Macrolide-resistance mechanisms in Streptococcus pneumoniae isolates from Chinese children in association with genes of tetM and integrase of conjugative transposons 1545

作者：Shen, Xuzhuang; Yang, Hui; Yu, Shangjie; Yao, Kaihu; Wang, Yonghong; Yuan, Lin; Yang, Yonghong^*

来源：Microbial Drug Resistance, 2008, 14(2): 155-161.

DOI：10.1089/mdr.2008.0773

• MOLECULAR CHARACTERIZATION
• ERYTHROMYCIN RESISTANCE
• TETRACYCLINE-RESISTANT
• ASIAN NETWORK
• EPIDEMIOLOGY
• SURVEILLANCE
• PREVALENCE
• PYOGENES
• BACTEREMIA
• CANADA

This study investigated macrolide-resistant Streptococcus pneumoniae carried by Beijing children presenting with respiratory tract infections. Nasopharyngeal S. pneumoniae strains were tested for sensitivity with 15 antibiotics and further analyzed for phenotypes of macrolide-resistant strains a rid by PCR for the macrolide-resistant genes ermB, mefA, tetM, and integrase of conjugative transposon (Tn1545) intTn. We found 185 strains of S. pneumoniae relatively highly resistant to erythromycin (78.9%), clindamycin (76.2%), tetracycline (86%), and SMZ-TMP (78.7%) but with relatively low resistance to amoxicillin (2.2%), cefaclor (15.5%), ceftriaxone (2.8%), and cefuroxime (14.1%). The 146 strains of erythromycin-resistant S. pneumoniae showed extensive cross-resistance to other macrolides like azithromycin (100%), clarithromycin (100%), acetylspiramycin (95.2%), and clindamycin (95.9%). Genes ermB and mefA were detected in all erythromycin-resistant strains, with ermB(+) 79.5%, ermB + mefA(+) 17.8%, and mefA(+) 2.7%. About 96.9% of tetracycline-resistant isolates were positive for tetM, compared to 26.9% of sensitive strains. Ninety percent of tetracycline-resistant strains were also erythromycin-resistant versus 11.5% of tetracycline-sensitive strains. The intTn gene was present in 87.6%) of S. pneumoniae strains and correlated with erythromycin and tetracycline resistance. The close relationship between the conjugative transposon Tn1545 and the genes ermB and tetM is probably one of the important mechanisms explaining the multiple drug resistance of S. pneumoniae.

• 出版日期2008-6
• 单位首都医科大学