Thus, three novel alleles were identified: purE70, which consisted of a synonymous substitution, SIS3 molecular weight purE110, which MG-132 cell line contained one synonymous and one non-synonymous substitution, as compared with the purE5 allele present in most of the Typhimurium strains reported; and sucA144 which consisted of a synonymous substitution, as compared with the predominant sucA9 allele. ST19 is the predominant Typhimurium genotype in the MLST database (227 out of 391 Typhimurium entries) and has a worldwide distribution (24 countries, representing all continents). STs 213 and 429 have been reported only in

Mexico, while ST302 has been reported in Mexico and Zimbabwe [45]. Despite the limitations of an analysis based on only four substitutions, an eBURST analysis of clonal relatedness among the different STs was consistent with the notion of ST19 as the founder genotype of the clonal complex, with the other three STs linked https://www.selleckchem.com/products/cbl0137-cbl-0137.html to ST19 as single-locus variants [see Additional file 1]. For the remaining 48 isolates we applied a three-gene scheme (see Methods) that allowed us to discriminate among STs (Table 1). The most abundant genotypes, ST213 and ST19, were found in the four geographic

regions and in almost all the sampled years (Table 1). These genotypes presented a differential distribution among the sources of isolation (Table 2). Interestingly,

ST213 was more prevalent in food-animals than in humans, where ST19 was predominant (59% vs 27%; p = 0.001, OR = 3.9). Table 1 Allelic profiles and sequence types (STs) assigned in the Salmonella MLST database for the Mexican Typhimurium strains.   Multilocus allelic profilea No of isolatesb     ST aroC dnaN hemD hisD purE sucA thrA Sevenb Threeb Total Statesc Years 19 10 7 12 9 5 9 2 24 17 41 YU, MI, SL, Pyruvate dehydrogenase lipoamide kinase isozyme 1 SO 2000–2005 213d 10 7 12 9 70d 9 2 37 31 68 YU, MI, SL, SO 2001–2005 302d 10 7 12 9 110d 9 2 4 0 4 SO 2002–2004 429d 10 7 12 9 5 144d 2 1 0 1 MI 2003 a Allele and ST numbers were those assigned in the Salmonella MLST database [45]. b Number of strains analyzed using the seven-locus or the three-locus scheme (see methods for details). c YU, Yucatán; MI, Michoacán; SL, San Luis Potosí; SO, Sonora. d Novel alleles and sequence types (ST) obtained in this work study. Table 2 Distribution of human and animal strains of STs 19 and 213 harbouring pSTV or pCMY-2.   Number of strains (%) Source ST19 ST213 pSTV pCMY-2 Human 30 (73) 28 (41) 25 (76) 23 (64) Animal 11 (27) 40 (59) 8 (24) 13 (36) Total 41 68 33 36 We found a temporal pattern in which the derived ST213 is replacing the founder ST19 in the four geographic regions (Figure 3). ST19 was predominant in Yucatán and San Luis Potosí in the first period (2000–2001).