Bannantine J P, Pattee P A
Department of Microbiology, Immunology, and Preventive Medicine, Iowa State University, Ames 50011, USA.
J Bacteriol. 1996 Dec;178(23):6842-8. doi: 10.1128/jb.178.23.6842-6848.1996.
The genome size and a partial physical and genetic map have been defined for the phage group II Staphylococcus aureus Ps55. The genome size was estimated to be 2,771 kb by pulsed-field gel electrophoresis (PFGE) using the restriction enzymes SmaI, CspI, and SgrAI. The Ps55 chromosome map was constructed by transduction of auxotrophic and cryptic transposon insertions, with known genetic and physical locations in S. aureus NCTC 8325, into the Ps55 background. PFGE and DNA hybridization analysis were used to detect the location of the transposon in Ps55. Ps55 restriction fragments were then ordered on the basis of genetic conservation between the two strains. Cloned DNA probes containing the lactose operon (lac) and genes encoding staphylococcal protein A (spa), gamma hemolysin (hlg), and coagulase (coa) were also located on the map by PFGE and hybridization analysis. This methodology enabled a direct comparison of chromosomal organization between NCTC 8325 and Ps55 strains. The chromosome size, gene order, and some of the restriction sites are conserved between the two phage group strains.
已确定噬菌体II组金黄色葡萄球菌Ps55的基因组大小以及部分物理图谱和遗传图谱。通过使用限制性内切酶SmaI、CspI和SgrAI的脉冲场凝胶电泳（PFGE）估计基因组大小为2771 kb。通过将在金黄色葡萄球菌NCTC 8325中已知遗传和物理位置的营养缺陷型和隐蔽转座子插入片段转导到Ps55背景中，构建了Ps55染色体图谱。PFGE和DNA杂交分析用于检测转座子在Ps55中的位置。然后根据两株菌之间的遗传保守性对Ps55限制性片段进行排序。还通过PFGE和杂交分析将含有乳糖操纵子（lac）以及编码葡萄球菌蛋白A（spa）、γ溶血素（hlg）和凝固酶（coa）的基因的克隆DNA探针定位在图谱上。这种方法能够直接比较NCTC 8325和Ps55菌株之间的染色体组织。这两种噬菌体组菌株之间的染色体大小、基因顺序和一些限制性位点是保守的。
