• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.1042-1052
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• 2010

Forty-seven Salmonella Typhimurium (33 zoonotic, 14 clinical) strains were tested for antimicrobial resistance using the standard disk diffusion method. The presence of relevant resistance genes and class 1 integrons were investigated by using PCR. Pulsed-field gel electrophoresis (PFGE) and plasmid profiling were carried out to determine the genomic diversity of Salmonella Typhimurium. Approximately 57.4% of the S. Typhimurium strains were multidrug resistant (MDR) and showed high resistance rates to tetracycline (70.2%), sulfonamides (57.4%), streptomycin (53.1%), ampicillin (29.7%), nalidixic acid (27.6%), kanamycin (23.4%), chloramphenicol (21.2%), and trimethoprim (19.1%). Resistance towards cephalosporins was noted for cephalothin (27.6%), cephradine (21.2%), amoxicillin clavulanic acid (17.0%), and cephalexin (17.0%). Resistance genes, $bla_{TEM}$, strA, aadA, sul1, sul2, tetA, tetB, and tetC, were detected among the drug-resistant strains. Thirtythree strains (70.2%) carried class 1 integrons, which were grouped in 9 different profiles. DNA sequencing identified sat, aadA, pse-1, and dfrA genes in variable regions on class 1 integrons. Thirty-five strains (74.4%) were subtyped to 22 different plasmid profiles, each with 1-6 plasmids (2.0 to 95 kb). PFGE subtyped the 47 strains into 39 profiles. In conclusion, high rates of multidrug resistance were found among the Malaysian Salmonella Typhimurium strains. The emergence of multidrug-resistant Salmonella Typhimurium to cephalosporin antibiotics was also observed. The strains were very diverse and no persistent clone was observed. The emergence of MDR Salmonella Typhimurium is a worldwide problem, and this report provides information for the better understanding of the prevalence and epidemiology of MDR S. Typhimurium in Malaysia.

• 한국임상약학회지
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• 제5권2호
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• pp.13-16
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• 1995

The Minimum Inhibitory Concentration (MIC) of a first-generation cephalosporin derivative, Cefazedone (CZD; $PAZERON^R$ inj.) was determined by the two-fold serial agar dilution method. The in-vitro antibacterial activity of CZD against a wide variety of clinical isolates was compared with those of other first generation cephalosporins such as Methylol Cephalexin (CEX), Cefazolin (CEZ), Cefadroxil (CDX), Cephradine (CED), Ceftezol (CTZ) and one of second generation cephalsporin antibiotics, Cefotaxime (CTX). CZD had the most potent inhibitory effect against Gram-positive strains, when compared to the first-generation cephalosporin antibiotics tested in this study and CTX. The geometric MIC mean of CZD for Gram-positive strains was calculated as 0.386 kg/m{\ell}$, and those of CEX, CEZ, CDX, CTZ, CED, and CTX were 6.073, 0.894, 3.399, 0.748, 7.884 and 1.502 $kg/m{\ell}$, respectively. In addition, the geometric mean of CZD for staphylococclJs aureus strains was obtained as 0.340 $kg/m{\ell}$ and those of CEX, CEZ, CDX, CTZ, CED, and CTX 6.145, 0.534, 4.126, 0.442, 10.51, and 2.500 $kg/m{\ell}$, respectively. Against Gram-negative strains, CZD showed better antibacterial activity than CEZ, CDX, CTZ, and CED.

• 한국환경보건학회지
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• 제32권5호
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• pp.462-468
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• 2006

Antibiotics are manufactured and used for specific physiological functions, hence they may exert adverse ecological consequences when they are in contact with nontarget organisms. In the last decade, many reports have been made on the occurrences of various antibiotic compounds in surface water, and their potential impact to the environment has become an increasing concern. This study was conducted to prioritize antibiotic substances with potential environment risk in Korea. Human use antibiotics with an EIC (Expected Introduction Concentration) value greater than $1{\mu}g/l$, US FDA's action limit criteria, were selected. In order to calculate a worst-case EIC for each substance, annual production volume (in kg) of each antibiotic substance was derived using the Korea Pharmaceutical Manufacturers Association (KPMA)'s monetary database. Sixteen substances were preliminarily selected. The EICs of the 16 antibiotic substances were refined with the excretion rate of the parent substances. Ten antibiotic substances were identified to have EIC-corrected greater than $1{\mu}g/l$, which include Amoxicillin ($15.8{\mu}g/l$), Cefaclor ($10.1{\mu}/l$), Roxithromycin ($4.2{\mu}g/l$), Cephradine ($4.5{\mu}g/l$), Cefatrizine ($2.6{\mu}g/l$), Cefadroxil ($3.3{\mu}g/l$), Aztreonam ($2.3{\mu}g/l$), Ceftazidime ($2.8{\mu}g/l$), Ribostamycin ($1.3{\mu}g/l$), and Ceftezole ($1.3{\mu}g/l$). Additional risk assessments for these antibiotic substances are suggested.

• 분석과학
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• 제23권6호
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• pp.572-578
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• 2010

본 연구에서는 하천수 중 6종의 의약물질(cephradine, cefadroxil, penicillin G, vancomycin, iopromide, and fenbendazole)에 대한 전처리법과 분석 방법을 확립하였다. 하천수 중의 분석물질을 HLB(Hydrophilic-Lipophilic Balanced) 카트리지를 사용하여 추출/정제 및 농축하였다. HPLC/ESI-MS/MS를 이용하여 6종의 물질들을 동시에 분석하였다. Fenbendazole을 제외한 의약물질은 71.1~92.6% 범위의 양호한 회수율을 나타내었고, 상대표준편차는 11.2% 이하로 나타났다. 정량분석을 위해서 0.007~1.2 ng/mL 범위에서 $r^2$=0.99 이상의 높은 직선성을 나타내는 검량선을 얻었다. 검출한계(LOD)와 정량한계(LOQ)는 각각 7.2~128.7 pg/mL, 23.8~429.1 pg/mL로 나타났다. 이 분석 방법은 하천수 중 의약품에 대한 모니터링에 유용하며, 하천수 중 iopromide과 fenbendazole은 높은 농도로 검출되었다.

• 분석과학
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• 제29권4호
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• pp.179-185
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• 2016

물 시료 중에 잔류하는 β-차단제 3종(아테놀롤, 메토프롤롤, 프로프라놀롤)과 β-락탐계 항생제 6종(아목시실린, 페니실린G, 세파클러, 세파드록실, 세파렉신, 세프라딘)을 다른 두 종류의 카트리지를 사용하여 효과적인 분석방법을 정립하였다. 고분자 친수성-친유성 균형 카트리지(Hydrophile-lipophile balance, HLB)와 강한 양이온 교환 혼합 모드인 고분자 흡수 카트리지(Mixed mode cation exchange, MCX)를 사용하여 자동고체상 추출장치(Solid-phase extraction, SPE)로 전처리를 하였다. 충분한 크로마토그래피 분리를 위해 XDB-C₁₈ (1.8 μm; 3.0 mm × 100 mm) 컬럼을 사용하였다. 정량을 위한 검정곡선의 상관계수(r²)가 0.995 이상으로 우수한 직선성을 나타내었다. 방법검출한계(Method detection limits, MDL)와 정량한계(Limit of quantitation, LOQ)는 각각 1.1~3.9 ng/L와 5~13 ng/L이었다. 이 분석방법으로 한강으로 유입되는 지천과 원수를 실태 조사 한 결과 N.D.~0.209 μg/L 농도로 검출되었다.