• International Journal of Oral Biology
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• 제35권1호
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• pp.7-12
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• 2010

The aims of this study were to investigate the nosocomial infection route of methicillin-resistant Staphylococcus aureus (MRSA) and explore preventative methods for this pathogen that involve blocking its dispersion. We cultured MRSA from nasal cavity swabs collected between June and July 2008 that we obtained from eight dental healthcare providers, 32 nurses and the sputum specimens of two patients from our hospital. In addition, we used VITEK 2 equipment to measure drug sensitivity, and we further performed biochemical testing and pulse-field gel electrophoresis (PFGE) to isolate MRSA colonies. The incidence of these bacteria on the nasal swabs was 25.0% from dental clinic healthcare providers, 13.6% from the internal medicine ward nurses and 30.0% from intensive care unit nurses. Moreover, MRSA was detectable in sputum specimens of ward patients. The antimicrobial agents resistance and partial PFGE types of MRSA showed a similar pattern. We suggest from these analyses that nasal cavity infection by MRSA could occur by cross contamination between healthcare providers and patients which underscores the importance of stringent MRSA management practices.

• 대한임상검사과학회지
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• 제46권4호
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• pp.136-139
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• 2014

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the severe nosocomial infectious agents. The traditional diagnostic methods including biochemical test, antibiotic susceptibility test and PCR amplification are time consuming and require much work. The Surface enhanced Raman spectroscopy (SERS) biosensor is a rapid and powerful tool for analyzing the chemical composition within a single living cell. To identify the biochemical and genetic characterization of clinical MRSA, all isolates from patients were performed with VITEK2 gram positive (GP) bacterial identification and Antibiotic Susceptibility Testing (AST). Virulence genes of MRSA also were identified by DNA based PCR using specific primers. All isolates, which were placed on a gold coated nanochip, were analyzed by a confocal Raman microscopy system. All isolates were identified as S. aureus by biochemical tests. MRSA, which exhibited antibiotic resistance, demonstrated to be positive gene expression of both femA and mecA. Furthermore, Raman shift of S. aureus and MRSA (n=20) was perfectly distinguished by a confocal Raman microscopy system. This novel technique explained that a SERS based confocal Raman microscopy system can selectively isolate MRSA from non-MRSA. The study recommends the SERS technique as a rapid and sensitive method to detect antibiotic resistant S. aureus in a single cell level.

• 한국임상수의학회지
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• 제22권2호
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• pp.114-118
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• 2005

Bacterial disease caused by Aeromonas are among the most common and troublesome diseases of fish raised in aquaculture systems. In this study, some strains identified as belonging to the Aeromonas were isolated from neon tetra (Hyphessobrycon herbertaxelrodi) skin and fin, as well as from water samples. VITEK system and API ZYM examination of the isolated strains were undertaken, and it seemed to correlate with the Aeromonas, proved to be Aeromonas veronii. The antibiotic susceptibility test of isolated strains to different groups of antibiotics was evaluated using the disc diffusion method. Cefixime was the most sensitive antibiotic.

• 한국동물위생학회지
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• 제37권1호
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• pp.67-71
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• 2014

In November 2012, a 4-month-old foal with anorexia, neurologic signs with ataxia and death was submitted for necropsy to the diagnostic laboratory of Jeju Self-Governing Provincial Veterinary Research Institute. Grossly, yellowish-white fibrinous materials were seen on the ventral cerebrum, cerebellum, medulla oblongata and cervical spinal cord of the foal. Histologically, severe fibrino-purulent meningitis characterized by the infiltration of neutrophils and fibrionous exudates with bacterial colonies were presented in cerebrum, cerebellum, brain stem and cervical spinal cord. In the bacterial isolation using meningeal exudate, the small white colonies on blood agar plate with ${\beta}$-hemolysis were observed. Isolated bacteria were Gram-positive cocci and confirmed as Streptococcus (S.) equi subsp. zooepidemicus by VITEK 2 system. Based on the histopathological features and the bacterial test, this case was diagnosed as meningitis associated with S. equi subsp. zooepidemicus infection in a foal. In our best knowledge, this is the first report for fibrino-purulent meningitis caused by S. equi subsp. zooepidemicus infection in Jeju.

