• Journal of Life Science
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• v.20 no.10
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• pp.1549-1555
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• 2010

Streptococcus suis is a worldwide pathogen of a variety of porcine infection and has also been described as a pathogen for humans. We studied biochemical characteristics, antimicrobial susceptibility, and identification of polymerase chain reaction (PCR) of S. suis isolated from diseased pigs in Gyeongbuk province from 2004 to 2009. Sixty-one isolates were identified as S. suis by biochemical characteristics and PCR from 40 farms. The biochemical characteristics of S. suis isolates were production of VP-negative, hippurate, esculin, and arginine decarboxylase-positive, and fermentation of carbohydrate was variable lactose, trehalose, inulin, and raffinose, which was typeable 11 phenotype. In an antimicrobial susceptibility test, the majority of isolates were highly susceptible to amoxicillin/clavulanic acid, ampicillin, cephalothin, cefoperazone and florfenicol, while being highly resistant to streptomycin, kanamycin, amikacin, neomycin, erythromycin, clindamycin, and tetracycline. The isolates were divided into 11 phenotypes of biochemistry. By using PCR, the 16S-rRNA gene DNA fragment was detected at 304 bp from all of isolates. These results may provide the basic information needed to establish strategies for the prevention of S. suis infection in pigs.

• Journal of fish pathology
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• v.27 no.1
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• pp.77-83
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• 2014

The monitoring was performed to survey the mortalities and medications occurred in the inland aquaculture farms of olive flounder in South Korea from May to October, 2012. Both of the indirect inquiry for entire inland farms and the sample survey for selected farms were carried out. The aquatic organism disease inspectors, who have the national licenses for the diagnosis and prevention of aquatic organism diseases and have close relationship with the farms, investigated the rates and causes of mortalities according to the standard manual. The cumulative mortalities rate by the indirect inquiry on 565 farms, was calculated to 27.18%, and the mortalities rate by infectious diseases was 22.64%. Otherwise, the mortalities rate by sample survey on 60 farms was 25.50%, 19.33% of them were caused by infectious diseases. The high mortality rates were recorded by scuticociliatosis, non-infectious loss, streptococcosis, VHS, artificial eliminations, vibriosis and gliding bacterial disease. Streptococcosis and non-infectious mortality caused to serious loss in productivity and economy of the farms, because of their outbreaks in the flounder groups over 600 g. The monitoring of medications in the selected farms revealed that formalin for the treatment of external parasites, such as scuticociliates, was the most commonly used drugs in the farms. As the antibiotic medications, amoxicillin and florfenicol for streptococcosis, and oxytetracycline and neomycin expecting wide antibacterial spectrum, were frequently prescribed.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.95-99
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• 1995

We have previously established a system for plant regeneration through somatic embryogenesis and Agrobacterium-mediated transformation of Korean ginseng. In this study to produce a fungus-resistant plant, we introduced a bean chitinase gene into ginseng using the transformation system. A binary vector pChi/748 was constructed by introducing the bean basic chitinase gene into EcoRI site of pGA748 which carries the CaMV 35S promoter governing the introduced gene and neomycin phosphotransferase II(NPT-II)gene as a positive selection marker. Cotyledonary explants were cocultured with A. tumefaciens strain LBA4404 harboring the binary vertor pChi/748 for 48 h, and transferred to MS medium supplemented with l mg/L2,4-D,0.1mg/L kinetin, 100 mg/L kanamycin, and 500mg/L carbenicillin. Kanamycin-resistant calli were formed on the cut surface of cotyledonary explants after one month of culture, and subsequently they gave rise to somatic embryos. Upon transfer onto medium containing 1 mg/L each of BA and GA$_3$, most of them converted to plantlets after 5 weeks of culture. The genomic DNA of eight kanamycin-resistant regenerants was subjected to polymerase chain reaction (PCR) using two specific 21-mer oligonucleotides derived from the chitinase gene. PCR-Southern blot analysis confirmed that the chitinase gene was incorporated into six out of the eight regenerants..

