The consumption of ready-to-eat side dishes is rapidly growing in South Korea. These foods are particularly vulnerable to microbiological contamination as they are often cooked without any treatment, such as heating or stored at room temperature after cooking. Hence, in 2022, we analyzed the ready-to-eat side dishes sold in Gyeongsangnam-do, South Korea for microbiological contamination. We collected 100 samples from supermarkets in 7 cities, and then examined them for presence of food-borne pathogens and sanitary indicator bacteria. In the analysis of the food-borne pathogens, Bacillus cereus and Clostridium perfringens were isolated from 51 samples (51.0%) and 3 samples (3.0%), respectively. However, both quantitatively met the Korean Food Standards Codex. Genes of five different enterotoxins and one emetic toxin were analyzed from the 51 isolated B. cereus strains. We detected enterotoxin entFM (100.0%), nheA (94.1%), hblC (58.8%), cytK (56.9%), and bceT (41.2%) in 51 isolates, and emetic toxin gene, CER, in only one (2.0%) isolate. We did not detect C. perfringens toxin gene (cpe) that causes food poisoning in any one of the three C. perfringens isolates. In the case of sanitary indicator bacteria, Kimchi had the highest levels of total aerobic bacteria and coliforms, followed by Saengchae, Jeotgal, Jeolim, Namul, and Jorim, respectively. We counted total aerobic bacteria at two different storage temperatures (4oC and 20oC) to determine the effect of storage temperature. When stored at 20oC, total aerobic bacteria count increased in most of the ready-to-eat side dishes, except for Jeotgal. This result conclusively shows the need for refrigerating the ready-to-eat side dishes after purchase. Further research is needed to assess the risk and safety of the ready-to-eat side dishes available in the market and determine appropriate safety management practices.

ABSTRACT
Materials and Methods
    시료
    식중독 원인균 분석
    식중독 원인균 독소 유전자 분석
    위생지표균 분석
    보관방법에 따른 일반세균의 정량 및 통계 분석
Results and Discussion
    식중독균 오염도 현황
    B. cereus와 C. perfringens의 독소 유전자 분포
    위생지표균 오염도 현황
    보관방법에 따른 일반세균수 변화
국문요약
Conflict of interests
ORCID
References

• 엄지연(경상남도보건환경연구원 식중독검사팀) | Ji-Yeon Um (Gyeongsangnam-do Provincial Government Health & Environment Institute, Jinju, Korea)
• 장혜정(경상남도보건환경연구원 식중독검사팀) | Hye-Jeong Jang (Gyeongsangnam-do Provincial Government Health & Environment Institute, Jinju, Korea)
• 최연주(경상남도보건환경연구원 식중독검사팀) | Yeon-Ju Choi (Gyeongsangnam-do Provincial Government Health & Environment Institute, Jinju, Korea)
• 김소영(경상남도보건환경연구원 식중독검사팀) | So-Young Kim (Gyeongsangnam-do Provincial Government Health & Environment Institute, Jinju, Korea)
• 조아름(경상남도보건환경연구원 식중독검사팀) | Areum Jo (Gyeongsangnam-do Provincial Government Health & Environment Institute, Jinju, Korea)
• 김민영(경상남도보건환경연구원 식중독검사팀) | Min Young Kim (Gyeongsangnam-do Provincial Government Health & Environment Institute, Jinju, Korea)
• 안지희(경상남도보건환경연구원 식중독검사팀) | Jihee Ahn (Gyeongsangnam-do Provincial Government Health & Environment Institute, Jinju, Korea) Corresponding author
• 김제동(경상남도보건환경연구원 식중독검사팀) | Jea-Dong Kim (Gyeongsangnam-do Provincial Government Health & Environment Institute, Jinju, Korea)