• Journal of Food Hygiene and Safety
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• v.39 no.1
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• pp.54-60
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• 2024

This study investigated the effectiveness of using pathogens and aqueous acids to reduce the Aspergillus ochraceus and Rhodotorula mucilaginosa contamination in livestock production environments. For this study, 1 mL of each bacterial suspension (10⁷-10⁸ spores/mL) was inoculated on a knife surface, dried at 37℃, and used under each treatment condition. First, to investigate the effect of organic acids, acetic, lactic, and citric acids were used. Subsequently, to select the appropriate concentration, they were prepared at concentrations of 0.5, 1, 2, 3, 4, and 5%, respectively. Accordingly, to further maximize the effect of organic acid treatment, we combined the treatment with ultraviolet light. The two strains showed a significant difference (P<0.05) compared to the initial strain, with a greater than 90% decrease in the concentrations of all organic acids. Consequently, acetic and lactic acids decreased by approximately 5 and 2 log colony forming unit (CFU)/cm², respectively, when treated with ultraviolet light (360 mJ/cm²); however, citric acid decreased by less than 1 log CFU/cm². However, when manufactured with 4% acetic acid, a severe malodor was emitted, making it difficult for workers to use it in a production environment. Accordingly, the optimal treatment conditions for organic acid and ultraviolet light for application were selected as follows: immersion in a 4% lactic acid solution for 1 minute and then, sterilization with ultraviolet light at 360 mJ/cm². Finally, when a pork meat sample was cut with a knife that was finally washed with lactic acid and treated with ultraviolet light, the low level of inoculum transferred from the cleaned knife to the surface of the sample was not detected. In conclusion, using this established method can prevent cross-contamination of the surface of the meat during processing.

• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.30-36
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• 2024

This study was conducted to determine the optimal working conditions when a recently developed blower-type onion stem cutter is utilized for cutting onion leaves at harvest time. The June 20 leaf cutting treatment group had the highest leaf dryness among the treatment groups (leaf dryness: 66.3%; leaf moisture content: 50.5%); the residual leaf length was 6.7 ± 3.5 cm. It is considered to have the best mechanical leaf cutting performance among the treatment groups because it is included in the optimal range of 4-10 cm. The average working speed of mechanical onion leaf cutting using the stem cutter was 0.17 m·s^-1, which is approximately 3.4 times faster than the average working speed of 0.05 m·s^-1 in the human leaf cutting treatment group. This is expected to save approximately 2.6 hours compared to human labor (based on one person) when working on a 10a area using this machine. In addition, the incidence of damaged bulbs in the machine leaf cutting treatment group was 1.3%, compared to 0.0% in the manual leaf cutting treatment group. This suggests that the mechanical leaf cutting treatment group had a higher average onion bulb decay rate during storage than the manual leaf cutting treatment group. When the storage characteristics of each treatment group were examined, the decay rate by bulb part (leaf connected or root connected) after 8 months of storage was higher in the treatment group with a residual leaf length of less than 5.0 cm after mechanical leaf cutting than in the treatment with a residual leaf length of more than 5.0 cm. This is thought to be due to the fact that treatments with a residual leaf length of less than 5.0 cm are more susceptible to infection by pathogens that cause decay during storage than treatments with a residual leaf length of 5.0 cm or more. Based on the results of this experiment, performance target of the experimental machine (residual leaf length after operation: 5 cm), and existing research on the optimal residual leaf length for onion harvesting, it is recommended to cut onion leaves so that the residual leaf length is 5-10 cm when using the stem cutter.

• Research in Plant Disease
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• v.30 no.3
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• pp.229-235
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• 2024

Conidial production is a critical factor in testing pathogenicity and studying the physiology and ecology of fungal pathogens. Therefore, selecting an appropriate condition and medium for consistent conidia production is essential. In this study, we investigated light conditions and suitable medium conditions using the slide culture method to establish optimal conditions for continuous spore acquisition of Bipolaris oryzae. Primarily, we observed conidial production using two B. oryzae isolates, CM23-042 and 23CM10, under two different light conditions: (1) consistent near-ultraviolet (NUV) with fluorescent light, and (2) a 12-hr shift of the NUV-dark cycle. Secondly, we examined conidial formation under seven different media on potato dextrose agar (PDA), V8-Juice agar, minimal medium (MM), sucrose-proline agar (SPA), rabbit food agar (RFA), rice bran agar (RBA), and rice leaf agar (RLA). Under consistent NUV light with fluorescent conditions, conidia were induced in both isolates, whereas conidia were not produced under other conditions after 7 days post-inoculation (dpi). Moreover, B. oryzae isolate CM23-042 produced the highest number of conidia in MM, while isolate 23CM10 yielded the highest number of conidia in PDA after 7 dpi. In summary, our data demonstrated that the consistent NUV light with fluorescent conditions were most conducive for conidia induction in B. oryzae. The selection of a medium for conidiation may vary depending on the B. oryzae isolates, but using MM and PDA or SPA and RFA medium could be effective for spore induction. These findings will contribute to improving conidiation according to the characteristics of collected isolates of B. oryzae.

