• 대한수의학회지
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• 제44권3호
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• pp.407-413
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• 2004

Specimens collected from various pyogenic lesions of dogs were culturally examined for staphylococci and all staphylococcal isolates obtained from the specimens were also tested for susceptibility to 14 antimicrobial agents. A total of 123 isolates of staphylococci were identified. Of these, 120 were Staphylococcus intermedius and 3 were S aureus. All isolates were susceptible to oxacillin, cefazolin, cephalothin and amikacin, whereas more than 85% of the isolates were resistant to ampicillin, penicillin G and tetracycline. S intermedius isolates could be divided into 8 different biotypes by biotyping with the most common type accounting for 66.7% of the isolates. One hundred and seventeen(97.5%) isolates could be also divided into 26 different antibiogram patterns. The predominant antibiogram type accounted for 34.2% of the isolates. Antibiogram typing was found to be effective in distinguishing epidemiologically related isolates of S intermedius.

• 한국축산식품학회지
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• 제26권3호
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• pp.394-401
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• 2006

Forty Clostridium perfringens isolates were obtained from twelve animal products, following the examination of eighty six beef, pork, broiler chicken and salami meat products, and eleven milk powder products. There were 21 isolates from salami stored at $25^{\circ}C$, 3 isolates from pork, 4 isolates from beef, 9 isolates from broiler chicken, and 3 isolates from milk powder. Only the cpa gene encoding a toxin among the 5 toxin genes tested (cpa, cpb, etx, iap, and cpe) was detected in all forty isolates, suggesting contamination with C. perfringens type A. DNA fingerprinting analysis using PCR of the tRNA intergenic spacer (tDNA-PCR) and the 16S-23S internal transcribed spacer (ITS-PCR), and randomly amplified polymorphic DNA (RAPD) analysis were attempted to differentiate the isolates. RAPD analysis was the most discriminating method among the three PCR analyses. Isolates from the same products tended to show similar RAPD patterns. Antimicrobial susceptibility tests showed that some isolates from broiler chickens had the same antibiogram with multiple resistance to streptomycin, colistin, and ciprofloxacin. Antibiograms were similar between isolates from the same livestock products, but differed considerably between the products.

• Journal of Microbiology and Biotechnology
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• 제25권9호
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• pp.1460-1466
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• 2015

In this study, the prevalence of Shiga toxin-producing Escherichia coli (STEC) was investigated among raw meat or meat products from slaughterhouses and retail markets in South Korea, and their potential for antibiotic resistance and virulence was further analyzed. A total of 912 raw meats, including beef, pork, and chicken, were collected from 2008 to 2009. E. coli strains were frequently isolated in chicken meats (176/233, 75.9%), beef (102/217, 42.3%), and pork (109/235, 39.2%). Putative STEC isolates were further categorized, based on the presence or absence of the Shiga toxin (stx) genes, followed by standard O-serotyping. Polymerase chain reaction assays were used to detect the previously defined virulence genes in STEC, including Shiga toxins 1 and Shiga toxin 2 (stx1 and 2), enterohemolysin (ehxA), intimin (eaeA), STEC autoagglutination adhesion (saa), and subtilase cytotoxin (subAB). All carried both stx1 and eae genes, but none of them had the stx2, saa, or subAB genes. Six (50.0%) STEC isolates possessed the ehxA gene, which is known to be encoded by the 60-megadalton virulence plasmid. Our antibiogram profiling demonstrated that some STEC strains, particularly pork and chicken isolates, displayed a multiple drug-resistance phenotype. RPLA analysis revealed that all the stx1-positive STEC isolates produced Stx1 only at the undetectable level. Altogether, these results imply that the locus of enterocyte and effacement (LEE)-positive strains STEC are predominant among raw meats or meat products from slaughterhouses or retail markets in Korea.

