Multidrug-resistant clones of community-associated meticillin-resistant Staphylococcus aureus isolated from Chinese children and the resistance genes to clindamycin and mupirocin

• Published in: Journal of medical microbiology Vol. 61; no. 9; pp. 1240 - 1247
• Main Authors: Wang, Lijuan, Liu, Yingchao, Yang, Yonghong, Huang, Guoying, Wang, Chuanqing, Deng, Li, Zheng, Yuejie, Fu, Zhou, Li, Changcong, Shang, Yunxiao, Zhao, Changan, Sun, Mingjiao, Li, Xiangmei, Yu, Sangjie, Yao, Kaihu, Shen, Xuzhuang
• Format: Journal Article
• Language: English
• Published: Reading Society for General Microbiology 01.09.2012
• Subjects: Adolescent; Anti-Bacterial Agents - pharmacology; Bacteriology; Biological and medical sciences; Child; Child, Preschool; China; Clindamycin - pharmacology; Community-Acquired Infections - microbiology; Drug Resistance, Multiple, Bacterial - genetics; Fundamental and applied biological sciences. Psychology; Humans; Infant; Infant, Newborn; Infectious diseases; Medical sciences; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Methicillin-Resistant Staphylococcus aureus - metabolism; Microbial Sensitivity Tests; Microbiology; Miscellaneous; Mupirocin - pharmacology; Sequence Analysis, DNA; Staphylococcal Infections - microbiology; Staphylococcus aureus - drug effects; Staphylococcus aureus - genetics; Staphylococcus aureus - isolation & purification; Staphylococcus aureus - metabolism; China; Human; β-Lactams; Clindamycin; Mupirocin; Meticillin; Penicillin derivatives; Antibiotic; Gene; Multiple resistance; Bacteria; Micrococcales; Micrococcaceae; Antibacterial agent; Child; Staphylococcus aureus
• ISSN: 0022-2615; 1473-5644
• DOI: 10.1099/jmm.0.042663-0

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.