• Journal of fish pathology
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• v.1 no.1
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• pp.5-30
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• 1988

This is a comprehensive study for considering the effective treatment and control program of bacterial disease occurring in common carp, israel carp, color carp, crucian carp, eel and tilapia by clarifying the causes, mechanism of infection and onset and the diagnostic criteria. As a first step, the authors investigated the external views, gross and histopathologic findings of diseased fish using 450 infected fishes obtained from various farmer of Korea. This infection was characterized by hyperemia, hemorrhage and swelling of body surface and fins, congestion of liver, spleen, kidney, inflammation of intestine, hemorrhagic inflammation of various tissues, and necrosis and ulcer of various tissues were accompanied in serious cases. Bacteriologically, Aeromonas hydrophila and Edwardsiella tarda were isoiated from these fishes. Particularly in the regular check on 222 eels, 177 strains were isolated as 29.94% of Aeromonas hydrophila, 48.58% of Edwardsiella tarda and 21.47% of Flexibacter columnaris. Hexibacter columnaris was isolated from corroded gill of eels. The identical disease was occurred by innoculating the isolated Aeromonas hydrophila and Edwardsiella tarda and the identical strains were isolated from infected experimental fishes. The eels which were diagnosed Aeromonas disease from Kwangju, Pusan accompanied hemorrhage, swelling of body surface and fins, inflammation of stomach and intestine containing mucous fluids mixed with the pathogens. Color carp and crucian carp which were innoculated with the isolated 5 strins of Aeromomas hydrorphil died within 3 or 4 days accompanying with the characteristics of Aeromonas disease. Edward disease was characterized by abscesses of body surface, pus formation with concentration on phagocytes. The size of absecsses increased with progression elf disease. There were also various abscesses at internal organ and white nodules appeared in kidney. Histologically, various progressive granuloma were examined without inflammation of intestine. Columnaris disease of eels showed no hemorrhage except slight white body color. In autopsy, most of internal organs appeared normal and there were no septic odors. The only character was corrosion of gills. In order to treat these bacterial diseases, infected fishes must bathe in 20ppm chloramphenicol or kanamycin solution for 1 hour. Besides, medication program in oral ingestion of 75mg/kg chloramphenicol per day continuing for 5 to 7 days. After injecting the formalin treated Aermonas hydrophila antigen into carp, relatively high agglutination titer showed between 3 weeks and 6 weeks. Though this titer decreased from that time, it was continued for 18 weeks. In the case of injecting the formalin treated Edwardsiella tarda antigen into tilapia, the titer also increased. But tilapia which were immersed in the suspension fluid of the formalin treated Edwardsiella tarda showed no increase of the titer.

• The Korean Journal of Mycology
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• v.18 no.3
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• pp.164-177
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• 1990

This study was carried out to obtain some useful data for increasing an effective ginseng production. There was a direct relationship (r=0.2645) between spore germination of Fusarium solani and soil pH, and (r=0.315) between Cylindrocarpon destructans and soil pH. On the other hand, there was a direct relationship (r=0.19) between relative hyphal growth of Rhizoctonia solani and soil pH. There was a direct relationship (r=0.21) between number of total bacteria and F. solani, (r=0.37) between actinomycetes and F. solani and (r=0.20) between celluloytic bacteria and F. solani. However, there was an inverse relationship (r=-0.20) between number of total fungi and F. solani. There was a direct relationship (r=0.24) between number of actinomycetes and R. solani. Each ginseng pathogen-suppressive soil screened was 40 in F. solani, 20 in C. destructans and 9 soil samples in R. solani among 146 soil samples, respectively. The mean contents of K, Ca and Mg were fairly lower in each ginseng pathogen-suppressive soil than conducive soil, whereas Na were somewhat lower. The mean contents of organic matter were over 2 times higher in each ginseng pathogen-suppressive soil than conducive soil. The mean contents of phosphate were fairly lower in F. solani and R. solani-suppressive soil than conducive soil and, on the other hand, were somewhat higher in C. destructans-suppressive soil than conducive soil. The mean soil pH was somewhat lower in each ginseng pathogen-suppressive soil than conducive soil. The mean contents of sand were about 2 times higher in each ginseng pathogen­suppressive soil than conducive soil, whereas silt and clay were somewhat lower. The microbial numbers of total bacteria, total fungi and celluloytic fungi were higher in F. solani-suppressive soil than conducive soil, whereas actinomycetes and celluloytic bacteria were lower. Each microbial number of total bacteria or total fungi indicated a significant difference (p=0.05) between F. solani­suppressive and conducive soil, and the microbial number of actinomycetes was a highly significant difference (p=0.01) between F. solani-suppressive and conducive soil. The microbial numbers of total bacteria, total fungi, actinomycetes and celluloytic fungi were higher in C. destructans-suppressive soil than conducive soil, whereas celluloytic bacteria were about 2 times lower. On the other hand, the microbial numbers of total fungi were higher in R. solani-suppressive soil than conducive soil, whereas total bacteria, actinomycetes, celluloytic bacteria and celluloytic fungi were lower. Fourteen of 16 F. solani-suppressive soils tested were suppressive to ginseng root rot, whereas fifteen of 16 C. destructans-suppressive soils were suppressive. Ginseng root rots of ginseng disease-suppressive soils were in the range of 1.0-17.4% in F. solani-suppressive soil and 0.2-20.4% in C. destructans-suppressive soil, respectively.

