회원논단 : 미생물 시험법의 분석원리와 국가별 공인시험법 운영 현황 분석

방현조 ( Hyeon Jo Bang ),이승훈 ( Seung Hun Lee ),김용수 ( Yong Soo Kim ),김상필 ( Sang Pil Kim ),이우정 ( Woo Jung Lee ),하상도 ( Sang Do Ha ) 한국식품위생안전성학회 2015 Safe Food Vol.10 No.3

다슬기(Semisulcospira libertine)의 미생물 오염도 평가 및 해감 제거공정에 따른 저감화 효과

최만석,전은비,최승호,방현조,박신영 한국식품위생안전성학회 2019 한국식품위생안전성학회지 Vol.34 No.4

In this study, microbial contamivation semisulcospira libertine and effect of sedimentation treatment of major bacterial and fungal pathogens were investigated. The total aerobic bacteria, coliforms, Escherichia coli, Staphylococcus aureus, and yeast and mold present in raw and water-dipped Semisulcospira libertine were enumerated using the standard plate count methods on using the standard plate method on potato dextrose agar (PDA), 3M Petrifilm for coliforms / E. coli, 3M Petrifilm for S. aureus, and plate count agar (PCA), respectively. In analysis of microbial contamination of raw Semisulcospira libertine, the total aerobic bacteria, coliforms, and yeast and mold were monitored as 6.40, 2.70, and 6.79 log 10 CFU/g, respectively. Both E. coli and S. aureus were not detected (detection limit: 10 CFU/g). However, Semisulcospira libertine dipped in ground water for 3 hours had higher contamination levels of all natural indigenous microorganisms than raw Semisulcospira libertine. Especially, E. coli was detected as 2.46 log 10 CFU/g in the ground water-dipped Semisulcospira libertine. The total aerobic bacteria in the ground water-dipped Semisulcospira libertine was not significantly reduced (p>0.05) compared to that in the raw Semisulcospira libertine. Moreover, coliforms were significantly increased (p>0.05) in all water-dipped Semisulcospira libertine. Only fungi were slightly reduced (less than 0.2 log) (p>0.05) in the tap water-dipped Semisulcospira libertine by comparison with the raw Semisulcospira libertine. The results of this study suggest that the use of chemical sterilizing agents and other physical methods in the washing stage will be necessary for the microbial reduction in raw Semisulcospira libertine because the use of sediment removal treatment by ground or tap water did not affect the microbiological safety of the raw Semisulcospira libertine.

축·수산·전통식품 중 황색포도상 구균의 정량적 분석을 위한 Petrifilm^TM Staph Express Count Plate의 성능 평가

유윤정,최유나,최승호,방현조,윤요한,하지명,이수민,Yoo, Yoonjeong,Choi, Yuna,Choi, Seungho,Bang, Hyunjo,Yoon, Yohan,Ha, Jimyeong,Lee, Soomin 한국식품위생안전성학회 2019 한국식품위생안전성학회지 Vol.34 No.3

본 연구는 식품으로부터 S. aureus를 분리하는 데 사용되는 선택배지들의 성능을 평가하였다. 먼저 BPA와 MSEY agar의 민감도 비교를 통해 BPA를 선택하였고, 이 배지의 회수율을 $3M^{TM}$ $Petrifilm^{TM}$ Staph Express Count Plate(STX petrifilm)의 회수율과 비교하였다. 축산식품 중 돼지고기 주물럭과 육회용 꾸릿살, 수산식품 중 쥐포와 반건조 오징어, 전통식품 중 떡과 잡채를 선정하여 S. aureus를 접종한 후 BPA와 STX Petrifilm 배지를 사용하여 회수율 분석 실험을 실시하였다. 6가지 식품에 대해 인위적으로 S. aureus를 저농도에서부터 고농도까지 접종한 후 0시간과 24시간 후의 검출률을 측정하였다. 두 배지 간의 유의 수준을 분석한 결과 식품의 종류, 접종 농도에 관계없이 두 선택배지 간에 통계적 유의차는 없는 것으로 확인되었다(P>0.05). 따라서 STX Petrifilm은 BPA를 대체할 수 있을 뿐만 아니라 배지의 준비 및 도말에 소요되는 분석시간을 절감하고 배양에도 최소한의 공간이 필요하게 되어 신속, 정확한 분석에 크게 기여할 수 있을 것으로 판단된다. To enumerate Staphylococcus aureus in food, Baird-Parker Agar (BPA) is usually used in the conventional method, However it requires time and space for the preparation and plating, and incubation. Thus, use of the $3M^{TM}$ $Petrifilm^{TM}$ Staph Express Count Plate (STX Petrifilm) might be appropriate to solve these challenging problems. The purpose of this study was to compare the efficiency of STX Petrifilm with BPA for enumeration of S. aureus in various foods. A mixture of S. aureus strains ATCC29213, ATCC25923, and ATCC13565 was inoculated on marinated pork chop, beef (chuck tender), dried filefish, semi-dried squid, rice cake, and Japchae (stir-fried glass noodles) at 2, 3, 5, and 7 Log CFU/g. S. aureus cell counts were enumerated by spread-plating on STX Petrifilm and BPA after 0 and 24 hours at $4^{\circ}C$ (marinated pork chop, beef, semi-dried squid, and stir-fried glass noodles) and $25^{\circ}C$ (dried filefish and rice cake). Recovery of STX Petrifilm for S. aureus from various food samples was compared with BPA, and the results showed that there were no significant differences between two selective media in all cases. The results indicated that STX Petrifilm had enough efficiency to recover S. aureus from various foods as well as saving time and space.

