• Safety and Health at Work
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• 제6권1호
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• pp.62-70
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• 2015

Background: Animal skin provides an ideal medium for the propagation of microorganisms and it is used like raw material in the tannery and footware industry. The aim of this study was to evaluate and identify the microbial load in oropharyngeal mucosa of tannery employees. Methods: The health risk was estimated based on the identification of microorganisms found in the oropharyngeal mucosa samples. The study was conducted in a tanners group and a control group. Samples were taken from oropharyngeal mucosa and inoculated on plates with selective medium. In the samples, bacteria were identified by 16S ribosomal DNA analysis and the yeasts through a presumptive method. In addition, the sensitivity of these microorganisms to antibiotics/antifungals was evaluated. Results: The identified bacteria belonged to the families Enterobacteriaceae, Pseudomonadaceae, Neisseriaceae, Alcaligenaceae, Moraxellaceae, and Xanthomonadaceae, of which some species are considered as pathogenic or opportunistic microorganisms; these bacteria were not present in the control group. Forty-two percent of bacteria identified in the tanners group are correlated with respiratory diseases. Yeasts were also identified, including the following species: Candida glabrata, Candida tropicalis, Candida albicans, and Candida krusei. Regarding the sensitivity test of bacteria identified in the tanners group, 90% showed sensitivity to piperacillin/tazobactam, 87% showed sensitivity to ticarcillin/clavulanic acid, 74% showed sensitivity to ampicillin/sulbactam, and 58% showed sensitivity to amoxicillin/clavulanic acid. Conclusion: Several of the bacteria and yeast identified in the oropharyngeal mucosa of tanners have been correlated with infections in humans and have already been reported as airborne microorganisms in this working environment, representing a health risk for workers.

• Clinical and Experimental Pediatrics
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• 제64권11호
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• pp.543-551
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• 2021

The human microbiome, which consists of a collective cluster of commensal, symbiotic, and pathogenic microorganisms living in the human body, plays a key role in host health and immunity. The human nasal cavity harbors commensal bacteria that suppress the colonization of opportunistic pathogens. However, dysbiosis of the nasal microbial community is associated with many diseases, such as acute respiratory infections including otitis media, sinusitis and bronchitis and allergic respiratory diseases including asthma. The nasopharyngeal acquisition of pneumococcus, which exists as a pathobiont in the nasal cavity, is the initial step in virtually all pneumococcal diseases. Although the factors influencing nasal colonization and elimination are not fully understood, the adhesion of opportunistic pathogens to nasopharyngeal mucosa receptors and the eliciting of immune responses in the host are implicated in addition to bacterial microbiota properties and colonization resistance dynamics. Probiotics or synbiotic interventions may show promising and effective roles in the adjunctive treatment of dysbiosis; however, more studies are needed to characterize how these interventions can be applied in clinical practice in the future.

• 한국수산과학회지
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• 제54권5호
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• pp.585-595
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• 2021

Even though most of aquatic animal pathogens are considered opportunistic and many pose a low direct risk to personnel, all personnel working with aquatic pathogens and facilities using these organisms must comply with the regulation to prevent the release of the pathogen into the environment and causing disease in aquatic animals. First of all, in order to establish a biosafety system for aquatic pathogen, the list of microorganisms that can infect aquatic animals and humans should be drawn up according to the microorganisms encountered within national boundaries. Second, risk assessment guideline for diseases of livestock and aquatic environment is desperately needed. Third, microorganisms should be classified into risk group based on their potential impact on human and aquatic environment. Fourth, facilities handling aquatic pathogens should ensure that these pathogens are securely contained and safely handled for experimental or commercial development purposes. In conclusion, classification is based on the pathogenicity, mode of transmission and host range of the aquatic microorganisms, availability of effective preventative measures and treatments. Furthermore, risk group of aquatic pathogens should be correlated with physical containment facility requirements according to domestic characteristics.

