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ISSN 0367-6315 (Print) / ISSN 2288-2162 (Online) Korean J. Soil Sci. Fert. 47(6), 437-442 (2014) http://dx.doi.org/10.7745/kjssf.2014.47.6.437 Article Microbial Contamination Levels of Strawberries at Domestic Farms of South Korea Won-Il Kim*, A-Ra Jo, Se-Ri Kim, Song Hee Ryu, Ki-Woong Nam 1, Yohan Yoon 2, Deok-Hoon Yoon 1, So-Yong Oh 1, Myeong Hyeon Nam 3, Jae-Gee Ryu, and Hwang-Yong Kim Microbial Safety Team, Department of Crop Life Safety, National Academy of Agricultural Science, RDA, Wanju-gun, 565-851, Republic of Korea 1 Research Institute of International Agriculture, Technology and Information, Hankyong National University, Ansung, 456-749, Republic of Korea 2 Department of Food & Nutrition, College of Human Ecology, Sookmyung Women s University, Seoul, 140-742, Republic of Korea 3 Nonsan Strawberry Experiment Station, Chungnam ARES, Nonsan, 320-862, Republic of Korea (Received: November 21 2014, Revised: December 24 2014, Accepted: December 25 2014) Foodborne illness due to the consumption of contaminated raw strawberries is a continuing food safety concern. This study investigated and evaluated contamination levels of bacteria on strawberries at farms stage to evaluate potential hazards associated with fresh strawberries. A total of 315 samples, 105 samples from 5 sampling sites (A to E) of 21 farms and 210 samples from 1 sampling site of 6 farms, was collected every month for four months and analyzed to enumerate aerobic bacterial counts, Coliforms/E. coli, Bacillus cereus and Staphylococcus aureus. In addition, the prevalence study of five pathogens (S. aureus, E. coli, E. coli O157:H7, Salmonella spp. and Listeria monocytogenes) was performed on each sample. Aerobic bacterial counts ranged from 0.48 to 6.36 Log CFU/g, with the highest bacterial cell counts recorded for D and E sites. Coliforms were detected in 71 samples (22.5%) with a minimum of 0.48 cfu/g and a maximum of more than 4 Log CFU/g. B. cereus was detected in 98 samples (31.1%) among total samples analyzed. S. aureus was detected in 2 samples with a minimum of 0.48 Log CFU/g and a maximum of 1.38 Log CFU/g. E. coli, E. coli O157:H7, Salmonella spp. and L. monocytogenes were not isolated from any of the samples. The microbial contamination levels of strawberries determined in this study may be used as the fundamental data for microbiological risk assessment. Key words: Strawberry, Microbiological quality, Food-borne pathogen Contamination levels of indicator bacteria in strawberries with sampling months. Sampling time sampling farms sample units : Total aerobic bacteria Mean ± S.D. b : Coliforms Mean ± S.D. : B. cereus <2 a 2-3 3-4 4-5 >5 <1 1-2 2-3 >3 <1 1-2 2-3 >3 Mean ± S.D. Feb. 6 60 3.3 20.0 48.3 25.0 3.3 1.90-5.07 3.57 ± 0.759A 95.0 3.3 1.6 0.0 ND c -2.46 0.17 ± 0.475A 95.0 3.3 1.6 0.0 ND-2.46 0.17 ± 0.607B Mar. 6 60 15.0 21.6 38.3 18.3 6.6 1.48-5.18 3.26 ± 0.994A 71.65.0 16.66.6 ND-4.78 0.74±1.284B 71.6 5.0 16.6 6.6 ND-4.78 0.74±0.468B Apr. 6 30 10.0 26.6 43.3 13.3 6.6 1.95-5.37 3.31 ± 0.885A 83.36.6 10.00.0 ND-2.49 0.34±0.787A 83.3 6.6 10.0 0.0 ND-2.49 0.34±0.448B May 6 60 23.3 25.0 16.6 21.6 13.3 1.48-5.82 3.30 ± 1.359A 85.05.0 5.0 5.0 ND-3.28 0.36±0.850A 85.0 5.0 5.0 5.0 ND-3.28 0.36±0.337A a The unit of number is Log CFU/g. b Standard deviation. c Not detected. 1) *Corresponding author : Phone: +82632383396, Fax: +82632383840, E-mail: kimwi@korea.kr Acknowledgement: This study was carried out with the support of the Cooperative Research Program for Agricultural Science and Technology Development (Project No. PJ009404), Rural Development Administration, Republic of Korea.

