쪽파로부터 분리된 유산균의 병원성균에 대한 항균활성

김길하,김완섭,Gil-Ha Kim,Natsag Lkhagvasuren,Batchimeg Namshir,Woan Sub Kim 한국낙농식품응용생물학회 2023 Journal of Dairy Science and Biotechnology (JMSB) Vol.41 No.3

In this study, we isolated lactic acid bacteria from Allium wakegi and examined the usability of culture supernatants obtained from these lactic acid bacteria. The antibacterial activity of the culture supernatant obtained from the isolated lactic acid bacteria against the pathogens Escherichia and Salmonella spp. was measured. The obtained lactic acid bacteria culture medium showed significant antibacterial activity against pathogenic bacteria in a dose-dependent manner. The effects of pH and heat denaturation on the observed anti-pathogenic bacterial activity was also investigated. Adjusting the culture supernatant to pH 7 resulted in loss of all antibacterial activity against pathogenic bacteria, suggesting that the antibacterial activity of the obtained culture supernatant against pathogenic bacteria is influenced by organic acids. Assessment of the heat stability of the anti-pathogenic bacterial activity revealed that heat treatment did not diminish activity. The obtained lactic acid bacteria culture medium is thus stable against heat.

즉석 섭취 야채샐러드의 미생물 오염조사

김진숙,방옥균,장해춘 한국식품위생안전성학회 2004 한국식품위생안전성학회지 Vol.19 No.2

식용이 간편한 즉석섭취용(ready-to-eat) 샐러드 제품의 수요는 나날이 증가하고 있으나 국내 유통 샐러드의 미생물오염수준은 기준 및 규격이 설정되어있지 않고 그 수준 또한 알려져 있지 않다. 따라서 소비가 집중되어 있는 대도시 지역을 중심으로 백화점, 대형할인점 또는 패밀리레스토랑 등에서 판매되는 즉석섭취용 샐러드 제품 120건을 대상으로 하여 coliform bacteria, E. coli, E. coli O157:H7, Staphylococcus aureus, Salmonella spp. Listeria monocytogenes 및 Bacillus cereus의 분리시험을 실시하고 일부 제품을 대상으로 일반세균수 및 세척효과를 조사하였다. 제품 120건 중 총 73건에서 coliform bacteria 둥이 검출되어 60.8%의 검출율을 보였다. E. coli가 17건, Staphylococcus aureus가 3건, Salmonella spp.가 1건에서 각각 검출되었고 기타 coliform bacteria는 59건에서 검출되었다. 샐러드는 양식방법에 따라 유기농샐러드와 비유기농샐러드로 나누었고, 종류는 야채로 구성된 야채샐러드와 튀긴 닭 등이 첨가된 혼합샐러드로 나누었으며 판매형태에 따라 완포장제품과 샐러드바 제품으로 나누었다. 양식방법 및 포장방법과 미생물오염과의 통계적 연관성은 없는 것으로 나타났다. 그러나 분리된 균주 수에 있어서는 야채샐러드와 혼합샐러드 간에 통계적으로 유의한 차를 보여 야채샐러드의 경우 좀 더 다양한 균종이 분리되는 것으로 나타났다 (p<0.005). E. coli는 일반 재배 야채샐러드의 경우 90건 중 10건에서 분리되었고 유기농재배 야채샐러드의 경우 30건 중 1건에서 분리되었다. 식중독 원인균은 비유기농 재배 야채샐러드 4건에서 Staphylococcus aureus가, 1건에서 Salmonella arizonia가 검출되었으나 유기농재배 야채에서는 검출되지 않았다. 널리 판매되는 일부 제품 4종을 5회에 걸쳐 검사한 결과 총 호기성 세균수는 평균 4.8±0.19 log_(10) cfu/g으로 조사되었다. 같은 제품을 생리식염수와 야채용세척제를 이용해 3분간 침지 후 세척효과를 본 결과 생리식염수는 5회, 야채용세척제는 1회 세척 시 95.5%의 세척효과를 내는 것으로 나타났다. 120 samples of ready-to-eat salad product were purchased at department stores, marts and family restaurants in metro area. Coliform bacteria and food borne pathogenic bacteria were isolated from these samples. In 73 samples among the 120 salad product samples, coliform bacteria and food borne pathogenic bacteria were detected by 60.8% of isolated rate. Salad were classified into organic and non-organic salad. According to a salad type, salad were classified into vegetable salad and mixed vegetable salad with fried chicken and extra food. According to a packing type, packed salad product and salad-bar product were classified. After the classification, the results of each cases were compared. There is no statistical relation between cultivation or packing methods and contaminated bacteria. But the incidence number of microbial strains was significantly different between vegetable salad and mixed vegetable salad(p<0.005). In vegetable salad, more various strains were detected. E. colt was isolated in 10 cases among the 90 cases in non-organic vegetable and in 7 cases among the 30 cases in organic salad. Food borne pathogenic bacteria were isolated in non-organic vegetable salad product. Staphylococcus aureus was isolated in 4 cases of vegetable salad product and Salmonella spp. isolated in 1 case. After 5 times examination of each 4 market products, the total number of aerobic bacteria was average 4.8 ± 0.19 log cfu/g. One sample from this product, saline and a detergent for vegetable were used for 3 minutes to notice the effect. As a result, when saline was used 5 times and detergent for vegetable was used I time, bacterial contamination was decreased up to 95.5%.

