title: Mycobacterium kansasiiSubtype I Is Associated With Clarithromycin Resistance in China.
abstract: Mycobacterium kansasiiis the second most common cause of slowly growing non-tuberculous mycobacteria diseases in China. The aim of the present study was to analyzeM. kansasiisubtypes isolated from patients in China, and to explore the antimicrobial susceptibility of the differentiation among these diverse subtypes. A total of 78M. kansasiistrains from 16 provinces of China were enrolled in this study. Amikacin (AMK) was the most highly active againstM. kansasiistrains, and only 4 isolates (5.1%) exhibitedin vitroresistance to AMK. The percentage of levofloxacin (LFX) resistant strains among the 78M. kansasiiisolates was 39.7% (31/78), which was significantly higher than that of moxifloxacin (16.7%,P= 0.001) and gatifloxacin (19.2%,P= 0.005). By using PCR-restriction fragment analysis of thehsp65gene (PRA), all the isolates were classified as four different subtypes. Of these four subtypes,M. kansasiisubtype I was the most frequent genotype in China, accounting for 71.8% (56/78) ofM. kansasiiisolates. Resistance to clarithromycin (CLA) was noted in 26.8% (15/56) of subtype I isolates, which was significant higher than that of other subtypes (4.5%,P= 0.031). DNA sequencing revealed that the presence of mutations in 23S rRNA was associated with 56.2% (9/16) of CLA-resistantM. kansasiiisolates. In conclusion, our data demonstrate that AMK is the most active agent againstM. kansasii in vitro, while the high proportion of CLA resistance is noted inM. kansasiiisolates. In addition, the predominant subtype I is associated with CLA resistance in China.
authors.affiliation: Graduate School, Peking Union Medical CollegeBeijing, China; Department of Respiratory and Critical Care Medicine, Beijing HospitalBeijing, China.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Li
authors.affiliation: National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention Beijing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Pang
authors.affiliation: Department of Geriatrics, Beijing Hospital Beijing, China.
authors.forename: Xunliang
authors.initials: X
authors.lastname: Tong
authors.affiliation: National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention Beijing, China.
authors.forename: Huiwen
authors.initials: H
authors.lastname: Zheng
authors.affiliation: National Center for Tuberculosis Control and Prevention, Chinese Center for Disease Control and Prevention Beijing, China.
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Graduate School, Peking Union Medical CollegeBeijing, China; Department of Respiratory Medicine, Chinese-Japanese Friendship HospitalBeijing, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
keywords: China; Mycobacterium kansasii; clarithromycin; drug susceptibility; subtype