438 Microbial Contamination Levels of Strawberries at Domestic Farms of South Korea Introduction 국민들의생활수준향상및건강에대한관심이고조되면서별도의조리과정없이섭취하는신선농산물의소비량이계속해서증가하고있다 (Burnett and Beuchat, 2001; Tian et al., 2012). 그중에서딸기는주요신선섭취농산물로써국내생산액이 2012 년기준 11,888 억원으로우리나라전체채소생산액 (101,537 억원 ) 의약 11.7% 를차지하는중요한농가의소득원이다 ( 농촌진흥청, 2013). 2000년대국내딸기생산량은평균약 20 만톤으로 80 년대에비해서는약 2.9 배, 90 년대에비해서는약 1.4 배증가하였다 ( 통계청, 2010). 딸기는국내에서대부분생식용으로이용되고있으며, 일부는잼, 아이스크림, 주스등의가공식품원료로도이용되고있다 (Lee et al., 2012). 한편, 국외에서는 Salmonella spp., Listeria monocytogenes, Escherichia coli O157 과같은식중독을일으키는병원성미생물이오염된과채류섭취에따른식중독사고가가정, 외식업체등에서발생하여많은인명및재산피해를가져와 (CDC, 2007), 소비자들이신선농산물의안전성에대한우려를표하고있기도하다. 국내에서는딸기가원인이된식중독사고발생사례가보고된바없으나, 미국의경우 E. coli O157:H7 등과같은인체병원성미생물이오염된신선딸기섭취에의한식중독사고가보고된바있다 (The Marler Clark Network, 2013). 각종인체병원성미생물들은생산과정에서오염된토양, 관개용수, 야생동물, 곤충등에의해매개될수있고, 수확, 수확후처리, 가공, 포장등의처리과정중에서도비위생적인작업자, 작업환경등에의해교차오염이일어날수있다 (Koseki and Isobe, 2005). 일반적으로농장에서바로섭취하는과일, 채소가안전한것으로여겨지지만 (Ackers et al., 1998; Beuchat, 1996; De Roever, 1998; Mead et al., 1999), 생산단계에있는그것에도인체병원성미생물이존재할가능성이있다. Salmonella spp., E. coli O157:H7 등의인체병원성미생물들이농산물에오염된이후에는농산물품질유지등의이유로완전히제거하기가어려우므로 (Beuchat and Scouten, 2002), 병원성미생물이오염되기전에사전예방적으로관리해야만한다. 국내의딸기의생물학적위해요소에관한연구현황으로는수확단계딸기의생물학적위해요소분석 (Shim et al., 2013), 재배단계딸기의각종위해요소분석 (Lee et al., 2012), 유통단계딸기의생물학적위해요소분석 (Yu et al., 2009), 재배방식에따른딸기의생물학적위해요소분석 (Yu et al., 2013) 등이수행되었으나, 딸기시료수집지및분석시기가한지역또는특정한시기로국한되어있어서국내의전반적인생물학적위해요소오염특성을나타내기에는한계가있다. 따라서본연구는국내주요생산단계딸기생산지를대상으로딸기의위생지표세균및유해미생물오염도를조사하였고딸기의주 요수확시기별로오염도의변화양상조사를통해국내생산단계딸기의전반적인위생지표세균및유해미생물오염특성을규명하고자한다. Materials and Methods 주산지의딸기시료수집경남소재 2지역 (9호농가 ), 경북소재 1지역 (4호농가 ), 전북소재 1지역 (4호농가 ), 전남소재 1지역 (4호농가 ) 으로총 5개지역 (21 호농가 ) 에서딸기 (Fragaria ananassa Duch.) 시료를수집하였다. 딸기는완숙되어출하가가능한과실을대상으로무작위로채취하였고, 3개의과실을 1점의시료로정하여 1호농가당 5점, 총 105 점의시료를수집하였다. 시료를수집할때에는교차오염을방지하고미생물밀도변화를최소화하기위하여멸균된장갑을착용하여폴리에틸렌재질의봉투에시료를채취한후, 즉시냉장박스에보관 이송하여빠른시간내에분석하였다. 시기별딸기시료수집충남소재 1개지역내 6호의농가에서 2, 3, 4, 5월에각월별 1회씩딸기시료를수집하였다. 위와같은방법으로시료를채취하여총 210 점을수집 분석하였다. 