title: Characterization and interstrain transfer of prophage pp3 of Pseudomonas aeruginosa.
abstract: Prophages are major contributors to horizontal gene transfer and drive the evolution and diversification of bacteria. Here, we describe the characterization of a prophage element designated pp3 in the clinical Pseudomonas aeruginosa isolate PA1. pp3 spontaneously excises from the PA1 genome and circularizes at a very high frequency of 25%. pp3 is likely to be a defective prophage due to its inability to form plaques on P. aeruginosa indicator strains, and no phage particles could be detected in PA1 supernatants. The pp3-encoded integrase is essential for excision by mediating site-specific recombination at the 26-bp attachment sequence. Using a filter mating experiment, we demonstrated that pp3 can transfer into P. aeruginosa recipient strains that do not possess this element naturally. Upon transfer, pp3 integrates into the same attachment site as in PA1 and maintains the ability to excise and circularize. Furthermore, pp3 significantly promotes biofilm formation in the recipient. Sequence alignment reveals that the 26-bp attachment site recognized by pp3 is conserved in all P. aeruginosa strains sequenced to date, making it possible that pp3 could be extensively disseminated in P. aeruginosa. This work improves our understanding of the ways in which prophages influence bacterial behavior and evolution.
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Shuguang
authors.initials: S
authors.lastname: Lu
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Mengyu
authors.initials: M
authors.lastname: Shen
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Le
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Yinling
authors.initials: Y
authors.lastname: Tan
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Gong
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Fuquan
authors.initials: F
authors.lastname: Hu
authors.affiliation: Department of Microbiology, Third Military Medical University, Chongqing, China.
authors.forename: Ming
authors.identifier: http://orcid.org/0000-0003-1662-6465
authors.initials: M
authors.lastname: Li
mesh_terms: D022761:Gene Transfer, Horizontal; D019426:Integrases / Q000235:genetics*; D039002:Prophages / Q000235:genetics*; D011550:Pseudomonas aeruginosa / Q000235:genetics*; D011995:Recombination, Genetic
chemical_list: D019426:Integrases