title: Multidrug-resistant clones of community-associated meticillin-resistant Staphylococcus aureus isolated from Chinese children and the resistance genes to clindamycin and mupirocin.
abstract: This study aimed to correlate the multidrug resistance (MDR) and sequence type (ST) clones of community-associated (CA) meticillin-resistant Staphylococcus aureus (MRSA) to identify the genes responsible for clindamycin and mupirocin resistance in S. aureus isolates from paediatric hospitals in mainland China. A total of 435 S. aureus isolates were collected. Compared with CA meticillin-susceptible S. aureus (MSSA), the resistance rates of CA-MRSA to ciprofloxacin, chloramphenicol, gentamicin and tetracycline were higher (19.0 vs 2.6 %, P<0.001; 14.7 vs 3.1 %, P<0.001; 14.7 vs 3.1 %, P<0.01; and 46.0 vs 13.3 %, P<0.001, respectively). Compared with hospital-associated (HA)-MRSA, the resistance rates of CA-MRSA to ciprofloxacin, gentamicin, rifampicin, tetracycline and trimethoprim-sulfamethoxazole were lower (19 vs 94.8 %, P<0.001; 14.7 vs 84.4 %, P<0.001; 5.5 vs 88.3 %, P<0.001; 46 vs 94.8 %, P<0.001; and 1.8 vs 9.1 %, P<0.01, respectively). The resistance rates of CA-MRSA, HA-MRSA and CA-MSSA to clindamycin (92.0, 77.9 and 64.1 %, respectively) and erythromycin (85.9, 77.9 and 63.1 %, respectively) were high. The MDR rates (resistance to three or more non-β-lactams) were 49.6, 100 and 14 % in the CA-MRSA, HA-MRSA and CA-MSSA isolates, respectively. Five of seven ST clones in the CA-MRSA isolates, namely ST59, ST338, ST45, ST910 and ST965, had MDR rates of >50 % (67.9, 87.5, 100, 50 and 83.3 %, respectively). The constitutive phenotype of macrolide-lincosamide-streptogramin B (MLS(B)) resistance (69 %) and the ermB gene (38.1 %) predominated among the MLS(B)-resistant CA S. aureus strains. The resistance rate to mupirocin was 2.3 % and plasmids carrying the mupA gene varied in size between 23 and 54.2 kb in six strains with high-level resistance as determined by Southern blot analysis. The present study showed that resistance to non-β-lactams, especially to clindamycin, is high in CA-MRSA isolates from Chinese children and that the profile of resistance is related to clonal type. This study revealed distinctive patterns of MLS(B)-resistant genes among CA S. aureus isolates.
authors.affiliation: Key Laboratory of Major Disease in Children and National Key Discipline of Pediatrics, Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, PR China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Major Disease in Children and National Key Discipline of Pediatrics, Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, PR China.
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Major Disease in Children and National Key Discipline of Pediatrics, Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, PR China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Pediatric Hospital of Fudan University, Shanghai, PR China.
authors.forename: Guoying
authors.initials: G
authors.lastname: Huang
authors.affiliation: Pediatric Hospital of Fudan University, Shanghai, PR China.
authors.forename: Chuanqing
authors.initials: C
authors.lastname: Wang
authors.affiliation: Guangzhou Children's Hospital, Guangzhou, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Deng
authors.affiliation: Shenzhen Children's Hospital, Shenzhen, PR China.
authors.forename: Yuejie
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Chongqing Children's Hospital, Chongqing, PR China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Fu
authors.affiliation: Affiliated Hospital of Wenzhou Medical College, Wenzhou, PR China.
authors.forename: Changcong
authors.initials: C
authors.lastname: Li
authors.affiliation: Shenyang Shengjing Hospital, Shenyang, PR China.
authors.forename: Yunxiao
authors.initials: Y
authors.lastname: Shang
authors.affiliation: Guangzhou Maternal and Child Health Hospital, Guangzhou, PR China.
authors.forename: Changan
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Major Disease in Children and National Key Discipline of Pediatrics, Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, PR China.
authors.forename: Mingjiao
authors.initials: M
authors.lastname: Sun
authors.affiliation: Key Laboratory of Major Disease in Children and National Key Discipline of Pediatrics, Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, PR China.
authors.forename: Xiangmei
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Major Disease in Children and National Key Discipline of Pediatrics, Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, PR China.
authors.forename: Sangjie
authors.initials: S
authors.lastname: Yu
authors.affiliation: Key Laboratory of Major Disease in Children and National Key Discipline of Pediatrics, Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, PR China.
authors.forename: Kaihu
authors.initials: K
authors.lastname: Yao
authors.affiliation: Key Laboratory of Major Disease in Children and National Key Discipline of Pediatrics, Ministry of Education, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, Beijing, PR China.
authors.forename: Xuzhuang
authors.initials: X
authors.lastname: Shen
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D002681:China; D002981:Clindamycin / Q000494:pharmacology; D017714:Community-Acquired Infections / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D016712:Mupirocin / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D002981:Clindamycin; D016712:Mupirocin