A Broad-Host-Range Tailocin from Burkholderia cenocepacia

Abstract

The Burkholderia cepacia complex (Bcc) consists of 20 closely related Gram-negative bacterial species that are significant pathogens for persons with cystic fibrosis (CF). Some Bcc strains are highly transmissible and resistant to multiple antibiotics, making infection difficult to treat. A tailocin (phage tail-like bacteriocin), designated BceTMilo, with a broad host range against members of the Bcc, was identified in B. cenocepacia strain BC0425. Sixty-eight percent of Bcc representing 10 species and 90% of non-Bcc Burkholderia strains tested were sensitive to BceTMilo. BceTMilo also showed killing activity against Pseudomonas aeruginosa PAO1 and derivatives. Liquid chromatography-mass spectrometry analysis of the major BceTMilo proteins was used to identify a 23-kb tailocin locus in a draft BC0425 genome. The BceTMilo locus was syntenic and highly similar to a 24.6-kb region on chromosome 1 of B. cenocepacia J2315 (BCAL0081 to BCAL0107). A close relationship and synteny were observed between BceTMilo and Burkholderia phage KL3 and, by extension, with paradigm temperate myophage P2. Deletion mutants in the gene cluster encoding enzymes for biosynthesis of lipopolysaccharide (LPS) in the indicator strain B. cenocepacia K56-2 conferred resistance to BceTMilo. Analysis of the defined mutants in LPS biosynthetic genes indicated that an α-d-glucose residue in the core oligosaccharide is the receptor for BceTMilo.IMPORTANCE BceTMilo, presented in this study, is a broad-host-range tailocin active against Burkholderia spp. As such, BceTMilo and related or modified tailocins have potential as bactericidal therapeutic agents against plant- and human-pathogenic Burkholderia.

Characterization of maltocin S16, a phage tail‐like bacteriocin with antibacterial activity againstStenotrophomonas maltophiliaandEscherichia coli

“…However, other components besides LPS might be required for the receptor function in E. coli . This is different from BceTMilo, which uses a common LPS receptor site on both P. aeruginosa PAO1 and B. cenocepacia K56‐2 (Yao et al ).…”

Pseudomonas chlororaphis Produces Multiple R-Tailocin Particles That Broaden the Killing Spectrum and Contribute to Persistence in Rhizosphere Communities

“…Additionally, it was hypothesized that bacteria may be insensitive to phage infection in soil, because the phage receptor is not expressed in the metabolic state supported by the soil environment (59). Lipopolysaccharides (LPS) are commonly the receptor targeted by tailocin particles (17,18,21,22), and LPS biosynthesis is altered by growth phase and nutrient availability (60)(61)(62). In our study, a predominantly clay soil was used, and the extent to which this may have affected either tailocin activity or target sensitivity is unknown.…”

“…UV induction of P. chlororaphis 30-84 cultures. R-tailocin production was induced using a method similar to that described previously (4,21). Briefly, overnight LB cultures of P. chlororaphis 30-84 and the appropriate mutants were collected by centrifugation, washed with sterile water, resuspended in 20 ml of fresh LB (optical density at 620 nm [OD 620 ], 0.05), and grown at 28°C with shaking (200 rpm).…”

“…Tailocin purification. A method similar to that described by Yao et al (21) was used for large-scale preparation and purification of tailocin particles. Briefly, ammonium sulfate (final concentration, 40% [wt/vol]) was slowly added to cell-free UV-induced tailocin lysate with stirring at 4°C and incubated at 4°C for 18 h. The ammonium sulfate precipitate was pelleted (17,000 ϫ g for 1 h at 4°C and resuspended in 1/10 of the original volume in cold Tn 50 buffer (10 mM Tris [pH 7.5], 50 mM NaCl).…”

The role of multispecies social interactions in shaping Pseudomonas aeruginosa pathogenicity in the cystic fibrosis lung

“…In particular, one Burkholderia bacteriocin named Tailocin has been proposed as a potential therapeutic with activity against P. aeruginosa (Yao et al. 2017 ). In order to fully appreciate how P. aeruginosa populations will respond to these classes of drugs it is vital that we understand how the species involved interact naturally on both ecological and evolutionary timescales.…”