Evaluation of Microbiological Safety of Lettuce and Cultivation Area

상추와 생산환경의 미생물 안전성 평가

  • 김세리 (농촌진흥청 국립농업과학원 농산물안전성부) ;
  • 이지영 (식품의약품안전성 식품기준과) ;
  • 이서현 (농촌진흥청 국립농업과학원 농산물안전성부) ;
  • 김원일 (농촌진흥청 국립농업과학원 농산물안전성부) ;
  • 박경훈 (농촌진흥청 국립농업과학원 농산물안전성부) ;
  • 윤혜정 (농촌진흥청 국립농업과학원 농산물안전성부) ;
  • 김병석 (농촌진흥청 행정법무담당관실) ;
  • 정덕화 (경상대학교 응용생명과학부) ;
  • 윤종철 (농촌진흥청 국립농업과학원 농산물안전성부) ;
  • 류경열 (농촌진흥청 국립농업과학원 농산물안전성부)
  • Received : 2011.09.05
  • Accepted : 2011.11.08
  • Published : 2011.12.31

Abstract

Produce, including leafy vegetables, has been implicated in several outbreaks of food illness. To evaluate microbiological safety of lettuce and it's cultivation area, a total of 147 samples were collected from lettuce farms and post harvest facility at Icheon, Gyeonggi province. The collected samples were assessed for presence of sanitary indicator microorganisms (Aerobic plate count, coliform count, Escherichia coli) and foodborne pathogens (Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, Bacillus cereus). The population of APC was over 4.0 log CFU from most of the samples. While the numbers of APC, and coliform of lettuce at 62 days after transplanting were 4.18 log CFU/g, and 1.00 log CFU/g, respectively, those of 10 days after transplanting were 5.37 log CFU/g, and 2.87 log CFU/g, respectively. B. cereus was highly detected from soil and balance which were contaminated with 3.5 log CFU/g, and 2.6 log CFU/100 $cm^2$, respectively. The number of E. coli recovered from gloves was 3.5 log CFU/hand. However, E. coli O157:H7, Salmonella spp., and L. monocytogenes were not detected. These data suggested that risk management system should be introduced to lettuce farms to enhance safety of lettuce.

본 연구는 상추를 대상으로 재배~수확 후 단계의 미생물학적 안전성을 평가하고자 이천지역 상추농가와 수확 후 처리시설에서 위생지표세균(일반세균수, 대장균군,E. coli)과 병원성미생물(Escherichia coli O157:H7, Salmonella spp., Stphylococcus aureus, Listeria monocytogenes, Bacillus cereus)을 조사하였다. 상추 생산과정의 미생물 오염도 조사 결과, 대부분의 시료에서 일반세균수 수준은 4.0 log CFU/(ml, g, $100\;cm^2$, hand)이었다. 또한 수확 후 처리시설에서 사용되는 장갑에서 E. coli가 3.5 log CFU/hand로 비교적 높게 검출되었고, B. cereus는 토양과 저울에서 각각 3.5 log CFU/g, 2.6 log CFU/$100\;cm^2$로 타시료에 비해 높았다. 특히 정식 후 10일 째 상추의 일반세균수, 대장균군수 및 B. cereus의 오염수준이 정식 후 62일째 상추 보다 각각 l.19, 1.87, and 1.94 log CFU/g 정도 높은 것으로 나타났다. 한편 E. coli O157:H7, Salmonella spp, 및 L. monocytogenes은 검출되지 않았다. 본 연구의 결과를 통하여 상추의 유해 미생물 오염은 생산단계부터 발생되고 있음이 확인되었고 이러한 유해미생물의 오염을 사전에 관리하기 위해서는 생산에서부터 소비까지 위해요소를 관리하는 시스템의 도입이 필요하다.

