title: High frequency of SCCmec type V and agr type I among heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) in north India.
abstract: The objective of this study was to compare the genetic features of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) and vancomycin-sensitive methicillin-resistant S. aureus (VS-MRSA) isolates.
  
  
  
  The presence of staphylococcal cassette chromosome mec (SCCmec) types, Panton-Valentine leukocidin (PVL), accessory gene regulator (agr) types, and vanA and vanB genes in hVISA and VS-MRSA isolates was evaluated by PCR. Genetic relatedness was studied by pulsed-field gel electrophoresis (PFGE).
  
  
  
  The distribution of SCCmec types in hVISA was as follows: 13/29 (44.8%) each of types II and V, 1/29 (3.4%) type III and 2/29 (6.9%) type IVa. Among VS-MRSA isolates, 20/50 (40.0%) were SCCmec type II, 17/50 (34.0%) were type III, 3/50 (6.0%) were type IVa and 10/50 (20.0%) were type V. SCCmec type V was significantly associated with hVISA, whereas SCCmec type III showed an association with VS-MRSA (P=0.020 and P=0.001, respectively). The PVL gene was detected in 9/29 hVISA (31.0%) and 13/50 VS-MRSA (26.0%). By PFGE analyses, both hVISA and VS-MRSA strains were found to be clonally unrelated. In hVISA isolates, 24/29 (82.8%) were agr type I, 3/29 (10.3%) were type III and 2/29 (6.9%) were non-typeable. However, in VS-MRSA isolates, 25/50 (50.0%) were type II, 15/50 (30.0%) were type I, 7/50 (14.0%) were type III and 3/50 (6.0%) were non-typeable.
  
  
  
  The study shows that healthcare-associated MRSA strains may harbour community-acquired MRSA genetic markers. The changing molecular epidemiology and role of agr I in reduced vancomycin susceptibility in hVISA requires further investigation.
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226 014, India; Amity Institute of Biotechnology, Amity University, Lucknow, Uttar Pradesh, India.
authors.forename: Avinash
authors.initials: A
authors.lastname: Singh
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226 014, India. Electronic address: kashinprasad@gmail.com.
authors.forename: Kashi Nath
authors.initials: KN
authors.lastname: Prasad
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226 014, India.
authors.forename: Mohibur
authors.initials: M
authors.lastname: Rahman
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226 014, India.
authors.forename: Ravi Prakash
authors.initials: RP
authors.lastname: Rai
authors.affiliation: Department of Microbiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226 014, India.
authors.forename: Satyendra Kumar
authors.initials: SK
authors.lastname: Singh
authors.affiliation: Amity Institute of Biotechnology, Amity University, Lucknow, Uttar Pradesh, India.
authors.forename: Janmejai Kumar
authors.initials: JK
authors.lastname: Srivastava
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics; D019729:Carbon-Oxygen Ligases / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005098:Exotoxins / Q000235:genetics; D005838:Genotype; D006801:Humans; D007194:India / Q000453:epidemiology; D007956:Leukocidins / Q000235:genetics; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification*; D017720:Molecular Epidemiology; D058889:Molecular Typing; D016133:Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D015534:Trans-Activators / Q000235:genetics*; D020713:Vancomycin Resistance
chemical_list: C095698:Agr protein, Staphylococcus aureus; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D015534:Trans-Activators; C071437:VanA ligase, Bacteria; D019729:Carbon-Oxygen Ligases
keywords: CA-MRSA; HA-MRSA; SCCmec; agr; hVISA; pvl