Journal of the Korean Society of Food Science and Nutrition (한국식품영양과학회지)

The Korean Society of Food Science and Nutrition (한국식품영양과학회)
권호 표지
DOI QR코드

DOI QR Code

Analysis of Foodborne Pathogens in Food and Environmental Samples from Foodservice Establishments at Schools in Gyeonggi Province

경기지역 학교 단체급식소 식품 및 환경 중 식중독균 분석

  • Oh, Tae Young (Food Safety Research Group, Korea Food Research Institute) ;
  • Baek, Seung-Youb (Food Safety Research Group, Korea Food Research Institute) ;
  • Koo, Minseon (Food Safety Research Group, Korea Food Research Institute) ;
  • Lee, Jong-Kyung (Department of Food and Nutrition, Hanyang Women's University) ;
  • Kim, Seung Min (Food Safety Research Group, Korea Food Research Institute) ;
  • Park, Kyung-Min (Department of Food Biotechnology, University of Science and Technology) ;
  • Hwang, Daekeun (Department of Food Biotechnology, University of Science and Technology) ;
  • Kim, Hyun Jung (Food Safety Research Group, Korea Food Research Institute)
  • Received : 2015.09.24
  • Accepted : 2015.11.12
  • Published : 2015.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Foodborne illness associated with food service establishments is an important food safety issue in Korea. In this study, foodborne pathogens (Bacillus cereus, Clostridium perfringens, Escherichia coli, pathogenic Escherichia coli, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Vibrio parahaemolyticus) and hygiene indicator organisms [total viable cell counts (TVC), coliforms] were analyzed for food and environmental samples from foodservice establishments at schools in Gyeonggi province. Virulence factors and antimicrobial resistance of detected foodborne pathogens were also characterized. A total of 179 samples, including food (n=66), utensil (n=68), and environmental samples (n=45), were collected from eight food service establishments at schools in Gyeonggi province. Average contamination levels of TVC for foods (including raw materials) and environmental samples were 4.7 and 4.0 log CFU/g, respectively. Average contamination levels of coliforms were 2.7 and 4.0 log CFU/g for foods and environmental swab samples, respectively. B. cereus contamination was detected in food samples with an average of 2.1 log CFU/g. E. coli was detected only in raw materials, and S. aureus was positive in raw materials as well as environmental swab samples. Other foodborne pathogens were not detected in all samples. The entire B. cereus isolates possessed at least one of the diarrheal toxin genes (hblACD, nheABC, entFM, and cytK enterotoxin gene). However, ces gene encoding emetic toxin was not detected in B. cereus isolates. S. aureus isolates (n=16) contained at least one or more of the tested enterotoxin genes, except for tst gene. For E. coli and S. aureus, 92.7% and 37.5% of the isolates were susceptible against 16 and 19 antimicrobials, respectively. The analyzed microbial hazards could provide useful information for quantitative microbial risk assessment and food safety management system to control foodborne illness outbreaks in food service establishments.

