Limits...
Genetic diversity among major endemic strains of Leptospira interrogans in China.

He P, Sheng YY, Shi YZ, Jiang XG, Qin JH, Zhang ZM, Zhao GP, Guo XK - BMC Genomics (2007)

Bottom Line: Because genes encoding proteins with potential pathogenic functions are located within GIs, these elements might contribute to the variations in disease manifestation.Differences in genes involved in O-antigen biosynthesis were also identified for strains belonging to different serogroups, which offers an opportunity for future development of genomic typing tools for serological classification.The strain-specific genes detected via this work will provide a knowledge base for further investigating the pathogenesis of L interrogans and/or for the development of effective vaccines and/or diagnostic tools.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Microbiology and Parasitology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. hpatsh@sjtu.edu.cn

ABSTRACT

Background: Leptospirosis is a world-widely distributed zoonosis. Humans become infected via exposure to pathogenic Leptospira spp. from contaminated water or soil. The availability of genomic sequences of Leptospira interrogans serovar Lai and serovar Copenhageni opened up opportunities to identify genetic diversity among different pathogenic strains of L. interrogans representing various kinds of serotypes (serogroups and serovars).

Results: Comparative genomic hybridization (CGH) analysis was used to compare the gene content of L. interrogans serovar Lai strain Lai with that of other 10 L. interrogans strains prevailed in China and one identified from Brazil using a microarray spotted with 3,528 protein coding sequences (CDSs) of strain Lai. The cutoff ratio of sample/reference (S/R) hybridization for detecting the absence of genes from one tested strain was set by comparing the ratio of S/R hybridization and the in silico sequence similarities of strain Lai and serovar Copenhageni strain Fiocruz L1-130. Among the 11 strains tested, 275 CDSs were found absent from at least one strain. The common backbone of the L. interrogans genome was estimated to contain about 2,917 CDSs. The genes encoding fundamental cellular functions such as translation, energy production and conversion were conserved. While strain-specific genes include those that encode proteins related to either cell surface structures or carbohydrate transport and metabolism. We also found two genomic islands (GIs) in strain Lai containing genes divergently absent in other strains. Because genes encoding proteins with potential pathogenic functions are located within GIs, these elements might contribute to the variations in disease manifestation. Differences in genes involved in O-antigen biosynthesis were also identified for strains belonging to different serogroups, which offers an opportunity for future development of genomic typing tools for serological classification.

Conclusion: CGH analyses for pathogenic leptospiral strains prevailed in China against the L. interrogans serovar Lai strain Lai CDS-spotted microarrays revealed 2,917 common backbone CDSs and strain specific genes encoding proteins mainly related to cell surface structures and carbohydrated transport/metabolism. Of the 275 CDSs considered absent from at least one of the L. interrogans strains tested, most of them were clustered in the rfb gene cluster and two putative genomic islands (GI A and B) in strain Lai. The strain-specific genes detected via this work will provide a knowledge base for further investigating the pathogenesis of L interrogans and/or for the development of effective vaccines and/or diagnostic tools.

Show MeSH

Related in: MedlinePlus

Comparative analysis of the diverged L. interrogans genomes observed by CGH with respect to their signatures defining genomic islands. (A) The presence/absence CDSs of all tested strains comparing to that of strain Lai ordered from LA0001 to LB367. Red and black areas denote the presence and absence of genes respectively. The blue bar indicates the GI A region, the grey bar indicates the rfb locus, and the yellow bar indicates the GI B region. These 3 regions are specifically drawn to the following sketches indicating the variations in strain Lai for properties of possible genomic islands: CG content (B), genome signature (C), codon usage (D), and amino acid usage (E).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC1936430&req=5

Figure 3: Comparative analysis of the diverged L. interrogans genomes observed by CGH with respect to their signatures defining genomic islands. (A) The presence/absence CDSs of all tested strains comparing to that of strain Lai ordered from LA0001 to LB367. Red and black areas denote the presence and absence of genes respectively. The blue bar indicates the GI A region, the grey bar indicates the rfb locus, and the yellow bar indicates the GI B region. These 3 regions are specifically drawn to the following sketches indicating the variations in strain Lai for properties of possible genomic islands: CG content (B), genome signature (C), codon usage (D), and amino acid usage (E).

Mentions: Three regions with large sets of missing CDSs detected by CGH in the 11 L. interrogans strains presented some characteristics of laterally transferred genomic elements. Besides the rfb gene cluster, the GC content, genome signature, as well as the codon and amino acid usage bias of the other two missing regions were analyzed along with the chromosomal DNA sequence of strain Lai (Fig. 3) [21] to verify their GI characteristics.


