title: Prevalence and characteristics of Listeria monocytogenes in bovine colostrum in Japan.
abstract: This study was conducted to determine the prevalence and characteristics of Listeria monocytogenes in bovine colostrum in Japan. We collected bovine colostrum samples from 210 dams from 21 dairy farms in Hokkaido prefecture (Japan) between March and June 2009. L. monocytogenes  was detected in samples from 6 (28.6%) of the 21 farms. Of the 210 samples, 16 (7.6%) were positive for L. monocytogenes. We recovered 80 L. monocytogenes isolates; 44 (55%) isolates were classified as serotype 1/2b and 36 (45%) were classified as serotype 4b. The isolates were  susceptible to penicillin, ampicillin, amoxicillin, gentamicin, kanamycin, streptomycin, erythromycin, vancomycin, tetracycline, chloramphenicol, ciprofloxacin, and trimethoprim-sulfamethoxazole. Pulsed-field gel electrophoresis (PFGE) characterization of the 80 isolates revealed six PFGE  types. Two PFGE types corresponded to human listeriosis cases. Most L. monocytogenes isolates possessed virulence-associated genes (actA, hly, iap, inlA, inlC, mpl, plcA, plcB, opuCA, prfA, and clpC). One PFGE type isolate possessed an epidemic clone II marker. Our findings  suggest that isolates from bovine colostrum have the potential to cause human and animal listeriosis. This is the first study on the prevalence and characteristics of L. monocytogenes isolated from bovine colostrum obtained from dairy farms. Our results have important implications for  improving public health and elucidating the epidemiology of L. monocytogenes in bovine colostrum.
authors: Department of Nutrition, School of Nursing and Nutrition, Tenshi College, Higashi-ku, Sapporo, Hokkaido 065-0013, Japan. hasegawa@tenshi.ac.jp
authors: Megumi
authors: M
authors: Hasegawa
authors: Eriko
authors: E
authors: Iwabuchi
authors: Shiori
authors: S
authors: Yamamoto
authors: Hidetake
authors: H
authors: Esaki
authors: Kazuhiko
authors: K
authors: Kobayashi
authors: Masahiko
authors: M
authors: Ito
authors: Katsuya
authors: K
authors: Hirai
mesh_terms: D000818:Animals; D002417:Cattle; D003126:Colostrum / Q000382:microbiology*; D003257:Consumer Product Safety; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005516:Food Microbiology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008089:Listeria monocytogenes / Q000145:classification / Q000302:isolation & purification*; D015995:Prevalence; D012703:Serotyping