• 한국축산식품학회지
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• 제31권1호
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• pp.47-53
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• 2011

Salmonella enterica serovar Typhimurium (ST) is one of the most common serovars isolated from humans and animals. It has been suggested that ST infections in Koreans are largely due to the consumption of contaminated pork and beef. To investigate the genotypes, phage types, and antimicrobial resistance patterns for ST isolates of different origins, a total of 70 ST strains, including 19 isolates from humans, 44 isolates from pigs, and 6 isolates from cattle, were analyzed using pulsedfield gel electrophoresis (PFGE), phage typing, and antimicrobial susceptibility tests. Forty-three distinct PFGE patterns were generated from 70 ST isolates, which were grouped into 14 PFGE groups (from A to N) at the level of 75% similarity. The most prevalent group was the A (A1-A17 subtypes) group, encompassing 54.5% (38/70) of ST isolates. ST isolates from pigs and cattle mostly belong to groups A and L, whereas ST isolates from humans mostly belong to groups F and C. Antimicrobial susceptibility tests using 11 antimicrobial agents showed that resistance to tetracycline (TE) (81.4%) was highly prevalent, followed by streptomycin (S) (64.3%) and nalidixic acid (NA) (31.4%) resistance. A total of seventeen antimicrobial resistance patterns were observed. Only 8.6% of isolates, including a reference strain, were susceptible to all antimicrobial agents tested. The most prevalent resistance pattern was TE-S (37.1%), which was seen in 66.6% of bovine, 40.8% of swine and 21.1% of human isolates. Three ST isolates from humans (15.9%) showed resistance to 7-8 antimicrobials. The most predominant phage type (PT) was U302 (64.3%), followed by DT170 (10.0%). PFGE types did not coincide with antimicrobial resistance patterns and phage types; therefore, the combination of those types allowed for further differentiation between tested ST isolates.

• 한국동물위생학회지
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• 제24권1호
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• pp.31-41
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• 2001

This study was carried out to identify causative agents from california mastitis test(CMT) positive mastitic milk, and to examine the antimicrobial susceptibility of 50 heads in Seongju and Chilgok area of Gyeongbuk province. Sulfadimethoxine sodium(SMS) was intramuscularly administered once to four mastitis Infected dairy cattle at the rate of 10mg/kg body weight. After injection of SMS, the depletion rate of serum and milk from the cattle were periodically measured for five days. The CMT positive number from 50 heads showed 46% and that of 200 quarters was 47(23.5%). From 39 quarters of 47 heads 39 different microorganisms were identified. These organisms were classified into 12 species : Staphylococcus aureus 8(20.5%), Sta hemolyticus 6(15.4%), Streptococcus bovis 4(10.3%), Sta hyicus 3(7.7%), Sta epidemidis. Sta xylosus, Sta sciuri 2(5.1%), Str agalactiae 2(5.1%), Escherichia coli(10.3%), three Enterobacter cloacae(7.7%), two Ent aerogenes(5.1%) and one Salmonella spp(2.6%). As the results of antibiotic susceptibility test, gentamicin(Gm, 11 species 27 strains, 69.5%), cephalotin(Cf, 9 species 24 strains, 61.5%), sulfamethoxazole(Stx, 8 species 14 strains, 43.6%), tetracycline(Tc, 8 species 14 strains, 35.9%), and streptomycin(Sm), lincomycin(Lm), cefoperazon(Cp) and penicillin(Pc) have a highly resistance(7.7% ～5.1%). However, carbenicillin (Cb), amikacin(Ah) have no susceptible for all drugs. The mean residual concentration of SMS in serum according to the time lapsed were showed 33.964 $\pm$ 4.435ppm at the 4 hours after intramuscularly injection(AII). It was significantly(p<.05) decreased to 6.596 $\pm$ 3.402, 0.217 $\pm$ 0.119 and 0.005 $\pm$ 0.004ppm at the 1st, 3rd and 5th day AII. The mean concentration of SMS in milk was significantly(p<.05) decreased from 0.920 $\pm$ 0.42ppm to 0.084 $\pm$ 0.016ppm between 8 hours and 1 day AII. As the results of this experiments, sulfadimethoxine was residued at the level of no less than 0.01ppm in milk on the 2nd day AII. Thus, this results would be able to be used the basic index for prevention of sulfonamides residue in milk after treatment of dairy mastitis.

