Development of multilocus single strand conformation polymorphism (MLSSCP) analysis of virulence genes of Listeria monocytogenes and comparison with existing DNA typing methods

Takahashi, Hiroki; Handa-Miya, Satoko; Kimura, Bon; Sato, Miki; Yokoi, Asami; Goto, Seitaro; Watanabe, Itaru; Koda, Takashi; Hisa, Kazuo; Fujii, Takeshi

doi:10.1016/j.ijfoodmicro.2007.07.047

Cited by 11 publications

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“…monocytogenes isolates were tested in this study, including 95 food and 21 listeriosis case isolates from Japan, and 42 clinical isolates from other countries, mainly the United States ( S1 Table ). The Japanese food isolates comprised of 61 RTE seafood isolates [ 19 – 21 ], 32 meat isolates (including 10 isolates from imported meat) [ 20 , 22 ], and 2 cutting board isolates. The Japanese clinical isolates had been collected by the Japanese National Institute of Health Sciences (NIHS isolates).…”

Section: Methodsmentioning

confidence: 99%

Genetic Characteristics of Japanese Clinical Listeria monocytogenes Isolates

et al. 2015

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Listeria monocytogenes causes foodborne illnesses through consumption of ready-to-eat foods. Although 135-201annual listeriosis cases have been estimated in Japan, the details regarding the clinical isolates such as infection source, virulence level, and other genetic characteristics, are not known. In order to uncover the trends of listeriosis in Japan and use the knowledge for prevention measures to be taken, the genetic characteristics of the past human clinical isolates needs to be elucidated. For this purpose, multilocus tandem-repeat sequence analysis (MLTSA) and multi-virulence-locus sequence typing (MVLST) were used in this study. The clinical isolates showed a variety of genetically distant genotypes, indicating they were from sporadic cases. However, the MVLST profiles of 7 clinical isolates were identical to those of epidemic clone (EC) I isolates, which have caused several serious outbreaks in other countries, suggesting the possibility that they have strong virulence potential and originated from a single outbreak. Moreover, 6 Japanese food isolates shared their genotypes with ECI isolates, indicating that there may be risks for listeriosis outbreak in Japan. This is the first investigational study on genetic characteristics of Japanese listeriosis isolates. The listeriosis cases happened in the past are presumably sporadic, but it is still possible that some isolates with strong virulence potential have caused listeriosis outbreaks, and future listeriosis risks also exist.

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Section: Methodsmentioning

confidence: 99%

Genetic Characteristics of Japanese Clinical Listeria monocytogenes Isolates

et al. 2015

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“…In addition, four InlA-truncated strains (Lma13, Lma15, Lma20, and Lma28) isolated from raw meat products were sequenced by Sanger sequencing for reference [29]. …”

Section: Methodsmentioning

confidence: 99%

Comparison of the major virulence-related genes of Listeria monocytogenes in Internalin A truncated strain 36-25-1 and a clinical wild-type strain

et al. 2014

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BackgroundInternalin A (InlA) facilitates the invasion of Listeria monocytogenes into a host cell. Some strains of Listeria monocytogenes express truncated forms of InlA, which reduces invasiveness. However, few virulence-related genes other than inlA have been analyzed in InlA-truncated strains. In the present study, we sequenced the draft genome of strain 36-25-1, an InlA-truncated strain, with pyrosequencing and compared 36 major virulence-related genes in this strain and a clinical wild-type strain.ResultsStrain 36-25-1 possessed all of the virulence-related genes analyzed. Of the analyzed genes, only 4 genes (dltA, gtcA, iap, and inlA) differed when the nucleotide sequences of strain 36-25-1 and the clinical wild-type strain were compared. Analysis of the deduced amino acid sequences found no mutations that significantly influenced virulence in genes other than inlA.ConclusionsThe virulence-associated genes in strain 36-25-1 differ little from those of the clinical wild-type strain, indicating that a slight mutation in the nucleotide sequence determines the virulence of the InlA-truncated strain. In addition, the results suggest that, aside from InlA-mediated cell invasiveness, there is almost no difference between the virulence of strain 36-25-1 and that of the clinical wild-type strain.

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“…Strains F2-382 and NIHS-28 were cultured overnight in brain-heart infusion broth (Eiken Chemical, Tochigi, Japan) at 37°C. Bacterial DNA was extracted using the phenol-chloroform extraction and ethanol precipitation methods [ 43 , 44 ]. For whole-genome shotgun sequencing, the GS Junior platform (Roche, Basel, Switzerland) was employed using a GS Junior Rapid Library Preparation Kit and a GS Junior emPCR Kit (Lib-L; Roche), according to the manufacturer’s protocol.…”

Section: Methodsmentioning

confidence: 99%

Genetic distance in the whole-genome perspective on Listeria monocytogenes strains F2-382 and NIHS-28 that show similar subtyping results

et al. 2014

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BackgroundGenome subtyping approaches could provide useful epidemiological information regarding food pathogens. However, the full genomic diversity of strains that show similar subtyping results has not yet been completely explored. Most subtyping methods are based on the differences of only a portion of the genome. We investigated two draft genome sequences of Listeria monocytogenes strain F2-382 and NIHS-28, which have been identified as closely related strains by subtyping (identical multi-virulence-locus sequence typing and multiple-locus variable number tandem repeat analysis sequence types and very similar pulsed-field gel electrophoresis patterns), despite their different sources.ResultsTwo closely related strains were compared by genome structure analysis, recombination analysis, and single nucleotide polymorphism (SNP) analysis. Both genome structure analysis and recombination analysis showed that these two strains are more closely related than other strains, from a whole-genome perspective. However, the analysis of SNPs indicated that the two strains differ at the single nucleotide level.ConclusionWe show the relationship between the results of genome subtyping and whole-genome sequencing. It appears that the relationships among strains indicated by genome subtyping methods are in accord with the relationships indicated by whole-genome analysis. However, our results also indicate that the genetic distance between the closely related strains is greater than that between clonal strains. Our results demonstrate that subtyping methods using a part of the genome are reliable in assessing the genetic distance of the strains. Furthermore, the genetic differences in the same subtype strains may provide useful information to distinguish the bacterial strains.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-014-0309-0) contains supplementary material, which is available to authorized users.

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Development of multilocus single strand conformation polymorphism (MLSSCP) analysis of virulence genes of Listeria monocytogenes and comparison with existing DNA typing methods

Cited by 11 publications

References 56 publications

Genetic Characteristics of Japanese Clinical Listeria monocytogenes Isolates

Genetic Characteristics of Japanese Clinical Listeria monocytogenes Isolates

Comparison of the major virulence-related genes of Listeria monocytogenes in Internalin A truncated strain 36-25-1 and a clinical wild-type strain

Genetic distance in the whole-genome perspective on Listeria monocytogenes strains F2-382 and NIHS-28 that show similar subtyping results

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