Enterophages, a group of phages infecting Enterococcus faecalis, and their potential as alternate indicators of human faecal contamination

摘要

We have developed a method for the detection of viruses in environmental samples that wenhave called enterophages, that specifically infect Enterococcus faecalis. This method hasnallowed us to determine the prevalence and to study the ecology of this group of phages.nThe enterophages replicate at 378C, and at 418C. The presence of NaN3 in the media inhibitsnthe growth of background microbiota and allows an accurate, specific and rapid detectionnof these viruses. Enterophages were present in raw domestic sewage at lower concentrationsn(average 1.8 £ 102nPFU/100mL) than those of coliphages (average 1.7 £ 105nPFU/100mL).nPhages were characterised by transmission electron microscopy showing icosahedral capsids,nsome with non-contractile tails as well as icosahedral non-tailed capsids. Different isolatesnhad capsid sizes ranging from 20 nm to about 75 nm in diameter. These data describe a newngroup of phages that may serve as alternate indicators of human faecal pollution, especiallynin recreational waters. The ecology of these enterophages indicates that these may benstrictly of human origin.