• 대한임상검사과학회지
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• 제36권2호
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• pp.76-88
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• 2004

본 연구에서는 임상검체에서의 Enterococcus sp.의 균종별 분리현황을 조사하고, 분리균의 항생제 감수성 양상을 알아보는 한편, aminoglycoside계 항생제에 내성을 나타내는 균주를 대상으로 Rep-PCR을 실시하여 유전적인 다양성을 알아보고자 하였다. 각종 임상검체로부터 E. faecalis 49주, E. faecium 34주, E. avium 9주, E. gallinarum 4주, E. casseliflavus 3주, E. hirae 1주 등 총 100주를 분리하였다. 대부분 외래를 통하기보다는 입원환자의 검체로부터 분리됨을 관찰하면서 원내감염의 원인균 중의 하나임을 알 수 있었다. Urine과 pus, sputum에서 대부분의 균들이 분리되었고 E. faecalis와 E. faecium이 주 종을 이루었다. 항생제 감수성양상으로는 disk법과 ViteK GPS-430의 MIC결과와 유사하게 관찰 되었으며, 대부분의 Enterococcus sp.가 cephalosporin계 항생제에는 80% 정도의 내성을 보였다. E. faecalis의 경우 항생물질에 대해 고른 감수성양상을 볼 수 있었고, E. faecium의 경우 다른 Enterococcus sp.와는 차별적으로 항생물질에 대해 높은 내성 양상을 볼 수 있었다. 또한 vancomycin에 대한 내성을 보이는 Enterococcus sp.는 전체 10%정도를 차지하였고 aminoglycoside계 항생제인 amikacin과 gentamicin에 대해서 높은 고도내성을 나타냈었고, streptomycin의 경우에는 50% 정도의 내성률을 나타내었다. Aminoglycoside계 항생제에 내성을 보이는 Enterococcus sp.를 대상으로 Rep-PCR을 실시하여 유전자 분획유형을 분석하였으나 유전적 다양성에 있어 크게 차이를 보이지 않아 DNA양상의 기원이 크게 다르지 않다는 것으로 생각되었다.

• 대한미생물학회지
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• 제19권1호
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• pp.11-24
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• 1984

Shigella remains to be an important enteric pathogen in this country for the present. Moreover, most of the isolates have become multiple resistant to various antibiotics which used to be drugs of choice for shigellosis. This study was made as an attempt to assess the present stage of antibiotic resistance and the incidence and transferability of R factors of Shigella. A total of one hundred and seventeen strains of Shigella isolated from patients in Seoul and provincial area between 1982 and 1983 were tested for their resistant to antimicrobial agents and transmission of R-plasmid. Antibiotic susceptibilities were determined by an agar dilution method. Muller hinton agar were used for the assay of drug resistance and tryptic soy broth were used for propagating medium for conjugation. Shigella isolated found to be one or more antibiotics were considered potential donor of R-plasmid. The following results were obtained. 1. Among 117 strains of Shigella isolated, 111 strains(94.9%) were found to be resistant to one or more drugs tested and 97.3% of these resistant strains were multiply resistant, indicating the multiply resistant strains were more than the single resistant strains. Only six strains were susceptible to all drugs tested. 2. Among 117 strains of Shigella isolated, 107 strains(91.5%) were resistant to Tetracyclin(Tc), 106 strains(90.6%) to Chloramphenicol(Cp) and Streptomycin(Sm), 97 strains(82.9%) to Ampicillin(Ap), 68 strains(58.1%) to Cephaloridine(Cr), 10 strains(8.5%) to Nalidixic acid(Na), 5 strains(4.3%) to Kanamycin(Km) and 2 strains(1.7%) to Rifampicin. No strain was resisfant to Amikacin(Ak) and Gentamicin(Gm). 3. All drug-resistant Shigella strains, except three, were multiply resistant to two or more drugs. Fifty eight strains were resistant to five drugs, followed by 26 strains resistant to dour drugs, 12 strains resistant to three drugs and 11 strains resistant to six drugs. 4. The 73% of multiply drug-resistant Shigella transferred their resistance to E. coli by conjugation and the resistance was considered to be mediated by R-plasmid. Resistance to Nalidixic acid and Rifampicin were not transferred by conjugation to recipient. As for the transferability of resistance to each seperate drug, Ap resistance was transferred with 73.2% frequence and Cm and Tc resistance were transferred with approximately 50-60% frequence whereas Sm and Cr resistance were transferred in 19.1-21.4% The other four drugs resistant failed to transfer their resistance to recipient. 5. As for the incidence and transferability of resistance to each seperate drug, the strains resistant to Tc and Cm were encountered most frequently with the rate of 91-92%, whereas transfer of Tc and Cm were low, 51-52%. The incidence of Sm resistance was very high(90.6%) but transferability of drugs resistance was much lower(25.4%). Though the incidence of Km reristance was much lower(4.3%) transferability of Km resistance was considerably higher(60%). 6. The greater the multiplicity of resistance, the greater was the likelihood that part of all of the resistance markers would be transferable.