위생지표세균오염도조사위생지표세균인일반호기성세균과대장균군 / 대장균의오염도를정량적으로분석하였다. 딸기시료를 stomacher bag 에넣고 1:3 (w/v) 의비율로 0.1% peptone water 를더해 Pulsifier PUL 100E (Microgen, UK) 로 15초동안균질화하였다. 일반호기성세균수측정을위해 Pulsifier 로균질화한희석용액 1 ml 을취해건조배지 (Aerobic Count Plant, 3M, Minn, USA) 에분주한후 30 C 배양기에서 48 시간동안배양하여나타난 colony 의수를계수하였다. 대장균군 / 대장균 (Coliforms/E. coli) 의밀도측정을위해희석용액 1 ml 을취해건조배지 (Coliforms/E. coli Count Plate, 3M, USA) 에분주한후 37 C 배양기에서 24 시간동안배양하여대장균군및대장균으로의심되는 colony 의수를계수하였다. 유해미생물오염도조사수집한딸기시료에대해 Bacillus cereus 와 Staphylococcus aureus 의오염도를정량적으로분석하였다. B. cereus 오염도조사를위해균질화한희석용액을 0.25 ml 씩 4개의 Mannitol Egg Yolk Polymyxin Agar (MYP, OXOID, UK) 에각각분주하여도말하였다. 30 C 배양기에서 24 시간동안배양한후 B. cereus 로의심되는 colony 의수를세었다. 보다정확한세균동정을위해시료당 5개의의심되는 colony 를 MYP 에계대배양한후 Nutrient Agar (NA, BD, USA) 배지를이용해순수분리하였다. 분리된균

Won-Il Kim, A-Ra Jo, Se-Ri Kim, Song Hee Ryu, Ki-Woong Nam, Yohan Yoon, Deok-Hoon Yoon, So-Yong Oh, Myeong Hyeon Nam, Jae-Gee Ryu, and Hwang-Yong Kim 439 주는 B. cereus Detection Kit (JS-BC050, Jinsung Uni-tech, Korea) 을이용한 groel, ces, cry1 유전자유무를판별해서 B. cereus 진위를검정하였다. 검정방법은각균주의 chromosomal DNA 를 boiling 방법으로추출하여 template DNA 를얻었다. Micro-tube 에 master mixture ( 멸균수 14.875, buffer 2.5, dntp 0.5, cry1 forward primer 1, cry1 reverse primer 1, groel forward primer 1, groel reverse primer 1, ces forward primer 1, ces reverse primer 1, Taq polymerase 0.125 ul) 24 ul 와 template DNA 1 ul 를분주한후중합효소연쇄반응장비 (C1000 TM Thermal Cycler, Biorad, USA) 를이용하여특이염기서열을증폭하였다 (Kim et al., 2012). 반응조건은 1. 95 C 에서 2분, 2. 95 C 에서 20 초, 3. 61 C 에서 20 초, 4. 72 C 에서 20 초, 5. 72 C 에서 2분으로하였고 2 번에서 4번과정은 30 cycle 로설정하였다. 반응후증폭산물의전기영동을통하여 target gene 인 cry1 (138bp), groel (250bp), ces (405bp) 의 band 유무를판별하였다. 판별된 B. cereus 수를최초에측정하였던추정 colony 의수에대입해최종세균수를산정하였다. S. aureus 오염도조사를위해균질화한희석용액을 0.25 ml 씩 4개의 Baird-Parker (BP, OXOID, UK) 에각각분주하여도말한후 37 C 의배양기에서 48 시간동안배양하였다. S. aureus 로의심되는 colony 를 Nutrient Agar 에순수분리한후 VITEK 2 (BIOMERIEUX, France) 를이용해분석 동정하여 S. aureus 진위를판별하였다. S. aureus, Listeria monocytogenes, Escherichia coli, Escherichia coli O157:H7, Salmonella spp. 