Escherichia coli O26 detection from foods using an enrichment procedure and an immunomagnetic separation method.
We found effective enrichment procedures for detecting Escherichia coli O26 in foods using methods that are used for E. coli O157. Ground beef or radish sprouts inoculated with approximately 6 colony-forming units of E. coli O26 were homogenized in 225 ml of various broths. After static incubation at 37 degrees C or 42 degrees C for 6 h or 18 h, we isolated the inoculated bacterium by plating onto Rainbow Agar O157 with novobiocin. In combination with the immunomagnetic separation method, E. coli O26 was isolated from all samples by using enrichment in tryptone soy broth at 37 degrees C for 6 h and in modified E. coli broth with novobiocin (mEC + n) at 42 degrees C for 18 h in ground beef and radish sprouts, respectively. Enrichment in mEC + n at 42 degrees C for 18 h was effective for isolating both E. coli O26 and E. coli O157 from both ground beef and radish sprouts.
Hara-Kudo
Y
Y
Department of Biomedical Food Research, National Institute of Infectious Diseases,Tokyo, Japan. ykudo@nih.go.jp
Konuma
H
H
Nakagawa
H
H
Kumagai
S
S
D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism; D001431:Bacteriological Techniques; D002417:Cattle; D003470:Culture Media; D004926:Escherichia coli / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D004927:Escherichia coli Infections / Q000382:microbiology; D005516:Food Microbiology; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D008461:Meat Products / Q000382:microbiology; D022622:Shiga Toxin 1; D014675:Vegetables / Q000382:microbiology
D001427:Bacterial Toxins; D003470:Culture Media; D022622:Shiga Toxin 1