• 미생물학회지
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• 제33권3호
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• pp.165-169
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• 1997

병원하수에서 분리한 gentamicin 저항성 세균으로부터 aacC2 유전자를 가지고 있는 R 플라스미드 pGM5와 pGM6를 선발하였다. 이들 플라스미드에서 gentamicin 저항성 유전자를 포함하는 부분을 pUC18의 BamHI 자리에 클로닝하여 재조합 플라스미드 pSY5와 pSY6를 각각 얻었다. 재조합 플라스미드의 삽입된 부분에 대한 제한효소 지도를 통해 Tn3 염기서열이 aacC2 유전자의 상류부위에 위치하는 것을 알았다. 재조합 플라스미드의 gentamicin에 대한 민감성의 비교를 통해 Tn3의 bla 유전자 부분과 3'역행중복 부위의 염기서열이 gentamicin 저항성 유전자의 발현에 중요한 역할을 담당하고 있었다.

• 한국식품위생안전성학회지
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• 제9권3호
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• pp.123-131
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• 1994

An enzyme-linked immunosorbent assay(ELISA) was developed for the detection of residual gentamicin(GM) in edible animal products. The immunogen(GM-KLH conjugate) and coating antigen(GM-BSA conjugate) were prepared by coupling GM sulfate to keyhole limpet hemocyanin(KLH) and bovine serum albumin(BSA) in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, respectively. Polyclonal antibody to GM was produced in rabbits(New Zealand White, female) by using the immunogen and the antibody titer was measured by indirect ELISA. A competitive ELISA was developed using GM-bovine serum albumin conjugate as a coating antigen, GM(as standards or sample), polyclonal antibody to GM, secondary antibody conjugated with horseradish peroxidase as an enzyme, and H2O2 and o-phenylenediamine dihydrochloride as a substrate and a chromophore, respectively. The detection limit of GM was 10 ng/ml and the standard curve of GM(n=26) was linear up to 10 $\mu\textrm{g}$/ml in this competitive ELISA system. There were no cross-reactivities of the partially purified antibody between GM and the various antibiotice such as amikacin, benzyl-penicillin, chloramphenicol, erythromycin, furazlidone, kanamycin, neomycin, oleandomycin, streptomycin, sulfathiazole and thiamphenicol(CR50<0.05%)

• The Korean Journal of Physiology and Pharmacology
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• 제17권5호
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• pp.435-440
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• 2013

While the anti-apoptotic effect of paricalcitol has been demonstrated in various animal models, it is not yet clear whether paricalcitol attenuates the apoptosis in gentamicin (GM)-induced kidney injury. We investigated the effect of paricalcitol on apoptotic pathways in rat kidneys damaged by GM. Rats were randomly divided into three groups: 1) Control group (n=8), where only vehicle was delivered, 2) GM group (n=10), where rats were treated with GM (150 mg/kg/day) for 7 days, 3) PARI group (n=10), where rats were co-treated with paricalcitol (0.2 ${\mu}g/kg/day$) and GM for 7 days. Paricalcitol attenuated renal dysfunction by GM administration in biochemical profiles. In terminal deoxynucleotidyl transferase dUTP nick end labeling staining, increased apoptosis was observed in GM group, which was reversed by paricalcitol co-treatment. Immunoblotting using protein samples from rat cortex/outer stripe of outer medulla showed increased Bax/Bcl-2 ratio and cleaved form of caspase-3 in GM group, both of which were reversed by paricalcitol. The phosphorylated Jun-N-terminal kinase (JNK) expression was increase in GM, which was counteracted by paricalcitol. The protein expression of p-Akt and nitro-tyrosine was also enhanced in GM-treated rats compared with control rats, which was reversed by paricalcitol co-treatment. Paricalcitol protects GM-induced renal injury by antiapoptotic mechanisms, including inhibition of intrinsic apoptosis pathway and JNK.

