Characteristics of qacA/B-positive Staphylococcus aureus isolated from patients and a hospital environment in China.

The Journal of antimicrobial chemotherapy 2015 Mar

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This study was designed to demonstrate the characteristics of qacA/B-positive Staphylococcus aureus in China. One hundred and forty-five MRSA and 178 MSSA from clinical specimens from seven hospitals in different regions of China, 70 MRSA from superficial sites of patients and 106 MRSA from environmental samples from an ICU were collected and screened for the presence of the qacA/B gene. The qacA/B-positive isolates and 72 randomly selected qacA/B-negative control isolates were further characterized by MLST, spa typing and detection of toxin genes, as well as antimicrobial and chlorhexidine susceptibility. SCCmec typing was conducted for MRSA. PFGE was conducted for qacA/B-positive isolates. Twenty-five (7.8%) of the 321 MRSA isolates harboured qacA/B, including 11 isolates from clinical specimens (7.6%), 12 isolates from patients' superficial sites (17.1%) and 2 isolates from an ICU environment (1.9%). Ten and five qacA/B-positive MRSA were identified as ST239-t030-MRSA-III and ST239-t037-MRSA-III, respectively. Six PFGE clusters and five singletons were identified among the 25 qacA/B-positive MRSA. Only one (0.6%) of the 178 MSSA isolates harboured qacA/B. qacA/B carriage in MRSA was statistically associated with spa-t037 and the presence of mupA. Compared with qacA/B-negative MRSA, the qacA/B-positive MRSA exhibited a lower susceptibility to chlorhexidine and higher resistance rates to clindamycin and trimethoprim/sulfamethoxazole. Carriage of qacA/B, although it had a low prevalence, might be the main reason for declining susceptibility to chlorhexidine in MRSA from Chinese patients and is probably associated with spa-t037 and the presence of the mupA gene. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Citation

Zhongyi Lu, Yong Chen, Wei Chen, Hui Liu, Qing Song, Xiaofeng Hu, Ziying Zou, Zhengxiang Liu, Libo Duo, Jiyong Yang, Yanwen Gong, Zhanke Wang, Xuqin Wu, Jingya Zhao, Changjian Zhang, Mengqiang Zhang, Li Han. Characteristics of qacA/B-positive Staphylococcus aureus isolated from patients and a hospital environment in China. The Journal of antimicrobial chemotherapy. 2015 Mar;70(3):653-7