• 대한수의학회지
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• 제29권1호
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• pp.37-44
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• 1989

This paper dealt with the distribution of Shigella spp. on 5 piggeries in Taegu and Kyungpook during the period from August to October 1987. Isolated Shigella were examined for serogrouping, antimicrobial drug resistance and detection of R plasmid. Genetic properties of R plasmid in Shigella have examined to fertility inhibition (Fi) and gel electrophoresis was performed for the isolation of plasmid DNA. The results obtained were summarised as followings; 1. Of total 2,978 samples from 5 piggeries, 82 strains (2.8%) of Shigella spp. were isolated from 82 samples. The isolated strains were identified as S dysenteriae (60 strains), S flexneri (20 strains) and S sonnei (2 strains). 2. Of the 82 strains examined 67 (95.1%) were resistant to one or more antibiotics, such as ampicillin (Am), chloramphenicol (Cm), kanamycin (Km), nalidixic acid (Na), rifampicin (Rf), streptomycin (Sm), sulfademethoxine (Su), and tetracycline (Tc) and higher resistant to Su (90.2%), Sm (63.4%) and Tc (63.4%). 3. Of the 78 resistant Shigella strains 26 (33.3%) harbored conjugative R plasmids and the transfer frequency of Sm (50.0%), Cm(33.3%) resistance was much higher than that of the other drug resistance. 4. The most common resistant patterns were SmSuTc, Su and AmSmSuTc. 5. Out of the 26 Shigella R plasm ids examined for Fi, 14(53.8%) were $Fi^+$ and the remainder were $Fi^-$. 6. The plasmid DNA profiles in Shigella spp. (9 strains) isolated from pigs were confirmed as being 2 to 9 fragments by the gel electrophoresis. Their molecular size ranged 2.17 to 87.62 kilobase (Kb). All strains of Shigella spp. consisted in 15.4 Kb plasmids.

• 한국어병학회지
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• 제13권2호
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• pp.111-119
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• 2000

군산내만에서 분리한 미생물총 Vibrio spp.(44균주), Pseudomonas spp.(42균주), Aeromonas spp.(26균주), Moraxella spp.(9균주), Enterobacteria spp.(6균주), Bordetella spp.(3균주), Alkaligenesis spp.(3균주), Staphylococcus spp.(3균주), Flavobacterium spp.(2균주)를 총 123주를 대상으로 Ampicillin(AM), Penicillin-G(PM), Rifampicin(RF), Streptomycin(SM), Oxolinic acid(OA), Nalidixic acid(NA), Oxytetracycline(OT), Amikacin(AK), 및 Enorfloxacin(EF)등의 약제에 대해서 감수성검사를 실시하였다. 공시약제에 대한 감수성균주는 42균주(34.1%)이었으며, 내성균주는 81균주(65.9%)로서 약제 내성율은 AM(54균주/43.9%), PM(47균주/38.2%) 및 RF(35균주/28.4%) 등에는 고빈도의 내성을 보였으며, SM(9균주/7.3%), OA(5균주/4.06%) 및 NA(1균주/0.8%)등에는 저빈도의 내성을 보였다. 그렇지만 OT, AK 및 NF에는 내성을 보이지 않았다. 내성 유형은 총 15유형(1-4제)으로서 이중 단일약제 내성 균주는 모두 35균주(28.4%)로서 AM(20균주/16.3%), PM(10균주/16.3%)및 RF(10균주/8.1%)약제에 내성 출현율이 높았다. 한편, 다제내성은 12유형을 나타내었으며, AM-PM-RF(16균주/13.4%), AM-PM(8균주/6.5%) 및 PM-RF(7균주/5.6%)유형이 비교적 출현빈도가 높았다. 따라서 본 해역은 다양한 약제에 내성을 나타내는 미생물총이 서식하고 있어서 향후 다제내성균이 빠르게 확산 되어 어류질병의 치료에 많은 어려움이 예상된다.