의오염도를정성적으로분석하였다. 각세균의선택적증균배지인 Baird- Parker (BP, OXOID, UK), Fraser Listeria (OXOID, UK), E. coli (EC, OXOID, UK), modified E. coli (mec, OXOID, UK), Rappaport-Vassiliadis R-10 (RV, OXOID, UK) 를사용하였다. 딸기시료를 stomacher bag 에넣고 1:3 (w/v) 비율로각각의증균용액을더해 37 C 배양기에서 24 시간동안증균배양하였다. 증균용액을각세균의선택배지인 BP, Oxford agar, Eosin-Methylene Blue agar (EMB, OXOID, UK), Sorbitol Macconkey agar (SMA, OXOID, UK), Xylose lysine deoxycholate agar (XLD, OXOID, UK) 에멸균된백금이를사용하여분리 배양하였으며각세균의생장에적절한온도의배양기에서배양하였다. 배양한후, 각선택배지별로병원균으로의심되는균주를육안으로선별하고의심되는 colony를 NA 배지에순수분리하였다. 분리한균주는정확한동정을위해 VITEK 2 (BIOMERIEUX, France) 를이용해최종동정하였다. 통계적분석딸기의지역별, 시기별위생지표세균및유해미생물오염도조사로부터얻은결과값에대해일원배치분산분석 (one-way ANOVA) 법으로시기별오염도차이를비교하였고, 분산분석결과가유의한수준일경우 (p < 0.05), LSD 법으로다중검정을실시하였다. 위의분석은 SAS 9.2 소프트웨어 (SAS Institute Inc., USA) 를이용하여실시하였다. Results and Discussion 딸기의위생지표세균및유해미생물오염도, 위생지표세균 ( 일반호기성세균, Coliforms) 일반호기성세균의밀도를식품의생산, 가공및유통상의위생조건및잠재적식품부패등을판정할수있는지표로유용하게사용될수있으며, 대장균군 (Coliforms) 은식품위생상분변오염의지표로사용되고있다 ( 강성태등, 2004). 본연구에서는국내딸기의전반적인위생지표세균오염도를파악하기위해총 5지역 (21 개농가 ) 에서수집한생산단계딸기의일반호기성세균, Coliforms 의오염도를분석하였다 (Table 1). 대상지역및농가의딸기의일반호기성세균오염도는평균 3.37 Log CFU/g, 0.48 6.36 Log CFU/g 범위, 대장균군의오염도는평균 0.41 Log CFU/g, N.D. (Not detected) 2.48 Log CFU/g 범위인것으로나타났다. 시료수집지역별딸기 Table 1. Contamination levels of indicator bacteria in strawberries with sampling sites. Sampling sites farms/site sample units samples in the : Total aerobic bacteria Mean ± S.D. b indicated interval : Coliforms Mean ± S.D. <2 a 2-3 3-4 4-5 5-6 >6 <1 1-2 >2 A 5 25 60 20 4 16 0 0 0.48-4.82 1.99 ± 1.372A 88 12 0 ND c -1.95 0.31 ± 0.613A B 4 20 55 20 10 15 0 0 0.48-4.72 2.09 ±1.344A 100 0 0 ND-0.48 0.02±0.107A C 4 20 55 30 15 0 0 0 1.48-3.65 2.09 ±0.704A 100 0 0 ND-0.48 0.05±0.147A D 4 20 5 5 35 50 5 0 1.95-5.00 3.91 ±0.720B 85 10 5 ND-2.48 0.33±0.709A E 4 20 5 35 10 15 30 5 1.48-6.36 3.91 ±1.363B 85 5 10 ND-2.38 0.31±0.717A a The unit of number is Log CFU/g. b Standard deviation. c Not detected.

