Center for Phage Technology, Texas A&M University, College Station, TX 77843-2128, USA.
Appl Environ Microbiol. 2011 Jan;77(2):669-83. doi: 10.1128/AEM.01952-10. Epub 2010 Nov 19.
The isolation and results of genomic and functional analyses of Rhodococcus equi phages ReqiPepy6, ReqiDocB7, ReqiPine5, and ReqiPoco6 (hereafter referred to as Pepy6, DocB7, Pine5, and Poco6, respectively) are reported. Two phages, Pepy6 and Poco6, more than 75% identical, exhibited genome organization and protein sequence likeness to Lactococcus lactis phage 1706 and clostridial prophage elements. An unusually high fraction, 27%, of Pepy6 and Poco6 proteins were predicted to possess at least one transmembrane domain, a value much higher than the average of 8.5% transmembrane domain-containing proteins determined from a data set of 36,324 phage protein entries. Genome organization and protein sequence comparisons place phage Pine5 as the first nonmycobacteriophage member of the large Rosebush cluster. DocB7, which had the broadest host range among the four isolates, was not closely related to any phage or prophage in the database, and only 23 of 105 predicted encoded proteins could be assigned a functional annotation. Because of the relationship of Rhodococcus to Mycobacterium, it was anticipated that these phages should exhibit some of the features characteristic of mycobacteriophages. Traits that were identified as shared by the Rhodococcus phages and mycobacteriophages include the prevalent long-tailed morphology and the presence of genes encoding LysB-like mycolate-hydrolyzing lysis proteins. Application of DocB7 lysates to soils amended with a host strain of R. equi reduced recoverable bacterial CFU, suggesting that phage may be useful in limiting R. equi load in the environment while foals are susceptible to infection.
报道了马红球菌噬菌体 ReqiPepy6、ReqiDocB7、ReqiPine5 和 ReqiPoco6（以下分别称为 Pepy6、DocB7、Pine5 和 Poco6）的分离和基因组及功能分析结果。两种噬菌体 Pepy6 和 Poco6，相似度超过 75%，其基因组组织和蛋白序列与乳球菌噬菌体 1706 和梭菌噬菌体元件相似。Pepy6 和 Poco6 中有 27%的蛋白被预测至少含有一个跨膜结构域，这一比例远高于从 36324 个噬菌体蛋白序列中确定的 8.5%的跨膜蛋白平均值。基因组组织和蛋白序列比较将噬菌体 Pine5 确定为 Rosebush 大簇中第一个非分枝杆菌噬菌体成员。DocB7 是四种分离株中宿主范围最广的，与数据库中的任何噬菌体或原噬菌体都没有密切关系，在 105 个预测编码蛋白中只有 23 个可以被赋予功能注释。由于红球菌与分枝杆菌的关系，预计这些噬菌体应该具有一些分枝杆菌噬菌体的特征。鉴定为红球菌噬菌体和分枝杆菌噬菌体共有的特征包括流行的长尾形态和存在编码 LysB 样的分枝菌酸水解裂解蛋白的基因。将 DocB7 裂解物应用于添加马红球菌宿主菌株的土壤中，可减少可回收细菌 CFU，这表明噬菌体可能有助于在马驹易感感染时限制环境中马红球菌的负荷。
