机构：[1]Pediatric Intensive Care Unit, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, No.56 Nan-Li-Shi Road, Beijing 100045, China.临床科室职能科室临床流行病与循证医学中心重症医学科首都医科大学附属北京儿童医院[2]Bacteriology Laboratory, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing 100045, China.医技科室职能科室检验中心临床流行病与循证医学中心首都医科大学附属北京儿童医院[3]MOE Key Laboratory of Major Diseases in Children, National Key Discipline of Pediatrics (Capital Medical University), National Clinical Research Center for Respiratory Diseases, Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing 100045, China.医技科室科研平台职能科室呼吸疾病研究室临床流行病与循证医学中心临床研究中心儿科研究所首都医科大学附属北京儿童医院[4]No. 56 Nan-li-shi Road, Beijing 100045, China.
BackgroundStaphylococcus aureus (S. aureus) with accessory gene regulator (agr) dysfunction occurs in health care settings. This study evaluated the prevalence and the molecular and drug resistance characteristics of S. aureus with dysfunctional agr in a pediatric population in Beijing, China.ResultsA total of 269 nonduplicate S. aureus clinical isolates were isolated from Beijing Children's Hospital, including 211 methicillin-resistant S. aureus (MRSA) from September 2010-2017 and 58 methicillin-sensitive S. aureus (MSSA) from February 2016-2017. Only 8 MRSA and 2 MSSA isolates were identified as agr dysfunction, and the overall prevalence rate was 3.7%. For MRSA isolates, ST59-SCCmec IV and ST239-SCCmec III were the most common clones, and the prevalence rate of agr dysfunction in ST239-SCCmec III isolates (17.39%) was significantly higher than in ST59-SCCmec IV (1.69%) and other genotype strains (P=0.006). Among the agr dysfunctional isolates, only one MRSA ST59 isolate and one MSSA ST22 isolate harbored pvl. No significant difference was detected between agr dysfunction and agr functional isolates regarding the biofilm formation ability (P=0.4972); however, 9/10 agr dysfunctional isolates could effectuate strong biofilm formation and multidrug resistance. Among MRSA, the non-susceptibility rates to ciprofloxacin, gentamicin, and trimethoprim-sulfamethoxazole were significantly higher in agr dysfunctional isolates than in isolates with functional agr (P<0.05). Two isolates belonging to ST239 had no mutations in agr locus, but a synonymous mutation was found in agrA in another ST239 isolate. The inactivating mutations were detected in other seven agr dysfunctional isolates. The variants were characterized by non-synonymous changes (n=5) and frameshift mutations (insertions, n=2), which mainly occurred in agrC and agrA.ConclusionsThe results showed that agr dysfunctional S. aureus was not common in Chinese children, and ST59-SCCmec IV was associated with lower prevalence of agr dysfunction as compared to ST239-SCCmec III isolates. The agr dysfunctional isolates were healthcare-associated, multidrug resistant and form strong biofilm, which suggested that agr dysfunction might offer potential advantages for S. aureus to survive in a medical environment.
基金：
Beijing Natural Science FoundationBeijing Natural Science Foundation [7172075]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China [81571948]
第一作者机构：[1]Pediatric Intensive Care Unit, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, No.56 Nan-Li-Shi Road, Beijing 100045, China.
共同第一作者：
通讯作者：
通讯机构：[1]Pediatric Intensive Care Unit, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, No.56 Nan-Li-Shi Road, Beijing 100045, China.[4]No. 56 Nan-li-shi Road, Beijing 100045, China.
推荐引用方式(GB/T 7714)：
Yang Xin,Dong Fang,Qian Suyun,et al.Accessory gene regulator (agr) dysfunction was unusual in Staphylococcus aureus isolated from Chinese children[J].BMC MICROBIOLOGY.2019,19(1):-.doi:10.1186/s12866-019-1465-z.
APA：
Yang, Xin,Dong, Fang,Qian, Suyun,Wang, Lijuan,Liu, Yingchao...&Zheng, Hongyan.(2019).Accessory gene regulator (agr) dysfunction was unusual in Staphylococcus aureus isolated from Chinese children.BMC MICROBIOLOGY,19,(1)
MLA：
Yang, Xin,et al."Accessory gene regulator (agr) dysfunction was unusual in Staphylococcus aureus isolated from Chinese children".BMC MICROBIOLOGY 19..1(2019):-