440 Microbial Contamination Levels of Strawberries at Domestic Farms of South Korea 의위생지표세균오염도는통계적으로같거나유의한차이가있는것으로나타났는데 (Table 1), 이러한차이는시료수집시기의차이에따른미생물증식요건에영향을미치는환경조건 ( 기온, 습도등 ) 차이, 토양재배, 수경재배등해당지역및농가별딸기재배유형의차이에따른토양으로부터미생물오염정도차이, 작물의생육단계차이에따른토양으로부터과실의이격거리, 생육환경 ( 기온, 습도등 ), 재배환경의생물학적위해요소오염도 ( 토양, 관개용수등 ), 작업자위생상태등여러가지요인이영향을미치는것으로판단된다. 유등 (Yu et al., 2009) 은백화점과대형할인매장에서수집한딸기시료에서일반호기성세균의밀도가각평균 5.25, 4.97 Log CFU/g, 대장균군의밀도가각평균 3.98, 3.91 Log CFU/g 로나타난것으로보고하였다. 본연구의생산단계딸기의위생지표세균의평균밀도와비교해봤을때비교적높은밀도로나타난것인데이것은분석시료의 background microflora 의밀도차이, 수확및수확후처리과정중교차오염발생혹은유통과정중미생물밀도변화등에의한것으로추측된다. 심등 (Shim et al., 2013) 은딸기의재배환경 ( 토양, 물 ), 작업자 ( 손, 장갑, 작업복 ), 수확도구 ( 수확상자 ) 의일반호기성세균및대장균군의밀도를조사하였고, 이러한환경에존재하는미생물들이딸기의수확및수확후처리과정중과실에직접닿아교차오염이될가능성이있음을시사하였다. 재배환경에존재하는미생물이농작물로이행될가능성은존재하며, 특히오염된관개수를통한유해미생물의작물로의이동성은여러연구자에의해밝혀진바있다 (Tyrrel et al., 2006; Mitra et al., 2009; Steele and Odumeru, 2004). 그리고농산물은재배단계중노출된환경뿐아니라수확단계에서도작업자, 수확바구니등과접촉되어유해미생물의교차오염이일어날가능성이있고, 수확된이후에도세척, 절단, 저장등의여러단계를거치는동안유해미생물의교차오염과증식이발생할수있는것으로알려져있다 (Wachtel and Charkowski, 2002; Kroupitski et al., 2009; Ukuku and Sapers, 2007; Gagliardi et al., 2003). 유등 (Yu et al., 2013) 이보고한생산단계딸기의부위별위생지표세균오염도분석에서는딸기과실에서일반호기성세균이 2.3-6.8 Log CFU/g, 대장균군이 2.1-4.5 Log CFU/g 범위로나타나본연구의일반호기성세균의오염도범위와유사한것으로나타났다. 다만, 대장균군의평균및오염도범위는다소차이가나는데이는딸기의재배방식 ( 수경, 토경 ) 및재배형태 ( 일반, 무농약, 유기농 ) 의차이에따른것으로판단된다. 본연구에서도수경재배법에비해토경재배법으로생산된딸기에서일반호기성세균, 대장균군, B. cereus 의오염도가상대적으로높게나타났는데 (data not shown), 이는생산단계주요오염원인토양과밀접한관계가있는것으로판단된다. 위생지표세균을비롯하여병원성미생물등의교차오염을예방 하기위해서는딸기재배, 수확, 수확후처리등의과정에있어서농자재, 작업장, 작업복및작업도구, 작업자의위생관리가중요하다. 유해미생물딸기는과육이연약하여수확후처리과정에서도세척과같은별도의과정이없고, 일반적으로생것으로섭취하는경우가많다. 국외의경우에는 S. enterica, E. coli O157:H7 와같은병원성미생물에오염된딸기섭취에의한식중독사고가보고된바있다 (Calder et al., 2003; CDC, 2013). 또한이집트에서생산단계딸기과실에서 Salmonella spp. 는 28%, E. coli 는 72% 의비교적높은빈도로검출되었다고보고된바있다 (Uyttendaele et al., 2014). 지금까지국내에서는딸기섭취에따른식중독사고발생이보고된적이없고, 생산단계및판매단계딸기에서위와같은유해미생물이검출된사례는없다. 