Freeman R, Sisson P R, Noble W C, Lightfoot N F
Public Health Laboratory, Newcastle General Hospital, Newcastle-upon-Tyne, UK.
Zentralbl Bakteriol. 1997 Jan;285(2):234-44. doi: 10.1016/s0934-8840(97)80030-8.
In a previously reported apparent outbreak of infection due to Acinetobacter calcoaceticus on a Regional Burns Unit in which both clinical and environmental isolates were available for study, investigations of the organisms by electrophoretic typing of surface proteins, plasmid profiling and antibiograms were inconclusive and unable to identify a single epidemic strain of the organism. The same collection of isolates has been analysed for inter-strain comparison by pyrolysis mass spectrometry (PyMS). PyMS analysis suggested that a few isolates were very different from the majority but that most of the collection comprised a group of closely similar but nonetheless distinct isolates. These isolates may well be representatives of a limited variety of strains occupying an ecological niche but not yet a single emergent strain. The ability of PyMS to detect a single epidemic strain of A. calcoaceticus when present in such a collection of isolates was demonstrated by analysis of a "constructed outbreak collection", using some of the original isolates. This study illustrates the versatility of PyMS for inter-strain comparison studies of species not yet amenable to conventional typing methods. The application of rapid, highly discriminatory, high-volume inter-strain comparison methods such as PyMS to apparent outbreaks of nosocomial infection is likely to reveal patterns of organism acquisition other than point-source transmission.
在先前报道的某地区烧伤病房因醋酸钙不动杆菌引发的一次明显感染暴发中，临床和环境分离株均可用于研究。通过对表面蛋白进行电泳分型、质粒图谱分析和抗菌谱分析来研究这些微生物，结果并不明确，无法确定该微生物的单一流行菌株。已对同一批分离株采用热解质谱法（PyMS）进行菌株间比较分析。PyMS分析表明，少数分离株与大多数分离株差异很大，但大多数分离株构成了一组密切相似但仍有区别的分离株。这些分离株很可能是占据某一生态位的有限几种菌株的代表，而非单一的新兴菌株。通过对一个“构建的暴发菌株集合”（使用部分原始分离株）进行分析，证明了PyMS在存在此类分离株集合时检测醋酸钙不动杆菌单一流行菌株的能力。本研究说明了PyMS在尚未适用于传统分型方法的物种菌株间比较研究中的通用性。将快速、高分辨、高通量的菌株间比较方法（如PyMS）应用于明显的医院感染暴发，可能会揭示除点源传播之外的微生物获得模式。
