• 제목/요약/키워드: Disease control

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Bacteriophages: A New Weapon for the Control of Bacterial Blight Disease in Rice Caused by Xanthomonas oryzae

  • Ranjani, Pandurangan;Gowthami, Yaram;Gnanamanickam, Samuel S;Palani, Perumal
    • 한국미생물·생명공학회지
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    • 제46권4호
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    • pp.346-359
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    • 2018
  • Xanthomonas oryzae, a bacterial pathogen causing leaf blight disease (BLB) in rice, can cause widespread disease and has caused epidemics globally, resulting in severe crop losses of 50% in Asia. The pathogen is seed-borne and is transmitted through seeds. Thus, control of BLB requires the elimination of the pathogen from seeds. Concern about environment-friendly organic production has spurred improvements in a variety of biological disease control methods, including the use of bacteriophages, against bacterial plant pathogens. The present study explored the potential of bacteriophages isolated from diseased plant leaves and soil samples in killing the bacterial pathogen in rice seeds. Eight different phages were isolated and evaluated for their bacteriolytic activity against different pathogenic X. oryzae strains. Of these, a phage designated ${\varphi}XOF4$ killed all the pathogenic X. oryzae strains and showed the broadest host range. Transmission electron microscopy of ${\varphi}XOF4$ revealed it to be a tailed phage with an icosahedral head. The virus was assigned to the family Siphoviridae, order Caudovirales. Seedlings raised from the seeds treated with $1{\times}10^8pfu/ml$ of ${\varphi}XOF4$ phage displayed reduced incidence of BLB disease and complete bacterial growth inhibition. The findings indicate the potential of the ${\varphi}XOF4$ phage as a potential biological control agent against BLB disease in rice.

Children with COVID-19 after Reopening of Schools, South Korea

  • Kim, Eun Young;Ryu, Boyeong;Kim, Eun Kyoung;Park, Young-Joon;Choe, Young June;Park, Hye Kyung;Jeong, Eun Kyeong
    • Pediatric Infection and Vaccine
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    • 제27권3호
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    • pp.180-183
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    • 2020
  • 목적: 국내 초중고 학교 등교재개 이후 소아에서의 코로나바이러스감염증-2019 (코로나19) 사례의 감염경로를 파악하고자 하였다. 방법: 2020년 5월 1일부터 7월 12일까지 국가감염병감시체계에 신고된 3-18세 소아 청소년 코로나19 확진자의 사례조사서 및 역학조사서를 분석하였다. 결과: 2020년 5월 국내 초중고 학교 등교 재개 이후 7월 12일까지 총 127명의 소아 청소년 코로나19 확진자가 신고되었다. 그 중 59명(46%)은 가족 및 친지로부터 전파된 사례였으며 18명(14%)은 학원 및 개인교습 중 전파되었다. 8명(6%)은 다중이용 시설에서 전파되었으며 3명(2%)은 학교에서 전파된 사례였다. 결론: 코로나19 감염예방을 위한 관리체계가 사전에 마련되고 준비된 경우 학교 내 코로나19 전파는 드물게 나타났다.

Enhancement of Disease Control Efficacy of Chemical Fungicides Combined with Plant Resistance Inducer 2,3-Butanediol against Turfgrass Fungal Diseases

  • Duraisamy, Kalaiselvi;Ha, Areum;Kim, Jongmun;Park, Ae Ran;Kim, Bora;Song, Chan Woo;Song, Hyohak;Kim, Jin-Cheol
    • The Plant Pathology Journal
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    • 제38권3호
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    • pp.182-193
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    • 2022
  • Turfgrass, the most widely grown ornamental crop, is severely affected by fungal pathogens including Sclerotinia homoeocarpa, Rhizoctonia solani, and Magnaporthe poae. At present, turfgrass fungal disease management predominantly relies on synthetic fungicide treatments. However, the extensive application of fungicides to the soil increases residual detection frequency, raising concerns for the environment and human health. The bacterial volatile compound, 2,3-butanediol (BDO), was found to induce plant resistance. In this study, we evaluated the disease control efficacy of a combination of stereoisomers of 2,3-BDO and commercial fungicides against turfgrass fungal diseases in both growth room and fields. In the growth room experiment, the combination of 0.9% 2R,3R-BDO (levo) soluble liquid (SL) formulation and 9% 2R,3S-BDO (meso) SL with half concentration of fungicides significantly increased the disease control efficacy against dollar spot and summer patch disease when compared to the half concentration of fungicide alone. In field experiments, the disease control efficiency of levo 0.9% and meso 9% SL, in combination with a fungicide, was confirmed against dollar spot and large patch disease. Additionally, the induction of defense-related genes involved in the salicylic acid and jasmonic acid/ethylene signaling pathways and reactive oxygen species detoxification-related genes under Clarireedia sp. infection was confirmed with levo 0.9% and meso 9% SL treatment in creeping bentgrass. Our findings suggest that 2,3-BDO isomer formulations can be combined with chemical fungicides as a new integrated tool to control Clarireedia sp. infection in turfgrass, thereby reducing the use of chemical fungicides.