• 한국어병학회지
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• 제9권2호
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• pp.195-201
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• 1996

군산근교의 양만장에서 애드와드병에 이환된 뱀장어로부터 총 96균주의 E.tarda균을 분리한 후 이들 분리균의 약제감수성 검사를 실시하고 아울러 내성균의 내성인자 전달 시험을 실시하였다. 공시한 모든 균주는 SM, AK, NF 및 GM등에는 100% 감수성을 보였으나, 대부분의 균주가 SD(86균주), AM(84균주), PM(80균주), NA(67균주), OT(44균주) 및 OA(37균주) 등의 내성을 보였다. 내성유형은 20유형으로서 거의 모든 균주가 2제 이상의 다제내성을 보였으며, 그중 SD-AM-PM-NA-OA(16균주), SD-AM-PM-NA(14균주), SD-AM-PM-NA-OT-OA(12균주), SD-AM-PM-OT(10균주) 및 SD-AM-PM-NA-OT(8균주) 유형등이 고빈도로 출현하였다. 내성균주의 내성인자 전달 빈도는 94균주중에서 78균주가 단계에서 6제까지의 다제내성인자의 전달을 보였다. 그중 AM 및 AM-PM-NA유형(8균주), PM,SD 및 AM-SD유형(6균주), AM-PM, PM-SD 및 AM-SD-OT유형(4균주)등이 고빈도 출현을 보였다. 이러한 결과는 양만장에서 다양한 항균제를 사용하였기 때문에 다제내성현상이 확산되어진 것으로 사료된다.

• 한국식품영양학회지
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• 제23권2호
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• pp.171-177
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• 2010

Serratia marcescens catabolic threonine dehydratase는 streptomycin sulfate treatment, Sephadex G-200 gel filtration, AMP-Sepharose 4B affinity chromatography 등의 방법으로 정제하였는데, 최종 단계에서 회수율은 15.5%이었으며 50배 정제되었다. Native 분자량은 native pore gradient polyacrylamide gel electrophoresis(PAGE) 방법으로는 120,000이었다. SDS-PAGE에 의한 subunit의 분자량은 30,000이었고, 즉 S. marcescens 효소는 4개의 동일한 subunit으로 구성된 homo-tetrameric protein임이 판명되었다. S. marcescens 효소의 L-threonine에 대한 Km값은 AMP가 있는 조건에서 7.3 mM, AMP가 없는 조건에서 92 mM이었다. S. marcescens 효소는 효소 1 mole 당 각각 2 mole의 pyridoxal 5'-phosphate(PLP), 16개의 free-SH group을 가지고 있었다. S. marcescens 효소는 AMP의 존재 하에서 $\alpha$-ketobutyrate, pyruvate, glyoxylate, phosphoenol pyruvate(PEP)에 의해 효소 활성이 억제되었으며, cAMP와 ADP에 의해서는 효소 활성이 증가되었다. 효소학적 성질면에서 S. marcescens 효소는 E. coli 효소보다는 S. typhimurium 효소와 유사하였다. 한편, E. coli 효소는 cAMP에 의하여 효소 활성이 증가되고, S. typhimurium 효소는 ADP에 의해 효소 활성이 증가되는 것과 다르게, S. marcescens 효소는 cAMP와 ADP 모두 효소 활성이 증가되었다. 따라서 이상의 연구 결과들은 세 enteric bacteria의 catabolic threonine dehydratase가 서로 작은 차이점이 있다는 것을 반영하며, 이러한 사실을 규명하기 위해서는 향후 보다 심층적인 연구를 수행하여야 할 것으로 사료된다.

