• 대한임상검사과학회지
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• 제54권1호
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• pp.23-27
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• 2022

제주특별자치도에 위치한 대중음식점에서 제공하는 일회용 물티슈를 대상으로 식품의약품안전처장이 정하는 표시사항을 준수하는지 여부와 세균의 오염도를 평가하였다. 일회용 물티슈 32종류 중 5 종류의 일회용 물티슈는 영업소의 명칭 및 소재지가 표기되어 있지 않았다. 제조연월일과 유통기한은 12 종류의 물티슈만 표시 되어있었다. 일회용 물티슈 32종류 중 9종류의 물티슈에서 세균 집락이 배양되었으며, 23종류(71.9%)의 물티슈에서는 세균이 배양되지 않았다. 세균을 동정한 결과 그람양성알균은 Staphylococcus haemolyticus 4균주, Staphylococcus hominis 1균주, Staphylococcus warneri 3균주, 그람음성막대균은 Pseudomonas fluorescens 1균주로 동정되었다. 동정된 그람양성알균 8균주에 대한 항균제감수성검사를 시행한 결과 oxacillin, vancomycin 감수성으로 MRCNS(methicillin resistant coagulase-negative Staphylococci)는 발견되지 않았으며, 동정된 그람음성막대균 1균주에 대한 항균제감수성검사 결과는 imipenem, meropenem에 모두 감수성으로 다약제내성균은 아니었다. 본 연구를 통해 위생용품으로 지정된 일회용 물티슈 개별 포장지 겉면에 반드시 제조년월일과 유통기한을 표기하고, 보관기준을 준수하여 오염되지 않은 깨끗한 물티슈를 사용해야 한다고 사료된다. 또한 위생관리 감독 강화와 개선방안 및 개인 위생관리 및 국민보건 수준향상에 기여하고자 한다.

• 생명과학회지
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• 제28권1호
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• pp.68-77
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• 2018

바이오제닉 아민 비생성 유산균의 선별을 위해 순창군에서 재배된 베리류 및 엑기스, 식초 등으로부터 42종의 유산균을 분리하였다. 분리주를 대상으로 세포외 효소 활성, 항균 활성, 항산화 활성과 같은 다양한 생리활성 분석을 실시하여 5종의 분리주를 1차 선별하였다. 분리주를 대상으로 바이오제닉 아민 생성 여부를 분석하여 최종적으로 SBB07을 선별하였고, 16S rRNA 염기서열 분석을 통해 Lactobacillus brevis SBB07로 명명하였다. SBB07의 프로바이오틱스 활용 가능성을 확인하기 위해 효소 생산 여부, 내산성, 내담즙성, 내열성, 항생제 내성을 조사하였고, pH 2.0에서의 내산성 및 0.5% oxgall을 함유한 내담즙성에서 각각 86% 이상과 54% 이상의 높은 생존율을 나타내었다. 또한 $60^{\circ}C$에서도 113% 이상의 생존율을 나타내어 내열성도 우수하며 다양한 항생제 내성을 갖는 것을 확인하였다. 프리바이오틱스 이용가능성을 확인한 결과에서는 GOS의 이용 능력이 가장 우수하였으며, FOS와 inulin의 이용 능력도 높게 나타났다. 따라서 SBB07은 세포외 효소 및 항균 활성이 우수하고, 내담즙, 내산성, 내열성 및 항생제 내성을 지니며 프리바이오틱스 기질 이용 능력도 우수한 프로바이오틱스 소재로 활용가능성이 높은 유산균으로 기대된다.