• The Korean Journal of Physiology
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• 제23권1호
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• pp.23-34
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• 1989

Gentamicin (GM) is a polybasic, aminoglycoside antibiotic used frequently for the treatment of serious gram-negative infections. The major limiting factors in the clinical use of GM as well as other aminoglycoside antibiotics are their nephrotoxicity and ototoxicity. The primary mechanism of cell injury in aminoglycoside toxicity appears to be the disruption of normal membrane function and the inhibition of $Na^{+}-K^{+}$ ATPase activity. There are both indirect and direct evidences which suggests that the effect of aminoglycoside antibiotics on $Na^{+}-K^{+}$ ATPase may explain, or contribute to, their toxicity. It has been shown that aminoglycoside reduce total ATPase activity (Kaku et al., 1973) and $Na^{+}-K^{+}$ ATPase activity (linuma et al., 1967) in the stria vascularis and spiral ligament of the guinea-pig cochlea. Lipsky and Lietman (1980) reported that aminoglycoside antibitoics inhibited the activity of $Na^{+}-K^{+}$ ATPase in microsomal fractions of the cortex and medulla of the guinea-pig kidney, isolated rat renal tubule and human erythrocyte ghosts. The present invstigation was undertaken to elucidate the mechanism of GM on human erythrocytes by examining its effect on $Na^{+}-K^{+}$ ATPase activity, actives sodium and potassium transport across red blood cell and $^{3}H-ouabain$ binding to red blood cell membranes. The results obtained are summarized as follows: 1) CM inhibited significantly both the activity of total ATPase and $Na^{+}-K^{+}$ ATPase at all concentrations tested. 2) GM inhibited active $^{22}Na$ efflux across red blood cell. When ouabain is present, the rate of $^{22}Na$ efflux was completely inhibited. When both GM and ouabain were added, the inhibitory effect of active $^{22}Na$ efflux was more pronounced. 3) Active $^{86}Rb$ influx was inhibited significantly by GM. In the presence of ouabain, the rate of $^{86}Rb$ influx is markedly inhibited. But $^{86}Rb$ influx is not appreciably altered by the presence of both GM and ouabain. 4) In the presence of GM, $^{3}H-ouabain$ binding to red blood cell membrane increased. From the above results, it may be concluded that the inhibition of active sodium and potassium transport across red blood cell by gentamicin appears to be due to the inhibition of $Na^{+}-K^{+}$ ATPase activity and an increase in ouabain binding to red blood cell membranes.

• 대한미생물학회지
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• 제21권1호
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• pp.1-16
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• 1986

Fifty-one strains of Pseudomonas aeruginosa were isolated from various clinical specimens. Among them, 26 (51%) strains were gentamicin-resistant (Gm') and 25 (49%) were susceptible to gentamicin (Gm'). The frequencies of resistant strains to piperacillin (Pi), cefotaxime, moxalactam, cefoperazone (Cz), and amikacin (Ak) ranged from 21.6 to 31.4%, and $MIC_{50}$ of these drugs were lower than the critical concentrations of susceptibility and resistance. Thirty (58.8%) strains were multiply resistant to 12 or more drugs. All Gm' strains were multiply resistant to 12 or more drugs and one was resistant to all 18 drugs tested, while only four Gm' strains were multiply resistant to 12 drugs and the multiplicity of resistance of the other Gm' strains were less than 10 drugs. Resistance to Gm appeared to have a significant correlation with the resistance to tobramycin (Tb), Ak, Pi, and Cz. All Gm' strains were resistant to Tb and about 38.4 to 46.1% of them were resistant to Ak, Pi, and Cz. The incorporation of $Ca^{++}$ and $Mg^{++}$ ions in Mueller-Hinton agar (MHA) did not influence the MICs of Gm, Tb, carbenicillin (Cb), Pi, and Cz as compared with the results obtained in MHA without these ions. Gm strains were studied on the combined effect of beta-lactam antibiotics and aminoglycosides by the methods of checkerboard and modified paper strip diffusion. Most Gm' strains showed significant synergistic effects by the FIC index between Ak and three beta-lactam antibiotics; Cb, Pi, and Cz, but these results did not in agreement the results obtained through the method of modified paper strip diffusion test. In order to know the nature of the drug resistance of P. aernginosa, the plasmid profile analysis was studied. Agarose gel electrophoresis of lysates processed by the method of Kado and Liu showed one or more plasmids in 22 (43.1%) strains. A group of 19 strains showed at least one band of plasmid and three strains two bands. The range of the molecular weight of plasmids was 3.8 to 243 Mdal. All strains carrying large plasmids larger than 200 Mdal were isolated from wound specimens. Three Gm' strains also harboured the plasm ids of 13 to 203 Mdal.

