• Korean Journal of Veterinary Research
• /
• v.20 no.2
• /
• pp.79-84
• /
• 1980

One hundred and eighteen cultures of Gram-negative rods isolated from cases of clinical bovine mastitis during lactation were examined for distribution of specific types, and activity of several antimicrobial agents to the isolates was determined by two-fold tube dilution method employing sterile whole milk as fluid medium. Of the isolates, 59.2% were Escherichia coli. Most of the remaining isolates were Klebsiella pneumoniae and Enterobacter aerogenes. Most Gram-negative rods(89.8%) were isolated from acute local and chronic mastitis. The cases of peracute systemic form with a marked symptoms of toxemia were associated with Escherichia coli and Klebsiella pneumoniae. The minimal lethal concentrations (MLC) of gentamicin and oxolinic acid in sterile whole milk were 16-128 times higher than the MLC obtained in trypticase soy broth (TSB), while the MLC of ampicillin and tetracycline in milk increased 2-4 times compared with TSB. Of the drugs tested, gentamicin was the most active antibiotics with MLC of $100{\mu}g/ml$ in sterile whole milk against all of Gram-negative rods isolated from bovine udder infections.

• Korean Journal of Veterinary Service
• /
• v.23 no.2
• /
• pp.137-142
• /
• 2000

In order to develop a good separation and simultaneous analysis of different sugar in an artificial mixed sugar solution, we analyzed 10 sugar components in an artificial mixed sugar solution composed of fructose, glucose, mannitol, sucrose, maltose, lactose, xylose, xylitol erythritol, and trehalose with using HPLC-ELSD or HPLC-RI. Separation and quantification by HPLC-ELSD was superior to those by HPLC-RI and detection sensitivity by HPLC-ELSD was higher then that by HPLC-RI as micorgram($\mu\textrm{g}$) level. 1. The units of minimal detectable limits were showed $\mu\textrm{g}$/$m\ell$ and ng/$m\ell$ by the HPLC-RI and HPLC-ELSD, respectively. 2. The condition of ELSD was drift tube temperature $82^{\circ}C$, $N_2$ gas flow rate 2.10 SLPM, and colum oven temperature $30^{\circ}C$, respectively. Isolation and recovery rates of single sugar from the multiple sugar solution was higher at the condition (time: flow rate: D.W.:ACN MeOH, min : $m\ell$/min:v:v:v) of linear gradient elution of mobile phase as 0 : 1.00 : 15 : 85 : 0.1 : 1.00 : 6 : 90 : 4, 17 : 1.00 : 10 : 70 : 20, 28 : 1.00 : 15 : 85 : 0 an 35 : 1.00 : 15 : 85 : 0, in order.

• The Journal of the Korean Society for Microbiology
• /
• v.22 no.3
• /
• pp.259-266
• /
• 1987

A total of 129 clinical isolates of Staphylococcus species was characterized by the tests of coagulase production, haemagglutination, mannitol fermentation, DNase production and hemolysis. Ninety-nine out of them showed positive reactions to the tests, therefore they were identified as Staphylococcus aureus. The isolates showing positive reaction in haemagglutination test also showed 100% of tube coagulase positive reaction. The haemagglutination test was a reliable method for identifying Staphylococcus aureus in the clinical laboratory. S. aureus produced stronger hemolysis with human blood agar than with sheep blood agar. Antibiotic resistant S. aureus isolates(S-46, S-112, S-126) had 4 to 6 p]asmid DNA elements. The S-112 strain had 6 plasmid DNA elements(1.8, 2.2, 3.7, $26.3{\sim}50$, and 70 Mdaltons), the S-126 had 4 elements(2.6, 4.2, $4.6{\sim}60Md$), and the S-46 had 1 element(${\sim}100Md$). PPSA strain had 4 plasmid DNA elements(2.5, 4.2, $4.6{\sim}60Md$) and S. aureurs(ATCC) strain contained 9.4, 26.3 and ${\sim}50Md$ plasmid DNA elements.