Effects of sterilization methods on the survival of pathogenic bacteria in potting soil stored at various temperatures

현정은,이수빈,정도영,김세리,최송이,황인준 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.1

Fresh food products can be contaminated with pathogenic bacteria in various agricultural environments. Potting soil is sterilized by heat sterilization and then reused. This study evaluated the effects of three sterilization methods (non-sterilized, pasteurized, and sterilized) on the survival of pathogenic bacteria in potting soil during storage for 60 days at 5, 15, 25, and 35 °C. The reduction in Escherichia coli O157:H7, Salmonella Typhimurium, and Staphylococcus aureus in potting soil was higher at higher temperatures (25 and 35 °C) than at lower temperatures (5 and 15 °C). The population of pathogenic bacteria in pasteurized and sterilized potting soil was reduced below the detectable levels within 30 days at 35 °C. In contrast, the population of Bacillus cereus did not change in potting soil during storage for 60 days at all temperatures. These results indicate that sterilization and storage temperature of potting soil are critical factors influencing the survival of pathogenic bacteria.

Food Science/microbiology : Article ; Endophytic Bacterial Diversity in the Young Radish and Their Antimicrobial Activity against Pathogens

( Weon Taek Seo ),( Woo Jin Lim ),( Eun Jin Kim ),( Han Dae Yun ),( Young Han Lee ),( Kye Man Cho ) 한국응용생명화학회 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.4

Endophytic bacteria have several ecological roles and can be used as biocontrol agents and also participate in antibiosis interactions. The diversity of endophytic bacteria associated with young radish (YR, yeulmu, Raphanus sativus L.) leaves and roots from Gyeongnam Agricultural Research and Extension Services in Jinju, Korea was investigated. A total of 264 colonies were isolated from the interior of YR leaves and roots. Phylogenetic analysis based on 16S rDNA sequences indicated that the isolates belonged to four major phylogenetic groups: high G+C Gram positive bacteria, low G+C Gram positive bacteria, Proteobacteria, and Bacteroidetes. Endophytic bacteria from the phylum Proteobacteria were predominant in the leaf (61.3%) and root (52.1%) samples. Most colonies that exhibited extracellular enzymatic activity belonged to the genus Bacillus, and Bacillus subtilis (YRL02, YRL07, YRR03, and YRR10) exhibited the stronger activities in extracellular enzyme such as amylase, cellulase, xylanase, mannase, PGAase, DNase, protease, and esterase than other colonies. In addition, Enterobacter sp. YRL01 and B. subtilis YRL02 had the highest amount of inhibitory action against human pathogenic bacteria, while B. subtilis YRR10 hand an inhibitory action against plant pathogenic fungi. Thus, these bacteria can be used as biocontrol agents against human and plant pathogens.