• Molecular & Cellular Toxicology
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• 제3권1호
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• pp.60-67
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• 2007

Gentamicin is a broad-spectrum aminoglycoside antibiotic used in the treatment of bacterial infection. Although side effects of gentamicin such as nephrotoxicity and ototoxicity have been investigated, the information on the hepatic effects of gentamicin is still limited. In the present study, gene expression profiles were analyzed in the liver of gentamicin treated mice using Affymetrix GeneChip$^{(R)}$ Mouse Expression 430A 2.0 Array. Totally, 400 genes were identified as being either up- or down-regulated over 1.5-fold changes (P<0.01) in the liver of gentamicin treated mice. Among these deregulated genes, 16 up-regulated genes mainly involved in transport (Kif5b, Pex14, Rab14, Clcn3, and Necap1) and 20 down-regulated genes involved in lipid and other metabolisms (Hdlbp, Gm2a, Uroc1, and Dak) were selected using k-means clustering algorithm. The functional classification of differentially expressed genes represented that several stress-related genes were regulated in the liver by gentamicin treatment. This data may contribute in understanding the molecular mechanism in the liver of gentamicin treated mice.

• 대한미생물학회지
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• 제21권3호
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• pp.375-380
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• 1986

Thirty-one strains of Pseudomonas aeruginosa were submitted to the synergistic activity test of amikacin(AK) and gentamicin(GM) combined with moxalactam(MX), ceftizoxime(CTZ) or cefoperazone(CFZ). The minimal inhibitory concentrations(MICs) of each drug and drugs combined in various ratios were measured by checkerboard dilution method. The synergism was determined through analysing the MIC distribution curve on isobologram and calculating the fractional inhibitory concentration index(FICI). MICs of GM, AK, MX, CFZ and CTZ against the 31 tested strains were distributed from $12.5{\mu}g/ml$ to $800{\mu}g/ml$, from $0.8{\mu}g/ml$ to $25{\mu}g/ml$, from $3.1{\mu}g/ml$ to $50{\mu}g/ml$, from $3.1{\mu}g/ml$ to $400{\mu}g/ml$, and from $12.5{\mu}g/ml$ to $100{\mu}g/ml$, respectively. The rate synergism of each drug combination by means of FICl was 45.5% in GM-MX, 36.4% in GM-CFZ, 63.6% in GM-CTZ, 48.6% in AK-MX, 35.3% in AK-CFZ, and 35.7% in AK-CTZ combination. Thus, it is suggested that Pseudomonas aeruginosa may effectively be inhibited by various aminoglycoside and cephalosporin combinations.

• 대한미생물학회지
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• 제21권1호
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• pp.17-31
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• 1986

Forty clinical isolates of Serratia marcescens were tested for their susceptibility to 19 antimicrobial drugs and studied on the molecular characteristics of R plasmids. Cefotaxime (Ct) was the most effective drug and only 2 (5%) strains were resistant to this drug. Thirteen to 18% of strains were resistant to cefoperazone (Cz), amikacin (Ak). and trimethoprim (Tp), and 28 to 40% were resistant to piperacillin (Pi), nalidixic acid (Na), gentamicin (Gm), and cefoxitin (Cx). A majority of strains were resistant to carbenicillin (Cb), tobramycin (Tp), kanamycin (Km), and cefamandole (Cd), and all to cephalothin. One half of the isolates were resistant to 10 or more drugs. $MIC_{90}$ of Pi to Gm-resistant strains (Gm') were 8 times higher than that to Gm-susceptible strains (Gm'), but $MIC_{90}$ of Ak, Cx, Ct, and Cz were almost the same between both Gm' and Gm' strains. Nine (23.7%) strains among 38 of multiply drug-resistant S. marcescens transferred conjugally their partial patterns of resistance to E. coli or Klebsiella strains, and two S. marcescens strains producing bacteriocin transferred their resistance to Klebsiella only, but not to E. coli. The plasmid profiles of S. marcescens were studied by the methods of SDS lysis and agarose gel electrophoresis. Twenty-four (60%) strains carried one to four plasmids of 1.4. to 144 Mdal, and conjugative R plasmids of 49 to 127 Mdal were noted in transconjugants. MIC levels of drugs in transconjugants were variable by the R plasmids and recipient strains.