• International Journal of Advanced Culture Technology
• /
• v.7 no.1
• /
• pp.8-13
• /
• 2019

Despite technical advances in healthcare, the rates of hospital-acquired pressure injury (HAPI) are still high although many are potentially preventable. The purpose of this study was to determine whether tree-based prediction modeling is suitable for assessing the risk of HAPI in ICU patients. Retrospective cohort study has been carried out. A decision tree model was constructed with Age, Weight, eTube, diabetes, Braden score, Isolation, and Number of comorbid conditions as decision nodes. We used RStudio for model training and testing. Correct prediction rate of the final prediction model was 92.4 and the Area Under the ROC curve (AUC) was 0.699, which means there is about 70% chance that the model is able to distinguish between HAPI and non-HAPI. The results of this study has limited generalizability as the data were from a single academic institution. Our research finding shows that the data-driven tree-based prediction modeling may potentially support ICU sensitive risk assessment for HAPI prevention.

• Journal of Radiation Protection and Research
• /
• v.46 no.3
• /
• pp.120-126
• /
• 2021

Background: This paper aims to evaluate the clinical utility and radiation dosimetry, for the mobile X-ray imaging of patients with known or suspected infectious diseases, through the window of an isolation room. The suitability of this technique for imaging coronavirus disease 2019 (COVID-19) patients is of particular focus here, although it is expected to have equal relevance to many infectious respiratory disease outbreaks. Materials and Methods: Two exposure levels were examined, a "typical" mobile exposure of 100 kVp/1.6 mAs and a "high" exposure of 120 kVp/5 mAs. Exposures of an anthropomorphic phantom were made, with and without a glass window present in the beam. The resultant phantom images were provided to experienced radiographers for image quality evaluation, using a Likert scale to rate the anatomical structure visibility. Results and Discussion: The incident air kerma doubled using the high exposure technique, from 29.47 µGy to 67.82 µGy and scattered radiation inside and outside the room increased. Despite an increase in beam energy, high exposure technique images received higher image quality scores than images acquired using lower exposure settings. Conclusion: Increased scattered radiation was very low and can be further mitigated by ensuring surrounding staff are appropriately distanced from both the patient and X-ray tube. Although an increase in incident air kerma was observed, practical advantages in infection control and personal protective equipment conservation were identified. Sites are encouraged to consider the use of this technique where appropriate, following the completion of standard justification practices.

• The Plant Pathology Journal
• /
• v.38 no.4
• /
• pp.403-409
• /
• 2022

In biological particles such as Fusarium species, ice nucleation activity (INA) has been observed. Fusarium strains isolated from apple declined trees in Korea were identified with a multilocus sequence analysis using the tef1 and rpb1 genes. Droplet-freezing and tube-freezing assays were used to determine the INA of the strains, using Pseudomonas syringae pv. syringae KACC 21200 as a positive control and resulting in seven INA+ fungal strains that were identified as F. tricinctum (KNUF-21-F17, KNUF-21-F18, KNUF-21-F29, KNUF-21-F32, KNUF-21-F38, KNUF-21-F43, and KNUF-21-F44). The effect of Fusarium INA+ KNUF-21-F29 was compared to that of INA- strains on Chrysanthemum morifolium cv. Shinma explants. A higher callus formation and no-shoot formation were observed, suggesting that fungal INA could play a role in cold injuries and be a factor to consider in rapid apple decline. To the best of our knowledge, this is the first report of INA fungal strains isolated in Korea.

• Food Science and Preservation
• /
• v.30 no.1
• /
• pp.42-51
• /
• 2023

This study aimed to characterize a lytic Salmonella Typhimurium-specific (ST) phage and its biofilm control capability against S. Typhimurium biofilm on polypropylene surface. ST phage was isolated, propagated, and purified from water used in a slaughterhouse. The morphology of ST phage was observed via transmission electron microscopy. Its bactericidal effect was evaluated by determining bacterial concentrations after the phage treatment at various multiplicities of infection (MOIs) of 0.01, 1.0, and 100. Once the biofilm was formed on the polypropylene tube after incubation at 37℃ for 48 h, the phage was treated and its antibiofilm capability was determined using crystal violet staining and plate count method. The phage was isolated and purified at a final concentration of ~11 log PFU/mL. It was identified as a myophage with an icosahedral head (~104 nm) and contractile tail (~90-115 nm). ST phage could significantly decrease S. Typhimurium population by ~2.8 log CFU/mL at an MOI of 100. After incubation for 48 h, biofilm formation on polypropylene surface was confirmed with a bacterial population of ~6.9 log CFU/cm². After 1 h treatment with ST phage, the bacterial population in the biofilm was reduced by 2.8 log CFU/cm². Therefore, these results suggest that lytic ST phage as a promising biofilm control agent for eradicating S. Typhimurium biofilm formed on food contact surfaces.