젓갈류에서의 위생지표 미생물 및 식중독균 모니터링을 통한 미생물학적 연구

이선미,임종미,김기현,조수열,박건상,신영민,정지연,조준일,유현정,김규헌,조대현,임철주,김옥희 한국식품위생안전성학회 2008 한국식품위생안전성학회지 Vol.23 No.3

In this study, microbial investigation is accomplished for 554 Jeot-kal samples (102 of Jeot-kal, 448 of Seasoned Jeot-kal and 4 of Sik-khe, respectively) that corresponds with Coliform-bacteria, Escherichia coli, Aerobic live bacteria as hygienic indicator microorganisms, and Staphylococcus aureus, Vibrio parahaemolyticus as Food-borne pathogenic microorganisms. Based on the methods in Korea Food Code, reliable data are obtained as follows; in 31.9% rate of the samples, Coliform bacteria are verified in the extent of 0~20,000 CFU/g as 2.3 logCFU/g. Especially, Seasoned Jeot-kal (37.7%, 2.3 logCFU/g) are detected to 6 and 2 folds higher than those of Jeot-kal, 5.9% and 1.4 logCFU/g. Likewise, Escherichia coli is detected from 9 samples only in Seasoned Jeot-kal, that includes seasoned squid, seasoned octopus, seasoned roe of pollack, seasoned large-eyed herring and seasoned hairtail. Aerobic live bacteria are also detected in the range of 0~8.9 × 108 CFU/g. Against salinity, E. coli are detected in samples only less than 10% salinity. Concomitantly, aerobic live bacteria count is decreased to 5.5~3.6 log CFU/g upon the salinity is increased up to 25%. However, S. aureus and V. parahaemolyticus are not detected in 554 samples, presumptively referring Jeot-kal products are somehow free from such food-borne pathogens. As the results above, we deliberately consider that the sanitary control in Jeot-kal, which be necessarily fermented- as well as non-microbially inactivated should be ensured in near future and also suggest an effectual microbial standard corresponding to the Negativity in E. coli for Jeot-kal products. In this study, microbial investigation is accomplished for 554 Jeot-kal samples (102 of Jeot-kal, 448 of Seasoned Jeot-kal and 4 of Sik-khe, respectively) that corresponds with Coliform-bacteria, Escherichia coli, Aerobic live bacteria as hygienic indicator microorganisms, and Staphylococcus aureus, Vibrio parahaemolyticus as Food-borne pathogenic microorganisms. Based on the methods in Korea Food Code, reliable data are obtained as follows; in 31.9% rate of the samples, Coliform bacteria are verified in the extent of 0~20,000 CFU/g as 2.3 logCFU/g. Especially, Seasoned Jeot-kal (37.7%, 2.3 logCFU/g) are detected to 6 and 2 folds higher than those of Jeot-kal, 5.9% and 1.4 logCFU/g. Likewise, Escherichia coli is detected from 9 samples only in Seasoned Jeot-kal, that includes seasoned squid, seasoned octopus, seasoned roe of pollack, seasoned large-eyed herring and seasoned hairtail. Aerobic live bacteria are also detected in the range of 0~8.9 × 108 CFU/g. Against salinity, E. coli are detected in samples only less than 10% salinity. Concomitantly, aerobic live bacteria count is decreased to 5.5~3.6 log CFU/g upon the salinity is increased up to 25%. However, S. aureus and V. parahaemolyticus are not detected in 554 samples, presumptively referring Jeot-kal products are somehow free from such food-borne pathogens. As the results above, we deliberately consider that the sanitary control in Jeot-kal, which be necessarily fermented- as well as non-microbially inactivated should be ensured in near future and also suggest an effectual microbial standard corresponding to the Negativity in E. coli for Jeot-kal products.

