Tradeoffs Between Evolved Phage Resistance and Antibiotic Susceptibility in a Highly Drug-Resistant Cystic Fibrosis-Derived Strain.

Background: Multi-drug resistant pathogens pose significant challenges towards the effective resolution of bacterial infections. A promising alternative strategy is phage therapy in which limited applications has afforded lifesaving resolution from drug resistant pathogens. However, adoption of this strategy is hampered by narrow bacteriophage host ranges, and as with antibiotics, bacteria can acquire resistance to phage.

Phages are unrecognized players in the ecology of the oral pathogen Porphyromonas gingivalis.

Background: Porphyromonas gingivalis (hereafter "Pg") is an oral pathogen that has been hypothesized to act as a keystone driver of inflammation and periodontal disease. Although Pg is most readily recovered from individuals with actively progressing periodontal disease, healthy individuals and those with stable non-progressing disease are also colonized by Pg. Insights into the factors shaping the striking strain-level variation in Pg, and its variable associations with disease, are needed to achieve a more mechanistic understanding of periodontal disease and its progression.