본 연구에서는 건당 환자수가 높아 식품안전관리 우선순위가 높은 단체급식소의 식품, 조리도구 및 환경에서 식중독균을 분석하고 이들 미생물의 병원성 인자 및 항생제 내성을 확인하여 미생물 위험분석을 위한 기본정보를 제공하고자 하였다. 경기도 소재 총 8개(농촌 3, 도시 4 및 벽지 1) 학교급식소에서 식품 시료(n=66), 조리도구(n=44) 및 환경 시료(n=56) 등 총 179점의 시료를 채취하여 지표세균 및 식중독균을 분석하였다. 식품 시료에서 총균수는 평균 4.7 log CFU/g, 최대 8.1 log CFU/g으로 대장균군의 평균 오염도 3.1 log CFU/g, 최대 오염도 4.0 log CFU/g으로 높았다. 선반 및 개수대 등 환경 시료의 총균수는 평균 2.7 log CFU/g, 최대 4.1 log CFU/g으로 식품 시료보다 낮은 수준으로 분석되었으나 대장균의 경우 평균 4.0 log CFU/g, 최대 5.4 log CFU/g으로 식품 시료보다 오염 수준이 높아 환경으로 부터의 교차오염 가능성을 배제할 수 없었다. 병원성 미생물 중 Bacillus cereus의 정량분석 결과 식품(원료, 조리단계 및 조리식품 포함) 시료에서 평균 2.1 log CFU/g, 최대 4.1 log CFU/g으로 분석되었으나, 이 중 조리된 식품의 오염도는 10,000 CFU/g 이하로 식품공전의 기준 이하로 오염되어 있었다. Escherichia coli는 식품 중 조리 전 시료(n=14)에서만 검출율 35.7%로 분석되었으며 조리단계의 식품, 조리도구 및 환경 시료에서는 검출되지 않았다. Staphylococcus aureus의 경우 조리 전 식품 원료(n=14)의 21.4%에서 검출되었으며 환경 시료(냉장고 손잡이)에서 1건 양성으로 검출되었고, 조리단계의 식품, 조리도구 및 환경 시료에서는 검출되지 않았다. 그 외 Clostridium perfringens, Listeria monocytogenes, Salmonella spp., Vibrio parahaemolyticus는 분석된 모든 시료에서 모두 음성이었다. 분리된 B. cereus의 독소유전자(hblACD, nheABC, entFM, cytK enterotoxin gene)를 분석한 결과 구토 유발 독소인 ces는 모두 음성이었으나 분석된 86주 모두 적어도 1종 이상의 설사 유발 독소유전자가 검출되었으며 66.2%의 균주는 설사 유발 독소유전자를 모두 보유하고 있었다. 식품과 환경에서 분리한 S. aureus(n=16)의 장독소 생성 유전자를 분석한 결과 모두 1종 이상의 독소유전자가 검출되었다. 전형적인 장독소유전자 중에서는 sea만 검출되었으며, 독소충격증후군 toxin(tst) 유전자는 모든 분리주에서 검출되지 않았다. 집단 식중독 발생 시 초기 진료에 결정적 영향을 주는 항생제 내성 여부를 분석한 결과 E. coli(n=41)의 92.7%는 분석한 항생제 16종에 대해 내성을 보이지 않았고 cefazolin에 대한 내성률이 4.9%로 가장 높았으며, 1개 균주에서만 2개 항생제에 대해 다제내성을 보여 국내외 항생제 내성률보다 낮았다. S. aureus(n=16)는 시험한 19종 항생제 중 gentamicin에 대한 내성률이 62.5%로 가장 높았으며 일부 균주에서 2주 항생제에 대해 다제내성이 관찰되었다. 한편 단체 급식소 2개소의 조리도구와 환경 중 미생물 군집을 분석한 결과 특정균이 도구와 환경에서 중복 검출되어 도구와 환경 중 교차오염 가능성을 간접적으로 시사하였다. 이와 같이 본 연구에서 단체급식소 식품, 조리도구 및 환경 중 위생지표균과 병원성 미생물의 오염패턴을 분석하고 분리된 균주의 독성인자와 항생제 내성 정보를 분석하였다. 관련 정보는 단체급식소 미생물 위험분석과 이를 바탕으로 사전적, 정량적 안전관리 기술 개발에 활용 가능할 것으로 사료된다. 한편 식중독 유발의 다른 원인인 바이러스류와 기타 원인에 대한 연구는 진행되지 않아 추가 연구가 필요하다.

