Lina B, Bes M, Vandenesch F, Greenland T, Etienne J, Fleurette J
Département de Recherche en Bactériologie Médicale et CERB, Faculté de Médecine Alexis Carrel, Lyon, France.
FEMS Microbiol Lett. 1993 May 15;109(2-3):273-7. doi: 10.1016/0378-1097(93)90032-w.
DNA analysis using pulsed-field gel electrophoresis (PFGE) has emerged as one of the most sensitive epidemiological tools for the characterization of coagulase-negative staphylococci (CNST). The significance of some minor differences observed between the DNA restriction pulsed patterns of two CNST strains are difficult to interpret since they can theoretically be due to minor chromosomal rearrangements or to phage DNA integration. The latter possibility was investigated by comparing DNA restriction patterns of Staphylococcus epidermidis strains with those of their lysogenized derivatives. In vitro lysogenisation was obtained by exposing the strains to phage 118II. The pulsed patterns of the lysogenized strains were compared to those of their parental strains, revealing a shift in size of approximately 50 kb in a single band which was shown by Southern blotting to contain prophage. One strain was lysogenized ten times, revealing a potential preferred attachment site for phage 118II. These results confirm that chromosomal integration of a phage can be responsible for minor stable variations in DNA restriction patterns.
使用脉冲场凝胶电泳（PFGE）进行DNA分析已成为表征凝固酶阴性葡萄球菌（CNST）最灵敏的流行病学工具之一。两种CNST菌株的DNA限制性脉冲图谱之间观察到的一些微小差异的意义难以解释，因为理论上它们可能是由于微小的染色体重排或噬菌体DNA整合所致。通过比较表皮葡萄球菌菌株与其溶原化衍生物的DNA限制性图谱，对后一种可能性进行了研究。通过将菌株暴露于噬菌体118II获得体外溶原化。将溶原化菌株的脉冲图谱与其亲本菌株的图谱进行比较，发现在一条单带中大小有大约50 kb的变化，Southern印迹显示该带含有原噬菌体。一个菌株被溶原化了十次，揭示了噬菌体118II的一个潜在优先附着位点。这些结果证实噬菌体的染色体整合可能是DNA限制性图谱中微小稳定变化的原因。