Endophytic Bacterial Diversity in the Young Radish and Their Antimicrobial Activity against Pathogens

Seo, Weon-Taek,Lim, Woo-Jin,Kim, Eun-Jin,Yun, Han-Dae,Lee, Young-Han,Cho, Kye-Man The Korean Society for Applied Biological Chemistr 2010 Applied Biological Chemistry (Appl Biol Chem) Vol.53 No.4

Endophytic bacteria have several ecological roles and can be used as biocontrol agents and also participate in antibiosis interactions. The diversity of endophytic bacteria associated with young radish (YR, yeulmu, Raphanus sativus L.) leaves and roots from Gyeongnam Agricultural Research and Extension Services in Jinju, Korea was investigated. A total of 264 colonies were isolated from the interior of YR leaves and roots. Phylogenetic analysis based on 16S rDNA sequences indicated that the isolates belonged to four major phylogenetic groups: high G+C Gram positive bacteria, low G+C Gram positive bacteria, Proteobacteria, and Bacteroidetes. Endophytic bacteria from the phylum Proteobacteria were predominant in the leaf (61.3%) and root (52.1%) samples. Most colonies that exhibited extracellular enzymatic activity belonged to the genus Bacillus, and Bacillus subtilis (YRL02, YRL07, YRR03, and YRR10) exhibited the stronger activities in extracellular enzyme such as amylase, cellulase, xylanase, mannase, PGAase, DNase, protease, and esterase than other colonies. In addition, Enterobacter sp. YRL01 and B. subtilis YRL02 had the highest amount of inhibitory action against human pathogenic bacteria, while B. subtilis YRR10 hand an inhibitory action against plant pathogenic fungi. Thus, these bacteria can be used as biocontrol agents against human and plant pathogens.

사료자원에 서식하는 세균의 소화효소활성, 항생제내성 및 병원성에 관한 특성

이권정 ( Kwon Jung Yi ),조상섭 ( Sang Seop Cho ),김수기 ( Soo-ki Kim ) 한국가축위생학회 2017 韓國家畜衛生學會誌 Vol.40 No.2

Among different types of spoilage, microbial contamination can cause feed decomposition, which results in decreases in feed intake and productivity, infection, and breeding disorder. During the storage time, various microbes have a chance to inoculate with depreciation of feed and to infect the animals. We investigated bacteria that inhabit diverse feed ingredients and complete feed which have been stored for a few months. We isolated and identified 30 genera and 62 species of bacteria. Among these 62 species, 21 species were of non-pathogenic bacteria, 18 species were of pathogenic bacteria, 9 species were of opportunistic pathogens, and 14 species were of unknown bacteria. Pantoea allii and 24 species showed proteolytic enzyme activity. We also confirmed that 6 species including Pseudomonas psychrotolerans showed α-amylase activity, and 29 species including Burkholderia vietnamiensis showed cellulase activity. Microbacterium testaceum and 3 species showed resistance to Ampicillin, Kanamycin, Streptomycin, Gentamicin, Carbenicillin, and Erythromycin (50 μg/mL). Using mealworm larvae (Tenebrio molitor L.) as a model for pathogenicity, we confirmed that 8 species including Staphylococcus xylosus had pathogenicity for mealworm larvae. Especially, Enterobacter hormaechei, Staphylococcus xylosus, and Staphylococcus hominis were reported as being pathogenic for humans. This research suggests that hygienic management of animal feed is essential because beneficial and harmful bacteria can inhabit animal feed differently during storage and distribution.