• Food Science of Animal Resources
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• v.29 no.1
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• pp.15-23
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• 2009

In order to develop a new starter for fermented milk, 2082 bacteria were isolated from raw milk. The strain that showed excellent acid forming and ${\gamma}$-aminobutyric acid (GABA) production ($711.40{\mu}g/g$ D.W) characteristics after incubation at $37^{\circ}C$ for 18 hr was selected and identified as Lactobacillus acidophilus by the result of API carbohydrate fermentation pattern and 16S rDNA sequence. L. acidophilus RMK567 was investigated for its physiological characteristics. RMK67 strain showed good GABA production compared with commercial lactic acid bacteria. The optimum growth temperature of L. acidophilus RMK567 was $40^{\circ}C$ and cultures took 15 hr to reach pH 4.3. L. acidophilus RMK567 showed higher sensitivity to penicillin-G, novobiocin, as compared to other 14 different antibiotics. However, it showed more resistance to kanamycin, neomycin, streptomycin. It showed higher leucine arylamidase and ${\beta}$-galactosidase activities compared to 16 other enzymes. It was comparatively tolerant to bile juice and able to survive at pH 2 for 3 hr. It showed resistence to Escherichia coli, Salmonella typhimurium and Staphylococcus aureus with rates of 29.2%, 39.1% and 51.4%, respectively. Based on these and previous results, L. acidophilus RMK567 could be an excellent starter culture for fermented milk with excellent GABA contents.

• Journal of Korean Society of Forest Science
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• v.77 no.2
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• pp.199-207
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• 1988

Three clones of Populus alba ${\times}$ P. grandidentata have been tested for susceptibility to Agrobacterium tumefaciens strains A281 and A348. We determined the optimum concentration of kanamycin sulfate for effective selection of leaf disc-derived, transgenic tissues transformed using Agrobacterium binary vector pGA472 containing a neomycin phosphotransferase gene (NPT-II) which confers kanamycin resistance. Of the wild type Ti plasmids contained by the two Agrobacterium strains, pTiBo542 of strain A281 appears to be best suited to serve as a helper plasmid for binary vector systems. A relatively low concentration (10mg/l) of kanamycin sulfate inhibited adventitious shoot initiation from leaf discs on regeneration medium. Transformed kanamycin-resistant calli were obtained by culturing Agrobacterium inoculated leaf discs on selective regeneration medium. The transformed kanamycin-resistant calli continued to grow on regeneration media supplemented with kanamycin sulfate to levels of 50 and 200mg/l. The growth of non-co-cultivated control calli was severely inhibited on regeneration medium containing 50mg/l kanamycin sulfate.

• Journal of Korean Society of Forest Science
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• v.84 no.1
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• pp.77-86
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• 1995

To effectively modify tree function with genetic engineering, transgenes must be expressed at the proper level in the appropriate tissues at suitable developmental stages. Toward understanding the spatial and temporal expression of transgenes in woody plants, transgene expression was evaluated in three greenhouse-grown, transgenic lines of Populus alba ${\times}$ P. grandidentata hybrid clone 'Hansen'. All transgenic poplar lines possess constructs containing the bacterial nopaline synthase(nos) promoter linked to a neomycin phosphotransferase II(NPT II) selectable marker gene. In addition, each transgenic poplar line contains one of the following gene constructs : 1) a wound-inducible potato proteinase inhibitor II (pin2) promoter linked to a chloramphenicol acetyltransferase(CAT) reporter gene. 2) a nos promoter linked to a PIN2 structural gene : or 3) a Cauliflower Mosaic Virus 35s promoter linked to a PIN2 structural gene. Polymerase chain reaction(PCR) was used to verify the presence of foreign genes in the poplar genome. Enzyme-linked immunosorbent assays(ELISAs) were used to evaluate organ specific expression of the nos-NPT II construct. NPT II expression was detected in leaves, petioles, stems, and roots of transgenic poplar, thereby indicating that the nos promoter is potentially effective for general constitutive expression of transgenes. NPT expression varied among transgenic poplar lines and among organs for one transgenic line, Tr15. With Tr15, NPT II levels were highest in older leaves and petioles. These results indicate that screening of several transgenic lines may be required to identify lines with optimal transgene expression.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.751-756
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• 1999

The inhibitory effect of antibiotics on growth of lactobacillus, streptococcus and bifidobacteria was examined to develop the selective media to isolate and enumerate bifidobacteria from the fermented foods containing various lactic bacteria. The growth of lactic bacteria was inhibited seriously but that of bifidobacteria was not inhibited by gentamycin or ripampicin at the concentration of more than $100\;{\mu}g/mL$. However lactic bacteria did not grow in MRS broth containing $50\;{\mu}g/mL$ of ampicillin and the growth inhibition of bifidobacteria occurred. The growth inhibition of bifidobacteria was more severe than lactic bacteria in $100\;{\mu}g/mL$ of fosfomycin. Therefore, the MRS medium containing $80\;{\mu}g/mL$ of neomycin sulfate, $50\;{\mu}g/mL$ of gentamycin, $50\;{\mu}g/mL$ of rifampicin, $15\;{\mu}g/mL$ of nalidixic acid and $3\;{\mu}g/mL$ of lithium chloride was concluded selective for bifidobacteria, but restrictive for the other lactic bacteria present in Kimchi and cheese.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.106-112
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• 2006

