• 대한치과기공학회지
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• 제35권4호
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• pp.321-332
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• 2013

Purpose: This study was examined the characteristics of bacteria isolated from the dental stone that is made ??in the dental laboratory. Methods: 104 dental stones samples were collected from the 4 dental laboratory. Characteristics of bacteria were investigated by microorganism isolation culture method using a Blood Tryptic Soy Agar(TSA) medium. Results: The detected various bacteria was confirmed as pathogenic bacteria, non-pathogenic bacteria and natural bacteria. The isolated bacterial number was confirmed $2.9{\times}10^3CFU$ and maxium bacterial number of $3.0{\times}10^4CFU$. Conclusion: Therefore, infection prevention education is required, it must be to live up the hand-washing and wear protective clothing to protect themselves when working in a dental laboratory.

• 한국잠사곤충학회지
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• 제39권2호
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• pp.146-153
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• 1997

The microsporidian infection with Nosema bombycis, reconfirmed its high virulence and transovarial tranmissibility, however, the characteristic symptom of the spots like pepper grains on the diseased larval skin was no more recognized by present varieties of the silkworm. Transovarial transmission rate detected from moth was above 90% in dead eggs or dead larvae in the rearing by mulberry leaves, 80% in the newly hatched larvae starved to death. Transovarially transmitted N. bombycis was easily observed from dead eggs and larvae, and were suggested an individual inspection of a few of dead eggs for detection of the pathogenic spores. The progeny population provided indicative factors on the sampling of predictive and corrective inspection. The higher concentration of N. bombycis spores included in the hindabdormal part of infected moth, applicative on the simple method of indivisual moth inspection. For the predictive inspection of growned 5th-instar larvae, N. bombycis infection was detectable without microscopic observation by the unique symptom of turbid milky-white spots on the silk gland. Inspection of the meconia artificially discharged from silkworm moth, was also succesful of microscopic observation before crossing, without killing or homogenize the moths. The results provided a basis of rational methods for the inspection of N. bombycis infection of the silkworm.

• 한국가금학회지
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• 제31권2호
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• pp.109-118
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• 2004

Avian influenza(AI) is an epizootic disease of variable severity caused by type A influenza viruses of the orthomyxovirus group. Chickens were the most frequently affected avian species with AI viruses. There were many outbreaks of fowl plague, now known as highly pathogenic AI(HP AI), throughout the world since Perroncito described the fowl plague in 1978 in Italy. In recent years HPAI viruses of different serotypes such as H5, H7 and H9 has been isolated from humans on several occasions either related with outbreak of HPAI in birds or not. In 1997, one of the most noteworthy events in AI history was the human mortality with H5N1 HPAI virus infection in Hong Kong. Six persons of total 18 persons with clinical signs of influenza were died. Recently the human cases with mortality related with HP AI outbreaks in poultry industry has been increased such as outbreaks of HP AI throughout Asia countries including Korea, Japan, China, Vietnam, Thailand and others in 2003. Although these outbreaks revealed the capable of spreading from birds to human, the capability for transmission between people was not clear. Therefore, this report will review the possibility of HP AI infection in human associated with HPAI outbreak in poultry industry.

• 한국산업보건학회지
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• 제29권3호
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• pp.289-297
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• 2019

Objectives: To identify the positive rate of and the risk factors associated with latent tuberculosis infection(LTBI) in mine workers, the objectives of the present study evaluated those among former mine workers. Methods: Between January 2015 and May 2017, former male mine workers who had been subjects for epidemiology research for work-related chronic obstructive pulmonary disease(COPD) and had received QuantiFERON-$TB^{(R)}$ Gold In-Tube(QFT-GIT) from the Institute of Occupation and Environment(IOE) under Korea Workers' Compensation and Welfare Service(KCOMWEL) were selected as the study subjects. To identify significant variables for increased risk of LTBI, logistic regression analysis was performed. Results: A total of 736 male former mine workers were selected as study subjects. The positive rate of LTBI among subjects was 69.2%(509/736). The current smoking[odds ratio(OR), 2.3; 95% confidence interval(CI), 1.1-4.9], COPD(OR, 1.4; 95% CI, 0.9-2.3), department loading(OR, 1.8; 95% CI, 0.9-3.4) and mining(OR, 1.5; 95% CI, 0.9-2.5), and working duration of over 20(OR, 1.6; 95% CI, 0.9-3.1) and over 30 years(OR, 2.2; 95% CI, 0.9-4.9) were associated with increased risk of LTBI. The interferon-gamma(IFN-${\gamma}$) level after stimulation with Mycobacterium tuberculosis(MTB)-specific antigens showed a significantly negative correlation with age(r=-0.126). Conclusions: The present study determined that the high positive rate of LTBI among mine workers was associated with not only the host factors but also the occupational exposure to mine dust.