• 미생물학회지
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• 제43권1호
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• pp.31-39
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• 2007

2000-2004년 국내에서 분리된 S. sonnei 135주를 선별하여 16종의 항균제 내성 유형, $bla_{TEM}$, suulII, tetA, strA등의 내성유전자형을 PCR등의 방법으로 항생제내성 표현형과 유전자형의 유연관계를 파악하였다. 균주들의 생화학적 성상은 전형적 인 이질성 세균의 특성을 나타내었으며, biotyping에서는 g type이 58.5%(79주), a type이 40.0%(54주), e type이 1.5%(2주)로 나타났다. 항균제 16종의 항균제 내성 패턴은 AN, CIP, C, GM등의 약제에는 감수성을 보였으나, SXT 약제에는95.6% (129주), TE 약제에는 93.3% (126주), SM에는 90.4% (122주)등의 순으로 내성을 나타내었다. 두 가지 이상 약제 내성균이 97.8% (132주), 그 중에서 R28 (AM, SAM, TE, TIC, SXT, K, SM, AmC : 8제 약제 내성) 형이 31.1% (42주)를 차지하였으며, 33가지 형태의 다양한 내성 패턴을 나타내었다. $bla_{TEM}$, sulII, tetA 및 strA등의 내성유전자 분포에서는 Disk diffusion법에서 내성을 보인 경우에는 모두 각각의 유전자 증폭산물이 검출되었다.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1620-1628
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• 2016

In this study, we investigated colistin resistance mechanisms associated with the regulation of the pbgP operon in Klebsiella pneumoniae, using four isogenic pairs of colistin-susceptible strains and their colistin-resistant derivatives and two colistin-resistant clinical isolates. Amino acid sequence alterations of PhoPQ, PmrAB, and MgrB were investigated, and mRNA expression levels of phoQ, pmrB, pmrD, and pbgP were measured using quantitative real-time PCR. The phoQ and pmrB genes were deleted from two colistin-resistant derivatives, 134R and 063R. We found that phoQ, pmrD, and pbgP were significantly upregulated in all colistin-resistant derivatives. However, pmrB was significantly upregulated in only two colistin-resistant derivatives and one clinical strain. pmrB was not overexpressed in the other strains. The minimum inhibitory concentration of colistin was drastically lower in both phoQ- and pmrB-deleted mutants from a colistin-resistant derivative (134R) that was overexpressing phoQ and pmrB. However, colistin susceptibility was restored only in a phoQ-deleted mutant from a colistin-resistant derivative (063R) without overexpression of pmrB. In conclusion, two different regulations of the pbgP operon may associate with the development of colistinresisant K. pneumoniae.

• Journal of Microbiology
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• 제35권3호
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• pp.177-180
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• 1997

The purpose of this study was to evaluate the efficiency of Line Probe Assay (LiPA) in detecting the rpoB gene mutation of clinically isolated Mycobacterium tuberculosis (MTB) and to compare the level of resistance to the various rifamycins with their mutation sites. The mutation in the rpoB gene was found in 84 (97.6%) out of 86 rifampicin (RMP) resistant strains as determined by LiPA. No mutation was observed in 2 RMP resistant strains and in any of 38 RMP susceptible strains tested. Only one of 3 strains with .DELTA.5/R5, one of 2 strains with .DELTA.3, and one of 3 strains with .DELTA.2/R2 LiPA profile showed a slightly lower level of resistance to the rifapentine than the other strains. Although we could not find correlations between mutation sites in the rpoB gene and the level of susceptibility to the various rifamycins, the LiPA is recommended as a fast screening tool for detection of RMP resistant MTB.

