• Journal of Veterinary Science
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• v.24 no.6
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• pp.82.1-82.12
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• 2023

Background: The current conventional serotyping based on antigen-antisera agglutination could not provide a better understanding of the potential pathogenicity of Salmonella enterica subsp. enterica serovar Brancaster. Surveillance data from Malaysian poultry farms indicated an increase in its presence over the years. Objective: This study aims to investigate the virulence determinants and antimicrobial resistance in S. Brancaster isolated from chickens in Malaysia. Methods: One hundred strains of archived S. Brancaster isolated from chicken cloacal swabs and raw chicken meat from 2017 to 2022 were studied. Two sets of multiplex polymerase chain reaction (PCR) were conducted to identify eight virulence genes associated with pathogenicity in Salmonella (invasion protein gene [invA], Salmonella invasion protein gene [sipB], Salmonella-induced filament gene [sifA], cytolethal-distending toxin B gene [cdtB], Salmonella iron transporter gene [sitC], Salmonella pathogenicity islands gene [spiA], Salmonella plasmid virulence gene [spvB], and inositol phosphate phosphatase gene [sopB]). Antimicrobial susceptibility assessment was conducted by disc diffusion method on nine selected antibiotics for the S. Brancaster isolates. S. Brancaster, with the phenotypic ACSSuT-resistance pattern (ampicillin, chloramphenicol, streptomycin, sulphonamides, and tetracycline), was subjected to PCR to detect the corresponding resistance gene(s). Results: Virulence genes detected in S. Brancaster in this study were invA, sitC, spiA, sipB, sopB, sifA, cdtB, and spvB. A total of 36 antibiogram patterns of S. Brancaster with a high level of multidrug resistance were observed, with ampicillin exhibiting the highest resistance. Over a third of the isolates displayed ACSSuT-resistance, and seven resistance genes (β-lactamase temoneira [bla_TEM], florfenicol/chloramphenicol resistance gene [floR], streptomycin resistance gene [strA], aminoglycoside nucleotidyltransferase gene [ant(3")-Ia], sulfonamides resistance gene [sul-1, sul-2], and tetracycline resistance gene [tetA]) were detected. Conclusion: Multidrug-resistant S. Brancaster from chickens harbored an array of virulence-associated genes similar to other clinically significant and invasive non-typhoidal Salmonella serovars, placing it as another significant foodborne zoonosis.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.6
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• pp.203-209
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• 2023

Cobalt sulfide nanocomposites were synthesized through a simple hydrothermal method as anode materials for sodium ion batteries (SIBs). In this work, a cobalt sulfide nanoparticle (CoS-NF) and a cobalt sulfide nanocomposite integrated with reduced graphene oxide (CoS@G-NC) were fabricated for electrochemical energy storage performance of battery. The as-prepared CoS@G-NC electrode exhibited reversible and stable cycle performance (62 % after 30 cycles at current density of 200 mA g^-1). The improved electrochemical property was attributed to the small grain growth and uniform distribution of cobalt sulfide during synthesis, which maximized the diffusion pathway for sodium ions and effectively suppressed the delamination and volume expansion of cobalt sulfide during the conversion reaction. The results provide promising anode materials for next-generation SIBs.

• Microbiology and Biotechnology Letters
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• v.51 no.3
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• pp.268-279
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• 2023

The pharmaceutical industry in Bangladesh produces a diverse range of antibiotics for human and animal use, however, waste disposal management is inadequate. This results in substantial quantities of antibiotics being discharged into water bodies, which provide suitable environment for the growth of antibiotic-resistant bacteria, capable of spreading resistance genes. This study intended for exploring the bacterial antibiotic resistance profile in adjoining aquatic environmental sources of pharmaceutical manufacturing facilities in Bangladesh. Seven surface water samples were collected from the vicinity of two pharmaceutical industries located in the Savar area and 51 Escherichia coli isolates were identified using both phenotypic and genotypic methods. Antibiotic susceptibility tests revealed the highest percentage of resistance against ampicillin, azithromycin, and nalidixic acid (100%) and the lowest resistance against meropenem (1.96%) out of sixteen different antibiotics tested. 100% of the study E. coli isolates were observed with Multidrug resistance phenotypes, with the Multiple Antibiotic Resistance (MAR) value ranging from 0.6-1.0. Furthermore, 69% of the isolates were Extended Spectrum Beta-Lactamases (ESBL) positive as per the Double Disk Diffusion Synergy Test (DDST). ESBL resistance genes bla_TEM, bla_CTX-M-13, bla_CTX-M-15, and bla_SHV were detected in 70.6% (n = 36), 60.8% (n = 32), 54.9% (n = 28), and 1.96% (n = 1) of the isolates, respectively, by Polymerase Chain Reaction (PCR). Additionally, 15.68% (n = 8) of the isolates were positive for E. coli specific virulence genes in PCR. These findings suggest that pharmaceutical wastewater, if not properly treated, could be a formidable source of antibiotic resistance spread in the surrounding aquatic environment. Therefore, continued surveillance for drug resistance among bacterial populations around drug manufacturing facilities in Bangladesh is necessary, along with proper waste disposal management.

