J Med Microbiol 56 (2007), 71-76; DOI: 10.1099/jmm.0.46788-0
© 2007 Society for General Microbiology
ISSN 1473-5644
In vitro activity of recombinant lysostaphin against Staphylococcus aureus isolates from hospitals in Beijing, China
Xin-Yi Yang1,
,
Cong-Ran Li1,
,
Ren-Hui Lou1,
Yue-Ming Wang1,
Wei-Xin Zhang1,
Hui-Zhen Chen1,
Qing-Shan Huang2,
Yan-Xing Han1,
Jian-Dong Jiang1 and
Xue-Fu You1
1 Laboratory of Pharmacology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, PR China
2 State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, PR China
Correspondence
Xue-Fu You
xuefuyou{at}hotmail.com
Jian-Dong Jiang
jiandong.jiang{at}mssm.edu
Received 17 June 2006
Accepted 8 September 2006
Lysostaphin is a glycylglycine endopeptidase. It cleaves the pentaglycine cross-bridge structure unique to the staphylococcal cell wall and is considered to be a potential drug for Staphylococcus aureus. In the present study, the in vitro activity of recombinant lysostaphin was investigated in 257 S. aureus isolates collected from hospital patients in Beijing, China, by determination of MIC and minimum bactericidal concentration (MBC) and a timekill curve test. An agar dilution method was used for MIC determination in all of the isolates and a macrobroth dilution method was employed to verify MIC values for a subset of the isolates. All of the S. aureus strains were sensitive to the recombinant lysostaphin with MICs ranging from 0.03 to 2 µg ml1 in the agar dilution assay. The antibacterial activity of lysostaphin was greater than that of vancomycin and other reference agents. For most of the isolates, the MICs from the agar dilution method were higher than those from the broth dilution method. The MBCs of lysostaphin in the test isolates were between 1- and 8-fold higher than their MIC values. Bactericidal activity (>99.9 % reduction) was observed after 2 h exposure of the isolates to lysostaphin at concentrations of
0.5 MIC. Lysostaphin showed a rapid bactericidal activity against the test strains of meticillin-susceptible S. aureus and meticillin-resistant S. aureus. Its activity at
0.5 MIC was sustained for at least 6 h. These results will be informative for the clinical application and evaluation of lysostaphin.
Abbreviations: MBC, minimum bactericidal concentration; MRSA, meticillin-resistant Staphylococcus aureus; MSSA, meticillin-susceptible Staphylococcus aureus.
These authors contributed equally to this work.
Copyright © 2007 Society for General Microbiology.