• International Journal of Oral Biology
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• 제35권4호
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• pp.185-190
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• 2010

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent pathogens in hospitals. To investigate cross contamination by this bacterium in both dental and medical settings, the pathogens that cause acute pyogenic infection and one of the major microbes responsible for nosocomial infection were isolated from health care providers, nurses and patients. We used VITEK II to measure drug sensitivity, and we further performed biochemical testing, coagulase serotype testing and pulse-field gel electrophoresis (PFGE) for isolated MRSA colonies. The isolation rate of Staphylococcus aureus from nasal swabs was 75.0% from dental health care providers and 18.8% from the medical health care providers. A total of 10 MRSA strains were isolated from 40 health care providers and 2 patients and the prevalent coagulase serotype from patients and health care providers was VII. The antimicrobial drug resistance and partial PFGE types of the isolated MRSA strains showed a similar pattern. These results suggest that MRSA may be one of the principal causes of nosocomial infection in dental and medical hospitals.

• 미생물학회지
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• 제33권2호
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• pp.136-141
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• 1997

한국의 전통 발효식품인 된장에서 단백질 분해효소를 분비하는 미생물의 존재를 규명하기 위해, skim milk 한천배지를 이용하여 투명환을 보이는 균주들을 얻었고, 각종 생리 및 생화학적 검사, VITEK system, MIDI system을 통해 이들 중, JH-1, SH-5, SH-7의 3 strain이 Bacillus cereus임을 동정하였다. JH-1과 SH-5 균주가 분비하는 단백질 분해효소는 pH 9와 40^{\circ}C.$에서 최적활성을 보였으며, SH-7 균주는 pH 8과 50^{\circ}C.$에서 최적활성을 보였다. 또한 이들 3균주는 blood agar plate에서 용혈능력을 보였다.

• 한국축산식품학회지
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• 제41권5호
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• pp.883-893
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• 2021

Clostridium difficile present in feces of food animals may contaminate their meats and act as a potential source of C. difficile infection (CDI) to humans. C. difficile resistance to antibiotics, its production of toxins and spores play major roles in the pathogenesis of CDI. This is the first study to evaluate C. difficile prevalence in retail raw animal meats, its antibiotics susceptibilities and toxigenic activities in Al-Jouf, Saudi Arabia. Totally, 240 meat samples were tested. C. difficile was identified by standard microbiological and biochemical methods. Vitek-2 compact system confirmed C. difficile isolates were 15/240 (6.3%). Toxins A/B were not detected by Xpect C. difficile toxin A/B tests. Although all isolates were susceptible to vancomycin and metronidazole, variable degrees of reduced susceptibilities to moxifloxacin, clindamycin or tetracycline antibiotics were detected by Epsilon tests. C. difficile strains with reduced susceptibility to antibiotics should be investigated. Variability between the worldwide reported C. difficile contamination levels could be due to absence of a gold standard procedure for its isolation. Establishment of a unified testing algorithm for C. difficile detection in food products is definitely essential to evaluate the inter-regional variation in its prevalence on national and international levels. Proper use of antimicrobials during animal husbandry is crucial to control the selective drug pressure on C. difficile strains associated with food animals. Investigating the protective or pathogenic potential of non-toxigenic C. difficile strains and the possibility of gene transfer from certain toxigenic/ antibiotics-resistant to non-toxigenic/antibiotics-sensitive strains, respectively, should be worthy of attention.

