title: A novel δ-hemolysis screening method for detecting heteroresistant vancomycin-intermediate Staphylococcus aureus and vancomycin-intermediate S. aureus.
abstract: We assessed a new screening method, based on δ-hemolysin production in the presence of 6 mg/liter vancomycin, to distinguish heteroresistant vancomycin-intermediate Staphylococcus aureus (hVISA) and vancomycin-intermediate S. aureus (VISA) from vancomycin-susceptible S. aureus (VSSA). On 37 clinical methicillin-resistant S. aureus (MRSA) isolates, hVISA and VISA displayed no δ-hemolysis whereas VSSA displayed strong δ-hemolysis, showing 91.6% sensitivity. These data, supported by real-time reverse transcription PCR (real-time RT-PCR) highlighting an hld downregulation, i.e., VSSA>hVISA>VISA, define this new assay as a valid screening method.
authors.affiliation: Department of Bio-Medical Sciences, Microbiology, University of Catania, Catania, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Cafiso
authors.forename: T
authors.initials: T
authors.lastname: Bertuccio
authors.forename: D
authors.initials: D
authors.lastname: Spina
authors.forename: S
authors.initials: S
authors.lastname: Purrello
authors.forename: G
authors.initials: G
authors.lastname: Blandino
authors.forename: Stefania
authors.initials: S
authors.lastname: Stefani
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001431:Bacteriological Techniques / Q000379:methods*; D003470:Culture Media / Q000737:chemistry*; D006460:Hemolysin Proteins / Q000235:genetics / Q000378:metabolism*; D006461:Hemolysis; D006801:Humans; D008403:Mass Screening / Q000379:methods; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000382:microbiology; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003470:Culture Media; D006460:Hemolysin Proteins; D014640:Vancomycin; C025994:delta hemolysin protein, Staphylococcus aureus