• 생약학회지
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• 제31권4호
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• pp.407-411
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• 2000

Antibacterial activities of magnolol (MGL) and honokiol (HKL) in combination with four representative antibiotics-amoxicillin (AMPC), oxytetracyclin (OTC), gentamicin (GM) and chloramphenicol (CAP)-were evaluated against four bacterial strains. When tested by disk-plate method, five out of eight combinations such as HKL-AMPC, HKL-CAP, MGL- AMPC, MGL-OTC, and MGL-CAP showed additive to synergistic interaction against gram- negative bacterium Salmonella typhimureum. Of these, MGL-AMPC combination turned out to be antagonistic against Sarcina lutea and Bacillus thurungiensis. Against these two grain-positive bacteria, only HKL-GM combination showed additivity to synergism. All the other combinations showed no interactions. Despite these results, however, no synergism was observed in checkerboard titration assay.

• 한국동물위생학회지
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• 제23권1호
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• pp.45-59
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• 2000

The present study was conducted to investigate the epidemiological properties of salmonellosis of poultry farms in Kyongbuk province during the relied from November 1998 to November 1999 And antibiotic susceptibility and biochemical characteristics of 120 Salmonella cultures isolated from chicken samples were also investigated. The results obtained through this study were summarized as follows, 1. Among 667,200 chickens of 31 flocks in 17 layer farms and 9 broiler farms, 61,350 chickens of 31 flocks were died with salmonellosis. The death rate of 25 farms varied from 0.1% to 75.0%, and the average death rate was 9.2%. 2. According to etiological agents, fowl typhoid was shown the most predominant outbreak among the salmonellosis during a year, which accounted for 8R.0%(22/25) of the total case 3. The serotypes of 120 Salmonella isolates were identified as 7 strains(5.8%) of S pullorum, 10 strains(8.4%) of S typhimurium and 103 strains(85.8%) of S gallinarum. 4. Most outbreak of fowl typhoid were prevalent on the layer chicken farms(77.1%), and the summer season(45.5%) also appeared the most hazardous season during the year. 5. It seemed that the Hyline breed(70.6%) was the most susceptible among the layer chicken breeds, and followed by Isabrown(23.5%), Tetra(5.9%) in order. 6. In layers, 76.4% of fowl typhoid occurred commonly from 14 to 40 weeks including the early laying peroid, but in broiler farms, all cases was outbreak within first second weeks. 7 All the strains of S pullorum were resistant to lincomycin(Lm), penicillin(Pm), and steptomycin(Sm), but sensitive to amikacin(Ak), ampicillin(Am), cephalothin(Ce), ciprofloxacin (CiP), chloramphenicol(Cm), colistin(Co), enrofloxacin(Enr), furazolidone(Fu), gentamicin(Gm), kanamycin(Km), neomycin(Nm), polymyxin(Po), and teracycline(Tc). All the strains of S typhimurium were resistant to Lm(100%), Pm(100%), Po(90%), and Sm(90%), but were sensitive to Ak, Am, Ce, CiP, Cm, Co, Enr, Fu, Gm, Km, Nm, and Tc. 8. Minimum inhibitory concentration(MIC) of 103 strains of S gallinarum were also evaluated and their patterns were much more variable than others. All the strains of S gallinarum were sensitive to Ak, Am, Ce, Cip, Cm, Enr, Fu, Km, and Nm, but resistant to Lm(100%), and Sm(100%), 99(96.1%) to Co, 83(80.6%) to Pm, and 83(80.6%) to Po, 55(53.4%) to Gm, and 33(32.0%) to Tc. 9. The multiple drug resistance patterns of 120 Salmonella strains were CoLmPmPo Sm pattern(34.2%), CoGmLmPmPoSmTc(20.8%), CoGmLmPmPoSm(13.3%), CoGmLmSm(7.5%), LmPmSm(7.5%), LmPm(6.7%), CoLmSmTc(3.3%),, CoGmLmSmTc(1.7%), GmLmSmTc(1.7%), CoGmLmPoSm(0.1%), LmPmPo(0.1%), CoLm Sm(0.1%), and LmSm(0.1%), in order.