만성질환아의 자기관리에 대한 개념 분석 (Concept Analysis of the Self Management in Children with Chronic Disease)

  • 이숙영
    • 한국보건간호학회지
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    • 제31권1호
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    • pp.121-134
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    • 2017
  • Purpose: The goal of this study was to define and clarify the concept of "self management" of children with chronic diseases. Methods: For analyzing the concept of self management, this study used the hybrid model. This study involved in-depth interviewing nine children with chronic disease. Results: The concept of self management of children with chronic disease can be categorized with three dimensions: internal, environmental, and behavioral aspects. Besides, five attributes and thirteen indicators were analyzed. The concept of self management of children with chronic disease can be expressed as a kind of process; a) re-established yourself (internal dimension), b) assistance by the surrounded (environmental dimension), and c) positive health management behavior with self control of daily life (behavioral dimension). Conclusion: The self management is important for children with chronic disease to control their disease for long time. The attributes and indicators drawn by this study could be used for tool development and useful resources of self management competence in children with chronic disease.

Larval Chigger Mites Collected from Small Mammals in 3 Provinces, Korea

  • Lee, In-Yong;Song, Hyeon-Je;Choi, Yeon-Joo;Shin, Sun-Hye;Choi, Min-Kyung;Kwon, So-Hyun;Shin, E-Hyun;Park, Chan;Kim, Heung-Chul;Klein, Terry A.;Park, Kyung-Hee;Jang, Won-Jong
    • Parasites, Hosts and Diseases
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    • 제52권2호
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    • pp.225-229
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    • 2014
  • A total of 9,281 larval chigger mites were collected from small mammals captured at Hwaseong-gun, Gyeonggi-do (Province) (2,754 mites from 30 small mammals), Asan city, Chungcheongnam-do (3,358 mites from 48 mammals), and Jangseong-gun, Jeollanam-do (3,169 for 62 mammals) from April-November 2009 in the Republic of Korea (= Korea) and were identified to species. Leptotrombidium pallidum was the predominant species in Hwaseong (95.8%) and Asan (61.2%), while Leptotrombidium scutellare was the predominant species collected from Jangseong (80.1%). Overall, larval chigger mite indices decreased from April (27.3) to June (4.9), then increased in September (95.2) and to a high level in November (169.3). These data suggest that L. pallidum and L. scutellare are the primary vectors of scrub typhus throughout their range in Korea. While other species of larval chigger mites were also collected with some implications in the transmission of Orientia tsutsugamushi, they only accounted for 11.2% of all larval chigger mites collected from small mammals.

2016년도 국내 해양환경내 병원성 비브리오균의 분포 및 해양환경인자간의 상관성 분석 (Distribution of Pathogenic Vibrios in the Aquatic Environment Adjacent to Coastal Areas of South Korea and Analysis of the Environmental Factors Affecting Their Occurrence)

  • 정영일;명고은;최은진;소상문;박기준;손태종
    • 한국환경보건학회지
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    • 제44권2호
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    • pp.133-142
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    • 2018
  • Objectives: The pathogenic Vibrios genus denotes halophilic bacteria that are distributed in aquatic environments, including both sea and freshwater. Vibrio cholerae, Vibrio vulnificus, and Vibrio parahaemolyticus are the most important species since they can be potent human pathogens and leading causes of septicemia, wound infections, and seafood borne gastroenteritis. The recent emergence of a potential pandemic clone, V. cholera serotype O1 and the cholera outbreak in South Korea in 2016 indicates the importance of consistent surveillance of pathogenic Vibrio genus within coastal areas. Methods: The present study was undertaken to determine where and how vibrios live in the aquatic environment adjacent to coastal areas of South Korea. For this survey, a total of 838 samples were obtained at 35 different sites in South Korean coastal areas during the period from January 2016 to December 2016. Pathogenic vibrios was determined using the real-time PCR method, and its clones were isolated using three selective plating media. We also monitored changes in seawater and atmospheric temperature, salinity, turbidity, and hydrogen ion concentration at the collection points. Results: The total isolation rates of V. vulnificus, V. cholera (non-pathogenic, non-O1, non-O139 serogroups), and V. parahaemolyticus from seawater specimens in 2016 were 14.2, 13.48, and 67.06%, respectively. Conclusions: The isolation rates of pathogenic vibrios genus showed a positive correlation with temperature of seawater and atmosphere but were negatively correlated with salinity and turbidity.

