Oxidation of erythromycin, sulfamethazine and sulfathiazole by ozone was experimentally investigated to see the effects of background water quality such as ultrapure water, humic acid and biologically treated wastewater and water temperature on the removal rate, consequently to provide design information when the ozone treatment process is adopted. Initial concentration of the antibiotics was spiked to 10 μg/l and ozone dose was 1, 2, 3, 5, 8 mg/l. While the removal rate of erythromycin under ultrapure water background by ozone oxidation was over 99%, that under humic acid and biologically treated wastewater background was markedly reduced to the range of 59.8%~99% and 17.0%~99%, respectively. When water temperature is decreased from 20℃ to 4℃, the removal rate is reduced from the range of 17.0%~99% to the range of 9.4%~97.4% under biologically treated wastewater background. The effects of background and temperature on the removal rate of sulfamethazine and sulfathiazole were similar to erythromycin, but the degree was different. Therefore, it is concluded that the background of water to be treated as well as water temperature should be taken into consideration when the design factor such as ozone dose is determined to meet the treatment objective in the ozone treatment process.

A rapid, simple and reliable LC-MS/MS method, which can be used on a routine basis, was developed for the simultaneous detection of 8 penicillin antibiotics (amoxicillin, ampicillin, penicillin-G, penicillin-V, oxacillin, cloxacillin, nafcillin and dicloxacillin) in swine muscle and kidney. The antibiotics were extracted from samples with water and methanol. The extract was centrifuged, filtered and analyzed by liquid chromatography coupled with a tandem mass spectrometer (LC-MS/MS), using a C18 reversed phase column with water/acetonitrile gradient containing 0.05 % formic acid. Mass spectral acquisition was achieved in an electrospray positive ion mode by applying multiple reaction monitoring (MRM) of 2 fragment ion transitions to provide a high degree of sensitivity and specificity. The ion rations were consistent and could be used for confirmation of identity of the penicillin antibiotics. Recoveries of eight penicillins at three fortification levels (10, 20 and 40㎍/㎏) ranged from 79.8 to 102.4% and 72.8 to 103.4% in swine muscle and kidney, respectively. The coefficient of variation was than 9% in all samples. The estimated limits of quantification (LOQs) ranged from 1.0 to 3.2㎍/㎏ in swine muscle and kidney, respectively. The LOQs of this method are below the MRLs of penicillin antibiotics in animal tissues established in Korea and other countries.

With the increase of the use of antibiotics and invasive procedures, infections caused by multidrug-resistant Acinetobacter baumannii(MRAB) are increasing. We screened the antibiotic producing strain B-51 for antibacterial activity against MRAB from the soils and studied the effects of culture medium on the antibiotic production of B-51. The medium conditions for maximum antibiotic productivity of B-51 was 2% glycerol, 0.5% soybean meal, 0.01% CaCl2, 0.01% MgSO4, 7H2O and 0.01% KH2PO4 at an initial pH of 6.0, at 30℃ for 76 h.

병원성 Pseudomonas에 유효한 항생물질을 생성하는 방선균 LAM 98-80을 분리하여 형태학적, 배양학적, 생리학적으로 동정한 결과 Streptomyces sp. LAM 98-80으로 동정·명명하였다. 이 균을 이용하여 병원선 Pseudomonas에 유효한 항생물질의 최적 생성 조건을 검토한 결과 탄소원으로 1.5%의 soluble starch, 질소원으로는 1.0%의 yeast extract가 가장 양호하였으며 무기염으로 Mn^2+을 0.04%을 첨가로 항생물질의 생성량을 80%나 증가시켰다. 배지의 초기 pH는 7.0, 최적 온도는 30℃ 그리고 배양일수는 5일만에 최고의 생육 및 생성을 나타내었다. 시험균으로 사용한 cephalosporins 내성 병원성 Pseudomonas는 cepha계 항생물질에 대하여 내성을 띠었으며 β-lactam계인 ampicillin, amoxicillin에 대해서는 민감하였다. 그리고 조정제한 항생물질의 열과 pH에 대한 안정성을 검토한 결과 70℃에서 1시간동안 안정하였고 pH 3에서 9까지 넓은 범위에서 안정하였다. 각 종균에 대한 항생작용은 그람 양성 및 음성균에 모두 효과적이었으며 진균인 효모와 곰팡이에는 효과가 없었다.

