title: Molecular Characteristics of Nasal Carriage Methicillin-Resistant Coagulase Negative Staphylococci in School Students.
abstract: BACKGROUND
  Coagulase-negative staphylococci (CoNS) are opportunistic pathogens. Methicillin resistance is common in CoNS and may play an important role as reservoir of staphylococcal cassette chromosome mec (SCCmec) for Staphylococcus aureus.
  
  
  OBJECTIVE
  The aim of this study was to determine molecular characteristics of nasal carriage of methicillin-resistant coagulase negative staphylococci among students.
  
  
  METHODS
  MR-CoNS from both nares of students were collected. Resistance to methicillin was determined by cefoxitin (30μg) disk diffusion test. SCCmec typing was performed using multiplex PCR by mec complex classes and ccr genes. Antimicrobial susceptibility profiles were determined on Mueller-Hinton agar according to CLSI.
  
  
  RESULTS
  A total of 600 consecutive students were enrolled in this study; 430 of whom (71.7%) had CoNS. Seventy-two MR-CoNS strains, 21 (29.2%) S. lugdunensis, 17 (23.6%) S. haemolyticus, 17 (23.6%) S. saprophyticus, 9 (12.5%) S. epidermidis and 8 (11.1%) S. schleiferi were isolated. MR-CoNS rate in nasal carriage was 16.7%. All strains were susceptible to vancomycin. Forty-eight (66.7%) had a single SCCmec type including types I (n = 5), II (n = 4), III (n = 7), IV (n = 19) and V (n = 13), whereas 5 (6.9%) had two types including III + IV (n = 2), III + V (n = 1) and IV + V (n = 2). Nineteen strains (26.4%) were non-typeable for their SCCmec and ccr. Types IV and V SCCmec were associated with S. lugdunensis and S. haemolyticus, respectively.
  
  
  CONCLUSIONS
  SCCmec types IV and V were prevalent in MR-CoNS and few isolates could harbor more than one type.
authors: Department of Microbiology and Immunology, Kashan University of Medical Sciences, Kashan, IR Iran.
authors: Mohammad
authors: M
authors: Iravani Mohammad Abadi
authors: Department of Microbiology and Immunology, Kashan University of Medical Sciences, Kashan, IR Iran.
authors: Rezvan
authors: R
authors: Moniri
authors: Department of Microbiology and Immunology, Kashan University of Medical Sciences, Kashan, IR Iran.
authors: Ahmad
authors: A
authors: Khorshidi
authors: Department of Microbiology and Immunology, Kashan University of Medical Sciences, Kashan, IR Iran.
authors: Ahmad
authors: A
authors: Piroozmand
authors: Trauma Research Center, Kashan University of Medical Sciences, Kashan, IR Iran.
authors: Seyed Gholam Abbas
authors: SG
authors: Mousavi
authors: Anatomical Sciences Research Center, Kashan University of Medical Sciences, Kashan, IR Iran.
authors: Kamran
authors: K
authors: Dastehgoli
authors: Department of Microbiology and Immunology, Kashan University of Medical Sciences, Kashan, IR Iran.
authors: Hamed
authors: H
authors: Mirzaei Ghazikalayeh
keywords: Coagulase-Negative Staphylococci; Methicillin-Resistant Staphylococcus aureus; Staphylococcus spp.