Isolation of Shiga Toxin-Producing Escherichia coli from the Surfaces of Beef Carcasses in Slaughterhouses in Japan

• Published in: Journal of food protection Vol. 87; no. 5; p. 100263
• Main Authors: Ikeuchi, Shunsuke, Hirose, Shouhei, Shimada, Kohei, Koyama, Ayako, Ishida, Shoji, Katayama, Naoto, Suzuki, Takehiko, Tokairin, Akiko, Tsukamoto, Mayumi, Tsue, Yuki, Yamaguchi, Kenichi, Osako, Hideo, Hiwatashi, Sachiko, Chiba, Yumi, Akiyama, Hiroshi, Hayashidani, Hideki, Hara-Kudo, Yukiko
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2024; Elsevier
• Subjects: Abattoirs; Aerobic plate count; Animals; Beef carcass; Cattle; Contamination; Food Contamination - analysis; Food Microbiology; Humans; Isolation; Japan; Red Meat - microbiology; Serogroup; Shiga-Toxigenic Escherichia coli - isolation & purification; Slaughterhouse; STEC; Japan; Beef carcass; Isolation; STEC; Aerobic plate count; Contamination; Slaughterhouse
• ISSN: 0362-028X; 1944-9097
• DOI: 10.1016/j.jfp.2024.100263

•STEC O157:H7 was isolated from 0.6% of beef carcasses in Japanese slaughterhouses.•stx-positive E. coli other than STEC O157:H7 was isolated at a rate of 4.6%.•The stx-positive E. coli isolates belonged to the minor O-serogroups.•It is crucial to reduce the STEC contamination of carcasses in slaughterhouses. Shiga toxin-producing E. coli (STEC) is an important foodborne pathogen worldwide. It is necessary to control and prevent STEC contamination on beef carcasses in slaughterhouses because STEC infection is associated with beef consumption. However, the frequencies of STEC contamination of beef carcasses in various slaughterhouses in Japan are not well known. Herein, we investigated the contamination of beef carcasses with STEC in slaughterhouses to assess the potential risks of STEC. In total, 524 gauze samples were collected from the surfaces of beef carcasses at 12 domestic slaughterhouses from November 2020 to February 2023. The samples were measured for aerobic plate counts and tested for pathogenic genes (stx and eae) and major O-serogroups (O26, O45, O103, O111, O121, O145, and O157) by real-time PCR screening. Subsequently, immunomagnetic separation (IMS) was performed on samples positive for stx, eae, and at least one of the seven O-serogroups of STEC. Isolation process without IMS was performed on samples positive for stx, including those subjected to IMS. STEC O157:H7 and stx-positive E. coli other than serotype O157:H7 were isolated from 0.6% and 4.6% of beef carcass surfaces, respectively. Although the STEC O157:H7 isolation rate was low and stx-positive E. coli other than serotype O157:H7 belonged to minor O-serogroups, the results mean a risk of foodborne illness. Furthermore, a moderate correlation was observed between aerobic plate counts and detection rates of stx-positive samples by real-time PCR screening. The STEC O157:H7 isolated facilities showed higher values on aerobic plate counts and detection rates of stx-positive samples than the mean values of total samples. Therefore, these results suggest that it is important to evaluate hygiene treatments against beef carcasses for the reduction of STEC contamination risk, particularly in facilities with high aerobic plate counts.