• The Korean Society of Law and Medicine
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• v.23 no.4
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• pp.29-74
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• 2022

As social disasters occur under the Disaster Management Act, which can damage the people's "life, body, and property" due to the rapid spread and spread of unexpected COVID-19 infectious diseases in 2020, information collected through inspection and reporting of infectious disease pathogens (Article 11), epidemiological investigation (Article 18), epidemiological investigation for vaccination (Article 29), artificial technology, and prevention policy Decision), (3) It was used as an important basis for decision-making in the context of an infectious disease crisis, such as promoting vaccination and understanding the current status of damage. In addition, medical policy decisions using infectious disease data contribute to quarantine policy decisions, information provision, drug development, and research technology development, and interest in the legal scope and limitations of using infectious disease data has increased worldwide. The use of infectious disease data can be classified for the purpose of spreading and blocking infectious diseases, prevention, management, and treatment of infectious diseases, and the use of information will be more widely made in the context of an infectious disease crisis. In particular, as the serious stage of the Disaster Management Act continues, the processing of personal identification information and sensitive information becomes an important issue. Information on "medical records, vaccination drugs, vaccination, underlying diseases, health rankings, long-term care recognition grades, pregnancy, etc." needs to be interpreted. In the case of "prevention, management, and treatment of infectious diseases", it is difficult to clearly define the concept of medical practicesThe types of actions are judged based on "legislative purposes, academic principles, expertise, and social norms," but the balance of legal interests should be based on the need for data use in quarantine policies and urgent judgment in public health crises. Specifically, the speed and degree of transmission of infectious diseases in a crisis, whether the purpose can be achieved without processing sensitive information, whether it unfairly violates the interests of third parties or information subjects, and the effectiveness of introducing quarantine policies through processing sensitive information can be used as major evaluation factors. On the other hand, the collection, provision, and use of infectious disease data for research purposes will be used through pseudonym processing under the Personal Information Protection Act, consent under the Bioethics Act and deliberation by the Institutional Bioethics Committee, and data provision deliberation committee. Therefore, the use of research purposes is recognized as long as procedural validity is secured as it is reviewed by the pseudonym processing and data review committee, the consent of the information subject, and the institutional bioethics review committee. However, the burden on research managers should be reduced by clarifying the pseudonymization or anonymization procedures, the introduction or consent procedures of the comprehensive consent system and the opt-out system should be clearly prepared, and the procedure for re-identifying or securing security that may arise from technological development should be clearly defined.

• Journal of Sericultural and Entomological Science
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• v.25 no.2
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• pp.1-31
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• 1984