CRISPR/Cas 시스템 기술을 활용한 고위험성 식중독 세균 신속 검출을 위한 바이오센서 개발

조선영,박종필 한국식품위생안전성학회 2023 한국식품위생안전성학회지 Vol.38 No.5

Rapid and accurate detection of pathogenic bacteria is crucial for various applications, including public health and food safety. However, existing bacteria detection techniques have several drawbacks as they are inconvenient and require time-consuming procedures and complex machinery. Recently, the precision and versatility of CRISPR/Cas system has been leveraged to design biosensors that offer a more efficient and accurate approach to bacterial detection compared to the existing techniques. Significant research has been focused on developing biosensors based on the CRISPR/Cas system which has shown promise in efficiently detecting pathogenic bacteria or virus. In this review, we present a biosensor based on the CRISPR/Cas system that has been specifically developed to overcome these limitations and detect different pathogenic bacteria effectively including Vibrio parahaemolyticus, Salmonella, E. coli O157:H7, and Listeria monocytogenes. This biosensor takes advantage of the CRISPR/Cas system's precision and versatility for more efficiently accurately detecting bacteria compared to the previous techniques. The biosensor has potential to enhance public health and ensure food safety as the biosensor’s design can revolutionize method of detecting pathogenic bacteria. It provides a rapid and reliable method for identifying harmful bacteria and it can aid in early intervention and preventive measures, mitigating the risk of bacterial outbreaks and their associated consequences. Further research and development in this area will lead to development of even more advanced biosensors capable of detecting an even broader range of bacterial pathogens, thereby significantly benefiting various industries and helping in safeguard human health

Recent advances in magnetic nanoparticle-based microfluidic devices for the pretreatment of pathogenic bacteria

Hyunsoo Han,Bokyeong Sohn,Jihun Choi,Sangmin Jeon 대한의용생체공학회 2021 Biomedical Engineering Letters (BMEL) Vol.11 No.4

Rapid and sensitive detection of pathogenic bacteria in various samples, including food and drinking water, is important to prevent bacterial diseases. Most bacterial solutions contain only a small number of bacteria in complex matrices with impurities; hence, pretreatment is necessary to separate and concentrate target bacteria before sensing. Among various pretreatment methods, iron oxide magnetic nanoparticle (MNP)-based pretreatment has drawn attention owing to the unique properties of MNP, such as high magnetic susceptibility, superparamagnetism, and biocompatibility. After target bacteria are captured by recognition molecule-functionalized MNPs, bacteria–MNP complexes can be easily separated and enriched by applying an external magnetic field. Various devices, such as optical, electrochemical, and magnetoresistance sensors, can be used to detect target bacteria, and their detection principles have been discussed in numerous review papers. Herein, we focus on recent research advances and challenges in magnetic pretreatment of pathogenic bacteria using microfluidic devices, which offer the advantages of process automation and miniaturization.

Bacteriophage Usage for Bacterial Disease Management and Diagnosis in Plants

Nguyen Trung Vu,Chang-Sik Oh 한국식물병리학회 2020 Plant Pathology Journal Vol.36 No.3

In nature, plants are always under the threat of pests and diseases. Pathogenic bacteria are one of the ma- jor pathogen types to cause diseases in diverse plants, resulting in negative effects on plant growth and crop yield. Chemical bactericides and antibiotics have been used as major approaches for controlling bacterial plant diseases in the field or greenhouse. However, the appearance of resistant bacteria to common antibiot- ics and bactericides as well as their potential negative effects on environment and human health demands bacteriologists to develop alternative control agents. Bacteriophages, the viruses that can infect and kill only target bacteria very specifically, have been demon- strated as potential agents, which may have no negative effects on environment and human health. Many bac- teriophages have been isolated against diverse plant- pathogenic bacteria, and many studies have shown to efficiently manage the disease development in both controlled and open conditions such as greenhouse and field. Moreover, the specificity of bacteriophages to cer- tain bacterial species has been applied to develop detec- tion tools for the diagnosis of plant-pathogenic bacteria. In this paper, we summarize the promising results from greenhouse or field experiments with bacteriophages to manage diseases caused by plant-pathogenic bacteria. In addition, we summarize the usage of bacteriophages for the specific detection of plant-pathogenic bacteria.