体限制性内切酶分析、核糖体分型及多位点酶电泳）来评估每次暴发事件中分离株的相关性。不同暴发事件的分型结果有所不同，但在每起事件中，患者和配方奶粉分离株具有相同的分型模式。唯一的例外是纸片抗菌谱分析，从每个分离株中选取的菌落之间其结果常常不同。质粒分析、染色体限制性内切酶分析、核糖体分型及多位点酶电泳均是有效的阪崎肠杆菌流行病学分型方法，尤其是联合使用时。通过使用这种分型方案，我们证实了来自内在污染的干燥婴儿配方奶粉中的阪崎肠杆菌是新生儿感染的来源。
