Submitted to: International Leptospirosis Society Meeting Abstracts and Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/28/2002
Publication Date: 11/28/2002
Citation: Victoria, B., Zuerner, R.L., Hartskeerl, R.A. 2002. The s10-spc-alpha operon is highly conserved among l. interrogans sensu stricto [abstract]. International Leptospirosis Society Meeting Abstracts and Proceedings. pg. 75.
Technical Abstract: The diagnostic primer pair G1/G2 amplifies part of the secY gene. Previously, it was shown that secY of Leptospira interrogans sensu stricto, serovar lai, is located within the S10-spc-alpha operon coding for ribosomal proteins. It appeared that this gene cluster is unique among other bacteria and shows a number of rearrangements with the other spirochaetes Borrelia burdorferi and Treponema pallidum. Analogous to the conclusions based on 16S rRNA sequences, the structure of the Leptospira S10-spc-a gene cluster revealed that spirochaetes form a diverse branch in eubacterial evolution with Leptospira forming its deepest node. This study was performed to investigate whether the S10-spc-alpha operon is well conserved among various pathogenic Leptospira species. As a start of the study, we investigated five strains of Leptospira interrogans sensu stricto (serovars copenhageni, icterohaemorrhagie, canicola, pomona, and hardjo) in addition to serovar lai that served as a reference and representative strains of some other pathogenic species, including L. borgptersenii. Eighteen sets of primers were used to amplify by PCR different DNA fragments covering the whole S10-spc-alpha operon. The conserved nature of the cluster was deduced from the sizes of the various amplicons as analyzed by agarose gel electrophoresis. Similarly sized fragments were obtained from all the strains of L interrogans sensu stricto for each of the primer pairs. However, different fragment sizes or no amplification were found for the strains from other species. The S10-spc-alpha operon is highly conserved among L. interrogans sensu stricto. This operon may be less conserved among other Leptospira species. Absence of amplification or generation of differently size fragments from the other Leptospira species can be due to: (1) a lower percentage of sequence identity between distinct species or/and (2) structural differences of the Leptospira S10-spc-alpha gene cluster due for example to gene rearrangements.