학교식당 및 교실배식 과정 전·후 미생물 오염에 관한 연구

Abstract

Objectives: The aim of this study is to investigate microbial contamination in the school food serviceenvironment for the assessment of microbial food safety. Methods: We collected both swab samples from tables and desks and airborne bacterial samples from anelementary school (School A) and a high school (School B). Heterotrophic plate count, total coliform,Staphylococcus aureus, and Bacillus cereus were measured with selective media to quantify microbialconcentration. PCR assay targeting 16S rRNA genes was performed to identify the strains of S. aureus and B. cereus isolated. In addition, we made a food service checklist for the locations to evaluate the food serviceenvironment. A Wilcoxon test was employed to examine the differences in microbial concentration betweenbefore lunchtime and afterwards. Results: Heterotrophic plate counts showed higher levels after-lunch compared to before-lunch at School B. However, levels of S. aureus were higher in the after-lunch period (p<0.05) in both classrooms and in thecafeteria in School A. B. cereus was only sparsely detected in School B. Several samples from food dining cartswere found to be contaminated with bacteria, and facilities associated with food delivery were found to bevulnerable to bacterial contamination. Although microbial concentrations in the air showed little differencebetween before- and after-lunchtime in the cafeteria in School A, those in classrooms were greater afterlunchtimeat both schools. Conclusion: Our results suggested that the microbial safety in schools after lunchtime of concern. Necessarypreventive measures such as hygiene education for students and food handlers should be required to minimizemicrobial contamination during food service processes in schools.