title: Prevalence of Listeria monocytogenes in retailed meat in the Tokyo metropolitan area.
abstract: This study was conducted to determine the prevalence of Listeria monocytogenes in retailed meats, comprising beef, chicken, and pork, in the Tokyo metropolitan area. A total of 379 samples of retailed meat were collected from 1998 to 2003, most of which were obtained by simultaneously purchasing the three classes of meat from a shop and then making another simultaneous purchase of meat from the same shop a few weeks later. The prevalence of L. monocytogenes was 28.0%, and the serotypes isolated were mainly 1/2a, 1/2b, 1/2c, and 4b. Comparison of the prevalence of each serotype among the classes of meat showed a predominant distribution of serotypes 1/2a, 1/2b, and 4b in chicken, while serotype 1/2c was dominant in pork. A total of nine cases considered to be due to persistence and/or cross-contamination were found. Most of the strains involved in persistence and/or cross-contamination were of serotypes 1/2c or 4b. These results suggest that contamination in retailed meat in Japan is at almost the same level as in other countries and that chicken has the highest potential as a source of contamination and infection. In addition, we suggest that the ecological niche of serotype 1/2c is distinct from those of 1/2a, 1/2b, and 4b, which may explain why human hosts have less opportunity to be exposed to serotype 1/2c and why there is a lower rate of isolation of this serotype from cases of human listeriosis.
authors.affiliation: Department of Veterinary Science, Nippon Veterinary and Life Sciences University, Musashino, Tokyo, Japan. yochiai@nvlu.ac.jp
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Ochiai
authors.forename: Fumiya
authors.initials: F
authors.lastname: Yamada
authors.forename: Otgonchimeg
authors.initials: O
authors.lastname: Batmunkh
authors.forename: Mariko
authors.initials: M
authors.lastname: Mochizuki
authors.forename: Takashi
authors.initials: T
authors.lastname: Takano
authors.forename: Ryo
authors.initials: R
authors.lastname: Hondo
authors.forename: Fukiko
authors.initials: F
authors.lastname: Ueda
mesh_terms: D000818:Animals; D002417:Cattle; D002645:Chickens; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008089:Listeria monocytogenes / Q000145:classification / Q000302:isolation & purification*; D008460:Meat / Q000382:microbiology*; D015995:Prevalence; D012703:Serotyping; D013045:Species Specificity; D013552:Swine