Detection of E. coli DH5alpha specific bacteriophage in the vicinity of a water treatment plant

Air in the vicinity of a water treatment plant scheduled for redevelopment was monitored for aerosols containing a bacteriophage specific for the Escherichia coli (E. coli) strain DH5alpha bacterium. An assay for the detection of the specific airborne bacteriophage was developed. Sampling was carried out prior to and after completion of development work to the plant. Preliminary experiments showed water from the plant contains the bacteriophage specific for the E. coli DH5alpha bacterium. Two field studies were completed before work on the treatment plant began. The first study, conducted under wet and windy conditions, used only passive air sampling to monitor air at 3 selected locations adjacent to the plant. E. coli DH5alpha specific bacteriophage was positively detected, albeit at low levels. However, both the passive and a new direct air sampling technique were employed in the second field study, conducted under dry and windy conditions. In this instance, neither method detected specific bacteriophage. Further work was undertaken 6 months after modifications to the plant had been completed. Passive and direct air sampling techniques were again employed at each of the same 3 selected locations. Samples from both of these methods contained no bacteriophage. As a check, the samples were also analysed using an alternative procedure. No bacteriophage was detected. The results generated indicate that the levels of airborne specific bacteriophage in the vicinity of the plant appear to be extremely low, and the direct air sampling technique successful.