축·수산·전통식품 중 황색포도상 구균의 정량적 분석을 위한 Petrifilm TM Staph Express Count Plate의 성능 평가

유윤정,최유나,최승호,방현조,윤요한,하지명,이수민 한국식품위생안전성학회 2019 한국식품위생안전성학회지 Vol.34 No.3

To enumerate Staphylococcus aureus in food, Baird-Parker Agar (BPA) is usually used in the conventional method, However it requires time and space for the preparation and plating, and incubation. Thus, use of the 3M TM Petrifilm TM Staph Express Count Plate (STX Petrifilm) might be appropriate to solve these challenging problems. The purpose of this study was to compare the efficiency of STX Petrifilm with BPA for enumeration of S. aureus in various foods. A mixture of S. aureus strains ATCC29213, ATCC25923, and ATCC13565 was inoculated on marinated pork chop, beef (chuck tender), dried filefish, semi-dried squid, rice cake, and Japchae (stir-fried glass noodles) at 2, 3, 5, and 7 Log CFU/g. S. aureus cell counts were enumerated by spread-plating on STX Petrifilm and BPA after 0 and 24 hours at 4 o C (marinated pork chop, beef, semi-dried squid, and stir-fried glass noodles) and 25 o C (dried filefish and rice cake). Recovery of STX Petrifilm for S. aureus from various food samples was compared with BPA, and the results showed that there were no significant differences between two selective media in all cases. The results indicated that STX Petrifilm had enough efficiency to recover S. aureus from various foods as well as saving time and space.

가정간편식(Home Meal Replacement, HMR) 샤브샤브 밀키트의 원료별 미생물 오염도 분석

전은비,김지윤,최만석,최승호,방현조,박신영 한국식품위생안전성학회 2020 한국식품위생안전성학회지 Vol.35 No.4

This study assessed the contamination levels of total aerobic bacteria, fungi, coliforms, Escherichia coli, Bacillus cereus, and Staphylococcus aureus and qualitative analysis of Salmonella spp. and Listeria monocytogens in six raw materials (beef, bean sprout, Chinese cabbage, king oyster mushroom, Korean cabbage, and sweet pumpkin) of home meal replacement (HMR) Shabu-Shabu meal kit distributed in markets. The total aerobic bacteria, fungi, and coliforms were detected as 3.98-6.50, 2.78-3.52, and 2.02-3.28 log CFU/g, respectively. Especially, beef was highly contaminated with total aerobic bacteria (6.50 log CFU/g) and coliforms (3.28 log CFU/g). Over 5 log CFU/g of total aerobic bacteria were also detected in bean sprout, Chinese cabbage, and sweet pumpkin. Less than < 2 log CFU/g of coliforms were detected in all vegetables. E. coli was not detected in any of the six samples (ND: < 1 log CFU/g). S. aureus was detected as 1.33-1.71 log CFU/g in most samples but it was not detected in beef and Korean cabbage. B. cereus was assessed as 1.15-2.01 log CFU/g in most samples but it was not detected in Korean cabbage. L. monocytogenes was qualitatively detected as 25-50% in most samples except for king oyster mushroom. Salmonella spp. were not qualitatively detected in any of the six samples. The microbial contamination levels determined in the current study may be potentially used as the basic data to execute microbial risk assessments of HMR foods such as Shabu-Shabu meal kit.

Listeria monocytogenes의 검출을 위한 loop-mediated isothermal amplification, real-time PCR, 배지 도말법의 검출 성능 및 특성 비교

변계환,한상하,최승호,방현조,강성일,김수경,하상도 한국식품저장유통학회 2022 한국식품저장유통학회지 Vol.29 No.3

Listeria monocytogenes is a foodborne pathogen causing listeriosis, which can be fatal in specific high-risk groups. The aim of this study was to compare the performance (accuracy, sensitivity, and specificity) of 3MTM Molecular Detection System (3MTM MDS) and Korean Food Codex [real-time PCR (RT-PCR) and selective agar] for the detection of L. monocytogenes in various food matrices. The detection performance of the three methods was determined against 100-103 CFU/mL of L. monocytogenes in vitro and showed high accuracy in the order of RT-PCR, 3MTM MDS, and selective agar. There was no difference in sensitivity and specificity of the three methods. Eleven food matrices, selected from agricultural, livestock, and seafood products, were artificially inoculated with 100-103 CFU/25 g of L. monocytogenes and enriched in 3MTM Demi-Fraser Broth. None of the three methods could completely detect low concentrations of L. monocytogenes in a food matrix. However, 3MTM MDS, which is a loop-mediated isothermal amplification (LAMP)-based technology for rapid detection, showed a higher positive detection rate than RT-PCR did, but lower than that of selective agar. These data indicated that 3MTM MDS was superior for the rapid detection of L. monocytogenes, compared to RT-PCR in food matrices containing various inhibitors. Consequentially, the study findings suggest that the LAMP method is a promising alternative to RT-PCR for the rapid detection of foodborne pathogens.