Genetic diversity among major endemic strains of Leptospira interrogans in China.

He P, Sheng YY, Shi YZ, Jiang XG, Qin JH, Zhang ZM, Zhao GP, Guo XK - BMC Genomics (2007)

Comparative analysis of the diverged L. interrogans genomes observed by CGH with respect to their signatures defining genomic islands. (A) The presence/absence CDSs of all tested strains comparing to that of strain Lai ordered from LA0001 to LB367. Red and black areas denote the presence and absence of genes respectively. The blue bar indicates the GI A region, the grey bar indicates the rfb locus, and the yellow bar indicates the GI B region. These 3 regions are specifically drawn to the following sketches indicating the variations in strain Lai for properties of possible genomic islands: CG content (B), genome signature (C), codon usage (D), and amino acid usage (E).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1936430&req=5

Figure 3: Comparative analysis of the diverged L. interrogans genomes observed by CGH with respect to their signatures defining genomic islands. (A) The presence/absence CDSs of all tested strains comparing to that of strain Lai ordered from LA0001 to LB367. Red and black areas denote the presence and absence of genes respectively. The blue bar indicates the GI A region, the grey bar indicates the rfb locus, and the yellow bar indicates the GI B region. These 3 regions are specifically drawn to the following sketches indicating the variations in strain Lai for properties of possible genomic islands: CG content (B), genome signature (C), codon usage (D), and amino acid usage (E).
Mentions: Three regions with large sets of missing CDSs detected by CGH in the 11 L. interrogans strains presented some characteristics of laterally transferred genomic elements. Besides the rfb gene cluster, the GC content, genome signature, as well as the codon and amino acid usage bias of the other two missing regions were analyzed along with the chromosomal DNA sequence of strain Lai (Fig. 3) [21] to verify their GI characteristics.

Bottom Line: Because genes encoding proteins with potential pathogenic functions are located within GIs, these elements might contribute to the variations in disease manifestation.Differences in genes involved in O-antigen biosynthesis were also identified for strains belonging to different serogroups, which offers an opportunity for future development of genomic typing tools for serological classification.The strain-specific genes detected via this work will provide a knowledge base for further investigating the pathogenesis of L interrogans and/or for the development of effective vaccines and/or diagnostic tools.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Microbiology and Parasitology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. hpatsh@sjtu.edu.cn

ABSTRACT

Background: Leptospirosis is a world-widely distributed zoonosis. Humans become infected via exposure to pathogenic Leptospira spp. from contaminated water or soil. The availability of genomic sequences of Leptospira interrogans serovar Lai and serovar Copenhageni opened up opportunities to identify genetic diversity among different pathogenic strains of L. interrogans representing various kinds of serotypes (serogroups and serovars).

Results: Comparative genomic hybridization (CGH) analysis was used to compare the gene content of L. interrogans serovar Lai strain Lai with that of other 10 L. interrogans strains prevailed in China and one identified from Brazil using a microarray spotted with 3,528 protein coding sequences (CDSs) of strain Lai. The cutoff ratio of sample/reference (S/R) hybridization for detecting the absence of genes from one tested strain was set by comparing the ratio of S/R hybridization and the in silico sequence similarities of strain Lai and serovar Copenhageni strain Fiocruz L1-130. Among the 11 strains tested, 275 CDSs were found absent from at least one strain. The common backbone of the L. interrogans genome was estimated to contain about 2,917 CDSs. The genes encoding fundamental cellular functions such as translation, energy production and conversion were conserved. While strain-specific genes include those that encode proteins related to either cell surface structures or carbohydrate transport and metabolism. We also found two genomic islands (GIs) in strain Lai containing genes divergently absent in other strains. Because genes encoding proteins with potential pathogenic functions are located within GIs, these elements might contribute to the variations in disease manifestation. Differences in genes involved in O-antigen biosynthesis were also identified for strains belonging to different serogroups, which offers an opportunity for future development of genomic typing tools for serological classification.

Conclusion: CGH analyses for pathogenic leptospiral strains prevailed in China against the L. interrogans serovar Lai strain Lai CDS-spotted microarrays revealed 2,917 common backbone CDSs and strain specific genes encoding proteins mainly related to cell surface structures and carbohydrated transport/metabolism. Of the 275 CDSs considered absent from at least one of the L. interrogans strains tested, most of them were clustered in the rfb gene cluster and two putative genomic islands (GI A and B) in strain Lai. The strain-specific genes detected via this work will provide a knowledge base for further investigating the pathogenesis of L interrogans and/or for the development of effective vaccines and/or diagnostic tools.

Show MeSH
Related in: MedlinePlus