• Journal of Microbiology and Biotechnology
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• 제24권10호
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• pp.1354-1367
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• 2014

In the present work, we describe a simple, cheap, and unexplored method for "green" synthesis of silver nanoparticles using cell extracts of the cyanobacterium Anabaena doliolum. An attempt was also made to test the antimicrobial and antitumor activities of the synthesized nanoparticles. Analytical techniques, namely UV-vis spectroscopy, X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and TEM-selected area electron diffraction, were used to elucidate the formation and characterization of silver-cyanobacterial nanoparticles (Ag-CNPs). Results showed that the original color of the cell extract changed from reddish blue to dark brown after addition of silver nitrate solution (1 mM) within 1 h, suggesting the synthesis of Ag-CNPs. That the formation Ag-CNPs indeed occurred was also evident from the spectroscopic analysis of the reaction mixture, wherein a prominent peak at 420 nm was noted. TEM images revealed well-dispersed, spherical Ag-CNPs with a particle size in the range of 10-50 nm. The X-ray diffraction spectrum suggested a crystalline nature of the Ag-CNPs. FTIR analysis indicated the utilization of a hydroxyl (-OH) group in the formation of Ag-CNPs. Ag-CNPs exhibited strong antibacterial activity against three multidrug-resistant bacteria. Additionally, Ag-CNPs strongly affected the survival of Dalton's lymphoma and human carcinoma colo205 cells at a very low concentration. The Ag-CNPs-induced loss of survival of both cell types may be due to the induction of reactive oxygen species generation and DNA fragmentation, resulting in apoptosis. Properties exhibited by the Ag-CNP suggest that it may be used as a potential antibacterial and antitumor agent.

• 한국축산식품학회지
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• 제31권4호
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• pp.609-616
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• 2011

전통발효식품으로부터 L. monocytogenes ATCC 19114에 강한 항균활성을 보이는 균주를 분리하였다. 분리된 균주의 형태학적 및 생화학적 특성과 16S rRNA 염기서열 분석을 통해 Lactobacillus salivarius LCH1227으로 동정되었다. L. salivarius LCH1227이 분비하는 항균물질은 L. monocytogenes 뿐만 아니라 vancomycin-resistant Enterococcus faecalis, Streptococcus agalactiae, Bacillus cereus, Lactobacillus fermentum 등과 같은 그람양성 세균에 대해 폭 넓은 항균 활성을 나타내었다. L. salivarius LCH1227의 생육에 따른 항균 활성을 측정한 결과, 생장정체기 초기에 최대 활성(300 AU/mL)을 나타내었고, 생장정체기 이후부터 활성이 점차 감소하였다. 항균물질의 활성은 pH 2-12 구간에서 비교적 안정하였으며, 열처리에 의해서도 활성이 소실되지 않아 열에 안정한 물질임을 알 수 있었다. L. salivarius LCH1227이 생산하는 항균물질은 단백질 분해효소 처리 후에 활성이 실활됨으로써 단백질성 물질인 것으로 추정되었으며, Tricine-SDS-PAGE 실험을 통하여 항균물질의 분자량은 약 5 kDa 정도임을 알 수 있었다.

• 한국축산식품학회지
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• 제30권5호
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• pp.804-810
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• 2010

This study was performed to select protease-producing Bacillus sp. as a potential probiotic starter for fermented meat products. In order to isolate protease-producing bacterium from meju, measured the diameter of the clear zone on agar plate (TSA, 1% (w/v) skim milk) and analyzed for intracellular protease activity, then 10 Bacillus-like strains were isolated. Three Bacillus-like strains (P19, P27, and P33) among 10 strains were able to tolerate in acidic condition (TSB, pH 2.5, 2 h incubation). These 3 strains were showed antimicrobial activity against food-borne pathogenic bacteria. These vegetative cells of 3 strains were showed a survival rate of 0.04% to 0.08% under the artificial gastric acidic condition (TSB, pH 2.5 with 1% (w/v) pepsin), but spore-forming cells were 56.29% to 84.77%. Vegetative cells of 3 strains were the least bile-resistant, while spore-forming cells of 3 strains showed higher survival rate more than 76% under artificial bile condition (TSB, 0.1% (w/v) oxgall bile). In these strains, P27 strain was finally selected as a good probiotic strain. P27 strain was tentatively identified as Bacillus amyloliquefaciens by API CHB kit and 16S rDNA sequence analysis. The results of this study suggest that B. amyloliquefaciens P27 can be used as a potential probiotic starter for fermented meat product.

• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.137-142
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• 2015

Trimethoprim-sulfamethoxazole (TMP-SMX) has been used for the treatment of urinary tract infections, but increasing resistance to TMP-SMX has been reported. In this study, we analyzed TMP-SMX resistance genes and their relatedness with integrons and insertion sequence common regions (ISCRs) in uropathogenic gram-negative bacilli. Consecutive nonduplicate TMP-SMX nonsusceptible clinical isolates of E. coli, K. pneumoniae, Acinetobacter spp., and P. aeruginosa were collected from urine. The minimal inhibitory concentration was determined by Etest. TMP-SMX resistance genes (sul and dfr), integrons, and ISCRs were analyzed by PCR and sequencing. A total of 45 E. coli (37.8%), 15 K. pneumoniae (18.5%), 12 Acinetobacter spp. (70.6%), and 9 Pseudomonas aeruginosa (30.0%) isolates were found to be resistant to TMP-SMX. Their MICs were all over 640. In E. coli and K. pneumoniae, sul1 and dfr genes were highly prevalent in relation with integron1. The sul3 gene was detected in E. coli. However, in P. aeruginosa and Acinetobacter spp., only sul1 was prevalent in relation with class 1 integron; however, dfr was not detected and sul2 was less prevalent than in Enterobacteriaceae. ISCR1 and/or ISCR2 were detected in E. coli, K. pneumoniae, and Acinetobacter spp. but the relatedness with TMP-SMX resistance genes was not prominent. ISCR14 was detected in six isolates of E. coli. In conclusion, resistance mechanisms for TMP-SMX were different between Enterobacteriaceae and glucose non-fermenting gram-negative bacilli. Class 1 integron was widely disseminated in uropathogenic gram-negative baciili, so the adoption of prudent use of antimicrobial agents and the establishment of a surveillance system are needed.

• 한국가금학회지
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• 제31권1호
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• pp.37-44
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• 2004

It has been recognized that the hen, like its mammalian counterparts, provides young chicks with antibodies as protection against hostile invaders. This system facilitates the transfer of specific antibodies from serum to egg yolk, and provides a supply of antibodies called immunoglobulin Y(IgY) to the developing embryo and the hatched chick. The protection against pathogens that the relatively immune-incompetent newly hatched chick has, is through transmission of antibodies from the mother via the egg. Egg yolk, therefore, can be loaded with a large amount of IgY against pathogens which can immobilize the existing or invading pathogens during the embryo development or in day-old chicks. Thus, the immunization of laying hens to various pathogens results in production of different antigen-specific IgY in eggs. Egg yolk contains 8∼20 mg of jmmunoglobulins (IgY) per ml or 136∼340 mg per yolk suggesting that more than 30 g of IgY can be obtained from one immunized hen in a year. By immunizing laying hens with antigens and collecting IgY from egg yolk, low cost antibodies at less than $10 per g compared to more than $20,000 per g of mammalian IgG can be obtained. This IgY technology opens new potential market applications in medicine, public health, veterinary medicine and food safety. A broader use of IgY technology could be applied as biological or diagnostic tool, nutraceutical or functional food development, oral-supplementation for prophylaxis, and as pathogen-specific antimicrobial agents for infectious disease control. This paper has emphasized that when IgY-loaded chicken eggs are produced and consumed, the specific antibody binds, immobilizes and consequently reduces or inhibits the growth or colony forming abilities of microbial pathogens. This concept could serve as an alternative agent to replace the use of antibiotics, since today, more and more antibiotics are less effective in the treatment of infections, due to the emergence of drug-resistant bacteria.