본연구에서는국내생산단계딸기의유해미생물오염도조사를수행하였고, B. cereus 를제외한 S. aureus, E. coli, E. coli O157:H7, Salmonella spp., L. monocytogenes은검출되지않았다 (data not shown). B. cereus 는총 105 점시료중 73 점 (69.5%) 의시료에서검출되었고, 정량적으로 1점을제외하고는모두 2 Log CFU/g 이하의비교적낮은오염도를나타냈다 (data not shown). B. cereus 의경우에는구토형또는설사형독소를생성하여인체에해를일으키는데, 일반적으로매개식품내에 5-8 Log CFU/g 으로존재할때생장활성이있는것으로알려져있다 ( 식품의약품안전처, 2010). 본연구결과에서는병원성미생물의오염도에있어우려할만한결과는나타나지않았다. 하지만병원성미생물은그오염경로가다양하고, 딸기는가열등 kill-step 이없이신선섭취하는경우가대부분이므로생산단계에서부터철저한위생관리를통해안전성을확보해야만한다. 시기별딸기의위생지표세균및유해미생물오염도시기별딸기의위생지표세균및유해미생물오염도변화를조사하기위하여시료수집시기를딸기과실의주요수확기인 2월에서 5월까지로하였고, 딸기재배력및위생관리의편차를줄이기위해 4개농가의동일한필지에서시료를수집 분석하였다. 위생지표세균중일반호기성세균의경우에는 2, 3, 4, 5월에각각 1.90-5.07, 1.48-5.18, 1.95-5.37, 1.48-5.82 Log CFU/g 범위로나타났고, 평균값은각각 3.57, 3.26, 3.31, 3.30 Log CFU/g 로써시기에따른일반호기성세균의오염도는유의한변화는없는것으로나타났다 (Table 2). 대장균군의경우에도 3월의오염도를제외하고나머지시기는유의한차이는없었으며 3월은다른시기에비해비교적오염도가높은것으로나타났다. B. cereus 의경우 5월이다른시기에비해오염도가낮게나타났는데, 이는작물이성장함에따라토양과딸기과실의간

Won-Il Kim, A-Ra Jo, Se-Ri Kim, Song Hee Ryu, Ki-Woong Nam, Yohan Yoon, Deok-Hoon Yoon, So-Yong Oh, Myeong Hyeon Nam, Jae-Gee Ryu, and Hwang-Yong Kim 441 Table 2. Contamination levels of indicator bacteria in strawberries with sampling months. Sampling time sampling farms sample units : Total aerobic bacteria Mean ± S.D. b : Coliforms Mean ± S.D. : B. cereus <2 a 2-3 3-4 4-5 >5 <1 1-2 2-3 >3 <1 1-2 2-3 >3 Mean ±S.D. Feb. 6 60 3.3 20.0 48.3 25.0 3.3 1.90-5.07 3.57 ± 0.759A 95.0 3.3 1.6 0.0 ND c -2.46 0.17 ± 0.475A 95.0 3.3 1.6 0.0 ND-2.46 0.17 ± 0.607B Mar. 6 60 15.0 21.6 38.3 18.3 6.6 1.48-5.18 3.26±0.994A 71.6 5.0 16.6 6.6 ND-4.78 0.74±1.284B 71.6 5.0 16.6 6.6 ND-4.78 0.74±0.468B Apr. 6 30 10.0 26.6 43.3 13.3 6.6 1.95-5.37 3.31±0.885A 83.3 6.6 10.0 0.0 ND-2.49 0.34±0.787A 83.3 6.6 10.0 0.0 ND-2.49 0.34±0.448B May 6 60 23.3 25.0 16.6 21.6 13.3 1.48-5.82 3.30±1.359A 85.0 5.0 5.0 5.0 ND-3.28 0.36±0.850A 85.0 5.0 5.0 5.0 ND-3.28 0.36±0.337A a The unit of number is Log CFU/g. b Standard deviation. c Not detected. 격이늘어나 B. cereus 의주요오염원인토양으로부터의교차오염가능성이줄어들기때문인것으로판단된다. 간접적인사례로본연구의시료수집대상농가중토경재배 (19 호농가 ) 시료와수경재배 (8호농가 ) 시료의일반호기성세균, 대장균군, B. cereus 의오염도를비교해보았을때, 토양재배는각평균 3.17, 0.29, 0.20 Log CFU/g, 수경재배는각평균 2.47, 0.25, 0.15 Log CFU/g 로써수경재배에비해토경재배농가의시료에서오염도가상대적으로높게나타난것을확인할수있었다 (data not shown). 