Fifty four acid-resistant and bile-resistant isolates of lactic acid bacteria were initially isolated from the faces of Korea native cattle and Holstein using MRS agar and LAPT agar, and ten strains with superior activity against bile salt were finally selected LS1, LS15, and LL6 isolates showed survival of 66.5%, 82.6% and 80.7% against the simulated stomach liquid(pH 2.5), respectively. LL6 and LL7 isolates had the highest inhibitory activities against the pathogenic bacteria such as Salmonella typhimurium, Staphylococcus aureus, and Clostridium perfringens. By using API 50 CHL kit LS1, LS2 and LM1 isolates were identified as a L. fermentum. LL6 and LL7 isolates as a L. acidophilus, and LS3 isolate as a L. plantarum. The other four isolates belong to genus Lactobacillus. All the isolates tested were sensitive to some antibiotics such as ampicillin, amoxicillin and erythromycin, but resistant to colistin and ciprofloxacin. LB1, LL6 and LL7 isolates were resistant to gentamicin and neomycin. Especially, the LL6 isolate showed the highest resistance to both of the simulated stomach liquid and bile salt, in addition to the highest inhibitory activities against Sal. typhimurium, Staph. aureus and Cl. perfringens.

• Korean Journal of Veterinary Research
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• v.40 no.4
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• pp.763-767
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• 2000

This study was performed to isolate and identify bacteria from uterus with pyometra and examine their susceptibility to antimicrobial agents. Uterus of 16 bitches with pyometra were surgically removed by ovariohysteroctomy and then bacteria were isolated and identified. Also, susceptibility test to 15 antimicrobial agents was performed. Out of 16 bitches, 11 strains of Escherichia coli, 2 strains of Serratia marcescens, and 1 strain of Staphylococcus aureus and Salmonella spp. were identified. In antimicrobial susceptibility test, the majority of isolates were susceptible to enrofloxacin, norfloxacin, chloramphenicol, nalidixic acid, gentamicin, trimethprim-sulfamethazole, tetracycline, and moderately susceptible to carbenicillin, amikacin, ampicillin, neomycin, but resistant to vancomycin, streptomycin, bacitracin and colistin. In conclusion, E coli was the most common bacteria isolated from bitches with pyometra and those susceptible antimicrobial agents could be recommended to medical therapy of pyometra.

• Journal of Life Science
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• v.27 no.2
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• pp.172-179
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• 2017

The fermentation of Panax ginseng can yield many compounds from ginsenosides that have a wide variety of biological functions. Lactic acid bacteria (LAB) strains are capable of converting ginsenosides. The purposes of this study were to: (1) characterize Enterococcus faecium SA5, an isolated LAB from Mongolian mare milk, (2) identify the existence of extracellular ${\beta}$-glucosidase activity in the milk, and (3) ascertain if the ${\beta}$-glucosidase has the capacity of converting ginsenoside in Korean ginseng. The results revealed that E. faecium SA5 was acid-resistant, bile salt-resistant, and has antibiotic activities against 4 pathogenic microorganisms (Salmonella typhimurium KCTC 3216, Listeria monocytogenes KCTC 3710, Bacillus cereus KCTC 1012, Staphylococcus aureus KCTC 1621). In addition, E. faecium SA5 had tolerance against some antibiotics such as colistin, gentamycin and neomycin. It was also found that E. faecium SA5 possessed bile salt hydrolase activity, which could lower blood cholesterol level. When incubated in 10% (w/v) skim milk as a yogurt starter, E. faecium SA5 caused to decrease pH of the medium as well as increase in viable cell counts. Using TLC and HPLC analysis on the samples incubated in MRS broth, our study confirmed that E. faecium SA5 can produce ${\beta}$-glucosidase, which was capable of converting ginsenoside $Rb_1$ into new ginsenosides $Rg_3-s$ and $Rg_3-r$. It was concluded that E. faecium SA5 possessed a potential of probiotic activity, which could be applied to yogurt manufacture as well as ginsenoside conversion in ginseng.