• 보건의료생명과학 논문지
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• 제11권2호
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• pp.393-405
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• 2023

구강질환은 전 세계적으로 약 35억 명의 인구에 영향을 미치는 것으로 보고되었고, 국내에서 치은염 및 치주질환이 2019년부터 2021년까지 다빈도 상병 1위를 차지하였다. 구강질환을 일으키는 대표적인 박테리아로 Streptococcus mutans, Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus gordonii, Leptotrichia buccalis, Prevotella, Treponema 등이 있고, 진균류로는 Candida albicans, 고세균으로 Methanobrevibacter oralis 등이 있다. 구강 미생물이 치주질환을 일으키는 과정을 살펴보면, Streptococcus mutans 와 같은 박테리아가 먼저 증식하여 바이오필름을 형성하고, 이어서 절대혐기성 미생물, 기회감염균 및 병원균이 부착하여 증식하면서 숙주의 치은연하에 치태를 형성하며 정착하게 된다. 이처럼 마이크로바이옴 군집 내 다양한 상호작용이 구강질환 발생에 중요하다. 나아가서 구강 미생물과 구강질환으로 인하여 생성된 물질 및 염증이 소화기질환, 당뇨병, 심혈관질환, 인지기능, 류마티스 관절염, 조산, 암과 같은 질환 발생과 밀접한 관련성이 있으며, 한편으로 이러한 질환들이 구강질환을 일으키는 원인이 된다.

• 대한방사선기술학회지:방사선기술과학
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• 제45권3호
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• pp.233-239
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• 2022

In the radiology department, where radiation is used in medical institutions to perform examinations with various equipment, the field of surgical treatment is the intervention angiography room. Accordingly, strict infection control is required. The purpose of this study was to determine the contamination status by detecting pathogens before and after disinfection in the intervention angiography room, and to determine the degree of death by using a disinfectant, sodium dichloride isocyanurate, which is mainly used in the intervention angiography room. The subjects were 10 medical institutions of general hospital level or higher with an intervention angiography room in the P city, and 12 places with high contact frequency during examinations and procedures were sampled and requested to an analysis institution. As for the sample collection method, up/down, left/right directions were used to increase precision. Before disinfection, all procedures were completed, and after disinfection, exposure was performed using a disinfectant for at least 10 minutes, and detection was performed using a transport medium. As a result, in the pathogen analysis, most pathogens were detected in a humid environment or in a place with high contact frequency for microorganisms to thrive. The detected pathogens were found in the general environment or were human flora. It is a pathogen that does not cause disease under normal healthy host conditions. However, it was found to be an opportunistic infection that causes opportunistic infection depending on the case or situation in which the body's resistance is weakened. In addition, as a result of using the disinfectant mainly used in the intervention angiography room, it was found that more than 93.3% of them died. Therefore, the data of this study will be used as good basic data for the evaluation of pathogens in the intervention angiography room and will be of great help in infection control.

• 상하수도학회지
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• 제20권5호
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• pp.755-761
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• 2006

Recently, there is growing interest in ultraviolet (UV) irradiation as a disinfection technic in drinking water production due to its effectiveness to inactivate microorganisms such as Crytosporidium parvum without forming disinfection byproducts. However, UV disinfection is known for its drawback such as photoreactivation. Despite many works concerning the photoreactivation, most of works were focused on indicator or non pathogenic microorganisms. The objective of this study is to examine the photoreactivation of Pseudomonas aeruginosa which is an opportunistic pathogen as UV radiation by LP and MP UV lamp was applied. The result showed that P. aeruginosa had high photo repair efficiency regardless of the type of UV irradiation. Both of the effective log repair values of LP and MP UV irradiation were found approximately 2.6 log. In addition, photo repaired P. aeruginosa was not significantly different in forming biofilm in comparison with non treated P. aeruginosa.

• International Journal of Oral Biology
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• 제39권3호
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• pp.137-143
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• 2014

Dental professionals are repeatedly exposed to many microorganisms present in both blood and saliva. Thus, dental professionals are at a greater risk of acquiring and spreading infections, and the implementation of infections control guidelines is necessary. Cellular phones have become a necessary device for communicating in hospitals. Cellular phones contaminated with bacteria may serve as a fomite in the transmission of pathogens by the hands of medical personnel. Nevertheless, studies about rate and levels of bacterial contamination of cellular phones have been extremely limited with regards to dental personnel. The purpose of this study was to identify bacterial flora on the cellular phones of dentists by a molecular biological method using the 16S rRNA cloning and sequencing method. We acquired total 200 clones from dentists' cell phones and identified the bacterial species. Pseudomonas (34.6%), Lactobacillus (18.5%), Azomonas (11.5%), and Janthinobacterium (6%) were the dominant genera on dentists' cell phones. The oral bacteria identified were Anaerococcus lactolyticus, Gibbsiella dentisursi, Lactobacills leiae, Streptococcus mitis, Streptococcus oligofermentans, and Streptococcus sanguinis. Pathogenic bacteria and opportunistic pathogens such as Carnobacterium funditum, Raoultella planticola, Shigella flexneri, Lactobacillus iners, Staphylococcus aureus, and Staphylococcus epidermidis were also identified.

