title: Molecular Characteristic and Virulence Gene Profiles of Community-AssociatedMethicillin-Resistant Staphylococcus aureusIsolates from Pediatric Patients in Shanghai, China.
abstract: Staphylococcus aureusis a globally important human pathogen, especially among children and immunocompromised patients. The emergence and spread of community-associated methicillin-resistantS. aureus(CA-MRSA) has become a serious public health problem worldwide. The aim of this study was to investigate the prevalence, molecular characteristics and virulence profiles of CA-MRSA infections from pediatric patients in a university hospital in Shanghai, China. A total of 80 CA-MRSA isolates were collected from July 2012 to December 2013 in Shanghai Children's Medical Center and analyzed by multilocus sequence typing, staphylococcus chromosomal cassettemec(SCCmec) typing, andspatyping. The detection of Panton-Valentine Leukocidin (pvl), superantigenic and exfoliative toxins, and adhesin genes was also performed. Overall, 16 distinct sequence types (STs) were identified among the 80 isolates. Among them, ST59 was found to be the most prevalent, followed by ST398 (11.3%, 9/80) and ST88 (8.8%, 7/80). SCCmectypes IV and V were observed, at 60 and 40%, respectively. Thirtyspatypes were identified,spa t437 (23.8%) was the most predominant type. All 80 isolates exhibited carriage of at least four virulence genes. Thirty-four (42.5%, 34/80) isolates harbored ≥10 tested virulence genes. Adhesion genes were present in most of the MRSA isolates, including the following:icaA(100%),clfA(100%),sdrC(95%), andsdrE(63.8%). The prevalence ofpvlgene was 20%, and multidrug resistance was observed in 36% of all strains. In addition, ST59-MRSA-IV witht437 accounted for 21.3% of occurrences, making it the most prevalent clone. Isolates that were carriers of toxin genes, andhla(100%) andhlg(87.5%) were the most frequent. In conclusion, simultaneous carriage of multiple virulence genes and genetically considerable diversity were very common among CA-MRSA from pediatric patients in Shanghai. ST59-MRSA-IV witht437 was still the most predominant type. The combination of virulence gene profiles and antibiotic resistance may help ST59 to be successfully spread among children.
authors.affiliation: Department of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine Shanghai, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Medical Microbiology and Immunology, University of California, Davis Davis, CA, USA.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine Shanghai, China.
authors.forename: Weichun
authors.initials: W
authors.lastname: Huang
authors.affiliation: Department of Laboratory Medicine, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine Shanghai, China.
authors.forename: Qihua
authors.initials: Q
authors.lastname: Fu
authors.affiliation: Department of Laboratory Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine Shanghai, China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
keywords: MLST-genotyping; SCCmec typing; community-associated methicillin-resistant staphylococcus aureus; spa typing; virulence factors