Prevalence and Risk Factors for Opisthorchis viverrini Infections in Upper Northeast Thailand

  • Thaewnongiew, Kesorn;Singthong, Seri;Kutchamart, Saowalux;Tangsawad, Sasithorn;Promthet, Supannee;Sailugkum, Supan;Wongba, Narong
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권16호
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    • pp.6609-6612
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    • 2014
  • Opisthorchis viverrini is an ongoing public health problem in Northeast Thailand. Despite continuous efforts for decades by healthcare organizations to overcome this problem, infection rates remain high. To enable related personnel to identify and address the various issues effectively, a cross-sectional study was performed to investigate prevalence and risk factors for opisthorchiasis. The target group was 3,916 Thai residents of Northeast Thailand who were 15 or over. Participants were recruited using the 30 clusters sampling technique. The data were gathered through questionnaires, focus group discussions, in-depth interviews, and stool examinations for parasite eggs (using the Modified Kato Katz method). The data were analyzed using descriptive and inference statistics; in order to ascertain the risk factors and test them using the odds ratio and multiple logistic regressions. The prevalence of opisthorchiasis was 22.7% (95%CI: 0.26 to 0.24). The province with the highest prevalence was Nakhorn Phanom (40.9%; female to male ratio =1:1.2). The age group with the highest prevalence was 40-49 year olds. All age groups had a prevalence >20%. Four of seven provinces had a prevalence >20%. The factors related to opisthorchiasis were (a) sex, (b) age (especially > 50), (c) proximity and duration living near a water body, and (d) eating raw and/or fermented fish. In order to reduce the prevalence of opisthorchiasis, the focus in populations living in upper Northeast Thailand should be changing their eating behaviors as appropriate to their tradition and context.

Prevalence of Enterobius vermicularis among Preschool Children in Muan-gun, Jeollanam-do, Korea

  • Hong, Sung-Hee;Jeong, Young-Il;Lee, Jin-Hee;Cho, Shin-Hyeong;Lee, Won-Ja;Lee, Sang-Eun
    • Parasites, Hosts and Diseases
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    • 제50권3호
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    • pp.259-262
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    • 2012
  • We assessed the prevalence of Enterobius vermicularis infection and changes in the egg positive rate (EPR) over 1-year time, using the adhesive cellophane-tape perianal swab method in 2,347 preschool children in Muan-gun, Jeollanam-do, Republic of Korea in 2008 and 2009. The overall EPR for E. vermicularis was 4.1% in 2008 and 4.5% in 2009. A study population of 389 children was repeatedly examined for 2 years. Within this group, the EPR in 2009 was twice higher than in 2008, and the EPR of the group of 5-7-year-old children was significantly higher than that of other age groups. Moreover, in the group of 5-7-year-old children in 2009, the rates of positive and negative conversion were significantly higher and lower, respectively, than in other age groups. Conclusively, enterobiasis was prevalent during 2008-2009 among preschool children in Muan-gun, Jeollanam-do, and the increased EPR in 2009 was due to an increase in newly acquired infections among 5-7-year-old children.

토마토 잎곰팡이병에 대한 키토산 제제의 방제 효과 (Disease Control Efficacy of Chitosan Preparations against Tomato Leaf Mold)

  • 장태현
    • 식물병연구
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    • 제15권3호
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    • pp.248-253
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    • 2009
  • 항균활성을 가진 키토산은 우리나라 포장에서 다양한 식물 방제와 식물 생장을 위해 넓게 사용하고 있다. 고분자와 저분자(키토올리고당)의 키토산 화합물을 혼합한 2가지 제제(SH-1, SH-2)에 대한 병 방제 효과를 Fulvia fulva에 의해 발생하는 토마토 잎곰팡이병에 대하여 비닐하우스에서 조사하였다. 두 제제(SH-1, SH-2)는 두 번의 포장 시험에서 병 방제에 대한 활성을 나타내었다. 두 제제의 예방적인 병 방제에 대한 활성은 합성농약인 thiophanate-M과 비교하여 수행하였다. 병 방제를 위한 제형의 활성유지는 살포 후 21일까지 지속되었다. 병 방제를 위한 키토산의 효과적인 농도는 1,200 mg a.i/L였다. 포트시험에서 키토산 제제는 600 mg a.i/L 농도에서 식물생장이 증진되었다. 결과적으로 키토산 제제는 토마토 잎곰팡이병방제를 위한 친환경제제로서 활력을 가지며 식물생장도 촉진하였다.

The Relative Influence of Diet and Physical Activity on Obesity in China

  • Cui Zhao-Hui;Li Yan-Ping;Di Yu-Feng;Ba Lei;Hu Xiaoqi;Ma Guan-Sheng
    • Journal of Community Nutrition
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    • 제6권3호
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    • pp.125-130
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    • 2004
  • The purpose of this study is to investigate the relative influence of diet and physical activity on obesity. The subjects were 155 adults aged 35-52 years from 24 neighborhood committees in 4 urban districts of Beijing (male : 78, female : 77). They were divided into normal weight, overweight and obese groups according to their BMI. The general information of the subjects was collected by interview-administered questionnaire. Dietary intake was obtained by three-day(two weekdays and one weekend day) food weighted method, physical activity was assessed by a validated combination of data obtained from activity monitors, bicycling information and activity records. There were no significant differences of age, gender, height, educational, family economic level, smoking and drinking between different groups. The proportion of flour intake was higher in obese group compared to normal weight and overweight groups, and that of vegetables is lower in obese group. The physical activity (PAL) was not significantly different between two groups of the normal, overweight and obese groups. After the adjustment for confounding factors using logistic regression model, we found that the proportion of flour intake was positively associated with obesity, while the proportion of vegetable intake was inversely associated with obesity. It is concluded that dietary patterns were associated with obesity and diets composed of more vegetables and less staple combined with physical activities could contribute to obesity prevention.