title: Evaluation of double locus (clfB and spa) sequence typing for studying molecular epidemiology of methicillin-resistant Staphylococcus aureus in Taiwan.
abstract: BACKGROUND
  Pulsed-field gel electrophoresis (PFGE) is the "gold standard" for epidemiological investigation of methicillin-resistant Staphylococcus aureus (MRSA), but several DNA sequence-based methods have been developed in MRSA typing because of the unambiguous results.
  
  
  METHODS
  Ninety-one MRSA isolates were collected from the blood cultures of different patients from July 2008 to December 2008 in central Taiwan. The molecular characteristics of each isolate, including double locus sequence typing (DLST; spa and clfB typing), Staphylococcus cassette chromosome mec (SCCmec), and PFGE were determined for comparison.
  
  
  RESULTS
  Five major clfB types (types A-E), 18 spa types, 33 DLST genotypes, five SCCmec types, 17 pulsotypes have been observed. Three major DLST genotypes (A1-t002, C0-t037, and B1-t437) and two major pulsotypes (6 and 8) were identified. Most clfB type A isolates (97.1%) were SCCmec type II and all clfB type C isolates (100%) were SCCmec type III. Most clfB type B isolates (88.9%) were SCCmec type IV (59.3%) and VT(29.6%). All (100%) clfB subtypes A1, A2, and C isolates and 70.4% of clfB type B isolates belonged to healthcare-associated-MRSA. The average congruence was 57.7% between DLST and PFGE, and 96.6% between clfB and SCCmec type. The index of discrimination of SCCmec, clfB, spa, PFGE, and DLST was 0.72, 0.79, 0.80, 0.81, and 0.87, respectively.
  
  
  CONCLUSIONS
  ClfB type has high congruence with SCCmec type. The DLST method in this study yielded a higher discriminatory power than PFGE in local investigation of molecular epidemiology of MRSA and a promising alternative to PFGE.
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Taichung Hospital, Ministry of Health and Welfare, Taichung, Taiwan; Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan.
authors.forename: Chen-Cheng
authors.initials: CC
authors.lastname: Huang
authors.affiliation: Department of Laboratory Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Cheng-Mao
authors.initials: CM
authors.lastname: Ho
authors.affiliation: Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Hui-Chen
authors.initials: HC
authors.lastname: Chen
authors.affiliation: Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan.
authors.forename: Chi-Yuan
authors.initials: CY
authors.lastname: Li
authors.affiliation: Department of Laboratory Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Ni
authors.initials: N
authors.lastname: Tien
authors.affiliation: Department of Laboratory Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Hsiu-Mei
authors.initials: HM
authors.lastname: Fan
authors.affiliation: Department of Laboratory Medicine, Linkou Chang-Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Mao-Cheng
authors.initials: MC
authors.lastname: Ge
authors.affiliation: Department of Laboratory Medicine, Linkou Chang-Gung Memorial Hospital, Taoyuan, Taiwan; Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Kweishan, Taoyuan, Taiwan. Electronic address: janglu45@gmail.com.
authors.forename: Jang-Jih
authors.initials: JJ
authors.lastname: Lu
mesh_terms: D018829:Adhesins, Bacterial / Q000235:genetics*; D000942:Antigens, Bacterial / Q000235:genetics*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000032:analysis; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification*; D017720:Molecular Epidemiology / Q000379:methods*; D058885:Multilocus Sequence Typing / Q000379:methods*; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013624:Taiwan / Q000453:epidemiology
chemical_list: D018829:Adhesins, Bacterial; D000942:Antigens, Bacterial; D004269:DNA, Bacterial; C434058:clfB protein, Staphylococcus aureus; C119204:streptococcal protective antigen
keywords: double locus sequence typing