• Journal of the Korean Magnetics Society
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• v.15 no.1
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• pp.42-47
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• 2005

Nanocrystalline Nd-Fe-B powder was synthesized by a new thermochemical process that combined with past reduction-diffusion process and spray-dry process. In this process, Ca reduction process is vary important due to formation of hard magnetic$Nd_{2}Fe_{14}B$ phase from various oxides by Ca powder. Therefore, the final products are essentially affected a shape, size, and composition etc. of the Ca reduced powders. Ca reduction was performed to way that raw powders just mixed with Ca powder in proper ratio unlike to compress into compact. The powders after mixture-type Ca reduction mainly composited with $Nd_{2}Fe_{14}B$ phase even relativily low reaction temperature ($800^{\circ}C$) and all particle size of powder were distributed less than 1 ${\mu}m$ except for powder after Ca oxides as magnetic properties of powders after cake-type Ca reduction, with the consequence that high magnetic properties has been expected. The magnetic properties of powders prepared by mixture-type Ca ruduction, with the conseqence that high magnatic properties has been expected. The magnetic properties of powders prepared by mixture-type Ca reduction process showed $_iH_c$ = 5.9 kOe, $B_r$ = 5.5 kG, (BH)max = $Nd_{2}Fe_{14}B{\to}Nd_{2}Fe_{17}B$ decomposition by violent exothermic reaction during washing.

• Korean Journal of Veterinary Research
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• v.5 no.1
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• pp.1-16
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• 1965

