title: Preliminary treatment of bovine mastitis caused by Staphylococcus aureus, with trx-SA1, recombinant endolysin of S. aureus bacteriophage IME-SA1.
abstract: Methicillin-resistant Staphylococcus aureus (MRSA) has become a great threat to human and animal health and there is an urgent need to develop novel antibacterial agents to control this pathogen. The objective of this study was to obtain an active recombinant endolysin from the novel bacteriophage (IME-SA1), and conduct an efficacy trial of its effectiveness against bovine mastitis. We isolated a phage that was virulent and specific for S. aureus with an optimal multiplicity of infection of 0.01. Electron microscopy revealed that IME-SA1 was a member of the family Myoviridae, with an isometric head (98nm) and a long contractile tail (200nm). Experimental lysis experiments indicated the phage had an incubation period of 20min with a burst size of 80. When host bacteria were in early exponential growth stages, a multiplicity of infection of 0.01 resulted in a complete bacterial lysis after 9h. The endolysin gene (804bp) was cloned into the pET-32a bacterial expression vector and recombinant endolysin Trx-SA1 was successfully obtained with molecular size of about 47kDa. Preliminary results of therapeutic trials in cow udders showed that Trx-SA1 could effectively control mild clinical mastitis caused by S. aureus. The endolysin Trx-SA1 might be an alternative treatment strategy for infections caused by S. aureus, including MRSA.
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, PR China.
authors.forename: Jindai
authors.initials: J
authors.lastname: Fan
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, PR China.
authors.forename: Zhiliang
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, PR China.
authors.forename: Kaijie
authors.initials: K
authors.lastname: Mai
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, PR China.
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Feng
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Bai
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, PR China.
authors.forename: Baoli
authors.initials: B
authors.lastname: Sun
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, PR China.
authors.forename: Qingmei
authors.initials: Q
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, PR China. Electronic address: tong.yigang@gmail.com.
authors.forename: Yigang
authors.initials: Y
authors.lastname: Tong
authors.affiliation: College of Animal Science, South China Agricultural University, Guangzhou, PR China. Electronic address: majy2400@gmail.com.
authors.forename: Jingyun
authors.initials: J
authors.lastname: Ma
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002417:Cattle; D010450:Endopeptidases / Q000235:genetics / Q000627:therapeutic use*; D005260:Female; D008414:Mastitis, Bovine / Q000382:microbiology / Q000628:therapy*; D046529:Microscopy, Electron, Transmission; D008892:Milk / Q000382:microbiology; D011994:Recombinant Proteins / Q000235:genetics / Q000627:therapeutic use*; D013203:Staphylococcal Infections / Q000382:microbiology / Q000628:therapy / Q000662:veterinary*; D013204:Staphylococcus Phages / Q000201:enzymology* / Q000235:genetics / Q000648:ultrastructure; D013211:Staphylococcus aureus; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D011994:Recombinant Proteins; D010450:Endopeptidases; C001143:endolysin
keywords: Bacteriophage; Bovine mastitis; Recombinant endolysin; Staphylococcus aureus