title: Moraxella catarrhalisMacrolide-Resistant Isolates Are Highly Concentrated in Two MLST Clonal Complexes -CCN10 and CC363.
abstract: To gain some insights into the molecular evolution ofMoraxella catarrhalismacrolide resistance, PCR and sequencing analysis of the 23S rRNA gene,copBtyping and multilocus sequence typing (MLST) were performed on 181M. catarrhalisisolates. The isolates were obtained from children (n= 47) and adults (n= 134) presenting with respiratory disease in the years 2010-2014. Macrolide resistance was highly age-related, and nucleotide position alterations at A2330T could be detected in all macrolide-resistant isolates.copB0 andcopBNT (non-typable) were only found in macrolide-susceptible isolates from adults. Furthermore,copBI/III was the main type in adult or macrolide-susceptible isolates, whilecopBII was the most common type in children or macrolide-resistant isolates. Twenty-two different MLST clusters (sharing 7 of the 8 identical loci) were detected and only four likely primary founders (ST224, ST363, STN08, and STN10) which belong to clonal complex (CC) 224, CC363, CCN08, and CCN10, were detected, respectively. Macrolide-resistantM. catarrhalisisolates were highly concentrated in two CCs (CCN10 and CC363), which indicates some potential evolutionary advantage or co-evolution to some extent. However, further studies are needed to fully elucidate the evolution of CCN10 and CC363 in macrolide resistance.
authors.affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences Beijing, China.
authors.forename: Ya-Li
authors.initials: YL
authors.lastname: Liu
authors.affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences Beijing, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Xiao
authors.affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences Beijing, China.
authors.forename: Jing-Wei
authors.initials: JW
authors.lastname: Cheng
authors.affiliation: Department of Clinical Laboratory, The First Affiliated Hospital of Xiamen University Xiamen, China.
authors.forename: He-Ping
authors.initials: HP
authors.lastname: Xu
authors.affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences Beijing, China.
authors.forename: Zhi-Peng
authors.initials: ZP
authors.lastname: Xu
authors.affiliation: Department of Clinical Laboratory, Bazhou People's Hospital Xinjiang, China.
authors.forename: Sha
authors.initials: S
authors.lastname: Ye
authors.affiliation: Department of Clinical Laboratory, Beijing Youan Hospital, Capital Medical University/Hospital for Infectious Diseases of Baoding Hebei, China.
authors.forename: Wen-Juan
authors.initials: WJ
authors.lastname: Zhang
authors.affiliation: Charles Sturt University, Orange Campus, OrangeNSW, Australia; Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR - Pathology West, Westmead Hospital, University of Sydney, WestmeadNSW, Australia.
authors.forename: Timothy
authors.initials: T
authors.lastname: Kudinha
authors.affiliation: Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR - Pathology West, Westmead Hospital, University of Sydney, Westmead NSW, Australia.
authors.forename: Fanrong
authors.initials: F
authors.lastname: Kong
authors.affiliation: Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences Beijing, China.
authors.forename: Ying-Chun
authors.initials: YC
authors.lastname: Xu
keywords: Moraxella catarrhalis; clonal complexes; copB; macrolide-resistance; mlst