농산물 접촉 표면 재질에 따른 Escherichia coli O157:H7의 생존 및 상추로의 교차오염도 조사 = Survival and Cross-contamination of Escherichia coli O157:H7 on Various Agricultural Product-Contact Surfaces

다국어 초록 (Multilingual Abstract)

To evaluate the effect of surface contaminated with Escherichia coli O157:H7 (E. coli O157:H7)on the microbiological safety of lettuce, this study was conducted to investigate the attachment, biofilm producing,survival, and cross-contamination of E. coli O157:H7 on stainless steel and polyvinyl chloride (PVC). The attachment rate of E. coli O157:H7 on PVC was 10 times higher than that on stainless steel after exposure 1 h in cell suspension.
However, there was not a difference between two types of surface after exposure for 6 h and 24h. The biofilm producing of E. coli O157:H7 was TSB > 10% lettuce extracts > 1% lettuce extracts > phosphate buffer. When two kinds of materials were stored at various conditions (20oC and 30oC, relative humidity (RH) 43%, 69%, and 100%), the numbers of E. coli O157:H7 at 30oC, RH 43% or RH 69% were reduced by 5.0 log CFU/coupon within 12 h regardless of material type. Conversely, the survival of E. coli O157:H7 at RH 100% was lasted more than 5 days. In addition, the reduction rate of E. coli O157:H7 was decreased in the presence of organic matter. The transfer efficiency of E. coli O157:H7 from the contaminated surface to lettuce was dependent upon the water amount of the surface of lettuce.
Especially, the transfer rate of E. coli O157:H7 was increased by 10 times in the presence of water on the lettuce surface.
From this study, the retention of E. coli O157:H7 on produce contact surfaces increase the risk cross-contamination of this pathogen to produce. Thus, it is important that the surface in post harvest facility is properly washed and sanitized after working for prevention of cross-contamination from surface.

국문 초록 (Abstract)

본 연구는 polyvinyl chroride (PVC)와 stainless steel 표면에서 E. coli O157:H7의 부착, 바이오필름형성, 온·습도에 따른 생존율을 조사하고, E. coli O157:H7이 오염된 작업대 표면에서상추로의 교차오염도 조사를 통하여 E. coli O157:H7에 오염된작업대가 상추의 미생물학적 안전성에 미치는 영향을 평가하고자 수행하였다. 작업대 표면 재질인 PVC와 stainless steel에E. coli O157:H7 배양액을 1시간 노출시켰을 때, PVC의 경우,stainless steel 보다 10배 정도 부착력이 높았으나, 6시간째는두 재질간의 차이가 없었다. 또한, E. coli O157:H7의 바이오필름 형성은 TSB > 10% 상추추출액 > 1% 상추추출액 > phosphatebuffer 순이었으며, 재질별로는 PVC에서 바이오필름형성능이높은 것으로 나타났다. 온도 20oC, 30oC, 습도 43%, 69%, 100%에서 각각 노출 시켰을 때, E. coli O157:H7은 온도 30oC, 습도 43%, 69% 조건에서 12시간 내에 약 5.0 log CFU/coupon이감소한데 반해, 상대습도 100%에서는 농도의 큰 변화 없이 5일 이상 생존이 지속되었다. 또한, 유기물이 작업대 표면에 존재 시, E. coli O157:H7의 감소 속도가 느렸다. E. coli O157:H7에 오염된 작업대에 상추를 접촉시키고 상추의 오염도를 조사한결과, 상추 표면에 수분이 존재할 때 오염된 작업대 표면에서E. coli O157:H7의 이동수준이 상추에 수분이 없을 때 보다 10배 이상 증가하는 것으로 나타났다. 따라서 E. coli O157:H7에오염된 작업대는 상추의 안전성에 직접적인 영향을 미칠 수 있어 작업 후에 세척, 소독을 통하여 위생적으로 관리하는 것이필요하다.

참고문헌 (Reference)

1 배영민, "재질 표면에 오염된 여러 병원성 세균에 대한 건열살균 및 살균소독제의 저해효과" 한국식품영양과학회 38 (38): 1265-1270, 2009

2 김세리, "상추와 생산환경의 미생물 안전성 평가" 한국식품위생안전성학회 26 (26): 289-295, 2011

3 CDC, "Update on Multi-State Outbreak of E. coli O157:H7 Infections From Fresh Spinach"

4 Park, E. J., "The decontaminative effects of acidic electrolyzed water for Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes on green onions and tomatoes with different organic demands" 26 : 386-390, 2009

5 Kusumaningrum, H. D., "Survival of foodborne pathogens on stainless steel surfaces and cross-contamination to foods" 85 : 227-236, 2003

6 Chai, L. C., "Simulation of cross-contamination and decontamination of Campylobacter jejuni during handling of contaminated raw vegetables in a domestic kitchen" 71 : 2448-2452, 2008

7 Bae, Y. M., "Resistance of pathogenic bacteria on the surface of stainless steel depending on attachment form and efficacy of chemical sanitizers" 153 : 465-473, 2012

8 Silagyi, K., "Production of biofilm and quorum sensing by Escherichia coli O157:H7 and its transfer from contact surface to meat, poultry, readyto- eat deli, and produce products" 26 : 514-519, 2009

9 Choi, J. W., "Microbial contamination levels of fresh vegetables distributed in markets" 20 : 43-47, 2005

10 Ailes, E. C., "Microbial concentrations on fresh produce are affected by postharvest processing, importation, and season" 71 : 2389-2397, 2008

11 FDA, "Guidance for Industry: Guide to Minimize Microbial Food Safety Hazards of Leafy Greens; Draft Guidance"

12 Watanabe, Y., "Factory outbreak of Escherichia coli O157:H7 infection in Japan" 5 : 424-428, 1999

13 Paul, J.H., "Evidience for separate adhesion mechanisms for hydrophilic and hydrophobic surfaces in Vibrio proteolytica" 50 : 431-437, 1985

14 Takahashi, H., "Desiccation survival of Listeria monocytogenes and other potential foodborne pathogens on stainless steel surface is affected by different food soils" 22 : 633-637, 2011

15 de Rezende, E. E., "Capsular polysaccharide surrounds smoothe and rugose types of Salmonella enterica serovar Typhimurium DT104" 71 : 7345-7351, 2005

16 Else, T. A., "Boundaries for biofilm formation : humidity and temperature" 69 : 5006-5010, 2003

17 Sinde, E., "Attachment of Salmonella spp. and Listeria monocytogenes to stainless steel, rubber and polytetrafluor-ethylene : the influence of free energy and the effect of commercial sanitizers" 17 : 439-447, 2000

18 Ryu, J. H., "Attachment and biofilm formation by Escherichia coli O157:H7 on stainless steel as influence by exopolysaccharide production, nutrient availability, and temperature" 67 : 2123-2131, 2004

19 KFDA, "Analysis on the trend of food-poising over the last 5 years"

20 KIM, G.H., "A survey on consumption pattern of minimally fruits and vegetables" 13 : 267-274, 1998

21 Kusumaningrum, H. D., "A quantitative analysis of cross-contamination of Salmonella and Campylobacter spp. via Domestic kitchen surfaces" 67 : 1892-1903, 2004

22 Johnston, L.M., "A field study of the microbiological quality of fresh produce" 68 : 1840-1847, 2005