Achromobacter species colonization of Cystic Fibrosis respiratory airways is an increasing concern. Two adult patients with Cystic Fibrosis colonized by Achromobacter xylosoxidans CF418 or Achromobacter ruhlandii CF116 experienced fatal exacerbations. Achromobacter spp. are naturally resistant to several antibiotics. Therefore, phages could be valuable as therapeutics for the control of Achromobacter. In this study, twelve lytic phages were isolated and characterized at the morphological and genomic levels for potential future use in phage therapy. They are presented here as the Achromobacter Kumeyaay phage collection. Six distinct Achromobacter phage genome clusters were identified based on a comprehensive phylogenetic analysis of the Kumeyaay collection as well as the publicly available Achromobacter phages. The infectivity of all phages in the Kumeyaay collection was tested in 23 Achromobacter clinical isolates; 78% of these isolates were lysed by at least one phage. A cryptic prophage was induced in Achromobacter xylosoxidans CF418 when infected with some of the lytic phages. This prophage genome was characterized and is presented as Achromobacter phage CF418-P1. Prophage induction during lytic phage preparation for therapy interventions require further exploration. Large-scale production of phages and removal of endotoxins using an octanol-based procedure resulted in a phage concentrate of 1 × 109 plaque-forming units per milliliter with an endotoxin concentration of 65 endotoxin units per milliliter, which is below the Food and Drugs Administration recommended maximum threshold for human administration. This study provides a comprehensive framework for the isolation, bioinformatic characterization, and safe production of phages to kill Achromobacter spp. in order to potentially manage Cystic Fibrosis (CF) pulmonary infections.
KAUST Repository Item: Exported on 2023-08-03
Acknowledgements: This study was funded by the Spruance Foundation and Cystic Fibrosis Research Inc. A.G.C.G. was funded by CONACyT and UCMEXUS. A.M.S. was partially funded by NIDDK grant RC2DK116713. We are grateful to Christine Pourcel, Christiane Essoh, and their colleagues for kindly sharing the Côte d’Ivoire Achromophages collection. We thank Marina Kalyuzhnaya and Dwayne Roach for providing access to lab equipment. We are grateful to Ingrid Niesman, the Director of the SDSU Imaging facility, for the electron micrographs of the SE2 and maay phages. Many thanks to Greg Peters and to Jacob Vander Griend for fruitful discussions during this research, and to Ryan Rowe, for constructing the two transducing donor strains. We are grateful to Margaret Field for revising the meaning of the Kumeyaay words.
- Infectious Diseases