Keywords

References

  1. Shin H, Lee S, Kim JS, Kim J, Han KH. 2010. Socioeconomic costs of food-borne disease using the cost-of-illness model: applying the QALY method. J Prev Med Public Health 43: 352-361. https://doi.org/10.3961/jpmph.2010.43.4.352
  2. Food Safety Korea. Available from: http://www.foodsafetykorea.go.kr/portal/healthyfoodlife/foodPoisoningStat.do?menu_no=519&menu_grp=MENU_GRP02 (accessed Sep 2015).
  3. Beuchat LR. 1996. Listeria monocytogenes incidence on vegetable. Food Control 7: 223-228. https://doi.org/10.1016/S0956-7135(96)00039-4
  4. Heiman KE, Garalde VB, Gronostaj M, Jackson KA, Beam S, Joseph L, Saupe A, Ricotta E, Waechter H, Wellman A, Adams-Cameron M, Ray G, Fields A, Chen Y, Datta A, Burall L, Sabol A, Kucerova Z, Trees E, Metz M, Leblanc P, Lance S, Griffin PM, Tauxe RV, Silk BJ. 2015. Multistate outbreak of listeriosis caused by imported cheese and evidence of cross-contamination of other cheeses, USA, 2012. Epidemiol Infect 30: 1-11.
  5. Hong SH. 2014. The microbiological assessment and identification of food utensils and foodservice facilities in school. J Fd Hyg Safety 29: 189-194. https://doi.org/10.13103/JFHS.2014.29.3.189
  6. Bae HJ. 2006. Analysis of contamination of bacteria from raw materials, utensils, and worker's hands to prepared foods in foodservice operations. J Korean Soc Food Sci Nutr 35: 655-660. https://doi.org/10.3746/jkfn.2006.35.5.655
  7. Lee JK, Kwak NS. 2004. Microbiological risk assessment for food safety control. Food Science and Industry 37: 61-71.
  8. Lee SH. 2011. Quantitative microbial risk assessment. Safe Food 6: 13-16.
  9. Kim HJ, Kim SM, Ok G, Koo M. 2015. Microbiological risk assessment for industry. Safe Food 10: 13-22.
  10. MFDS. 2014. Food Code. Ministry of Food And Drug Safety, Seoul, Korea. 10-3-1_1.
  11. Pruss BM, Dietrich R, Nibler B, Mrtlbauer E, Scherer S. 1999. The hemolytic enterotoxin HBL is broadly distributed among species of the Bacillus cereus group. Appl Environ Microbiol 65: 5436-5442.
  12. Hwang JH. 2009. Biochemical characteristics and enterotoxin gene distribution of food-borne Bacillus cereus. MS Thesis. Kyungwon University, Gyeonggi, Korea.
  13. Ryan PA, Macmillan JD, Zilinskas BA. 1997. Molecular cloning and characterization of the genes encoding the L1 and L2 components of hemolysin BL from Bacillus cereus. J Bacteriol 179: 2551-2556. https://doi.org/10.1128/jb.179.8.2551-2556.1997
  14. Granum PE, O'Sullivan K, Lund T. 1999. The sequence of the non-haemolytic enterotoxin operon from Bacillus cereus. FEMS Microbiol Lett 177: 225-229. https://doi.org/10.1111/j.1574-6968.1999.tb13736.x
  15. Lee DS, Kim KS, Kwon KS, Hong KW. 2008. A multiplex PCR assay for the detection and differentiation of enterotoxin-producing and emetic toxin-producing Bacillus cereus strains. Food Sci Biotechnol 17: 761-765.
  16. Asano SI, Nukumizu Y, Bando H, Iizuka T, Yamamoto T. 1997. Cloning of novel enterotoxin genes from Bacillus cereus and Bacillus thuringiensis. Appl Environ Microbiol 63: 1054-1057.
  17. Stenfors LP, Granum PE. 2001. Psychrotolerant species from the Bacillus cereus group are not necessarily Bacillus weihenstephanensis. FEMS Microbiol Lett 197: 223-228. https://doi.org/10.1111/j.1574-6968.2001.tb10607.x
  18. Ehling-Schulz M, Svensson B, Guinebretiere MH, Lindback T, Andersson M, Schulz A, Fricker M, Christiansson A, Granum PE, Martlbauer E, Nguyen-The C, Salkinoja-Salonen M, Scherer S. 2005. Emetic toxin formation of Bacillus cereus is restricted to a single evolutionary lineage of closely related strains. Microbiology 151: 183-197. https://doi.org/10.1099/mic.0.27607-0
  19. Hwang SY, Kim SH, Jang EJ, Kwon NH, Park YK, Koo HC, Jung WK, Kim JM, Park YH. 2007. Novel multiplex PCR for the detection of the Staphylococcus aureus superantigen and its application to raw meat isolates in Korea. Int J Food Microbiol 117: 99-105. https://doi.org/10.1016/j.ijfoodmicro.2007.02.013
  20. Oh SK, Koo M, Lee N, Kim HJ, Oh SW, Choi SY. 2011. Distribution of newly described enterotoxin-like genes in Staphylococcus aureus isolated from ready-to-eat foods in Korea. Food Sci Biotechnol 20: 579-584. https://doi.org/10.1007/s10068-011-0082-x
