title: A novel prophage lysin Ply5218 with extended lytic activity and stability against Streptococcus suis infection.
abstract: Streptococcus suis (S. suis) is an emerging zoonotic agent that exhibits high level resistance to classic antibiotics and a heavy burden in the swine industry. Therefore alternative antibacterial agents need to be developed. A novel endolysin derived from the S. suis temperate phage phi5218, termed Ply5218, was identified. The minimum inhibitory concentration (MIC) of Ply5218 was 2.5 μg ml(-1) against S. suis strain HA9801, an activity many times greater than the lysins reported previously (MIC of LY7917 and Ply30 against HA9801 were 80 and 64 μg ml(-1), respectively). Ply5218 at 10 μg ml(-1) in vitro exerted broad antibacterial activities against S. suis strains with OD600 ratios decreased from 1 to <0.2 within 1 h. Moreover, Ply5218 showed favorable thermal stability. It was stable at 50°C >30 min, 4°C >30 days, -80°C >7 months, and >60% of the enzyme activity remained after 5 min pre-incubation at 70°C. In vivo, a 0.2 mg dose of Ply5218 protected 90% (9/10) of mice after infection with S. suis HA9801. Finally, Ply5218 maintained high antibacterial activity in some bio-matrices, such as culture media and milk. The data indicate that Ply5218 has all the characteristics to be an effective therapeutic agent against multiple S. suis infections.
authors.affiliation: Shanghai Jiao Tong University, School of Agriculture and Biology, 800 Dongchuan Road, Shanghai, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Shanghai Jiao Tong University, School of Agriculture and Biology, 800 Dongchuan Road, Shanghai, China.
authors.forename: Chuanpeng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Shanghai Jiao Tong University, School of Agriculture and Biology, 800 Dongchuan Road, Shanghai, China.
authors.forename: Hengan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Shanghai Jiao Tong University, School of Agriculture and Biology, 800 Dongchuan Road, Shanghai, China.
authors.forename: Ya Xian
authors.initials: YX
authors.lastname: Yan
authors.affiliation: Shanghai Jiao Tong University, School of Agriculture and Biology, 800 Dongchuan Road, Shanghai, China sunjhe@sjtu.edu.cn.
authors.forename: Jianhe
authors.initials: J
authors.lastname: Sun
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D010450:Endopeptidases / Q000378:metabolism* / Q000494:pharmacology*; D004795:Enzyme Stability; D051379:Mice; D008826:Microbial Sensitivity Tests; D039002:Prophages / Q000201:enzymology; D013290:Streptococcal Infections / Q000188:drug therapy* / Q000382:microbiology / Q000517:prevention & control; D017108:Streptococcus Phages / Q000201:enzymology*; D017011:Streptococcus suis / Q000187:drug effects* / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D010450:Endopeptidases; C001143:endolysin
keywords: antibacterial; lytic activity; prophage lysin; S. suis; thermal stability