• 생명과학회지
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• 제9권4호
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• pp.358-367
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• 1999

Thirty strains of methicillin resistant Staphylococcus aureus were obtained from the clinical isolates. In order to investigate the pursuit of the pathogens of nosocomial infection, these strains were studied for antibiotic sensitivity as well as its resistant pattern. Among the methods of hybridization which directly confirm the specific antibiotic resistant genes by means of the recently developed specific probe DNA, dot blot hybridization and southern blot hybridization were performed and these two methods were compared in their sensitivity and specificity. Strains that is sensitive to cephalothin to the subject of methicillin resistant Staphylococcus aureus were in 43%. Those that are sensitive to cefoperazone and cefuroxime were 26% and 23%, respectively. In case of MIC, MIC50 of cefoperazone was 8 $\mu\textrm{g}$/$m\ell$, and MIC90 was 128 $\mu\textrm{g}$/$m\ell$ to be the lowest. As the results of plasmid DNA electrophoresis, most of methicillin resistant Staphylococcus aureus strains had more than 4 plasmids. These plasmids digested by BamHI, methicillin resistant Staphylococcus aureus is distributed as 10 fragments with the size of 65 kb to 1.5 kb. Dot blot hybridization were performed to examine the existence of mecA gene to show the detection rate of 50%. Southern blot hybridization were done to see if DNA bands which amplify the activity of digoxigenium-labeled probe by PCR were actually PCR products of mecA gene and it showed the detection rate of 53%. It can be concluded that the southern blot hybridization seemed to be better in sensitivity and specificity when it is compared with the results of dot blot hybridization.

• 대한미생물학회지
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• 제35권2호
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• pp.171-180
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• 2000

Ninety two strains of Streptococcus pyogenes were isolated from patients with pharyngitis, scarlet fever, skin infection, and invasive streptococcal infections in Seoul, Korea from January to December, 1998. All isolates were epidemiologically characterized by T protein serotype, and serum opacity factor (OF) detection to phenotypes. To analyze the genetic relationship, fifty two isolates including 32 erythromycin-clindamycin (Em-Cm) resistant strains, 20 antimicrobial susceptible strains were attempted to the pulsed-field gel electrophoresis (PFGE). T protein serotype showed 16 kinds in distribution including T12 and T4. Among the total isolates, 40 strains (43.5%) belonged to the T12 serotype and twenty strains (21.7%) to T4 serotype. On the other hand, when infection aspect of S. pyogenes isolates were analysed by T serotype distribution, T12 type was predominant for pharyngitidis which contributed to 21 strains (53%) and for skin infection isolates which contributed to 11 strains (28%), respectively. In case of T4 type, it was the most predominant pharyngitidis isolates which contributed to 8 strains (40%). In T serotype distribution of Em-Cm resistant strains, 27 strains (84%) of the thirty two showed T12 serotype. In minimum inhibitory concentration (MIC) values of Em-Cm resistance isolates, thirty two isolates showed resistant to erythromycin 27 strains (84%), had high MIC of >$128\;{\mu}g/ml$. And also to clindamycin, twenty two strains (69%) had high MIC of >$128\;{\mu}g/ml$. When OF detection of Em-Cm resistance of S. pyogenes isolates were analyzed by T serotype distribution, T12 serotype isolates revealed that all of the isolates except one strain were OF negative. In PFGE profile analysis to Em-Cm resistance isolates, of the twenty seven, Em-Cm resistance of T12 serotype isolates, 26 strains showed identical PFGE profile and all of these isolates revealed that OF negative. Eighty four percent of Em-Cm resistance S. pyogenes isolates had identical phenotype and PFGE profile. These results strongly suggested that the Em-Cm resistant S. pyogenes isolates from Seoul area showed close genetic correlation and PFGE could be available tool for molecular epidemiology.

