Re-characterization of an extrachromosomal circular plasmid in the pathogenic Leptospira interrogans serovar Lai strain 56601  

作　　者：Lili Huang Weinan Zhui Ping He Yan Zhang Xuran Zhuang Guoping Zhao Xiaokui Guo Jinhong Qin Yongzhang Zhu 

机构地区：[1]Department of Microbiology and Immunology, Institute of Medical Science, Shanghai Jiao Tong University School of Medicine, 280 SouthChongqing Road, Shanghai 200025, China [2]CAS-Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, ChineseAcademy of Sciences, Shanghai 200032, China

出　　处：《Acta Biochimica et Biophysica Sinica》2014年第7期605-611,共7页生物化学与生物物理学报（英文版）

基　　金：This work was supported in part by the grants from the National Natural Science Foundation of China （30770820, 30970125,81101264, and 81171587） and the National Key Program for Infectious Diseases of China （2009ZX10004-712）.

摘　　要：In China, Leptospira interrogans serovar Lai strain 56601 （str.56601） is one of main pathogenic strains that cause severe leptospirosis in both human and animals. The genome of this organism was completely sequenced in 2003. However, in 2011, we identified and corrected some assembly errors in the str.56601 genome due to the repeat sequences widely distributed in the Leptospira genome. In this study, we re-analyzed the previously reported mobile, phage-related genomic island in the chromosome and rectified detailed sequence information in both the plasmid and chromosome using various experimental methods. The presence of a separate circular extrachromosomal plasmid was also confirmed, and its location in the genomi~ region was determined relative to the genomic island reported in L. interrogans serovar Lai by a combination of pulsed-field gel electrophoresis -based and plasmid extraction-based Southern blot analysis. This report confirmed that the sep arate extrachromosomal circular plasmid is not integrated into the chromosome of. interrogans str.56601 and markedly improved our understanding of the genomic organization, evolution, and pathogenesis of L. interrogans. In particular, characterization of this extrachromosomal cir cular plasmid will contribute to the development of genetic manipulation systems in pathogenic Leptospira species.In China, Leptospira interrogans serovar Lai strain 56601 （str.56601） is one of main pathogenic strains that cause severe leptospirosis in both human and animals. The genome of this organism was completely sequenced in 2003. However, in 2011, we identified and corrected some assembly errors in the str.56601 genome due to the repeat sequences widely distributed in the Leptospira genome. In this study, we re-analyzed the previously reported mobile, phage-related genomic island in the chromosome and rectified detailed sequence information in both the plasmid and chromosome using various experimental methods. The presence of a separate circular extrachromosomal plasmid was also confirmed, and its location in the genomi~ region was determined relative to the genomic island reported in L. interrogans serovar Lai by a combination of pulsed-field gel electrophoresis -based and plasmid extraction-based Southern blot analysis. This report confirmed that the sep arate extrachromosomal circular plasmid is not integrated into the chromosome of. interrogans str.56601 and markedly improved our understanding of the genomic organization, evolution, and pathogenesis of L. interrogans. In particular, characterization of this extrachromosomal cir cular plasmid will contribute to the development of genetic manipulation systems in pathogenic Leptospira species.

关 键 词：genomic island Leptospira interrogans extrachromosomal circular plasmid 

分 类 号：S858.28[农业科学—临床兽医学] Q782[农业科学—兽医学]