Flacherie, as one of the most prevalent silkworm diseases, causes severe economic damage to sericultural industry and its pathogens have been proved to be flacherie virus (FV) and densonucleosis virus (DNV). Multiplications of the viruses in the larvae of the silkworm, Bombyx mori, were studied by the sucrose density gradient centrifugation and electron microscopy. The quantitative and qualitative changes of nucleic acids and proteins were investigated from the midgut and hemolymph in the silkworm larvae infected separately with FV and DNV. The histopathological changes of epithelial cells of infected midgut also were examined by an electron microscope. 1. Purified fractions of FV or DNV in a sucrose density gradient centrifugation yielded one homogenous and sharp peak without a shoulder, suggesting no heterogenous materials in the preparation. Electron microscopy also revealed that FV and DNV were spherical particles, 27nm and 21nm in diameter, respectively. 2. Silkworm larvae showed a decrease in body weight on the 6th day and in midgut weight on the 3rd day after inoculation with FV or DNV. 3. DNA content was higher in the midgut when infected with FV or DNV, but the hemolymph of the infected larvae showed no difference during first 6 days after inoculation, after which DNA concentration declined rapidly. 4. RNA synthesis of silkworm larvae infected separately with FV and DNV was stimulated in the midgut, but RNA content was reduced in the hemolymph at the early stage of virus multiplication. At the late stage of virus multiplication, however, it was extremely reduced in both midgut and hemolymph. 5. The concentration of protein in the midgut and hemolymph of silkworm larvae infected separately with FV and DNV showed no difference from that of the healthy larvae at the early stage of virus multiplication, but it was significantly reduced at the late stage of virus multiplication. 6. There was no difference in the electrophoretic patterns of RNAs extracted from the midgut of healthy or virus-infected larvae. 7. The electrophoresis of proteins extracted from the midgut infected with FV or DNV, when carried out on the 1st and 5th day after virus inoculation, showed no difference from that of the healthy larvae. But, there was an additional band with medium motility in the proteins on the 8th day after virus inoculation, while a band with low mobility shown in the proteins of healthy larvae disappeared in the infected larvae. However, a band with high mobility in the healthy larvae was separated into two fractions in the infected larvae. 8. The electrophoretic pattern of hemolymph proteins of the silkworm larvae infected separately with FV and DNV was similar to that of the healthy larvae, but the concentration of hemolymph proteins in the infected larvae was lower than that of the healthy larvae at the late stage. 9. Two types of inclusion bodies were shown by the double staining of pyronin-methyl green in the columnar cell of the midgut on the 8th day after FV inoculation. 10. Electron microscopy of the infected midgut revealed that the 'cytoplasmic wall' of the goblet cell thickened on the 5th day after FV inoculation and several types of the cytopathogenic structures, such as virus$.$specific vesicles, virus particles, linear structures, tubular structures, and high electron-dense matrices were observed in the cytoplasm of the goblet cell. The virus particles were also observed in the microvilli and the structures similar to spherical virus particles were observed around the virus-specific vesicles, suggesting the virus assembly in the cytoplasm. 11. Fluorescence micrograph of the infected midgut stained with acridine orange showed that the nucleus, the site of DNV multiplication in the columnar cell, enlarged on the 5th day after virus inoculation. 12. Electron microscopic examination of DNV infected midgut revealed that the nucleolus of the columnar cell was broken into granules and those granules dispersed into apical region of the nucleus on the 5th day after virus inoculation. On the 8th day after inoculation, it was also observed that the nucleus of the columnar cell was full with the high electron-dense virogenic stroma which were similar to virus particles. These facts suggest that the virogenic stroma were the sites of virus assembly in the process of DNV multiplication.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.69-76
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• 2013