• 대한의생명과학회지
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• 제10권4호
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• pp.501-506
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• 2004

Extended spectrum β-lactamase (ESBL) generated Enterobacteriaceae including Escherichia coli is responsible for resisting antibiotics, which is clinical problem. This study was performed to investigate the isolation rates of 111 strains having positive of VITEK ESBL test 111 ESBL-strains in each month and season and statistically to determine their patterns of antibiotic test. One hundred eleven ESBL-strains were collected among 1,688 strains of E. coli isolated from various clinical specimen of one general hospital in Busan during 2002 to 2003. Month rates of ESBL-strains were 0％ to 13.3％, while the seasonal rates were highest at autumns during two years. The resistance to ampicillin, cefazolin, azteronam, ceftriaxone, and cefepime were 100％ in 2002. In ampicillin and cefazolin the resistances were 100％ during the two years. There were significant differences of cefoxitin and piperacillin/tazobactam between the two years but not significant between specimens. Four groups were divided according to the pattern of resistance and then the highest group had 93∼100％ of the resistance to 8 drugs but not resistant to imipenem.

• Clinical and Experimental Pediatrics
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• 제49권5호
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• pp.494-499
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• 2006

목 적: Acinetobacter baumannii는 숙주 저항력이 저하된 고위험군에서 주요 원내 감염균으로 잘 알려져 있으나 A. baumannii 이외의 Acinetobacter species의 경우 드물게 감염과 연관된 것으로 받아들여지는 등 임상적 중요성과 원내 감염원으로써의 역학에 대해 알려진 바가 적다. 저자들은 신생아 집중치료실에서 A. baumannii가 아닌 것으로 확인된 Acinetobacter species에 의해 집단 발생한 패혈증 11례를 경험하였기에 이에 대한 임상적, 역학적 특징을 알고자 본 연구를 실시하였다. 방 법: 2004년 2월 4일부터 24일까지 일신기독병원 신생아 집중치료실에서 감염되었던 환아의 혈액에서 Acinetobacter species가 배양된 11례를 대상으로 임상적 특징을 조사하였고, 집단 발생의 역학을 조사하기 위해 두 차례에 걸쳐 의료진 및 환경 검체에 대한 배양을 실시하였으며, 항생제 감수성 검사를 통해 환아에서 배양된 균주가 동일 균주인지를 알고자 하였다. 결 과: 임상 양상은 발열, 수유 부진, 복부 팽만, 설사, 혈변, 구토, 빈호흡, 무호흡 등 다양하였으나 다른 원인에 의한 감염증과 비슷하였다. 집중 치료를 요하는 중증 경과를 보인 경우가 없었고 항생제 치료에 즉각적인 반응을 보이며 회복되어 A. baumannii 감염증에서 흔히 보이는 중증의 임상 증상과 높은 사망률(11-57%)과 비교하여 경한 경과를 보였다. 도관 관련 균혈증 2례, 도관 관련 균혈증 의증 9례로 말초 정맥 도관이 중요 유발 인자로 고려되었다. 감염의 역학을 알고자 두 차례에 걸쳐 의료진의 손과 환경 검체에 대한 배양 검사를 실시하였으나 동일 균주를 분리하는데는 실패하였다. 결 론: 우리의 연구를 통해 A. baumannii 이외의 Acinetobacter species의 경우 상대적으로 비병원성으로 여겨졌으나 임상 증상이 동반되면서 환자에서 배양되면 감염의 원인균임을 알 수 있었다.

• 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.

• 한국동물위생학회지
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• 제20권1호
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• pp.19-26
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• 1997

The present study was conducted to investigate the general epidemiological situations with 18-pullorum infected chickens from Kyongbuk provinces during the period from June 1995 to January 1996. On the Salmonella pullorum isolation tests by rectal swab culture method from infected chickens (386-samples), any Salmonella spp was not isolated from infected live-birds. But 2-S pullorum were isolated of 2-dead chickens(33.3% ) from 6-dead chickens which were positively reacted by serological tests. On the other hand, we could not isolated any Salmonella spp. in any parts of egg-contents ; egg-shell, egg-white and egg-yolks with 25-infected bird eggs. On the tests of antibiogram, 2-S pullorum strains were highly sensitive to GM, AM, SXT, CZ, K, FIM, ENR, C, AN, N, NN, LIN＋SP, CF, TE and PB, respectively and intermediate sensitive to the CB, CFP, CL, S, P and XNL. But 2-strains were resistant to CC, DP, E, L, OX, TLA and TyLO. In the serological tests, pullorum antibody titers of 18-infected birds was from 2.76 to 9.18 with average by the microplate test. During the 6-months, pullorum antibody average titers were not changed generally. To validate the effects of the antimicrobial agent treatments to the serological antibody titers, infected 6-chickens was medicated with 0.5%-futazolidone. The titer of premeditated birds was average 4.26 but after medication with furazolidone, the titers of treated 6-birds was average 4.08.

