• 한국산림과학회지
• /
• 제86권4호
• /
• pp.407-414
• /
• 1997

외래 저항성 유전자, Proteinase inhibitor II가 형질전환된 3계통의 벨기에 포플러를 대상으로 딱정벌레에 대한 유전자 발현정도가 기내에서 조사되었다. 포플러 계통은 선발 유전자로서 Nos-promoter와 Neomycin phosphotransferase gene에 의하여 조절되고 곤충에 대한 저항성 유전자로서 CaMV-35S와 Pin2(Proteinase inhibitor II)에 의한 형질전환체이다. 특히, 형질전환된 포플러의 내충성 저항력을 조기검정하기 위하여, 조직배양을 응용한 새로운 방법으로서 곤충의 알을 표면 살균하여 기내의 조직배양묘와 배양하는 동시배양 방법이 이용되었다. 형질전환된 포플러의 저항성은 기내에서 유충에 의해 섭취된 잎면적, 잎 섭취에 의한 유충의 무게 증감, 유충의 성장단계 등에 의하여 조사되었다. 특히, 잎면적은 각각의 LPI(Leaf plastochron index)별로 측정되었고, 잎면적, 유충의 무게, 곤충의 성장 속도는 형질전환체와 비형질전환체 간에 큰 차이를 보였다. 기내에서 무병상태로 배양된 알들이 부화된 후, 유충의 잎 섭취도는 LPI 4와 5사이에서 가장 높았다. 본 실험의 기내 배양법은 외래유전자를 삽입한 이후에 곧바로 발현을 빠른 시간내에 조기검정 할 수 있는 새로운 방법의 개발이라 할 수 있다.

• 한국동물위생학회지
• /
• 제32권1호
• /
• pp.93-102
• /
• 2009

In this study, antimicrobial resistance of E. coli isolated from domestic beef on sale in Busan and Gyeongnam province was investigated from March to October 2008. A total of 400 beef samples were collected for the monitoring of antimicrobial resistance, and 39 (9.8%) strains of E. coli were isolated. Antimicrobial resistance test was carried out by agar disc diffusion method with 17 antimicrobials. In general, E. coli isolates showed the highest antimicrobial resistance to tetracycline (85.3%), followed by doxycycline (76.5%), streptomycin (61.8%) and sulfamethoxazole/trimethoprim (61.8%). Then they showed higher resistance to several antimicrobials like kanamycin and neomycin (55.9%). However, They had low antimicrobial resistance to amikacin (8.8%), amoxicillin/clavulanic acid (2.9%). Of 39 isolates, 31 (79.5%) were resistant to more than 2 antimicrobials. Among 17 antimicrobials examined, tetracyclines were the most resistant, followed by aminoglycosides, sulfonamides. The resistance was seemed to be correlated to amounts of antimicrobial use. In the result of this study, we suggest that there be need to regulate the abuse of antimicrobial on food-producing animals in Korea because the concern on antimicrobial resistant is gradually increased worldwide.

• 대한수의학회지
• /
• 제17권1호
• /
• pp.1-4
• /
• 1977

Two hundred and twenty-seven strains of Escherichia coli isolated from 25 hens (12 hens received tetracycline neomycin and sulfadimethoxine, and 13 hens not received antibiotics) were studied for the drug resistance and distribution of R factors. About 74 per cent of E. coli strains isolated from hens of a herd received antibiotics were resistance to tetracycline (TC) streptomycin (SM), chloramphenicol (CM), kanamycin (KM), ampicillin (AP) and sulfisomidine (Su), alone or in combination thereof, but only a hen among a herd not received antibiotics excreted E. coli resistant to TC and SM. Among resistant strains, about 7% were found to be resistant to TC and SM, whereas 93% were resistant to three or more antibiotics. The most common pattern was the quadruple resistant to SM, TC, KM and Su (28.7%), and followed by triple ones to SM, TC and Su (25.3%), and SM, TC and KM (24.7%). About 84% of resistant strains carried R factors which were transferable to the recipient by conjugation.

• 한국미생물·생명공학회지
• /
• 제13권4호
• /
• pp.345-348
• /
• 1985

Mannitol hypertonic regeneration media를 사용하는 PEG-induced protoplast transformation system을 이용해서 pUB110과 pE194의 recombinant plasmid로 B. subtilis BR151을 transformation 시킴으로써 두 plasmid에서 유래되는 각각의 Neo$^{R}$와 Em$^{R}$을 동일한 recipient cell 내에서 동시에 발현시킬 수 있었다. Neomycin과 erythromycin을 함께 함유하는 mannitol regeneration media상에서 recombinant plasmid의 transformation frequency는 6.5 $\times$ $10^{-5}$이었다. 한편 transformant cell 내에서 recombinant plasmid의 replication이 agarose gel electrophoresis로 확인되었다.