  21. Clinical and Laboratory Standards Institute. 2014. Performance standards for antimicrobial susceptibility testing; 24th informational supplement (M100-S24). Clinical and Laboratory Standards Institute, Wayne, PA, USA. p 68-75.
  22. Cho SK, Park JH. 2012. Microbial contamination analysis for drinking water, foodstuff, and cooked food for foodservice operation. Korean J Food Sci Technol 44: 478-483. https://doi.org/10.9721/KJFST.2012.44.4.478
  23. Solberg M, Buckalew JJ, Chen CM, Schaffner DW, O'Neill K, McDowell J, Post LS, Bodeck M. 1990. Microbiological safety assurance system for foodservice facilities. J Food Technol 44: 68,70-73.
  24. Granum PE, Lund T. 1997. Bacillus cereus and its food poisoning toxins. FEMS Microbiol Lett 157: 223-228. https://doi.org/10.1111/j.1574-6968.1997.tb12776.x
  25. Andersson A, Ronner U, Granum PE. 1995. What problems does the food industry have with the spore-forming pathogens Bacillus cereus and Clostridium perfringens?. Int J Food Microbiol 28: 145-155. https://doi.org/10.1016/0168-1605(95)00053-4
  26. U.S. Department of Agriculture/Food Science & Inspection Service. 2004. Examination of meat and poultry products for Bacillus cereus. U.S. Department of Agriculture/Food science & Inspection Service Microbiology Guidebook. Available from http://www.fsis.usda.gov/wps/wcm/connect/7aa41946-bd89-4ba9-91cf-7ea72e15e677/Mlgchp12.pdf?MOD=AJPERES (accessed Sep 2015).
  27. U.S. Food & Drug Administration. 2004. Bacteriological analytical manual. U.S. Food & Drug Administration Center for Food Safety & Applied Nutrition. Available from http://www.fda.gov/Food/FoodScienceResearch/LaboratoryMethods/ucm070875.htm (accessed Sep 2015).
  28. Kim SR, Cha MH, Chung DH, Shim WB. 2015. Profiles of toxin genes and antibiotic susceptibility of Staphylococcus aureus isolated from perilla leaf cultivation area. J Fd Hyg Safety 30: 51-58. https://doi.org/10.13103/JFHS.2015.30.1.51
  29. Tan SL, Lee HY, Mahyudin NA. 2014. Antimicrobial resistance of Escherichia coli and Staphylococcus aureus isolated from food handler's hands. Food Control 44: 203-207. https://doi.org/10.1016/j.foodcont.2014.04.008
  30. Kim JB, Kim JM, Cho SH, Oh HS, Choi NJ, Oh DH. 2011. Toxin genes profiles and toxin production ability of Bacillus cereus isolated from clinical and food samples. J Food Sci 76: 25-29.
  31. Chen TR, Chiou CS, Tsen HY. 2004. Use of novel PCR primers specific to the genes of staphylococcal enterotoxin G, H, I for the survey of Staphylococcus aureus strains isolated from food-poisoning cases and food samples in Taiwan. Int J Food Microbiol 92: 189-197. https://doi.org/10.1016/j.ijfoodmicro.2003.10.002
  32. Jarraud S, Cozon G, Vandenesch F, Bes M, Etienne J, Lina G. 1999. Involvement of enterotoxins G and I in staphylococcal toxic shock syndrome and staphylococcal scarlet fever. J Clin Microbiol 37: 2446-2449.
  33. Aydin A, Sudagidan M, Muratoglu K. 2011. Prevalence of staphylococcal enterotoxins, toxin genes and genetic-relatedness of foodborne Staphylococcus aureus strains isolated in the Marmara Region of Turkey. Int J Food Microbiol 148: 99-106. https://doi.org/10.1016/j.ijfoodmicro.2011.05.007
  34. Yoo YA, Kim MS, Kim KS, Park SH, Jung SK. 2010. Antimicrobial resistance and implicated genes of E. coli isolated from commercial and cooked foods in Seoul. J Fd Hyg Safety 25: 220-225.
  35. Kim SM, Oh T, Kim HJ. 2015. Antimicrobial resistance, molecular, and phenotypic diversity of Escherichia coli isolates from fresh vegetable products in Korea. J Korean Soc Appl Biol Chem 58: 745-750. https://doi.org/10.1007/s13765-015-0104-0
  36. Kim HJ, Koo M. 2012. Estimation of dietary exposure to antimicrobial resistant Staphylococcus aureus from porkbased food dishes. Korean J Food Sci Ani Resour 32: 91-97. https://doi.org/10.5851/kosfa.2012.32.1.91

Cited by

  1. Modelling of tetracycline resistance gene transfer by commensal Escherichia coli food isolates that survived in gastric fluid conditions vol.49, pp.1, 2017, https://doi.org/10.1016/j.ijantimicag.2016.10.009
  2. 2019년 충남지역 고등학교에서 발생한 다병원체에 의한 집단식중독의 역학적 분석 vol.45, pp.5, 2015, https://doi.org/10.5668/jehs.2019.45.5.434
  3. 2019년 충남지역에서 발생한 식중독 현황과 원인분석 vol.46, pp.2, 2015, https://doi.org/10.5668/jehs.2020.46.2.184
  4. 2020년 충남지역 집단급식소에서 발생한 대형 식중독의 사례 보고 vol.46, pp.5, 2015, https://doi.org/10.5668/jehs.2020.46.5.525