title: Autolytic activity and molecular characteristics of Staphylococcus haemolyticus strains with induced vancomycin resistance.
abstract: The aim of this study was to investigate the molecular characteristics of induced vancomycin resistance in Staphylococcus haemolyticus. Autolytic properties and phenotypic characteristics of passage-selected vancomycin-resistant S. haemolyticus strains were examined. In addition, expression of autolysis-related genes (atl, lrgAB, sarA and lytS) was investigated using the RNase protection assay (RPA). The RPA results indicated that only the expression of the atl gene was significantly upregulated (2.5- to 6-fold increase) in vancomycin-intermediate and vancomycin-resistant strains. The vancomycin-resistant strains exhibited lower expression of murein hydrolase proteins and reduced autolytic activity compared with the parent strain. In addition, a reduced growth rate, cell wall thickening and higher survival rate in the presence of lysostaphin were observed in vancomycin-intermediate and vancomycin-resistant induced strains compared with the parent strain. In conclusion, altered autolytic properties, in particular upregulation of the atl gene, may contribute to vancomycin resistance in S. haemolyticus.
authors: Division of Antimicrobial Resistance, Center for Infectious Diseases, Korea National Institute of Health, Osong, Republic of South Korea.
authors: Jung Wook
authors: JW
authors: Kim
authors: Division of Antimicrobial Resistance, Center for Infectious Diseases, Korea National Institute of Health, Osong, Republic of South Korea.
authors: Gyung Tae
authors: GT
authors: Chung
authors: Division of Antimicrobial Resistance, Center for Infectious Diseases, Korea National Institute of Health, Osong, Republic of South Korea.
authors: Jung Sik
authors: JS
authors: Yoo
authors: Division of Antimicrobial Resistance, Center for Infectious Diseases, Korea National Institute of Health, Osong, Republic of South Korea.
authors: Yeong Seon
authors: YS
authors: Lee
authors: Division of Antimicrobial Resistance, Center for Infectious Diseases, Korea National Institute of Health, Osong, Republic of South Korea.
authors: Jae Il
authors: JI
authors: Yoo
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001329:Autolysis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001433:Bacteriolysis / Q000235:genetics / Q000502:physiology*; D003902:Detergents / Q000494:pharmacology; D006801:Humans; D046529:Microscopy, Electron, Transmission; D009154:Mutation; D017830:Octoxynol / Q000494:pharmacology; D056910:Republic of Korea / Q000453:epidemiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology; D041162:Staphylococcus haemolyticus / Q000187:drug effects* / Q000235:genetics / Q000648:ultrastructure; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance / Q000235:genetics / Q000502:physiology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003902:Detergents; D014640:Vancomycin; D017830:Octoxynol