• 한국동물위생학회지
• /
• 제23권1호
• /
• pp.61-69
• /
• 2000

Thirty-one dairy cow from two farm(more than 500,000 cells/ml of bulk milk) in Kyongbuk northern province were selected because of their high somatic cell(more than 500,000 cells/ml of milk In individual cow). Each cow received. staphylococcus aureus vaccine(Labac Staph) and immunostimulant(Ultracon) by intramuscular injection to be repeated every fifteen days for S times. The present study was investigated variation of somatic cell after administration of Labac Staph and Ultracon, and antibiotics resistance of isolated staphylococcus spp from milk in selected cow. The results obtained through the survey were summarized as follows ; 1. Ten dairy cow was injected in A farm. Chronic mastitic two cow after 2rd injection was weeded out the herd. Decrease rate of somatic cell after 1st, 2nd, ,3rd, 4th and 5th administration were 41.4%, 35.6%, 56.4%, 65.4% and 36.7%, respectively. Twenty-one cow was injected in B farm. Chronic mastitic five cow after ,3rd injection was weeded out the herd. Decrease rate of somatic cell after 1st, 2nd, 3rd, 4th and 5th administration were 36.9%, 59.9%, 24.5%, 62.6% and 78.4%, respectively. 2. In A farm, isolated staphylococcus spp were identified as S hyicus 2 strains(11.8%), coagulase negative staphylococcus 15 stains(89.2%) and S epidermidis 6strain(35.3%). In B farm, isolated staphylococcus spp were identified as S aureus 19 strains(55.98%) and coagulase negative staphylococcus 15 strains (44.2%). 3. In A fm, antibiotics resistant rate of isolated staphylococcus spp was high at ampicillin, penicillin and kanamycin, and middle at neomycin, streptomycin and erythromycin. in B farm, antibiotics resistant rate was moderate at ampicillin, penicillin, gentamicin, ka-namycin, neomycin, streptomycin, erythromycin and tetracycline, and coagulase negative staphylococcus spp was moderate at streptomycin.

• Journal of Dairy Science and Biotechnology
• /
• 제33권2호
• /
• pp.93-102
• /
• 2015

본 연구는 원유로부터 면역증진 젖산균을 분리 및 동정하고, 이 균주의 생리적 특성을 규명하여 상업적으로의 이용가능성을 검토하고자 실시하였다. 이를 위해 Modified MRS 분별배지를 사용하여 노란색 집락을 형성하는 균주를 대상으로 면역활성이 높은 균주를 선발한 결과, D205 균주가 최종 선발되었다. D205 균주는 $IL-1{\alpha}$, $TNF-{\alpha}$, NO 값이 각각 2,500pg 이상/mL, 2,000 pg 이상/mL, $11.55{\pm}2.95{\mu}M$로 나타났으며, 동정결과 Lactobacillus fermentum으로 판명되었고, Lactobacillus fermentum 450으로 명명하였다. Lactobacillus fermentum 450의 최적 생장 온도는 $40^{\circ}C$이었으며, 답즙산과 산성의 pH에서 모두 우수한 생존력을나타내었다. 효소활성은 leucine arylamidase와 acid phosphatase가 비교적 높게 나타났다. 항생제 내성 실험 결과, kanamycin, neomycin, polymyxin B에 내성이 있는 반면 novobiocin에 감수성을 나타냈으며, Salmonella Typhimurium에 대해 63.86%의 억제 효과를 지니고 있으나, Escherichia coli와 Staphylococcus aureus에 대해서는 항균력이 거의 없는 것으로 나타났다.

• 한국발생생물학회:학술대회논문집
• /
• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
• /
• pp.86-86
• /
• 2003