• 대한의생명과학회지
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• 제29권4호
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• pp.256-262
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• 2023

The purpose of this study is to investigate microbial contamination in water purifiers from two universities (A and B) in Chungcheong region and to evaluate about the harmfulness of the isolated bacteria to the human. The degree of microbiological contamination of six water purifiers at university A was investigated three times from July 2018 to September 2019, and nine water purifiers at university B were investigated in 2023. The isolated bacteria were biochemically identified using an API kit and Vitek-2 system, and then the bacteria were identified to the species level using MALDI-TOF MS. In addition, the possibility of human infection of the isolated bacteria was evaluated through a literature search. In July 2018 and September 2019, the number of bacteria isolated inside the faucet was below the acceptable standard for hot water, but exceed for cold water in all water purifiers. In January and September 2019, bacteria exceeding the acceptable standards were isolated nine times from the cold water of six water purifies (a total of 12 water purifiers). Bacteria identified by MALDI-TOF MS included anaerobic bacteria (Clostridium novyi, Clostridium themopalmarium etc.), Gram-positive bacilli (Microbacterium testaceum, Arthrobacter woluwensis etc.), and Gramnegative bacilli (Acinetobacter nosocomialis, Comamonas kerstersii etc.), which are difficult identify by biochemical methods. In conclusion, bacteria exceeding the acceptable standard were isolated from the cold water of most of the water purifiers. Most of the isolated bacteria were low-pathogenic bacteria from natural environment, but opportunistic bacteria that can cause infection in humans were also isolated from some water purifiers.

• 한국환경과학회지
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• 제6권3호
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• pp.249-258
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• 1997

Mercury- and cadmium-resistant bacteria were Isolated from an Industrial complex wastewater of Taejon area. All of them were motile, gram negative rods. In the results of physicochemical test and VITEK card test. HM1 was Identified with Achetobacter cd- coaceucus, CM3 was Identified 65 Commonas acidovorns, HM2, HM3, CMI , and CM4 were Pseudomonas sp., but HM4 and CM2 were unidenteed. They were tested for subceptlbility to 14 heavy metals. Mercury-resistant bacteria(HM1, HM2, HM3, and HM4) were sensitive to low concentration(100~400ppm) of $Cd^{2+}$, $Co^{2+}$. $Zn^{2+}$, and Ni2+, while cadmium-resistant bacteria(CM1, CM2, CM3, and CM4) showed resistance up to the high concentration(600~ 1, 200ppm) of these metal loons. As a result of resistance spectrum test of mercury-resistant bacteria, HM1 was broad-spectrum strain, HM2. HM3, and HM4 were narrow-spectrum stratas. Transmission electron microscopic examination of cell wall of HM1 culture grown with and without 100ppm of $HgCl_2$ showed remarkably merphological abnormalities. In the result of atomic absorption spectrometric analysis of cadmium-resistant bacteria grown at 200ppm of $CdCl_2$ for 6h, all of them accumulated cadrnium(14ppm~57ppm) In cell. In cadinium-resistant bacteria, CM1, CM2, and CM4 were spared from the Inhibitory effect of $Cd^{2+}$ by the addition of $Mn^{2+}$, CM4 were also spared from the Inhibitory effect of $Cd^{2+}$ by the addition of $Mn^{2+}$ as well as $Zn^{2+}$.

• 미생물학회지
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• 제39권1호
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• pp.51-55
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• 2003

환경친화적인 미생물인산비료를 개발하기 위하여 불용성 인산을 가용화 시킬 수 있는 세균을 콩의 근권 토양으로부터 분리하였다. 분리균주의 분류학적 위치를 검토한 결과, Pantoea agglomerans로 동정되었다. 불용성 인산인 $Ca_{3}(PO_{4})_{2}$)로부터 가용성 인산을 생성하기 위한 최적 배지 및 배양조건은 glucose 3%, $NH_{4}NO_{3}$ 0.1%, $MgSO_{4}\cdot\7H_{2}O$ 0.02%, $CaCl_{2}\cdot\2H_{2}O$, 0.06%,초기 pH 7.5, 배양온도 $30^{\circ}C$이었으며, 최적조건에서 배양 5 일 후,898 mg/L의 인산이 생성되었다. 불용성 인산 가용화 기작은 유기산 생성에 의한 배양액의 pH감소와 밀접한 관계가 있었다. 분리균주는 $CaHPO_{4}$, hydroxyapatite로부터 각각 698,912 mg/L의 가용성 인산을 생성하였으나 $FePO_{4}\cdot\4H_{2}O$, $AIPO_{4}$로부터는 각각 28,19 mg/L.의 가용성 인산을 생성하였다.