title: Phylogenetic study of clonal complex (CC)198 capsule null locus (cnl) genomes: A distinctive group within the species Neisseria meningitidis.
abstract: Capsule null locus (cnl) strains, one type of specific unencapsulated Neisseria spp., only have regions D and E of the capsule gene cluster which encodes the genes for capsule biosynthesis, modification, and transportation. Compared with encapsulated strains, regions A and C of cnl strains have been replaced by 113 or 114 bp conserved non-coding sequences. Cnl strains include multiple clonal complexes (CC). According to previous studies, CC198 is the major clonal lineage in both cnl patients and healthy cnl carriers. We hypothesized that CC198 possesses different genome characteristics compared with other cnl strains. In this study, we obtained the draft genomes of two CC198 strains from healthy carriers. Using 75071 single nucleotide polymorphisms located in 1163 core genes, we constructed the phylogenetic relationships between a batch of representative Neisseria meningitidis genomes. CC198 and CC1136 clustered together, but apart from other N. meningitidis strains including CC53. We also aligned the sequences of genes located in regions D and E of the capsule gene locus from encapsulated and unencapsulated strains. A number of possible recombination events were identified in the galE and tex genes between different serogroups of encapsulated N. meningitidis and CC53 strains, especially in tex. In contrast, there is almost no recombination in N. meningitidis CC198 strains. These results showed that CC198 belongs to a phylogenetically distinct group within the species N. meningitidis, which may be directly derived from the cnl-type ancestor of N. meningitidis. The encapsulated strains may acquire other necessary genes for capsule formation by horizontal transfer.
authors.affiliation: National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Xu
authors.affiliation: National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Du
authors.affiliation: National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors.forename: Bingqing
authors.initials: B
authors.lastname: Zhu
authors.affiliation: National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.affiliation: National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors.forename: Haiyin
authors.initials: H
authors.lastname: Wang
authors.affiliation: National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors.forename: Haijian
authors.initials: H
authors.lastname: Zhou
authors.affiliation: National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: National Institute for Communicable Disease Control and Prevention, and State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China. Electronic address: shaozhujun@icdc.cn.
authors.forename: Zhujun
authors.initials: Z
authors.lastname: Shao
mesh_terms: D016667:Bacterial Capsules / Q000235:genetics; D001483:Base Sequence; D019143:Evolution, Molecular; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D009345:Neisseria meningitidis / Q000235:genetics*; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D017422:Sequence Analysis, DNA
keywords: CC198; Capsule; Evolution; Neisseria meningitidis; cnl