• Journal of Microbiology and Biotechnology
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• 제34권4호
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• pp.795-803
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• 2024

Microorganisms usually coexist as a multifaceted polymicrobial community in the natural habitats and at mucosal sites of the human body. Two opportunistic human pathogens, Pseudomonas aeruginosa and Staphylococcus aureus commonly coexist in the bacterial infections for hospitalized and/or immunocompromised patients. Here, we observed that autolysis of the P. aeruginosa quorum-sensing (QS) mutant (lasRmvfR) was suppressed by the presence of the S. aureus cells in vitro. The QS mutant still displayed killing against S. aureus cells, suggesting the link between the S. aureus-killing activity and the autolysis suppression. Independent screens of the P. aeruginosa transposon mutants defective in the S. aureus-killing and the S. aureus transposon mutants devoid of the autolysis suppression revealed the genetic link between both phenotypes, suggesting that the iron-dependent metabolism involving S. aureus exoproteins might be central to both phenotypes. The autolysis was suppressed by iron treatment as well. These results suggest that the interaction between P. aeruginosa and S. aureus might be governed by mechanisms that necessitate the QS circuitry as well as the metabolism involving the extracellular iron resources during the polymicrobial infections in the human airway.

• 한국안광학회지
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• 제18권1호
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• pp.67-73
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• 2013

목적: 최근 시력 교정용 기구 및 주변용품들에 대한 미생물의 오염이 안과 질병요인으로 지목됨에 따라 시력 교정용 안경에 대한 세균의 오염 실태를 조사하였다. 방법: 초등학생 36명, 중학생 37명, 고등학생 30명, 대학생 10명, 노인 32명으로 총 145명의 안경으로부터 세균을 채취하여 분리 배양한 후 동정하였다. 결과: 시력 교정용 안경으로부터 검출된 세균은 총 17종으로 Bacillus cereus, Bacillus licheniformis, Bacillus sp., CNS, Enterococcus, Escherichia coli, Proteus sp., Pseudomonas sp., Serretia sp., Streptococcus sp., Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus hemolyticus, Acinetobacter, Enterobacter cloacae, GNR, Pseudomonas aeruginosa이었다. 안과질환과 관련한 세균류는 각막염을 유발하는 Enterobacter cloacae, Pseudomonas aeruginosa, Staphylococcus epidermidis, 각막궤양을 유발하는 Pseudomonas sp., Staphylococcus aureus, 급성누낭염, 안와봉소염, 망막정맥주위염, 눈꺼풀테염을 유발하는 Staphylococcus aureus와 급성결막염 등을 유발하는 Streptococcus hemolyticus가 포함되었다. 결론: 시력 교정용 안경에서 고위험군 기회감염성 균류들이 다량으로 존재하는 것을 확인하였으며 이를 통한 감염에 따른 질병의 유발이 예측되므로 안경의 청결관리를 위한 대안이 필요하다고 사료된다.

• 한국환경보건학회지
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• 제37권4호
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• pp.279-288
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• 2011

Objectives: This study investigated the levels and components of floor-settled dust in two elementary schools located at different sites (one near the Shihwa industrial complex and the other in a rural area) in order to evaluate the amounts of trace metal elements (As, Cd, Co, Cr, Cu, Ni, Pb and Zn) and microorganisms. Methods: Over twenty settled-dust samples were collected from the two elementary schools. Trace metal elements were extracted from the dust using hydrochloric acid and nitric acid, and the amounts were measured by ICP-OES. Microbiological analysis was performed by bacterial culturing using R2A medium and denaturing gradient gel electrophoresis (DGGE). Results: The results showed that the amounts of three metal elements (Cr, Pb, and Zn) were significantly different between the schools (${\alpha}$=0.05, p<0.04). In addition, microbial communities in each school were highly correlated with one another. Among the identified microorganisms, a number of potentially opportunistic microorganisms, including antibiotic-resistant bacteria such as Acinetobacter baumannii, were found. Conclusions: This study will provide preliminary data for assessing levels and types of chemical and microbiological agents in elementary schools and for further evaluating human health risks associated with the agents.