Instituto de Productos Lácteos de Asturias (IPLA-CSIC), Apdo. 85, 33300, Villaviciosa, Asturias, Spain.
Curr Microbiol. 2010 Dec;61(6):601-8. doi: 10.1007/s00284-010-9659-5. Epub 2010 May 7.
Bacteriophages infecting Staphylococcus epidermidis were isolated by mitomycin C induction. Three distinct phages (vB_SepiS-phiIPLA5, vB_SepiS-phiIPLA6, and vB_SepiS-phiIPLA7)-defined by plaque morphology, structure, virion proteins pattern, DNA restriction bands, and host range-were obtained. One-step growth curves of bacteriophages under optimal growth conditions for S. epidermidis F12 revealed eclipse and latent periods of 5-10 and 10-15 min, respectively, with burst sizes of about 5 to 30 PFU per infected cell. Transmission electron microscopy revealed that the phages were of similar size and belonged to the Siphoviridae family. Phage phi-IPLA7 had the broadest host range infecting 21 out of 65 S. epidermidis isolates. Phage phi-IPLA5 seemed to be a virulent phage probably derived from phi-IPLA6. Phages phi-IPLA5 and phi-IPLA7 exhibited increasing plaques surrounded by a halo that could be indicative of a polysaccharide depolymerase activity. Viable counts, determined during the infection of S. epidermidis F12, confirmed that phi-IPLA5 had a potent lytic capability and reduced S. epidermidis population by 5.67 log units in 8 h of incubation; in the presence of the mixture of phi-IPLA6 and phi-IPLA7, however, a reduction of 2.27 log units was detected.
采用丝裂霉素 C 诱导法分离到表皮葡萄球菌噬菌体。通过噬菌斑形态、结构、病毒粒子蛋白图谱、DNA 限制带和宿主范围等特征，鉴定出三种不同的噬菌体（vB_SepiS-phiIPLA5、vB_SepiS-phiIPLA6 和 vB_SepiS-phiIPLA7）。在表皮葡萄球菌 F12 的最佳生长条件下，一步生长曲线显示，噬菌体的潜伏期和潜伏时间分别为 5-10 min 和 10-15 min，爆发量约为每个感染细胞 5 到 30 个 PFU。透射电子显微镜显示，噬菌体大小相似，属于长尾噬菌体科。噬菌体 phi-IPLA7 的宿主范围最广，可感染 65 株表皮葡萄球菌分离株中的 21 株。噬菌体 phi-IPLA5 似乎是一种毒性噬菌体，可能来源于 phi-IPLA6。噬菌体 phi-IPLA5 和 phi-IPLA7 表现出逐渐增大的噬菌斑，周围有一个晕圈，这可能表明它们具有多糖解聚酶活性。在感染表皮葡萄球菌 F12 的过程中进行的活菌计数证实，噬菌体 phi-IPLA5 具有很强的裂解能力，在 8 小时的孵育过程中，使表皮葡萄球菌的数量减少了 5.67 个对数单位；然而，在噬菌体 phi-IPLA6 和 phi-IPLA7 的混合物存在的情况下，仅检测到减少了 2.27 个对数单位。
