Sequence-Based Characterization of Listeria monocytogenes Strains Isolated from Domestic Retail Meat in the Tokyo Metropolitan Area of Japan

Japanese journal of infectious diseases

Yoshitsugu Ochiai¹  Yuko Yoshikawa² 

[1] Department of Applied Science, School of Veterinary Nursing and Technology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University;Laboratory of Veterinary Public Health, School of Veterinary Medicine, Nippon Veterinary and Life Science University

关键词: Listeria monocytogenes;    iap;    sigB;    actA;    subtyping;   

DOI  :  10.7883/yoken.JJID.2017.582

学科分类：传染病学

来源: National Institute of Infectious Diseases

【 摘 要 】

The level of Listeria monocytogenes contamination of domestic retail meat in Tokyo, Japan, was assessed by comparison of isolates from 2004 to 2007 with those isolated before 2003. The overall prevalence of L. monocytogenes among these samples significantly diminished over time (1998–2003, 28.0%; 2004–2007, 17.6%) reflecting a significant decrease in the frequency of contamination of beef. Serotype 1/2a was isolated most frequently, reflecting a change in the predominant serotype in pork from 1/2c to 1/2a. We performed a simple genetic subtyping method based on 3 genes, iap, sigB, and actA, as well as traditional multilocus sequence typing to classify the allele types (ATs). No extensive variation among sequence types was detected. However, increased genetic diversity among the ATs of the 3 genes in the 2004–2007 isolates was evident. We identified AT 26 of the iap gene, which was not previously reported in Japanese isolates, and 6 ATs of the sigB gene, including 4 with nonsense mutations not currently registered in L. monocytogenes DNA databases. sigB is an evolutionally conserved gene that plays a role in the stress response. Our results indicate that the sigB gene may be relatively unstable among L. monocytogenes strains circulating in Japan.

【 授权许可】

Unknown