Keywords

References

  1. Choi, J.W., Park, S.Y., Yeon, J.H., Lee, M.J., Chung, D.H., Lee, K.H., Kim, M.G., Lee, D.H., Kim, K.S. and Ha, S.D.: Microbial contamination levels of fresh vegetables distributed in markets. Korean J. Fd. Hyg. Safety, 20, 43-47 (2005).
  2. FDA: Guidance for Industry: Guide to Minimize Microbial Food Safety Hazards of Leafy Greens; Draft Guidance Available from: http://www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/ GuidanceDocuments/ProduceandPlanProducts/ ucm174200.htm Accessed January 15, 2010 (2009).
  3. CDC: Update on Multi-State Outbreak of E.coliO157:H7 Infections From Fresh Spinach, October 6, 2006. Available from:http://www.cdc.gov/ecoli/2006/september/updates/100- 606.htm Accessed Febrary 20, 2010 (2006).
  4. Patel, J. and Sharma, M.: Differences in attachment of Salmonella enteric serovars to cabbage and lettuce leaves. Int. J. Food Microbiol., 139, 41-47 (2010). https://doi.org/10.1016/j.ijfoodmicro.2010.02.005
  5. KFDA: Analysis on the trend of food-poising over the last 5 years. Available from: http://www.foodnara.go.kr/portal/site/ kfdaportal/template. Accessed Aug. 25, (2010).
  6. Sewell, A.M., and Farber, J.M.: Foodborne outbreaks in Canada linked to produce. J. Food Prot., 64, 1863-1877 (2001).
  7. Beuchat, L.R.: Ecological factors influencing survival and growth of human pathogens on raw fruits and vegetables. Microbes Infect., 4, 413-423 (2002). https://doi.org/10.1016/S1286-4579(02)01555-1
  8. FDA: Guidance for industry, Guide to minimize microbial food safety hazard for fresh fruits and vegetables. Available From: http://csan.fda.gov. Accessed Oct. 26, (2005).
  9. Burnett, S.L. and Beuchat, L.R.: Human pathogens associated with raw produce and unpasteurized juices and difficulties in decontamination. J. Int. Microbiol. Biotechnol., 27, 104-110 (2001). https://doi.org/10.1038/sj.jim.7000199
  10. Kim, S.Y.: Indication system for the verification in agricultural food safety. In: Symposium on GAP application strategy for the safety agricultural production. July 29, Gyeongsang National University, Jinju, Korea. The Center of Agri-food Safty. Jinju, Korea pp.23-42 (2004).
  11. Sveum, W.H., Moberg, L.J., Rude, R.A. and Frank, J.F.: Microbiological monitoring of the food processing environment. 3rd ed. American Public Health Association, Washington D.C., USA. pp. 51-74 (1992).
  12. Anonymous: Guidelines for effectiveness testing of surgical hand scrub (glove juice test). Fed. Regist. 43, 1242-1243 (1978).
  13. KFDA: Korean Food code. Korea Food and Drug Administration, Seoul, Korea. pp.75-105 (2002).
  14. Choo, E.Y., Jang, S.S., Kim, K.S., Lee, K.G., Heu, S.G. and Ryu, S.R.: Prevlence and genetic diversity of Bacillus cereus in dried red pepper in Korea. J. Food Prot., 70, 917-922 (2007).
  15. Islam, M., Doyle, M.P., Phatak, S.C., Millner, P. and Jiang, X.: Survival of Escherichia coli O157:H7 in soil and on carrots and onions grown in fields treated with contaminated manure composts or irrigation water. Food Microbiol., 22, 63-70 (2005). https://doi.org/10.1016/j.fm.2004.04.007
  16. Oliveira, M., Usall, J., Vinas, I., Solsona, C. and Abadias M.: Transfer of Listeria innocua from contaminated compost and irrigation water to lettuce leaves. Food Microbiol., 28, 590- 596 (2011). https://doi.org/10.1016/j.fm.2010.11.004
  17. Solomon, E.B., Yaron, S. and Mattews, K.R.: Transmission of Escherichia coli O157:H7 from contaminated manure and irrigation water to lettuce plant tissue and its subsequent internalization. Appl. Environ. Microbiol., 68, 397-400 (2002). https://doi.org/10.1128/AEM.68.1.397-400.2002
  18. Solomon, E.B., Potenski, C.J. and Mattews K.R.: Effect of irrigation method on transmission to and persistence of Escherichia coli O157:H7 on lettuce. J. Food. Prot., 65, 673- 676 (2002).
  19. Perez-Rodriguez, F., Todd, E.C.D., Valero, A., Carrasco, E., Garcia, R.M., and Zurera, G.: Linking quantitative exposure assessment and risk management using the food safety objective concept: an example with Listeria monocytogenes in different cross-contamination scenarios. J. Food Prot., 69, 2384-2394 (2006).
  20. Kim, S.R., Lee, J.Y., Lee, S.H., Ko, H.S., Yoon, Y.H., Kwon, S.H., Ryu, K.Y., Yun, H.J., Kim, W.I., Yun, J.C., Kim, D.H. and Chung, D.H.: Distribution of Hazardous Microorganisms in Perilla Leaf Cultivation Areas. Korean J. Food Sci. Technol., 43, 243-248 (2001).
  21. Kim, J.S., Shim, W.B., Kim, J.H., Kim, S.B. and Chung D.H.: Sanitary microbial distribution at the tomato farms in western Gyeongnam. Korean J. Env. Hlth., 32, 77-88 (2006).
  22. Ryu, J.H. and Beuchat, L.R.: Biofilm formation and sporulation by Bacillus cereus on a stainless steel surface and subsequent resistance of vegetative cells and spores to chlorine, chlorine dioxide, and a peroxyactic acid-based sanitizer. J. Food Prot., 68, 2614-2622 (2005).
  23. Johnston, L.M., Jaykus, L.A., Moll, D., Martinez, M.C., Anciso, J., Mora, B. and Moe, C.L.: A field study of the microbiological quality of fresh produce. J. Food Prot., 68, 1840- 1847 (2005).
  24. Ailes, E.C., Leon, J.S. Jaykus, L.A., Johnston, L.M., Clayton, H.A., Blanding, S., Kleinbaum, D.G., Backer, L.C., and Moe, C.L.: Microbial concentrations on fresh produce are affected by postharvest processing, importation, and season. J. Food Prot., 71, 2389-2397 (2008).