• 한국수정란이식학회지
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• 제27권1호
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• pp.57-62
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• 2012

Efficient oocyte activation is a key step for the success of nuclear transfer in cloning. Ionomycin sequentially combined with 6-DMAP is now widely used to activate normal oocytes for analytical studies of oocyte activation and to activate reconstructed oocytes after nuclear transfer. The present study investigated sources of oocytes, duration of ionomycin and 6-DMAP, laser and electric stimulation in goat oocyte activation in order to optimize the protocols. Goat ovaries were collected in individual abattoirs during the breeding season and were delivered to the laboratory within 6 h in saline with 100 IU/ml streptomycin and 0.05 mg/ml penicillin. The oocytes were denuded from the cumulus cell by pipetting with 0.2% hyaluronidase in PBS at 20~22 hr post maturation. Oocytes with the polar body were selected and assigned to four groups for parthenogenetic activation. To examine the effect of duration of ionomycin treatment, oocytes after 20~22 hr of maturation were treated with 2.5 uM ionomycin for 1 or 5 min times and then cultured in 2 mM 6-DMAP for 2 or 4 hr. The activated oocytes were cultured in mSOF at $38.5^{\circ}C$ in $CO_2$ 5%, $O_2$ 5% and $N_2$ 90% multi incubator. Cleavage and blastocyst development was observed at 48 hr and day 8 of culture $in$ $vitro$, respectively. Activation rates of oocytes exposed to ionomycin for 1 min(86.4%) were significantly higher than those treated for 5 min(74.3%) duration. This indicated that 1 min ionomycin treatment was most suitable for activation of goat oocytes. The duration of 6-DMAP treat duration was in 2 mM 6-DMAP for 2 hr after 1 min exposure to 2.5 uM ionomycin. The activation rate of oocytes incubated in 6-DMAP for 2 hour(82.5%) was significantly higher than those in oocytes treated with 4 hr(75.5%).

• Journal of Periodontal and Implant Science
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• 제32권4호
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• pp.865-873
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• 2002

The primary cause of tooth loss after 30 years of age is periodontal disease. Destruction of alveolar bone by periodontal disease is done by bone resorbing activity of osteoclasts. Understanding differentiation and activation mechanism of osteoclasts is essential for controling periodontal disease. The purpose of this study is to identify the possible effects of Vitamin D and cytokines affecting osteoclasts and its precursor cells. Four to six week-old mice were killed and humerus, radius, tibia and femur were removed aseptically and washed two times with Hank's solution containing penicillin-streptomycin and then soft tissue were removed. Bone marrow cells were collected by 22 gauge needle. Cells were cultured in Hank's solution containing 1 mg/ml type II collagenase, 0.05% trypsin, 41mM EDTA. Supernatant solution was removed 5 times after 15 minutes of digestion with above mentioned enzyme solution, and remained bone particles were maintained in alpha-MEM for 15 minutes and $4^{\circ}C$ temperature. Bone particles were agitated for 1 minute and supernatant solution containing osteoclast precursor cells were filtrated with cell stainer. These separated osteoclast precursor cells were dispensed with 100-mm culture dish by $1{\times}10^7$ cells unit and cultured in ${\alpha}$- MEM containing 20 ng/ml recombinant human M-CSF, 30 ng/ml recombinant human soluble osteoclast differentiation factor and 10% fetal calf serum for 2 and 7 days. Total RNA of osteoclast precursor cells were extracted using RNeasy kit. One ${\mu}g$ of total RNA was reverse transcribed in $42^{\circ}C$ for 30 minutes using SuperScriptII reverse transcriptase. Expression of transcribed receptors of each hormone and cytokine were traced with 1 ${\mu}l$ of cDNA solution by PCR amplification. Vitamin D receptor WAS found in cells cultured for 7 days. TNF-${\alpha}$ receptor was found in cells cultured for 2 days and amount of receptors were increased by 7 days. IL-1 type I receptor was not found in cells cultured 2 and 7 days. But, IL-1 receptor type II was found in cells cultured for 2 days. TGF-${\alpha},{\beta}$type I receptor was found in cells cultured 2 and 7 days, and amount of receptors were increased by 7 days of culture. These results implies Vitamin D and cytokines can affect osteoclasts directly, and affecting period in differentiation cycle of osteoclasts is different by Vitamin D and cytokines.

