striatum strains. The profile of the type strain of C. striatum was different from those of the clinical isolates; differences between the isolates were also observed (see Additional file 5: Figure S1). Multilocus sequence typing Seven genes were determined for most of the strains studied. The 16S rRNA gene was excluded from the exhaustive analysis because of the high conservation between all of the strains studied; it was only used as a control to check the authenticity of the strains. Clinical isolates 16 and 17, characterised by
phenotypical methods as C. pseudodiphtheriticum, were affiliated with the C. striatum species as determined by molecular methods. The ermX, aphA and sodA genes were also excluded from the analysis because of the high conservation between all strains. The ITS1, gyrA and rpoB genes were used to discriminate between strains, MM-102 clinical trial although the genes differed at few nucleotide changes within the sequences. The sequence analysis of ITS1 demonstrated the presence of more than one rrn operon in most of the strains, which was not appreciable in the agarose gel as a double band but was detectable in the sequence electropherogram. The presence of more than one operon was checked by cloning of four PCR products (data not shown). Analysis of the gyrA and rpoB genes revealed that the variability
between different Corynebacterium species occurred throughout the gene, while the variability in the clinical C. striatum isolates was confined MK-0457 datasheet to certain areas near the beginning of the gene. Distinct allele sequences were assigned arbitrary allele numbers for each locus (Table 1). Calculated allele and nucleotide diversities are shown in Table 2. The number of
polymorphic sites and the haplotype and nucleotide diversity were not calculated for the ITS1 region because, in most cases, more than one operon was detected. 16S rDNA, ermX, aphA, sodA and hsp65 were not appropriate genes for studying the genetic diversity of the strains, although these genes could be used to differentiate between Corynebacterium species. gyrA and rpoB were appropriate genes to check details study genetic diversity, with 116 and 39 polymorphic sites, respectively. In the ITS1 region, the most abundant BVD-523 ic50 alleles were 4 (23.2%), 6 (19.6%), 7 (12.5%), 3 (10.7%), and alleles 1 and 2 (7.1%). Each one of the other alleles for ITS1, representing 19.6% of the population, is represented by a single strain. For the gyrA gene, two alleles (number 2 and 3) were predominant (90%). For the rpoB gene, allele 2 is the most abundant and is found in 39 strains (69.6%). Considering these three genes, four STs were the most abundant: ST2, ST4, ST1 and ST11, occurring in 11, 10, 6 and 6 strains, respectively. Table 1 STs at the eight loci examined in the C. striatum and C.