• 대한의생명과학회지
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• 제5권2호
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• pp.135-145
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• 1999

임상가검물에서 생화학 검사와 항생제 감수성 검사를 통하여 45주의 Staphylococcu aureus를 분리하여 역학적 연구를 위한 형별 분류로써 항생제 감수성 검사, bacteriophage typing,효소중합 연쇄반응 등을 실시하였으며, methicillin 내성과 관련이 있는 mecA 유전자를 검출 및 역학적 변별력이 있는 가변지역의 중합효소증폭반응을 실시하여, 약제 내성과 관련된 구조 유전자의 발현 양상을 비교하여 특정 유전자 배열의 상동성을 밝히고자 하였다. 45주의 Staphylococcus aureus중에서 mecA 유전자 양성주는 30주였으며, 그 중에서 26주가 methicillin에 내성을 보였다. 약제 내성양상에 따라 9개의 antibiogram으로 분류되었으며, SA6을 제외한 균주에서 penicillin, oxacillin, gentamicin 및 chloramphenicol 에서는 높은 내성을 보였으며, SAl3, SAl4 및 SA27에서는 rifampin에 내성을 보였다. 27주에서 bacteriophage 형별 분류가 가능하였으며, Iytic group III가 12주로 가장 많았다. mecA 유전자와 mec관련 가변부위의 polymerase chain reaction을 실시한 결과 모든 methicillin resistant Staphylococcus aureus 에서는 533 bp의 증폭 band가 관찰되었으나, methicillin 감수성 균주에서는 증폭된 band가 관찰되지 않았다. mec관련 가변부위의 polymerase chain reaction에서는 200 bp에서 600 bp사이에 분포하여 4개의 유형으로 분류되었으며, 410bp인 C형이 10균주로 가장 많았다. C형 가변부위의 DNA sequence에서 40 bp가 반복되는 dru sequence를 관찰할 수 있었으며, 이러한 dru sequence는 4 unit가 직접적으로 중복됨을 알 수 있었다.

• 대한미생물학회지
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• 제13권1호
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• pp.31-36
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• 1978

1977년(年) 대구지방(大邱地方)에서 분리(分離)한 20주(株)의 Salmonella paratyphi A, 55주(株)의 S. typhi, 7주(株)의 Shigella flexneri, 14주(株)의 Sh. sonnei에 대(對)하여 항균제감수성(抗菌劑感受性)을 실험(實驗)하였다. S. paratyphi A는 전부(全部)가 salfisomidine(Sa)에 내성(耐性)이었으나 기타공시약제(其他供試藥劑)에는 전부(全部)가 감수성(感受性)이었고 특(特)히 gentamicin, amikacin, kanamycin에 감수성(感受性)이 강(强)하였다. S. typhi는 1주(株)가 chloramphenical(Cm), tetracycline(Tc), streptomycin(Sm) 및 Sa에 내성(耐性)이었고 R(Cm Tc Sm Sa)를 보유(保有)하고 있었으나 기타(其他) 균주(菌株)는 모든 약제(藥劑)에 감수성(感受性)이었고 특(特)히 ampiallin에 감수성(感受性)이 강(强)하였다. Shigella는 1주(株)를 제외(除外)한 20주(株)가 Cm, Tc, Sm 및 Sa에 고도내성(高度耐性)이었으며 기중(其中) 19주(株)가 plasmid R(Cm Tc Sm Sa)를 보유(保有)하고 있었다.

• Tuberculosis and Respiratory Diseases
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• 제64권6호
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• pp.422-426
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• 2008

연구배경: Mycobacterium abscessus는 빠른 성장성을 지닌 비결핵균중에서 높은 병원성과 약제 내성을 나타내는 종이며, clarithromycin과 azithromycin 항결핵제가 M. abscessus에 효과가 있는 유일한 경구용 항결핵제이다. 본 연구에서는 역교잡반응법과 약제감수성검사법을 이용하여 clarithromycin 약제에 대한 M. abscessus 임상 내성균주 검출을 시도하였다. 방 법: 역교잡반응법과 약제감수성검사법을 이용하여 220개의 M. abscessus 임상 균주를 대상으로 내성 균주를 분리하였다. 결 과: 약제감수성검사법으로 7개의 임상 내성 균주들을 검출하였고, 이들 중 3개의 내성 균주는 점 돌연변이 균주로서 역교잡반응법으로도 확인하였다. 결 론: M. abscess 균주에서는 점 돌연변이 및 다른 종류의 내성 특성을 나타내고 있음을 확인할 수 있었다.