I. A Comparison of Sodium Sulfate Precipitation and Zone(Paper, Agar) Electrophoresis; Many kinds of techniques have been used for fractionating serum proteins. In the present study, using bovine serum, the fractions obtained with sodium sulfate were compared with those determined by zone electrophoresis. 1. Fibrinogen was precipitated with 4 to 10 percent of sodium sulfate. 2. ${\gamma}$-globulin required 10 to 16 percent of the salt for precipitation. 3. ${\beta}$-globulin began to precipitate at 12 percent sodium sulfate, and completed precipitation at approximately 26 percent in paper electrophoresis, while at 22 percent in agar electrophoresis. 4. ${\alpha}$-globulin completed precipitation at 13 to 28 percent sodium sulfate in paper electrophoresis and at 22 percent in agar electrophoresis. 5. Albumin began to precipitate at 14 percent of the salt, and was free from the mixture of globulins approximately at 28 percent in paper electrophoresis, while at 22 percent in agar electrophoresis. The results of comparing fractions by the two methods were as follows: 1. Euglobulin (15%) was equal to the sum of the most ${\gamma}$-globulin and a small quantity of the ${\alpha}$-, and ${\beta}$-globulins. 2. Pseudoglobulin I (15-17.5%) corresponded to the most ${\alpha}$-, ${\beta}$-globulins and a small quantity of albumin. 3. Pseudoglobulin II(18-22%) was a mixture of the ${\alpha}$-, ${\beta}$-globulins and albumin fraction. 4. Albumin (above 22%) contained the most albumin fraction separated by zone electrophoresis and a small quantity of the ${\alpha}$-, and ${\beta}$-globulins. As mentioned above the fractions obtained with sodium sulfate were a mixture of the various proportion of the fractions determined by zone electrophoresis. The solubility of serum fractions to sodium sulfate coincided with the mobility of those by zone electrophoresis. (By percent of sodium sulfate we mean gram of sodium sulfate contained in $100m{\ell}$ of solution). II. Immunological Studies on Serum Protein Fractions with Sodium Sulfate; In the previous report the fractions of bovine serum protein with sodium sulfate compared with those obtained by zone electrophoresis, and the findings were that the former contained various proportion components of the latter. In this study the author studied whether or not the fractions with sodium sulfate are simple component antigenically by immunoelectrophoresis and micro double diffusion test (Immuno-precipitation), using rabbit antiserum to bovine serum. In immunoelectrophoresis, normal bovine serum developed with rabbit antibovine serum showed about ten distinct precipitin arcs. The distribution of these arcs was as follows: 1 albumin, 2 ${\alpha}_1$-, 3 ${\alpha}_2$-, 2 ${\beta}_1$-, ${\beta}_2$-, and 1 ${\gamma}$-globulin (Fig. 7, 9). In micro double diffusion test, five to six precipitation bands could be seen between antigens and antibody, the order of the precipitation bands location is albumin, ${\alpha}$-, ${\beta}$-, and ${\gamma}$-globulin from the side of antiserum well (Fig.19). Frequently the ${\alpha}$-, and ${\beta}$-precipitation bands were separated into two or three precipitation bands, which indicated that these globuline are not a pure component antigenically as shown in immuno-electrophoresis. In both Immunological methods, the two ${\alpha}$-, ${\beta}$-precipitin arcs and bands appeared clear and strong, indicating that the two globulins reacted as strong antigens. The precipitate reaction of ${\gamma}$-globulin was shown at 12 to 16 percent sodium sulfate; ${\beta}$-globulin at 12 to 20 percent; ${\alpha}$-globulin at 12 to 22 percent (immuno-electrophoresis), at 12 to 26 percent (Diffusion); and albumin at above 22 percent. Antigenically euglobulin contained ${\gamma}$-, ${\beta}$-, and ${\alpha}$-globulins, Pseudoglobulin I and Pseudoglobulin II were composed of ${\alpha}$-, and ${\beta}$-globulins, and albumin was a mixture of ${\alpha}$-globulin and albumin determined by zone electrophoresis. The results indicated that the fractions of serum protein obtained by either method were constituents of various proteins antigenically except ${\gamma}$-globulin and albumin by Zone electrophoresis.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.14-14
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• 2011

W (tungsten)-alloys will be the most promising plasma facing armor materials in highly loaded plasma interactive components of the next step fusion reactors due to its high melting point, high sputtering resistance and low deuterium/tritium retention. The bonding technology of tungsten to Cu alloy was one of the key issues. In this paper, W/CuCrZr diffusion bonding has been performed successfully by inserting pure metal interlay. The joint microstructure, interfacial elements migration and phase composition were analyzed by SEM, EDS, XRD, and the joint shear strength and micro-hardness were investigated. The mock-ups were fabricated successfully with diffusion bonding and the cladding technology respectively, and the high heat flux test and thermal fatigue test were carried out under actively cooling condition. When Ni foil was used for the bonding of tungsten to CuCrZr, two reaction layers, Ni4W and Ni(W) layer, appeared between the tungsten and Ni interlayer with the optimized condition. Even though Ni4W is hard and brittle, and the strength of the joint was oppositely increased (217 MPa) due primarily to extremely small thicknesses (2~3 ${\mu}m$). When Ti foil was selected as the interlayer, the Ti foil diffused quickly with Cu and was transformed into liquid phase at $1,000^{\circ}C$. Almost all of the liquid was extruded out of the interface zone under bonding pressure, and an extremely thin residual layer (1~2 ${\mu}m$) of the liquid phase was retained between the tungsten and CuCrZr, which shear strength exceeded 160 MPa. When Ni/Ti/Ni multiple interlayers were used for bonding of tungsten to CuCrZr, a large number of intermetallic compound ($Ni_4W/NiTi_2/NiTi/Ni_3T$) were formed for the interdiffusion among W, Ni and Ti. Therefore, the shear strength of the joint was low and just about 85 MPa. The residual stresses in the clad samples with flat, arc, rectangle and trapezoid interface were estimated by Finite Element Analysis. The simulation results show that the flat clad sample was subjected maximum residual stress at the edge of the interface, which could be cracked at the edge and propagated along the interface. As for the rectangle and trapezoid interface, the residual stresses of the interface were lower than that of the flat interface, and the interface of the arc clad sample have lowest residual stress and all of the residual stress with arc interface were divided into different grooved zones, so the probabilities of cracking and propagation were lower than other interfaces. The residual stresses of the mock-ups under high heat flux of 10 $MW/m^2$ were estimated by Finite Element Analysis. The tungsten of the flat interfaces was subjected to tensile stresses (positive $S_x$), and the CuCrZr was subjected to compressive stresses (negative $S_x$). If the interface have a little microcrack, the tungsten of joint was more liable to propagate than the CuCrZr due to the brittle of the tungsten. However, when the flat interface was substituted by arc interfaces, the periodical residual stresses in the joining region were either released or formed a stress field prohibiting the growth or nucleation of the interfacial cracks. Thermal fatigue tests were performed on the mock-ups of flat and arc interface under the heat flux of 10 $MW/m^2$ with the cooling water velocity of 10 m/s. After thermal cycle experiments, a large number of microcracks appeared at the tungsten substrate due to large radial tensile stress on the flat mock-up. The defects would largely affect the heat transfer capability and the structure reliability of the mock-up. As for the arc mock-up, even though some microcracks were found at the interface of the regions, all microcracks with arc interface were divided into different arc-grooved zones, so the propagation of microcracks is difficult.