토양에서 분리한 Streptomyces lydicus YSK-681이 생산하는 메치실린내성 황색 포도상구균에 유효한 항생물질을 정제하여 물리화학적 특성을 조사하였다. 물질정제는 chloroform으로 추출한 후 silica gel column chromatography, Si, ODS, GPC HPLC순으로 진행하였다. FAB MS의 분자량 측정결과 m/z 1022.4와 1036.4(M+H)^+의 두 개의 피크가 분석되었으며, NMR 분석에서는 -OH와 leucine으로 추정되는 관능기가 조사되었다. 정제된 항생물질의 MIC는 그람 양성균에 대해서 1∼32 ug/ml그람음성균과 효모에서는 125 ug/ml 이상이었다. 임상에서 분리된 129개의 MRSA에 대한 MIC는 8 ug/ml이었으며, 암세포인 P388, HeLa, S180에 대한 세포독성은 없었다.

항생제에 대한 내성균의 출현은 매년 급격하게 증가되고 있으며 이에 대한 약제 개발이 요구되고 있다. 특히 메치실린내성 황색 포도상구균(MRSA)은 여러 항생물질에 대하여 다제내성을 나타내므로 감염증 치료에 어려운 문제점으로 남아 있다. 이러한 감염증치료에 사용할 목적으로 임상 가검물에서 분리한 MRAS를 시험균으로 사용하여 항균 활성이 강한 방선균인 YSK-681을 선별하였다. 균주 동정을 위하여 선별된 YSK-681을 형태적, 배양학적, 생리적, 화학적 분석을 하였으며 41개의 단위 항목을 조사하여 TAXON program으로 수리 동정한 결과 주군집 29에서 속하는 Streptomyces lydicus로 동정하였다.

A simple, rapid and simultaneous analytical method is described for the detection of Sulfonamide and Tetracycline residues, i.e., Sulfamerazine (SMR), Sulfamethazine (SMT), Sulfamonomethoxine (SMM), Sulfadimethoxine (SDM), Sulfaquinoxaline (SQN), Oxytetracycline (OXY), Tetracycline (TC), Chlortetracycline (CTC). Blank control and sulfonamide and tetracycline fortified fish muscle samples (0.5 g) were blended with octadecylsilyl (C,e, 40 gm, 21% load, 60Å) derivatized silica packing material (2 g). Blended fish samples were washed with hexane, then, benzene and dichloromethane were used for the elution of tetracycline and sulfonamide, respectively, The eluants containg tetracycline and sulfonamide were analyzed by HPLC. Correlation coefficients of standard curves for individual sulfonamide and tetracycline isolated from fortified samples were linear (0.9993±0.0003-0.9997±0.0003, 0.9493±0.078-0.9753±0.036), respectively, The average percentage recoveries of sulfonamide and tetracycline ranged as 80.86-96.52% to 85.88-92.23%, and 30.01-37.12% to 65.89-73.40%, for the concentration range (0.1--1.0 ppm) examined, respectively. Limit of detection for sulfonamide was 0. 05 ug/g, then, tetracycline was 0.1 ug/g. Detection of quantitation of sulfonamide residue was 0.0012 ppm for SMR in Paralichthys Odiuacleus and 0.0020 ppm for SMR, 0.015 ppm for SMM in Cyprinus Carpio. The applicability of this procedure is demonstrated by separation and detection of incurred tetracycline and sulfonamide residues in fish muscle tissue.

Recently, as concern about the residual antibiotics in milk increase, the detection methods of residual antibiotics used extensevely at the present time were investigated and compared to their properties and the detection limits of variable antibiotics. At first, comparative tests of the detectable sensitivity of 4 teat organisms, B.cereus, B.subtilis, M.luteus, B. stearothermophilus C-953, were performed by disc assay. As a result, B.stearotleermoph.ilus was the most sensitive strain of all other strains and showed the detect limit of 5-50 ppb for penicillins (PCs). And also, B.subtilis was showed the more effective detection limit, 200-400 ppb, for aminoglycosides (AGs) and M.luteus was showed predominant sensitivity , 50-500 ppb for macrolides(MLs) and B.cereus was the most sensitive strain for tetracyclines (TCs) and showed the detection limit of 100-400 ppb. Therefore, each test strains were showed a different sensitivity in the detection of the different antibiotic families. When the detection limit of disc assay and other methods were compared, TTCmethod was less sensitive than other methods showing 5-50 ppb detectable lebel for PCs. Also, for the detection of other antibiotic families TTC method was showed the worst sensitivity and Delvo and Charm Farm tests were similar to the detectable properties of AGs and MLs. Although disc assay was showed the similar detection limit for PCs with Delvo and Charm Farm, it was more widely effective for the detection of kanamycin, erythromycin, chlortetracycline, doxycycline, verginiamycin and so on than Delvo or Charm Farm. CharmII test was showed the best sensitivity for the most of antibiotics except neomycin and gentamycin. But it was necessary that different tests must be performed to each antibiotic family and so it was regarded that the effectiveness of that method was low.