DairySafe Group, Department of Technology and Biotechnology of Dairy Products, Instituto de Productos Lácteos de Asturias-IPLA-CSIC, Paseo Río Linares, 33300 Villaviciosa, Asturias, Spain.
BMC Genomics. 2012 Jun 8;13:228. doi: 10.1186/1471-2164-13-228.
Staphylococcus epidermidis is a commensal bacterium but can colonize the hospital environment due to its ability to form biofilms favouring adhesion to host tissues, medical devices and increasing resistance to antibiotics. In this context, the use of phages to destroy biofilms is an interesting alternative.
The complete genomes of two Staphylococcus epidermidis bacteriophages, vB_SepiS-phiIPLA5 and vB_SepiS-phiIPLA7, have been analyzed. Their genomes are 43,581 bp and 42,123 bp, and contain 67 and 59 orfs. Bioinformatic analyses enabled the assignment of putative functions to 36 and 29 gene products, respectively, including DNA packaging and morphogenetic proteins, lysis components, and proteins necessary for DNA recombination, regulation, modification and replication. A point mutation in vB_SepiS-phiIPLA5 lysogeny control-associated genes explained its strictly lytic behaviour. Comparative analysis of phi-IPLA5 and phi-IPLA7 genome structure resembled those of S. epidermidis ϕPH15 and ϕCNPH82 phages. A mosaic structure of S. epidermidis prophage genomes was revealed by PCR analysis of three marker genes (integrase, major head protein and holin). Using these genes, high prevalence (73%) of phage DNA in a representative S. epidermidis strain collection consisting of 60 isolates from women with mastitis and healthy women was determined. Putative pectin lyase-like domains detected in virion-associated proteins of both phages could be involved in exopolysaccharide (EPS) depolymerization, as evidenced by both the presence of a clear halo surrounding the phage lysis zone and the phage-mediated biofilm degradation.
Staphylococcus epidermidis bacteriophages, vB_SepiS-phiIPLA5 and vB_SepiS-phiIPLA7, have a mosaic structure similar to other widespread S. epidermidis prophages. Virions of these phages are provided of pectin lyase-like domains, which may be regarded as promising anti-biofilm tools.
表皮葡萄球菌是一种共生菌，但由于其形成生物膜的能力有利于与宿主组织、医疗器械黏附，并增加对抗生素的耐药性，因此可以在医院环境中定植。在这种情况下，噬菌体用于破坏生物膜是一种很有前途的替代方法。
分析了两株表皮葡萄球菌噬菌体 vB_SepiS-phiIPLA5 和 vB_SepiS-phiIPLA7 的全基因组。它们的基因组分别为 43581bp 和 42123bp，包含 67 和 59 个或基因。生物信息学分析分别对 36 和 29 个基因产物的功能进行了预测，包括 DNA 包装和形态发生蛋白、裂解成分以及 DNA 重组、调控、修饰和复制所必需的蛋白质。vB_SepiS-phiIPLA5 溶原控制相关基因的点突变解释了其严格的裂解行为。phi-IPLA5 和 phi-IPLA7 基因组结构的比较分析与表皮葡萄球菌 ϕPH15 和 ϕCNPH82 噬菌体的结构相似。通过对三个标记基因（整合酶、主要头部蛋白和溶孔蛋白）的 PCR 分析，揭示了表皮葡萄球菌前噬菌体基因组的镶嵌结构。利用这些基因，从乳腺炎和健康女性的 60 个代表表皮葡萄球菌分离株的菌株中，确定了噬菌体 DNA 的高流行率（73%）。在两种噬菌体的病毒相关蛋白中检测到的果胶裂解酶样结构域可能参与了胞外多糖（EPS）的解聚，这一点从噬菌体裂解区周围清晰的晕环的存在和噬菌体介导的生物膜降解都得到了证实。
表皮葡萄球菌噬菌体 vB_SepiS-phiIPLA5 和 vB_SepiS-phiIPLA7 具有与其他广泛分布的表皮葡萄球菌前噬菌体相似的镶嵌结构。这些噬菌体的病毒粒子含有果胶裂解酶样结构域，可作为有前途的抗生物膜工具。