• Clinical and Experimental Pediatrics
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• v.46 no.9
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• pp.846-853
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• 2003

Purpose : Pneumoccocus is one of the most important causes of invasive infection through the childhood period and the prevelance of antibiotics resistance of pneumococcus is increasing worldwide. A 7-valent conjugate vaccine has been developed. It is important to know the prevalence of each serotype of pneumococci in the countries where the vaccine is used to estimate the coverage rate by the vaccine. Methods : One hundred and twenty seven strains of clinical isolates and 72 strains from healthy carriers recovered from Korean children during the period from 1997 to 2002 were subjected to determination of serotype by Quellung reaction and penicillin susceptibility with oxacillin disc diffusion test. Results : Forty-three per cent of clinical isolates were obtained from children under two years of age. Thirty strains(24%) were isolated from normally sterile body fluids. The frequent serotypes were 19F, 19A, 23F, 6A, 6B and 9V. Fifty-six per cent of the clinical isolates were represented in the current 7-valent protein conjugate pneumococccal vaccine, and 84% when the cross-reactive serotypes were included. Frequent serotypes of strains isolated from one to five year-old healthy children were 19F, 14, 11A, 23F, 18C, and 19A. Seventy-one per cent of the carrier strains were included in the 7-valent vaccine. Ninety-three per cent of the clinical isolates and 86% of carrier strains were not susceptible to penicilline. Conclusion : Fifty-six to 84% of pneumococci recovered from Korean children are covered by the current 7-valent protein conjugate pneumococcal vaccine and the prevalence of penicillin resistance was very high.

• Research in Plant Disease
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• v.14 no.1
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• pp.15-20
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• 2008

Three isolates of Cucumber mosaic virus (CMV) were isolated from weed hosts showing typical mosaic symptoms, and some properties of the viruses were investigated. CMV isolates, designated as Is-CMV, Jd-CMV and Pla-CMV from Isodon inflexus, Jeffersonia dubia and Phryma leptostachya var. asiatica, respectively, were identified and characterized by biological reaction in several host plants, serological property, dsRNA analysis, reverse transcription-polymerase chain reaction (RT-PCR), restriction fragment-length polymorphism (RFLP). All isolates systemically infected in Nicotiana benthamiana, Cucurbita pepo cv. Black beauty and Cucumis sativus, and did not reveal any differences in these host plants between the isolates. However, remarkable difference in the symptoms was found between the CMVs in Capsicum annuum. Is-CMV induced an asymptomatic symptoms, while Jd-CMV and Pla-CMV produced severe mosaic symptoms in C. annuum plants. In dsRNA analysis, all isolates revealed four major bands with estimated molecular size of 3.4, 3.2, 2.1 and 1.0 kbp. The cDNAs of coat protein gene of the isolates were amplified by RT-PCR using a genus-specific single pair primers that designed to amplify a DNA fragment of approximately ranging from 938 to 966 bp. By restriction mapping analysis using RFLP of the RT-PCR products as well as by serological properties of gel diffusion test, the CMV isolates belong to a typical members of CMV subgroup IA. This is the first report on the occurrence of CMV in the three weed hosts.