토양은관개, 범람, 부적절한퇴비시용등여러경로를통해병원성미생물에오염될수있다고알려져있으며 (Santamaria and Toranzos, 2003), 유사한작물의사례로써 Barak 과 Liang (Barak and Liang, 2008) 은 Salmonella enterica 와같은인체병원균을토양에인위적으로접종하였을때 6주이상생존이가능하여이것이토마토식물체의과실, 잎, 줄기등의지상부로오염되어장기간생존이가능하다는것을보고하였다. 본연구에서는시기별로수집한딸기에서 S. aureus, E. coli, E. coli O157:H7, Salmonella spp., L. monocytogenes 모두불검출로나타났다. 생산단계딸기의안전성향상을위해서는관개, 범람, 야생동물출입등을통한외부로부터의토양오염을방지하고충분히부숙된퇴비를사용하며비닐필름등을이용한멀칭과같은토양피복을통해흙이과실로묻지않도록관리하는것이필요하다. Conclusion 본연구는생산단계딸기를국내 5개지역소재의 21 호농가에서총 105 점의시료를수집하여위생지표세균및유해미생물의오염도를분석하였다. 또한주산지 1개지역의 6호농가를대상으로시기별 (2, 3, 4, 5월 ) 로총 210 점의시료에대해위생지표세균및유해미생물의오염도를조사하였다. 생산단계딸기의위생지표세균중일반호기성세균은 0.48 6.36 Log CFU/g 범위로나타났고, Coliforms 는 ND 4.78 Log CFU/g 범위로써 105 점시료중 53 점 (50.4%) 에서검출되었다. B. cereus 의경우에는 105 점의시료중 73 점 (69.5%) 에서검출되었고 1점을제외하고는모두 2 Log CFU/g 이하인것으로나타났다. 시기별조사에서는 3월의대장균군의밀도가다른시기에비해유의하게높았고, 5월의 B. cereus 가다른시기에비해유의하게낮은것으로나타났다. 본연구에서수행한 S. aureus, E. coli, E. coli O157:H7, Salmonella spp., L. monocytogenes 오염도조사에서는이들모두불검출로나타났다. 본연구는국내생산단계딸기의위생지표세균및유해미생물오염도를조사를통해지역별또는농가별로위생지표세균오염도가유의한차이가있는것을확인하였고, 시기별유해미생물조사결과를통하여토양으로부터의이격거리가 B. cereus 의오염도에상관성이있음을간접적으로시사하였다. 본연구결과는생산단계농산물안전성향상및국내딸기의미생물위해성평가 (Microbiological Risk Assessment) 의기초자료로활용될수있을것으로기대한다. References Tian, J. Q., Bae, Y. M., Choi, N. Y., Kang, D. H., Heu, S. and Lee, S. Y. 2012. Survival and growth of foodborne pathogens in minimally processed vegetables at 4 and 15 C. J. Food Sci., 77(1):M48-M50. RDA(Rural Development Administration). 2013. Strawberry, pp. 20. Statistics Korea. Korean Statistical Information Service (http:// kosis.kr). Lee, C. Y., Lee, W. G., Song, J. E., Kim, K. Y., Shim, W. B., Yoon, Y. H., Kim, Y. S. and Chung, D. H. 2012. Hazard analysis for the cultivation stage of strawberry farms for securing preliminary data to establish the Good Agricultural Practices. J. Agric. Life Sci., 46(3):97-108. Centers for Disease Control and Prevention (CDC). 2007. Morbidity and mortality weekly report (MMWR). 56(35):909-911.

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