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

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.

A retrospective study of SARS-CoV-2 antibodies in children with allergies.

BACKGROUND: The dynamics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children are continually changing. We conducted a survey of pediatric allergy patients attending our department to determine the prevalence of antibodies against SARS-CoV-2 in children. METHODS: A retrospective study was performed among children aged <11 years, referred to a pediatric allergy department between February 2020 and January 2022 with a chief complaint of allergy. The data of children with blood examination findings were retrospectively studied. Qualitative testing for anti-SARS-CoV-2 IgG and IgM antibodies was performed using a SARS-CoV-2 rapid antibody test. Participants were retested 1 year later to evaluate changes in antibody levels. RESULTS: In total, 310 patients with a median age of 26 months (interquartile range: 11.6-58.4 months) and male/female ratio of 1.31 were included. A total of 32 patients tested positive for anti-SARS-CoV-2 IgG or IgM antibodies. No differences were observed in the severity of allergic disease. The prevalence of antibodies was higher among children enrolled in preschool or school (odds ratio: 13.19, 95% confidence interval; 2.30-249.7). A total of 66.7% of patients underwent follow-up testing. The antibody positivity rate increased between the first and second testing, but this was not related to the number of medical visits or the severity of allergic disease. CONCLUSION: Antibody prevalence in children was low but increased during the study period. The majority of children who tested positive for SARS-CoV-2 antibodies did not have a history of coronavirus disease 2019, suggesting that most infections were subclinical.