• Animal Bioscience
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• 제35권3호
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• pp.367-376
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• 2022

Objective: The highly pathogenic avian influenza virus (HPAIV) is a threat to the poultry industry as well as the economy and remains a potential source of pandemic infection in humans. Antiviral genes are considered a potential factor for HPAIV resistance. Therefore, in this study, we investigated gene expression related to cytokine-cytokine receptor interactions by comparing resistant and susceptible Ri chicken lines for avian influenza virus infection. Methods: Ri chickens of resistant (Mx/A; BF2/B21) and susceptible (Mx/G; BF2/B13) lines were selected by genotyping the Mx dynamin like GTPase (Mx) and major histocompatibility complex class I antigen BF2 genes. These chickens were then infected with influenza A virus subtype H5N1, and their lung tissues were collected for RNA sequencing. Results: In total, 972 differentially expressed genes (DEGs) were observed between resistant and susceptible Ri chickens, according to the gene ontology and Kyoto encyclopedia of genes and genomes pathways. In particular, DEGs associated with cytokine-cytokine receptor interactions were most abundant. The expression levels of cytokines (interleukin-1β [IL-1β], IL-6, IL-8, and IL-18), chemokines (C-C Motif chemokine ligand 4 [CCL4] and CCL17), interferons (IFN-γ), and IFN-stimulated genes (Mx1, CCL19, 2'-5'-oligoadenylate synthase-like, and protein kinase R) were higher in H5N1-resistant chickens than in H5N1-susceptible chickens. Conclusion: Resistant chickens show stronger immune responses and antiviral activity (cytokines, chemokines, and IFN-stimulated genes) than those of susceptible chickens against HPAIV infection.

• Clinical and Experimental Pediatrics
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• 제63권4호
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• pp.135-140
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• 2020

Background: Breastfeeding reportedly reduces the overall frequency of infections. Respiratory syncytial virus (RSV), the most common respiratory pathogen in infants, involves recurrent wheezing and has a pathogenic mechanism related to airway structural damage. Purpose: This study aimed to investigate whether breastfeeding has a beneficial effect against RSV-induced respiratory infection compared to formula feeding among infants in Korea. Methods: We retrospectively reviewed the medical records of infants under 1 year of age who were admitted with RSV infection between January 2016 and February 2018 at the department of pediatrics of 4 hospitals. We investigated the differences in clinical parameters such as cyanosis, chest retraction, combined infection, fever duration, oxygen use, oxygen therapy duration, intensive care unit (ICU) admission, and corticosteroid treatment of exclusive breast milk feeding (BMF), artificial milk formula fed (AMF), and mixed feeding (MF) groups. Results: Among the 411 infants included in our study, 94, 161, and 156 were included in the BMF, MF, and AMF groups, respectively. The rates of oxygen therapy were significantly different among the BMF (4.3%), MF (8.1%), and AMF (13.5 %) groups (P=0.042). The odds ratios (ORs) for oxygen therapy was significantly higher in the AMF group than in the BMF group (adjusted OR, 3.807; 95% confidence interval, 1.22-11.90; P=0.021). The ICU admission rate of the BMF group (1.1%) was lower than that of the MF (3.5%) and AMF (4.5%) groups; however, the dissimilarity was not statistically significant (P=0.338). Conclusion: The severity of RSV infection requiring oxygen therapy was lower in the BMF than the AMF group. This protective role of human milk on RSV infection might decrease the need for oxygen therapy suggesting less airway damage.

