The pathogen can cause serious diseases, such as septicemia and meningitis, especially in high-risk groups (pregnant women, neonates, and immunocompromised people) with
a high mortality rate of 20–30% [1]. L. monocytogenes is ubiquitous in nature; it can survive under conditions of high salt and low pH. Because, it can grow even at low temperatures, the bacterium can be found in many kinds of foods during storage [2]. In particular, ready-to-eat (RTE) foods, which do not require heat cooking, are a main source of foodborne listeriosis cases [3–5]. Internalin A (InlA) plays an important role in L. monocytogenes invasion by attaching to host cells [6–9]. However, some L. monocytogenes strains express a truncated form of InlA, which GSK1838705A in vitro lowers the invasion rate [10–14]. Truncated InlA, caused by a premature stop codon (PMSC) in inlA, often lacks the LPXTG motif that anchors InlA to the surface of the pathogen, leading
to a decrease in invasiveness [12, 13]. Some reports have shown that find more InlA-truncated strains account for 35–45% of L. monocytogenes in RTE foods [15, 16]. However, aside from invasiveness, the virulence www.selleckchem.com/products/Cyclosporin-A(Cyclosporine-A).html of these mutated strains has not been studied. Our previous study showed that an InlA-truncated strain had wild-type PrfA, which regulates the expression of virulence related genes Farnesyltransferase [11]. On the other hand, Tèmoin et al. (2008) reported that all of 5 InlA-truncated strains analyzed had the same amino acid sequence mutations in the migration factor plcA and the invasion factor inlB[17]. However, approximately 50 genes are related to the L. monocytogenes infection cycle [18], and most of them have not been investigated in strains with truncated InlA. A small number of studies have investigated virulence-related genes in InlA-truncated strains
[11, 17]; the studies do not completely explain the virulence of the strains. This study aimed to identify the major virulence-related gene sequences present in InlA-truncated strains. In recent years, the analysis of bacterial whole genomes has become faster and easier with the development of next-generation sequencing methods such as pyrosequencing. In this study, we used pyrosequencing to construct a draft sequence of strain 36-25-1, and we compared 36 main virulence-related genes in the InlA-truncated strain and a clinical wild-type strain. Results Presence of virulence-related genes After de novo assembly of the reads for strain 36-25-1, the total contig length was 2,957,538 bp with a peak depth of 11.0. The contigs aligned to 2,861,194 bp of the EGDe whole genome sequence, and showed 99.84% identity (Table 1).