title: Trend in vancomycin susceptibility and correlation with molecular characteristics of methicillin-resistant Staphylococcus aureus causing invasive infections in Taiwan: results from the Tigecycline in vitro Surveillance in Taiwan (TIST) study, 2006-2010.
abstract: This study was intended to investigate the trend in vancomycin susceptibility and correlation with molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) causing invasive infections. A total of 670 MRSA isolates were collected from patients with invasive infections as part of bacterial collection in the Tigecycline in vitro Surveillance in Taiwan (TIST) from 2006 to 2010. MICs of the isolates to vancomycin were determined using the agar dilution method. Characteristics of staphylococcal cassette chromosome mec (SCCmec), mec-associated hypervariable region (dru), and accessory gene regulator (agr) of the isolates were identified by polymerase chain reaction methods. MRSA isolates with SCCmec types I, II, and III were molecularly defined as hospital-associated MRSA (HA-MRSA), and those with SCCmec types IV, V, and VT were assigned as community-associated MRSA (CA-MRSA). All but 1 MRSA isolates exhibited vancomycin MICs ≤1 mg/L. A declining trend in vancomycin MICs among MRSA isolates was noted, which was associated with the decline in proportion of HA-MRSA. The percentage of CA-MRSA increased from 25.6% in 2006 to 46.0% in 2010. An increase in the geometric mean of vancomycin MICs was found in MRSA with particular molecular types such as SCCmec types II and III, agr groups I and II, and dru10-14. A significant correlation among particular molecular types was found, including SCCmecII-agr group II-dru4, SCCmecIII-agr group I-dru11-14, SCCmecIV-agr group II-dru9, and SCCmecVT-agr group I-dru9 and dru11. There was no vancomycin creep among MRSA isolates, and the declining trend of vancomycin MIC against MRSA was attributed to the increasing prevalence of CA-MRSA over time.
authors: Division of Infectious Diseases, Internal Medicine Department, Institute of Microbiology and Immunology, Chung Shan Medical University, and University Hospital, Taichung, Taiwan.
authors: Shin-Ming
authors: SM
authors: Tsao
authors: Department of Internal Medicine, Fong-Yuan Hospital, Taichung, Taiwan.
authors: Wei-Yao
authors: WY
authors: Wang
authors: Department of Medicine, National Cheng Kung University Medical College and Hospital, Tainan, Taiwan.
authors: Wen-Chien
authors: WC
authors: Ko
authors: Division of Infectious Diseases, Department of Internal Medicine, Cathay General Hospital, Taipei, Taiwan.
authors: Cheng-Hua
authors: CH
authors: Huang
authors: Section of Infectious Diseases, Department of Internal Medicine, Lotung Poh-Ai Hospital, Luodong Township, Taiwan.
authors: Chin-Te
authors: CT
authors: Lu
authors: Department of Internal Medicine, Chi-Mei Medical Center, Tainan, Taiwan.
authors: Yin-Ching
authors: YC
authors: Chuang
authors: Section of Infectious Diseases, Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei, Taiwan.
authors: Chia-Ying
authors: CY
authors: Liu
authors: Section of Infectious Diseases, Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei, Taiwan.
authors: Chun-Hsing
authors: CH
authors: Liao
authors: Section of Infectious Diseases, Shuang Ho Hospital, Taipei Medical University and School of Medicine, Taipei, Taiwan; Section of Infectious Diseases, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
authors: Yao-Shen
authors: YS
authors: Chen
authors: Section of Infectious Diseases, Shuang Ho Hospital, Taipei Medical University and School of Medicine, Taipei, Taiwan; Section of Infectious Diseases, Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
authors: Yung-Ching
authors: YC
authors: Liu
authors: Section of Infectious Diseases, Department of Internal Medicine, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.
authors: Wei-Yu
authors: WY
authors: Chen
authors: Section of Infectious Diseases, Department of Internal Medicine, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.
authors: Tsrang-Neng
authors: TN
authors: Jang
authors: Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors: Hsiu-Chen
authors: HC
authors: Lin
authors: Section of Infectious Diseases, Department of Internal Medicine, Tungs' Taichung MetroHarbor Hospital, Wuqi Township, Taiwan.
authors: Chih-Ming
authors: CM
authors: Chen
authors: Section of Infectious Diseases, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors: Zhi-Yuan
authors: ZY
authors: Shi
authors: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors: Sung-Ching
authors: SC
authors: Pan
authors: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors: Jia-Ling
authors: JL
authors: Yang
authors: Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors: Hsiang-Chi
authors: HC
authors: Kung
authors: Section of Infectious Diseases, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan.
authors: Chun-Eng
authors: CE
authors: Liu
authors: Section of Infectious Diseases, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan.
authors: Yu-Jen
authors: YJ
authors: Cheng
authors: Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University Medical College, Kaohsiung, Taiwan.
authors: Jien-Wei
authors: JW
authors: Liu
authors: Department of Infection Control, Pao-Chien Hospital, Pingtung, Taiwan.
authors: Wu
authors: W
authors: Sun
authors: Section of Infectious Diseases, Department of Internal Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan.
authors: Lih-Shinn
authors: LS
authors: Wang
authors: Division of Infectious Diseases, Department of Internal Medicine, Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors: Kwok-Woon
authors: KW
authors: Yu
authors: Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Medical Foundation Linkou Branch, Tao-Yuan, Taiwan.
authors: Ping-Cherng
authors: PC
authors: Chiang
authors: Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Medical Foundation Linkou Branch, Tao-Yuan, Taiwan.
authors: Ming-Hsun
authors: MH
authors: Lee
authors: Section of Infectious Diseases, Department of Internal Medicine, Mackay Memorial Hospital, Taipei, Taiwan.
authors: Chun-Ming
authors: CM
authors: Lee
authors: Division of Infectious Diseases, Department of Internal Medicine, Ditmanson Medical Foundation Chiayi Christian Hospital, Chiayi, Taiwan.
authors: Gwo-Jong
authors: GJ
authors: Hsu
authors: Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, and Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Yen-Hsu
authors: YH
authors: Chen
authors: Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, and Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Po-Liang
authors: PL
authors: Lu
authors: Division of Chest Medicine, Department of Internal Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan. Electronic address: tcyt@csmu.edu.tw.
authors: Chang-Yao Tsao
authors: CY
authors: Thomas
authors: Departments of Laboratory Medicine and Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan. Electronic address: hsporen@ntu.edu.tw.
authors: Po-Ren
authors: PR
authors: Hsueh
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D058889:Molecular Typing; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013624:Taiwan / Q000453:epidemiology; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D014640:Vancomycin
keywords: Community-associated MRSA; Hospital-associated MRSA; Minimum inhibitory concentrations; SCCmec; Vancomycin