• Journal of Periodontal and Implant Science
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• 제28권1호
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• pp.17-35
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• 1998

Chitosan, with a chemical structure similar to hyaluronic acid, has been implicated as a wound healing agent. The purpose of this research was to evaluate the effects of chitosan on the characteristics of periodontal ligament cells, calvaria cells and gingival fibroblasts and to define the effects of chitosan on bone formation in vitro. In control group, the cells were cultured alone with Dulbecco's Modified Eagle's Medium contained with 10% Fetal bovine serum, 100unit/ml penicillin, $100{\mu}g/ml$ streptomycin, $0.5{\mu}g/ml$ amphotericin-B. In experimental group, chitosan($40{\mu}g/ml$) is added into the above culture condition. And then each group was characterized by examining the cell proliferation at 1,3,5,7,9,12,15 day, the amount of total protein synthesis, alkaline phosphatase activity at 3, 7 day and the ability to produce mineralized nodules of rat calvaria cell at 11 day. The results were as follows : 1. At early time both periodontal ligament cells and calvaria cells in chitosan-treated group proliferated more rapidly than in non-treated control group, but chitosan-treated group of periodontal ligament cells at 9 days and calvaria cells at 12days showed lower growth rate than control group. Gingival fibroblast in chitosan-treated group had lower growth rate than in control group but the difference was not statistically significant (P< 0.01).2. Both periodontal ligament cells and calvaria cells in chitosan-treated group showed much protein synthesis than in control group at 3 days, but showed fewer than in control group at 7 days. Amount of total protein synthesis of gingival fibroblast didn't have statistically significant difference among the two groups(P< 0.01). 3. At 3 and 7 days, alkaline phosphatase activity of periodontal ligament cells and calvaria cells was increased in chitosan-treated group, but at 7 days there was not statistically significant difference among the two groups of calvaria cells (P< 0.01). Alkaline phosphatase activity of gingival fibroblast didn't have statistically significant difference among the two groups(P<0.01). 4. Mineralized nodules in chitosan-treated group of rat calvaria cells were more than in control group. In summery, chitosan had an effect on the proliferation, protein systhesis, alkaline phosphatase activity of periodontal ligament cells and calvaria cells, and facilitated the formation of bone. It is thought that these effects can be used clinically in periodontal regeneration therapy.

• 농업과학연구
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• 제3권1호
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• pp.85-94
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• 1976

유산양(乳山羊)의 자연발생(自然發生) 괴저성유방염(壞疽性乳房炎) 6예(例)에 대하여 임상소견(臨床所見)을 관찰(觀察)하는 한편 분리균(分離菌)에 의한 인공감염시험(人工感染試驗), 각종항생물질(各種抗生物質)에 대한 감수성시험(感受性試驗)을 통(通)하여 치료법(治療法)을 확립(確立)할 목적(目的)으로 실시(實施)한 시험성적(試驗成績)을 다음과 같이 요약(要約)한다. 1. 유산양(乳山羊)에 자연발생(自然發生)한 6예(例)에 유방염(乳房炎)은 임상소견(臨床所見)에 있어 이미 보고(報告)된 우(牛), 면양(緬羊) 및 산양(山羊)의 저성유방염(疽性乳房炎)과 같았다. 2. 환산양(患山羊)에서 분리(分離)한 Micrococcus Pyogenes Var Aureus는 병원성(病原性)이 강(强)한 균주(菌株)로서 산양(山羊)의 유방내접종(乳房內接種)에 의하여 괴저성유방염(壞疽性乳房炎) 또는 경도(輕度)의 유방염(乳房炎)을 일으킬 수 있었다. 3. 산양(山羊)의 괴저성유방염(壞疽性乳房炎)은 유선간질내(乳腺間質內)의 대소정맥지(大小靜脈枝) 혈전(血栓)이 형성(形成)되었을 때 야기(惹起)될 수 있다. 4. 환산양(患山羊)에서 분리(分離)한 Micrococcus Pyogens Var Aureus는 Penicillin에 대(對)하여 6예중(例中) 2예(例)만이 내성(耐性)이 있고 나머지는 모두 Strepomycin, Chloromycetin, Oxytetracycline, Erythromycin, Achromycin, Aurcomycin, Neomycin 및 Kanamycin등과 같이 예민(銳敏)한 감수성(感受性)을 나타내었다. 5. 치료시험(治療試驗)에 있어 괴저부(壞疽部)가 편측성(片側性)이고 한국성(限局性)인 것은 외과적(外科的) 유방적출술(乳房摘出術), 심(甚)한 괴저(壞疽)와 한계(限界)가 광범(廣範)하여 유두(乳頭)까지 괴사(壞死)한것은 유두절제술(乳頭切除術)과 근육주사(筋肉注射)하고 괴저(壞疽)가 경미(輕微)한것은 유두관내주입법(乳頭管內注入法)과 유방조직내주사법(乳房組織內注射法)이 가(可)할것이다.