Primer pairs were designed U0126 molecular weight to target these genes and PCR were performed. Analyzing the PCR products, we excluded primer pairs that could generate false-positive results in strains belonging to other serogroups and selected primer pairs that could discriminate as many strains belonging to the serogroups to be tested as possible. The primer pairs listed in Table 1 were our final selections. As shown in Fig. 1, DNA from strains belonging to the corresponding serogroups were able to produce PCR products of the expected size, but
no PCR products were obtained
from strains belonging to all other serogroups. The results of 75 reference strains are listed in additional file 1 Table S1. We also tested the specificity of six primer pairs using 40 clinically isolated strains; the results are listed in additional file 2 Table S2. All strains belonging to the six serogroups gave PCR products of the expected size with the exception of four reference strains (M49, H18, 34 and A81) belonging to the serogroup Sejroe. We speculate that the O-antigen gene clusters of these strains have been undertaken a process of recombination, where target genes may lose through recombination events. Since a few sequences of O-antigen Tariquidar gene clusters from
Leptospira are available, only six serogroups of strains have been discriminated so far. There are also six strains cannot be discriminated by both MAT and O-genotyping in clinical isolates. We proposed that they are from other serogroups which beyond the field we can characterize. Figure 1 Analysis of amplification products by electrophoresis. Clostridium perfringens alpha toxin Amplification products obtained by PCR of DNA pools from 18 serogroups belonging to Leptospira and DNA of two non-Leptospira strains using primer pairs ict-F/R (a), can-F/R (b), aut-F/R (c), gri-F/R (d). heb-F/R (e), sej-F/R (f). 1: Icterohaemorrhagiae; 2: Javanica; 3: Canicola; 4: Ballum; 5: Pyrogenes; 6: Autumnalis; 7: Australis; 8: Pomona; 9: Grippotyphosa; 10: Hebdomadis; 11: Bataviae; 12: Tarassovi; 13: selleck screening library Manhao; 14: Sejroe; 15: Mini; 16: Celledoni; 17: Ranarum; 18: Sarmin; 19: S. enteritidis H9812; 20: S. aureus N315; M: DNA marker, bands with lengths of 10 kb, 8 kb, 5 kb, 2 kb 1000 bp, 700 bp, 500 bp, 400 bp, 300 bp, 200 bp and 100 bp, respectively.