Research has been in progress for more than a decade to production of useful proteins by genetic modification in cattle. However, the levels of protein production in transgenic cattle have been reported very low. To enhance protein production in transgenic animal, we tried homologous recombination to donor cells for production of transgenic clone cattle through nuclear transfer procedure. Thus, we constructed the two targeting vectors of human thrombopoietin (TPO) at bovine $\beta$-casein locus using homologous recombination with 13.6 kb and 9.6 kb homology. In two targeting vectors, positive selection was through the neomycin resistance gene and negative selection was by the diphtheria toxin (DT). Gene targeting was attempted in bovine embryonic fibroblasts (bEF) and bovine ear skin fibroblasts (bESF). To determine the most appropriate concentration of neomycin for bEF and bESF, G4l8 resistance was confirmed by culturing the cells in various concentrations of the drug and both of the cells were optimally selected at $900 \mu g/ml$ of neomycin. The transfected bEF and bESF by the targeting vectors were colonized efficiently at the ratio of DNA to transfection reagent such as $4 \mu g$:2 ${mu}ell$ and $1 \mu g$:$2 \mu l$. Comparing number of healthy clones from passage 4 to passage 8, bESF (17%) persist in culture for much longer than bEF (6%). The two gene-targeted bESF clones of 30 random-integrated clones with 9.6 kb homology length were confirmed, however, nothing was out of 72 random integration clones with 13.6 kb homology length, The DT also worked more efficiently in clones transfected with the vector of 9.6 kb homology length. Our data suggests that the choice of donor cell for long culture period should be considered to obtain targeted cell clone, and the gene-targeting frequency and the DT working efficiency are dependent on the length of target homology.

• 한국동물위생학회지
• /
• 제26권2호
• /
• pp.95-103
• /
• 2003

Isolates of 70 Proteus mirabilis were tested against 10 different antibiotics by a disc diffusion method as recommended by National Committee for Clinical Laboratory Standards (NCCLS). The isolates were resistant in order of tetracycline(100.0%), enrofloxacin(95.7%), ampicillin(74.3%), choramphenicol(62.9%), cephalothin(58.6%), streptomycin(50%), kanamycin(47.2%), neomycin(35.8%), gentamicin(15.7%), and amikacin(2.9%). In the antibiotic resistant patterns, 37 kinds of multiple resistance patterns of P mirabilis isolates were detected. The highest resistant pattern was ampicillin-cephalothin-chloramphenicol-enrofloxacin-tetracycline(11.6%).

• 대한수의학회지
• /
• 제29권4호
• /
• pp.487-492
• /
• 1989

The capsular serogroupes and drug susceptibility of 111 isolates of Pasteurella multocida from pigs with atrophic rhinitis and pneumonic lesions were investigated. Of the 111 P multocida isolates, 42 were from lung lesions, 47 from nasal turbinate lesions and the remaining 22 from the nasal swabs. P multocida isolates were typed for capsular serogroupes A by hyaluronidase inhibition of capsule and D by acriflavine auto-agglutination. Most isolates(64.9%) were type A, 23.4% were type D and the remaining 11.7% were untypable. Resistance to triple sulfa(97.3%) was most frequent, followed by resistance to tiamulin(71.2%), tylosin(56.8%), streptomycin(36.9%), and neomycin(36.0%). The majority of the organisms were susceptible in order of prevalence to baytril(100%), ampicillin(98.2%), linsmycin(97.3%), colistin(97.3%), cephalothin(94.6%), gentamicin(93.7%), amikacin(92.3%), tetracycline(91.9%), trimethoprim/sulfamethoxazole(91.0%), and kanamycin(90.1%). No differences in drug resistance in relation to capsular serogroupes of P multocida and the origin of lesions were noted. A high prevalence of multiple drug resistance was observed and the most common resistant patterns were Sss, Tm, Ty(12.6%) and Sm, Sss, Tm, Ty(8.1%) patterns.

• 대한수의학회지
• /
• 제47권1호
• /
• pp.43-50
• /
• 2007

Staphylococci are Gram-positive, facultatively anaerobic cocci, normally found on the skin andmucosal surfaces of most warm-blooded animals and often involved in a wide variety of diseases in animals.Staphylococcal infections are treated with antibiotics and, consequently, antibiotic resistance and/or acquiredresistance have developed. Staphylococcus (S.) intermedius and Staphylococcus (S.) aureus are 2 comonveterinary isolates that are frequently associated with suppurative infections. This study was undertaken toexamine antimicrobial susceptibility of S. aureus (23 isolates) and S. intermedius (160 isolates) isolatedfrom dogs in Gwangju, Korea and investigate whether the antibiotic resistance of S. aureus and S.intermedius is efected by the site of isolation, age, and sex of dogs. More isolates were isolated fromadult dogs (71.3%) than juveniles (20.5%). Antimicrobial resistance was commonly found for Penicillin,Tetracycline, Trimethoprim-Sulphamethoxazole in both Staphylococcus species. All of the isolates weresusceptible to Amoxicillin/Clavulanic Acid, Cephalothin, Oxacilin, Neomycin, and Vancomycin. Appropriateprotocol for antibiotic use and strategies to reduce antimicrobial resistance rate will be needed. Periodicsubstitution of antimicrobial agents and limitation of antibiotic use should also be considered.