• Applied Biological Chemistry
• /
• v.22 no.3
• /
• pp.166-172
• /
• 1979

A series of experiments was planned for practical application of rhizobia in grass lands in Korea. This is the report for the studies mainly on the isolation and characterization of alfalfa nodule bacteria, and on the assessment of their nodulation abilities and nitrogen fixation capacities. 1. Total number of 47 strains was isolated from nodules which were taken from alfalfa grown in Daekwanyong, Cheju and other places. 2. Morphological and cultural characteristics of the strains were studied, and attempts. were also made to investigate their antigenic properties and to demonstrate lysogenic strains. The results were; i) the isolates varied in their cultural characteristics on yeast mannitol broth and agar, and in degree of congo red absorption; ii) similarities in their antigenic prorerties were found between the strains: SU 47/M-11, M-13/M-15, and M-3/M-5; iii) no lysogeny was found in the strains. 3. Plant infection test by test tube method in light room were carried out to elucidate the ability of the strains to nodulate Luna alfalfa and of the capacity of such nodules to fix atmospheric nitrogen. The isolates were grouped info non-invasive, ineffective, or effective to the legumes. Those strains which produced effective nodules, supporting similar/higher level of growth as nitrate control were: M-8, 9, 14, 20, 21, 25 and 34.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.11 no.1
• /
• pp.19-24
• /
• 1978

The differences in Vibrio parahaemolyticus detection ratio were compared between the isolation methods, the Most Probable Number technique and single dilution tube method. During the period from February to October in 1976, 298 samples of sea water, 112 of bottom deposit, 169 of shellfish, and 80 of fish samples collected along the south coastal area of Korea were examined to determine the detection ratio of Vibrio parahaemolyticus. It was often observed that Vibrio parahaemolyticus was detected in higher diluted samples even through negative in lower dilution. Three hundred and forty three samples out of 659 samples submitted to the test by MPN procedure appeared positive for Vibrio parahaemolyticus showing $52\%$ detection ratio. Whereas only 149 samples, corresponding $22.5\%$, were positive for Vibrio parahaemolyticus in the lowest dilution grade. The positive result was $24.5\%$ in the lowest dilution grade and $50\%$ by MPN Procedure in sea water samples, $28.6\%$ and $65.2\%$ in bottom deposit, $22.5\%$ and $56.2\%$ in shellfish and $7.5\%$ and $32.5\%$ fish samples. When tested by triplicate tubes, $61.7\%$ of 149 Vibrio parahaemolyticus positive samples appeared positive in one tube, $28.9\%$ of them were positive in two tubes and $9.4\%$ of them were positive in all three tubes. The detection ratio determined by MPN procedure was more than two times higher than that of single dilution in triplicate tubes.

• Korean Journal of Microbiology
• /
• v.50 no.3
• /
• pp.254-260
• /
• 2014

Sulfur compound includes major electron acceptors for anaerobic respiration. In this study, cultivation-based study on sulfate- and sulfur-reducing bacteria of various wetlands of Korea was attempted. To isolate sulfate- and sulfur-reducing bacteria, anaerobic roll tube method was used to obtain typical black colonies of sulfate- and sulfur-reducing bacteria. Total 11 strains obtained were tentatively identified based on comparative 16S rDNA similarity and physiological property analysis. All sulfate-reducing bacteria (8 strains) belonged to genus Desulfovibrio with >99% 16S rDNA similarities. Three sulfur reducing bacteria were also isolated: two and one isolates were affiliated with Sulfurospirillum and Desulfitobacterium, respectively. These sulfate- and sulfur-reducing bacteria were able to utilize lactate and pyruvate and sulfite and thiosulfate as common electron donors and electron acceptors, respectively. This case study will provide fundamental information for obtaining useful indigenous sulfate- and sulfur-reducing bacteria from Korean wetlands employing various combinations of cultivation conditions.