CRISPR sequence analysis is one of the cheaper and faster methods for Salmonella subtyping [22]. For the majority of isolates analyzed, CRISPR-MVLST could be completed in less than 24 hours, including DNA isolation and analysis. Additionally, by virtue of their nature, sequencing data are more robust and tractable; this type of data is unequivocal and, with regards to inter-laboratory

or database use, is highly consistent. They also provide increased downstream utilities that involve analysis of sequence information, such as phylogenetic https://www.selleckchem.com/products/kpt-330.html studies. This approach is also in line with other high-throughput subtyping approaches, including real-time CRISPR analysis [32] and whole genome sequence analysis [43–47]. Conversely, although protocols exist that allow PFGE to be completed in 24 hours, it can often take 1–3 days, requires skilled personnel, inter-laboratory data analysis can be challenging and the data have no utility beyond subtyping. Given the advancement of whole-genome sequencing technologies, typing methods based on these are in development [48]. While highly discriminatory, limitations to this

approach that are not issues with either CRISPR-MVLST or PFGE LXH254 manufacturer include the time required for analysis and space learn more required for data storage. CRISPR spacer analysis alone has been used to analyze several different Salmonella serovars [32]. Fabre and colleagues showed that among 50 isolates of S. Typhimurium and its I,4, [5],12:i- variant, combined CRISPR1 and CRISPR2 sequence information is comparable to PFGE (D = 0.88

and 0.87, respectively). Both methods were more discriminatory than phage typing analysis of the same set of isolates. The same study also analyzed spacer content of S. Typhimurium and S. Enteritidis from 10 outbreaks and in all cases CRISPR sequences exhibited high epidemiologic concordance. A preliminary investigation showed that addition of CRISPR spacer analysis to an MVLST scheme Astemizole improves discrimination, beyond that provided by either approach independently, in eight out of nine of the most common illness-causing Salmonella serovars [33]. We wanted to extend our evaluation of CRISPR-MVLST utility among predominant and clinically relevant Salmonella serovars. To date we have tested and compared CRISPR-MVLST to PFGE on large numbers of S. Enteritidis [34], S. Newport [41]S, Heidelberg and S. Typhimurium isolates. Among the total 175 isolates analyzed here, we found significantly fewer alleles of fimH and sseL, compared to alleles of either CRISPR locus (Table 2; Figure 2). Given the reduced contribution of the virulence genes to defining STs, their addition may seem superfluous within this subtyping scheme. However, in this data set, fimH alleles define two STs, HST13 and TST20 and sseL alleles define five STs, TST16, TST19, TST23, TST29 and TST36.