• 한국축산식품학회지
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• 제28권1호
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• pp.1-8
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• 2008

최근까지 박테리오신 생산균주의 분리, 분자생물학적 메커니즘, 정제, 구조 및 작용기작, 산업적인 적용 등의 논문 등이 보고되고 있다. 또한 50개국 이상에서 치즈, 통조림식품 등에서 식품보존제로서 승인되어 있다. 박테리오신의 여러 장점으로 인해 현재 추진되고 있는 축산업 분야의 HACCP의 범위인, 사육장에서부터 식품제조에 이르기까지 항생물질, 인공적인 방부제나 식품첨가물이 적게 들어가거나 첨가되지 않은 자연식품을 선호하고 있는 실정에 적합하다. 향후 축산업에서 항생제 대체방안의 하나로서 박테리오신의 사용은 확대되리라 기대된다. 경제적인 가격 경쟁력을 갖기 위해, 대량생산에 대한 연구가 이루어져야 하며, 적절한 제형으로 보다 구체적인 적용실험이 수행되어 산업화를 앞당겨야 한다.

• Childhood Kidney Diseases
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• 제23권1호
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• pp.22-28
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• 2019

Purpose: We studied the pathogens and trends in antibiotic sensitivity pattern in children with urinary tract infection (UTI) over 8 years in order to evaluate adequate treatment. Methods: We performed a retrospective review of medical records of children with UTI from January 2009 to December 2016 in Daegu Fatima Hospital. Uropathogens and antibiotic sensitivity patterns were selected. Only 1 bacterial species with a colony count of ${\geq}105CFU/mL$ was considered a positive result. We compared 2 periods group (A: 2009~2012, B: 2013~2016) to investigate trends of antibiotic sensitivity pattern. Results: During the 8 year period, 589 cases are identified (E. coli was cultured in 509 cases, 86.4%). Among all patients, this study investigated the antibiotic sensitivity of E. coli. Antimicrobial susceptibility to ampicillin was steadily low for both periods (A: 32.6%, B: 40.1%, P=0.125), and to amikacin was consistently high for both periods (A: 99.4%, B: 99.3%, P=1.000). Antibiotic sensitivity to third-generation cephalosporin decreased from period A to B (A: 91.7%, B: 75.5%, P=0.000). Antibiotic sensitivity to quinolone significantly decreased from A to B (A: 88.4%, B: 78.2%, P=0.003). The prevalence of extended-spectrum ${\beta}$-lactamase-producing E. coli increased from period A to B (A: 6.1%, B: 17.1%, P=0.000). Conclusion: This study showed that conventional antibiotic therapy for the treatment of pediatric UTI needs to be reevaluated. A careful choice of antibiotic is required due to the change in antibiotic sensitivity and the emergence of antibiotic-resistant bacteria.

• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1862-1869
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• 2020

The spread of plasmid-mediated colistin resistance has posed a serious threat to public health owing to its effects on the emergence of pandrug-resistant bacteria. In this study, we investigated the prevalence and characteristics of mcr-1-positive Escherichia coli isolated from retail meat samples in Korea. In total, 1,205 E. coli strains were isolated from 3,234 retail meat samples in Korea. All E. coli strains were subjected to antimicrobial susceptibility testing and were examined for the presence of mcr-1 gene. All mcr-1-positive E. coli (n = 10, 0.8%) from retail meat were subjected to pulse-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS). The transferability of mcr-1 gene was determined by conjugation assays. The mcr-1-positive strains exhibited diverse clonal types. Our mcr-1 genes were located in plasmids belonged to the IncI2 (n = 1) and IncX4 (n = 8) types, which were reported to be prevalent in Asia and worldwide, respectively. Most mcr-1 genes from mcr-1-positive strains (9/10) were transferable to the recipient strain and the transfer frequencies ranged from 2.4 × 10-3 to 9.8 × 10-6. Our data suggest that the specific types of plasmid may play an important role in spreading plasmid-mediated colistin resistance in Korea. Furthermore, our findings suggest that the retail meat may be an important tool for disseminating plasmid-mediated colistin resistance.