• 대한수의학회지
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• 제22권2호
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• pp.161-165
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• 1982

Biochemical and antimicrobial susceptibility tests were conducted on 40 strains of Pseudomonas aeruginosa originated from diseased chicken submitted for diagnosis to this Institute during 1978-80. An extensive study of the biochemical properties revealed that the tested strains can be identified with Pseudomonas aeruginosa. Antibiogram showed that all the strains were susceptible to gentamicin, colistin and amikacin but resist to nitrofurantoin, trimethoprim+sulfamethoxazole, ampicillin, methicillin and kanamycin, and had varing degreed of resistance to other antimicrobials including carbenicillin, sulfomamides, neomycin, streptomycin, tetracycline and chloramphenicol. Three of the most frequent resitance patterns observed were FM SXT AM ME KM CM TC SM NE SSS Pattern, FM SXT AM ME KM CM TC SM NE SSS CB Pattern and FM SXT AM EKM CM TC SM Pattern, and these resistance patterns contained 72.5% of the tested strains.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.106-113
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• 2002

One-hundred and twenty-four trimethoprim-resistant Shigella sonnei isolates extracted in Korea during the last two decades were investigated for their epidemiological relationship and mechanisms of resistance to trimethoprim. The S. sonnei isolates were distributed into two groups by three different epidemiological tools: biotyping, antibiogram, and pulsed-field gel electrophoresis. One group contained the isolates from the 1980s and the other group included the isolates from the 1990s. The geometric mean MICs of trimethoprim in S. sonnei isolates from the 1980s and 1990s were found to be $672.9{\mu}g/ml\;and\;>2,048{\mu}g/ml$, respectively. Trimethoprim resistance was associated with dfrA5, dfrA12, and dfrA13 genes in the isolates from the 1980s, dfrA1, dfrA5, and dfrA12 in the isolates from 1991, and dfrA1 and dfrA12 in the isolates from 1992 to 1999. The dfrA1 gene was located downstream of the intI2 gene in Tn7, which was located on chromosome. Some dfrA12 genes were found as gene cassettes in the class 1 integron. The dfrA5 and dfrA13 genes were located on conjugative plasmids. These results suggested that a clonal change occurred in S. sonnei isolates in Korea during the last two decades and that dfr genes located on different transposable genetic elements had gradually changed.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1764-1768
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• 2010

In this study, the prevalence of antibiotic resistance was examined among 74 Staphylococcus pseudintermedius strains recently isolated from clinical cases of canine pyoderma and otitis externa at the veterinary teaching hospital at Konkuk University, Korea. Bacterial resistance to the nine commonly used antibiotics was evaluated by a standard disk diffusion technique based on the guidelines of the Clinical and Laboratory Standards Institute. The results demonstrated that most S. pseudintermedius isolates were resistant to penicillin (95.9%) or tetracycline (91.9%), but highly susceptible to amoxicillin/clavulanic acid (90.5%). Among the 74 isolates, 13 mecA-positive and methicillin-resistant S. pseudintermedius (MRSP) strains were identified, displaying a high level of resistance (84.6-100%) to each of the individual antibiotics evaluated, with the exception of amoxicillin/clavulanic acid (46.2% resistance). Notably, all of the MRSP isolates exhibited simultaneous resistance to four or more different antibiotics, indicating that they are multiple drug resistant (MDR) strains. Taken together, these results imply that more careful selection or prescription of antibiotics for canine pyoderma and otitis externa should be required for reducing the emergence and/or spread of MDR strains, especially MDR-MRSP isolates, in veterinary pet clinics in Korea.