The incidence of globally infectious and pathogenic diseases such as H1N1 (swine flu) and Avian Influenza (AI) has recently increased. An infectious disease is a pathogen-caused disease, which can be passed from the infected person to the susceptible host. Pathogens of infectious diseases, which are bacillus, spirochaeta, rickettsia, virus, fungus, and parasite, etc., cause various symptoms such as respiratory disease, gastrointestinal disease, liver disease, and acute febrile illness. They can be spread through various means such as food, water, insect, breathing and contact with other persons. Recently, most countries around the world use a mathematical model to predict and prepare for the spread of infectious diseases. In a modern society, however, infectious diseases are spread in a fast and complicated manner because of rapid development of transportation (both ground and underground). Therefore, we do not have enough time to predict the fast spreading and complicated infectious diseases. Therefore, new system, which can prevent the spread of infectious diseases by predicting its pathway, needs to be developed. In this study, to solve this kind of problem, an integrated monitoring system, which can track and predict the pathway of infectious diseases for its realtime monitoring and control, is developed. This system is implemented based on the conventional mathematical model called by 'Susceptible-Infectious-Recovered (SIR) Model.' The proposed model has characteristics that both inter- and intra-city modes of transportation to express interpersonal contact (i.e., migration flow) are considered. They include the means of transportation such as bus, train, car and airplane. Also, modified real data according to the geographical characteristics of Korea are employed to reflect realistic circumstances of possible disease spreading in Korea. We can predict where and when vaccination needs to be performed by parameters control in this model. The simulation includes several assumptions and scenarios. Using the data of Statistics Korea, five major cities, which are assumed to have the most population migration have been chosen; Seoul, Incheon (Incheon International Airport), Gangneung, Pyeongchang and Wonju. It was assumed that the cities were connected in one network, and infectious disease was spread through denoted transportation methods only. In terms of traffic volume, daily traffic volume was obtained from Korean Statistical Information Service (KOSIS). In addition, the population of each city was acquired from Statistics Korea. Moreover, data on H1N1 (swine flu) were provided by Korea Centers for Disease Control and Prevention, and air transport statistics were obtained from Aeronautical Information Portal System. As mentioned above, daily traffic volume, population statistics, H1N1 (swine flu) and air transport statistics data have been adjusted in consideration of the current conditions in Korea and several realistic assumptions and scenarios. Three scenarios (occurrence of H1N1 in Incheon International Airport, not-vaccinated in all cities and vaccinated in Seoul and Pyeongchang respectively) were simulated, and the number of days taken for the number of the infected to reach its peak and proportion of Infectious (I) were compared. According to the simulation, the number of days was the fastest in Seoul with 37 days and the slowest in Pyeongchang with 43 days when vaccination was not considered. In terms of the proportion of I, Seoul was the highest while Pyeongchang was the lowest. When they were vaccinated in Seoul, the number of days taken for the number of the infected to reach at its peak was the fastest in Seoul with 37 days and the slowest in Pyeongchang with 43 days. In terms of the proportion of I, Gangneung was the highest while Pyeongchang was the lowest. When they were vaccinated in Pyeongchang, the number of days was the fastest in Seoul with 37 days and the slowest in Pyeongchang with 43 days. In terms of the proportion of I, Gangneung was the highest while Pyeongchang was the lowest. Based on the results above, it has been confirmed that H1N1, upon the first occurrence, is proportionally spread by the traffic volume in each city. Because the infection pathway is different by the traffic volume in each city, therefore, it is possible to come up with a preventive measurement against infectious disease by tracking and predicting its pathway through the analysis of traffic volume.

• Korean Journal of Agricultural Science
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• v.6 no.1
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• pp.69-95
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• 1979

The study was conducted to search developmental process of plant protection science from review of forty-three hundreds literatures presented since 1900 in Korea and to forecast future statues of the science to be done. About 80 percent of literatures related to plant protection science such as plant pathology, applied entomology, weed science and agricultural pharmacology were collected from publications of agricultural and forestry reseach organizations attached to Office of Rural Development and Office of Forestry. The rest of literatures were mainly collected from Korean Journal of Plant Protection Society and small number of literatures were also collected from publications of the other journals of crop science and thesis collection of agricultural colleges. In Korea, research organizations of plant protection science are divided into two main groups such as exclusive agricultural research organizations and agricultural colleges. It is pointed out that the former contributions to plant protection science are very great compared to those of the latter since 1900. From periodical consideration of developmental process of the science since 1900, the history or the science are divided into three eras such as introduction and sprout of modern plant protection science during the first forty years, distress of the science during the following twenty years including the Second World War and the Korean War and rapid growth of the science after 1961. In spite of long time distress of the science during the Second World War and the Korean War, the researches on plant protection science in post-war have been done twice as many as pre-war. From consideration of the subject plants in researches of plant protection, it is shown that a great many researches on protection of rice plant have been done and occupy 37 percent of plant protection researches since 1900. And also researches on protection of fruit-trees and cash-crops are not so many as those of rice plant but have been done in noticeable numbers. In fact, researches on protection of fruit-trees and cashcrops were the most important subjects of plant protection researches in pre-war while those of rice plant were the most important subjects after 1930, particulary in post-war. From consideration of contents of plant protection researches, it is said that more fundamental researches than applied ones such as practical control methods of diseases, insect pests and weeds were done in pre-war while more applied researches than fundamental ones were done in post-war, Among applied researches, those of chemical control were the most important subjects. Researches on disease and insect-pest resistance have been done in both pre-war and post-war while researches on forecasting of disease and insect-pest and race of plant pathogens have been done in post-war. And also researches on weed control mainly have been done after 1960. Researches on agricultural chemicals for control of diseases, insect pests and weeds still belong to a new field which must be expected in future, and there is nothing to notice with the exception of practical application of agricultural chemicals introduced from foreign countries. Some of important researches on diseases and insect pests were discussed in relation to developmental process of plant protection science in Korea since 1900. In future, researches on plant protection will be develop to the direction supporting importance of integrated control for plant protection. Therefore, it is pointed out that security of highly educated and trained scientists with enlargement of reseach fields of plant protection science are necessary and role of agricultural colleges for future development of the science must be emphasized.