• Parasites, Hosts and Diseases
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• 제31권3호
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• pp.239-248
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• 1993

원발성 아메바성 수막뇌염을 일으키는 병원성 자유생활아메바인 Naegleria fowleri 및 Acanthamoeba culbertsoni를 CSH/HeJ 마우스에 감염시켜 자연살세포를 활성화시킬 수 있는 감염 최소량 및 활성도를 최대치가지 이르게 하는 감염 최대량을 결정하여 수막뇌염의 발생여부 및 사망율을 조사하고, 이와 함께 비병원성 자유생활아메바인 Naegleria fowleri를 감염시켜 자연살세포가 활성화되는지 조사하였다 자연살세포 활성도를 병원성 자유생활아메바 감염군과 비교하였으며, 병원성, 비병원성 자유생활아메바 감염군에서의 자연살세포의 세포독성의 변화를 단세포 독성검사법을 이용하여 표적세포 결합능, 활성 자연살세포, 더 나아가 최대 재순환능을 측정하여 조사하였다. Naegleria fowleri 감염 군에서 자연살세포를 활성화 시킬 수 있는 감염 최소량인 아메바 영양형 $1{\times}10^4$개 감염 군에서 사망률이 5.9%이었으며 최대량인 $1{\times}10^5$개 영양형 감염군에서는 72.2%이었다. Acnnthamoebn culbertsoni 감염 군에서의 감염 최소량인 아메바 영양형 $1{\times}10^3$개 감염군에서의 사망률은 6.9%이었으며 최대량인 $1{\times}10^5$개 감염군에서는 65.5%이었다. 자연살세포의 세포독성은 병원성 자유생활아메바 감염군 모두에서 감염후 1일째에 대조군과 비교하여 통계학적으로 유의하게 증가하였으며, 감염후 2일과 5일째에는 감소하였고, 아메바 감염량간에는 유의한 차이를 발견할 수 없었다. 아메바 감염 군에서의 자연살세포의 활성도의 증가는 표적세포 결합능 및 활성 자연살세포의 증가에 기인한 것이었으며 재순환능에는 차이가 없음을 알 수 있었다. 비병원성 자유생활아메바인 Naegleria fowleri 감염 군에서는 자연살세포의 활성도는 대조군과 비교하여 유의한 차이를 발견할 수 없었으며 병원성 자유생활아메바 감염 군과는 자연살세포의 세포독성 통계학적으로 유의한 차이가 있음을 알 수 있었다.

• 한국지리정보학회지
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• 제23권4호
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• pp.140-155
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• 2020

본 연구는 가축질병이 밀집되어 발생했던 지역인 경기도 남부-충청도의 감염농가 입지 특성을 파악하여 가금농가의 질병 발생 확률을 분석하고 조건에 해당하는 지역을 도출하여 가축질병 발생예방과 차별적인 방역지역 선정 및 방역전략 설정의 근거와 보완대책의 기초자료로 사용하기 위해 수행되었다. 로지스틱 회귀분석 결과, 반경 3km내 가금농가 1개가 증가하면 HPAI에 감염될 확률이 전 단위에 비해 10.9% 증가한다. 2차선 이상 주요 도로와의 거리 1m가 증가하면 HPAI에 감염될 확률이 전 단위에 비해 0.001% 감소한다. 주요 철새도래지와의 15km 이내에 가금농가가 위치한 경우에서 15~30km로 변화하면 HPAI에 감염될 확률이 46.0% 감소한다. 주요 철새도래지와의 거리가 15km 이내에 가금농가가 위치한 경우에서 30km 이상으로 변화하면 HPAI에 감염될 확률이 88.5% 감소한다. 로지스틱 회귀분석 결과를 바탕으로 예측확률을 생성하고 도출된 입지요인인' 반경 3km내 가금농가 15개 초과, 주요 도로와의 거리 1km이내, 주요 철새도래지와의 거리 30 km이내'의 실제 지역을 도출하고 감염 비율을 측정하였다. 본 연구의 결과가 지역 내에서 가축질병이 발생할 확률이 높은 지역을 판별하여, 방역 주체가 대상 지역과 농가에 대해 선제적 방역을 실시하거나 차량을 통제하는 등의 차별적인 방역지역과 방역전략을 설정할 때, 그 근거와 보완대책 마련에 기초자료로 활용될 수 있을 것이라 기대한다.

