Phage isolation
Sewage samples were collected from various aquatic ecosystems
in the Taichung Veterans General Hospital (Taichung, Taiwan)
and E-Da Hospital (Kaoshiung, Taiwan) for phage isolation. The
presence of phages was investigated using a phage enrichment
technique [28]. A 50-ml supernatant form centrifugated sewage
was mixed with 50 ml double-strength Luria-Bertani broth
containing exponential-phase A. baumannii strains. After a 24-h
incubation at 37uC, the bacterial cells were centrifuged and the
supernatant was filtered through a 0.22- mm membrane filter.
Then, 10 ml of filtrate and the indicator strain were mixed with
soft agar and poured onto an LB agar plate. Phage plaques would
be visible after overnight incubation at 37uC. Single plaques were
selected by a sterile tooth pick and suspended in 500 ml PBS.
Followed by double layer plaque assay was perform to obtain pure
phage strains.