title: A novel endolysin disrupts Streptococcus suis with high efficiency.
abstract: Streptococcus suis serotype 2 (S. suis 2) is a zoonotic pathogen that exhibits high-level resistance and multi-drug resistance to classic antibiotics and causes serious human casualties and heavy economic losses in the swine industry worldwide. Therefore, alternative therapies or novel antibacterial agents need to be developed to combat this pathogen. A novel endolysin derived from the S. suis temperate phage phi7917, termed Ly7917, was identified, which had broad lytic activity against S. suis type 1, 2, 7 and 9. Ly7917 consisted of an N-terminal cysteine, histidine-dependent amidohydrolases/peptidase catalytic domain and C-terminal SH3b cell wall binding domain. The endolysin maintained activity at high pH and its catalytic activity could be improved by addition of 10 μM 1.5 mM Ca(2+). In animal studies, 90% of BALB/c mice challenged with typical virulent strain HA9801 of S. suis 2 were protected by Ly7917 treatment. The bacterial load in the blood of HA9801-challenged mice was efficiently reduced almost 50% by Ly7917 while that of penicillin-G-treated mice kept almost unchanged. Our data suggest that Ly7917 may be an alternative therapeutic agent for infections caused by virulent S. suis strains.
authors.affiliation: Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai 200240, China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Ji
authors.affiliation: Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai 200240, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Huang
authors.affiliation: School of Veterinary Medicine, Gansu Agricultural University, Lanzhou, Gansu 730070, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Sun
authors.affiliation: Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai 200240, China.
authors.forename: Hengan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai 200240, China.
authors.forename: Yaxian
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Shanghai Key Laboratory of Veterinary Biotechnology, School of Agriculture and Biology, Shanghai Jiao Tong University, Key Laboratory of Urban Agriculture (South), Ministry of Agriculture, Shanghai 200240, China sunjhe@sjtu.edu.cn.
authors.forename: Jianhe
authors.initials: J
authors.lastname: Sun
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D058491:Bacterial Load / Q000187:drug effects; D010450:Endopeptidases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*; D006801:Humans; D008807:Mice, Inbred BALB C; D008826:Microbial Sensitivity Tests; D010400:Penicillin G / Q000627:therapeutic use; D039002:Prophages / Q000201:enzymology; D013290:Streptococcal Infections / Q000097:blood / Q000188:drug therapy / Q000382:microbiology; D017108:Streptococcus Phages / Q000201:enzymology*; D017011:Streptococcus suis / Q000187:drug effects* / Q000648:ultrastructure / Q000821:virology
chemical_list: D000900:Anti-Bacterial Agents; D010450:Endopeptidases; C001143:endolysin; D010400:Penicillin G
keywords: S. suis; endolysin; lytic activity; prophage