• 한국가금학회지
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• 제47권1호
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• pp.9-19
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• 2020

본 연구는 고병원성 조류 인플루엔자 바이러스(high pathogenic avian influenza virus; HPAIV)와 저병원성 조류인플루엔자 바이러스(low pathogenic avian virus; LPAIV)가 감염된 오리의 폐세포에서 보고된 기존 전사체 데이터를 재분석하여 조류 인플루엔자 감염에 대응하는 숙주의 공통 전사체를 발굴하고, 생물정보 분석을 실시하여 바이오 마커로서 가능성을 제시하기 위하여 수행하였다. 이전 연구에서 생산된 microarray 데이터 세트를 재분석하여, HPAIV와 LPAIV가 각각 감염된 오리의 폐세포에서 각각 총 731 및 439개의 차등발현 유전자를 발굴하였다. 이들 차등발현 유전자 중에서, 227개의 유전자가 HPAIV와 LPAIV가 감염된 세포에서 공통적으로 조절되어, 193개의 유전자는 발현이 증가한 반면, 34개의 유전자는 발현이 감소하였다. 생물정보 분석을 통하여 차등발현 유전자들의 기능에 대한 주석달기를 실시하여, 리보솜과 단백질 대사 및 유전자 발현 관련 GO가 풍부해짐을 확인하였다. REACTOME 분석을 통하여 단백질 및 RNA 대사 경로 및 콜라겐 생합성과 변형을 포함한 조직 복구 경로가 조절됨을 확인하였다. 보다 구체적으로, 번역 및 RNA 품질 관리 경로에 관여하는 단백질을 코딩하는 유전자는 HPAIV 및 LPAIV 감염에 반응하여 발현의 증가 또는 감소하는 방향으로 조절되어 AIV가 숙주 번역 기계를 억제함으로써 숙주 방어 시스템을 회피할 수 있거나 번역을 위해 세포질로 내보내기 전에 AIV가 억제될 수 있음을 시사한다. AIV 감염은 바이러스 감염으로 인한 조직의 병변 형성을 조절하는 경로를 활성화시킬 수 있음을 시사한다.

• Journal of Periodontal and Implant Science
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• 제45권6호
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• pp.223-228
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• 2015

Purpose: The goal of this study was to characterize the patterns of antimicrobial resistance and virulence genes in samples of Staphylococcus aureus (S. aureus) isolated from periodontitis patients. Methods: From July 2015 to August 2015, oral saliva was collected from a total of 112 patients diagnosed with periodontitis, including 80 outpatients in dental hospitals and 32 patients in dental clinics located in Seoul and Cheonan. The samples were subjected to a susceptibility test to evaluate the prevalence of antimicrobial resistance, and the pathogenic factors and antimicrobial resistance factors in the DNA of S. aureus were analyzed using polymerase chain reaction. Results: A susceptibility test against 15 antimicrobial agents showed that 88% of cultures were resistant to ampicillin, 88% to penicillin, and 2% to oxacillin. Resistance to at least two drugs was observed in 90% of cultures, and the most common pattern of multidrug resistance was to ampicillin and penicillin. Enterotoxins were detected in 65.9% of samples. The cell hemolysin gene hld was detected in 100% of cultures and hla was detected in 97.6% of samples. All strains resistant to penicillin and ampicillin had the blaZ gene. The aph(3')IIIa gene, which encodes an aminoglycoside modifying enzyme, was detected in 46.3% of samples. Conclusions: In the treatment of oral S. aureus infections, it is important to identify the pathogenic genes and the extent of antimicrobial resistance. Furthermore, it is necessary to study patterns of antimicrobial resistance and cross-infection in the context of periodontological specialties in which antimicrobials are frequently used, such as maxillofacial surgery, where the frequency of antimicrobial use for minor procedures such as implant placement is increasing.