Discovery, Induction, and Screening of Prophages in Clinical Acinetobacter baumannii Isolates.

BACKGROUND

Acinetobacter baumannii is a common bacterial pathogen in nosocomial infections. It has become one of the greatest threats to human health for its growing resistance to "last resort" antibiotics, which has led to a revival of phage therapy as a potential treatment. However, conventional methods for isolating A. baumannii-infecting phages are labor-intensive and often unsuccessful.

METHODS

Our approach involves a computational pipeline to identify temperate phages (prophages) integrated into A. baumannii genomes, followed by mitomycin C (MMC) induction of those strains to screen for active prophages.

RESULTS

Here we show a prophage analysis for nearly 900 A. baumannii genomes. We observed MMC-triggered excision of nine prophages from eight A. baumannii strains by Polymerase Chain Reaction (PCR) and sequencing. Further, we show four prophage-formed virions detectable by transmission electron microscopy and two that can plaque on other A. baumannii isolates.

CONCLUSION

This work demonstrates the utility and diversity of prophages for further development as therapeutics for antibiotic-resistant A. baumannii.