Comparison of Double-Locus（clfB and spa）Sequence Typing with Pulsed-Field Gel Electrophoresis in Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus in Central Taiwan

Autor: Chen-Cheng Huang, 黃丞正
Rok vydání: 2012
Druh dokumentu: 學位論文 ; thesis
Popis: 100
Several DNA sequence-based methods have been developed for the epidemiological investigation of methicillin-resistant Staphylococcus aureus (MRSA). Ninety-one MRSA isolates were collected from the blood cultures of different patients from July to December of 2008 in central Taiwan. The molecular characteristics of each isolate, double locus sequencing typing (DLST, including spa and clfB typing), multilocus sequencing typing (MLST), Staphylococcus cassette chromosome mec (SCCmec) and pulsed-field gel electrophoresis (PFGE) were determined for comparison. There are 5 major clfB types (types A to E), 18 spa types, and 33 DLST genotypes, 5 SCCmec types, 17 pulsotypes with 80% similarity observed. Three major DLST (clfB and spa) genotypes A1-t002, C0-t037, and B1-t437, two major pulsotye：types 6 and 8, were identified. In the 3 major clfB types A, B and C, clfB subtype A1 and A2 isolates were all SCCmec type II (100%), ST5, and all clfB type C isolates were SCCmec type III (100%), ST239. Most clfB type B isolates（88.9%） were SCCmec type IV (59.3%) and VT (29.6%) and all belonged to ST59. All clfB subtype A1, A2 and type C isolates (100%) belonged to HA-MRSA, and about 30% clfB type B isolates also belonged to CA-MRSA. Patients carrying clfB type A or C have higher mortality than those with clfB type B, the index of discrimination (ID) of double-locus (spa and clfB) sequence typing was 0.8676, which has a comparable discriminatory power to 85% similarity in PFGE. In conclusion, this DLST method can give a compatible discriminatory power to PFGE with saving time, cost, and labor in local investigation of molecular epidemiology of MRSA. The method is a promising alternative to PFGE and even had a good asociation with mortality.
Databáze: Networked Digital Library of Theses & Dissertations
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