• Parasites, Hosts and Diseases
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• v.26 no.2
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• pp.73-86
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• 1988

The sensitivity and specificity of crude and affinity-purified antigens of Clcnorchis sinensis obtained from the infected rabbits were studied. Stage-specific antigenic proteins from the eggs, metacercariae and adult worms were characterized by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunosorbent astray (ELISA). The results were as follows: 1. The antibody.binding antigen (ABA) purified from whole worm crude antigen (IVWA) by CNBr-activated Sepharose 4B affinity chromatography made :l specific bands against rabbit antisera on Ouchterlony gel diffusion plate, while WWA made 7 bands. Major WWA protein bands by SDS-PAGE were found at 16, 300~18, 500 and 28, 000~29, 000 daltons, while major ABA protein bands were at 18, 000~21, 000 and 29, 000~31, 000 daltons. The reactivity of ABA with rabbit anti-sera in ELISA was remarkably less sensitive than that of WWA. 2. Molecular weights of egg antigen (EGA), metacercarial antigen (MEA) and adult worm antigen (WWA) of C. sinensis ranged from 15, 000-200, 000 daltons, 15, 000-100, 000 daltons and 11, 000~80, 000 daltons, respectively. Major WWA proteins consisted mainly of polypeptide bands of low molecular weight, less than 31, 000 daltons, while those of EGA and MEA consisted of higher molecular T.eights than 30, 000 daltons. 3. The ELISA reactivities of WWA to rabbit anti.sera were remarkably greater than those of MEA. EGA showed negative reaction throughout the experiments. WWA showed higher optical density (O.D.) than 1.0, when reacted with rabbit anti-sera obtained at 4~6 weeks after the infection. In the rabbit anti-sera later than 12 weeks after the infection, the O.D. reacting witll WWA showed a plateau without variation. MEA shoT.ed relatively low O.D. values (<0.6), when reacted with anti-sera from lightly in(ected groups throughout the experiments, althougll there were some wealth positive cases (O.D.>0.6) ill heavily infected groups. MEA reacted with rabbit anti-sera showed negative results on Ouchterlony gel diffusion plates. Summarizing the above results, it is suggested that the whole worm antigen prepared from the adult worms of C. sinensis is most highly antigenic. However, this antigen might reveal cross reactions with other trematodes such as Paragonimus westermani, therefore, purification of antigenic proteins from the crude antigen is essential 18 increase the sensitivity and specificity for the immuncdiagnosis of clonorchiasis.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.342-351
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• 2006

The aim of this study was to survey susceptibilities of Escherichia coli and Klebsiella pneumoniae isolates against cefotaxime and to determine the prevalences of CTX-M type extended-spectrum $\beta$-lactamases (ESBLs) producing E. coli and K. pneumoniae in Korea. During the period of February to July, 2005, 153 E. coli and 52 K. neumoniae isolates were collected from 2 hospitals in Busan. Antimicrobial susceptibilities to cefotaxime were tested by the disk diffusion method. ESBL production of E. coli and K. pneumoniae was determined by the double disk synergy test. MICs of $\beta$-lactam antibiotics were determined by the agar dilution method. Blac$_{CTX-M}$ genes of the organism were detected by PCR. Among 153 isolates of E. coli and 52 isolates of K. neumoniae, 27 (17.6%) and 25 (48.0%) were intermediate or resistant to cefotaxime, respectively. Twenty-three (15.0%) isolates out of 153 E. coli and 13 (25.0%) out of 52 K. neumoniae isolates showed positive results for ESBL by the double disk synergy test. Twenty isolates out of 23 ESBL producing E. coli and 12 out of 13 ESBL producing K. neumoniae isolates harbored biacTx-M gene,11 of ESBL producing E. coli and 12 of ESBL producing K. neuinoniae isolates harbored bla$_{CTX-M}$ gene, 11 of the ESBL producing E. coli and 2 of ESBL producing K. neumoniae isolates harbored bla$_{TEM}$ gene, and 1 of the ESBL producing E. coli and 12 of ESBL producing K. neumoniae isolates harbored bla$_{SHV}$ gene. E. coli and K. neumoniae isolates producing CTX-M-type ESBLs were not uncommon in Korea. It is thought that continuous survey are necessary for inspecting the spread and novel variants of CTX-M-type ESBL genes. Further me]'e investigation and research on ESBL producing strains are needed in order to prevent the spread of resistant bacteria.