• 제목/요약/키워드: Killing curve

검색결과 22건 처리시간 0.024초

가감섭영전(加減攝營煎)의 Gardnerella vaginalis에 대한 시험관내 항균력 및 Clindamycin과의 병용효과 (In Vitro Antibacterial Effects of Gagam-seopyoungjeon Aqueous Extracts and Their Combination Effects with Clindamycin against Gardnerella Vaginalis)

  • 오자영;김동철
    • 대한한방부인과학회지
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    • 제27권1호
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    • pp.65-80
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    • 2014
  • Objectives: The object of this study was to observe the in vitro antibacterial effects of Gagam-seopyoungjeon aqueous extracts (GGSYJ) against Gardnerella vaginalis and the possible synergic combination effects with clindamycin. Methods: Antibacterial activities against Gardnerella vaginalis of GGSYJ were detected using minimal inhibition concentration (MIC), and the effects on the bacterial growth curve were also monitored at MIC and MIC${\times}$2 levels. The combination effects of GGSYJ with clindamycin were observed by checkboard microtiter assay, and the effects of bacterial growth curve treated with GGSYJ MIC+clindamycin MIC, 1/2 MIC and 1/4 MIC, respectively. The effects on the bacterial invasion and intracellular killing of GGSYJ were also observed using human vaginal epithelial (VK2) and murine macrophage (Raw264.7) cells with combination effects with clindamycin after treatment of GGSYJ MIC+clindamycin 1/2 MIC, 1/4 MIC and 1/6 MIC, respectively. Results: The MIC of clindamycin and GGSYJ against Gardnerella vaginalis were detected as $0.012{\pm}0.006$ (0.004~0.016)${\mu}g/ml$ and $1.016{\pm}0.524$ (0.391~1.563) mg/ml, respectively. Clindamycin and GGSYJ were also showed marked dosage-dependent inhibition of bacterial growth, and significant decreases of viable cells were detected in clindamycin MIC+GGSYJ MIC and clindamycin 1/2 MIC+GGSYJ MIC treatment as compared with each of single clindamycin MIC and GGSYJ MIC treatments. And significant decreases of intraepithelial and intra-macrophage viable bacteria numbers were detected in clindamycin 1/2 MIC+GGSYJ 1/2 MIC and clindamycin 1/4 MIC+GGSYJ 1/2 MIC treatment as compared with each of single clindamycin GGSYJ 1/2 MIC treatments, respectively. Conclusions: GGSYJ showed slight antibacterial effects against Gardnerella vaginalis, but they showed dosage-dependent inhibitory effects on the bacterial growth and VK2 epithelial invasions of bacteria with favorable accelerating effects of intracellular killing activities of macrophages. In addition, combination of GGSYJ also increased the inhibitory effects of clindamycin on the epithelial invasions of Gardnerella vaginalis and intracellular killing activities of macrophages against Gardnerella vaginalis as 2-fold higher as compared with clindamycin single treatment, respectively. Therefore, we expected that the clinical dosages of clindamycin can be reduced as 1/2 levels as combination with GGSYJ.

Antibacterial activity of enrofloxacin loaded gelatin-sodium alginate composite nanogels against intracellular Staphylococcus aureus small colony variants

  • Luo, Wanhe;Liu, Jinhuan;Algharib, Samah Attia;Chen, Wei
    • Journal of Veterinary Science
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    • 제23권3호
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    • pp.48.1-48.12
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    • 2022
  • Background: The poor intracellular concentration of enrofloxacin might lead to treatment failure of cow mastitis caused by Staphylococcus aureus small colony variants (SASCVs). Objectives: In this study, enrofloxacin composite nanogels were developed to increase the intracellular therapeutic drug concentrations and enhance the efficacy of enrofloxacin against cow mastitis caused by intracellular SASCVs. Methods: Enrofloxacin composite nanogels were formulated by an electrostatic interaction between gelatin (positive charge) and sodium alginate (SA; negative charge) with the help of CaCl2 (ionic crosslinkers) and optimized by a single factor test using the particle diameter, zeta potential (ZP), polydispersity index (PDI), loading capacity (LC), and encapsulation efficiency (EE) as indexes. The formation mechanism, structural characteristics, bioadhesion ability, cellular uptake, and the antibacterial activity of the enrofloxacin composite nanogels against intracellular SASCVs strain were studied systematically. Results: The optimized formulation was comprised of 10 mg/mL (gelatin), 5 mg/mL (SA), and 0.25 mg/mL (CaCl2). The size, LC, EE, PDI, and ZP of the optimized enrofloxacin composite nanogels were 323.2 ± 4.3 nm, 15.4% ± 0.2%, 69.6% ± 1.3%, 0.11 ± 0.02, and -34.4 ± 0.8 mV, respectively. Transmission electron microscopy showed that the enrofloxacin composite nanogels were spherical with a smooth surface and good particle size distributions. In addition, the enrofloxacin composite nanogels could enhance the bioadhesion capacity of enrofloxacin for the SASCVs strain by adhesive studies. The minimum inhibitory concentration, minimum bactericidal concentration, minimum biofilm inhibitory concentration, and minimum biofilm eradication concentration were 2, 4, 4, and 8 ㎍/mL, respectively. The killing rate curve had a concentration-dependent bactericidal effect as increasing drug concentrations induced swifter and more radical killing effects. Conclusions: This study provides a good tendency for developing enrofloxacin composite nanogels for treating cow mastitis caused by intracellular SASCVs and other intracellular bacterial infections.

5종 단미제의 Staphylococcus aureus에 대한 in vitro 항균력 평가 (A Study on Antibacterial Effects of Five Single Herbs Aqueous Extracts against Staphylococcus aureus)

  • 박은영;김동철
    • 대한한방부인과학회지
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    • 제26권1호
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    • pp.25-40
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    • 2013
  • Objectives: The object of this study was to observe the in vitro antibacterial effects of five single(Pulsatillae Radix, Patrinae Radix, Sanguisorbae Radix, Sophorae Flos, and Sophorae Radix) aqueous herbal extracts, traditionally used for treating various gynecological diseases including mastitis in Korea, against Staphylococcus aureus. Methods: Antibacterial activities against Staphylococcus aureus of aqueous extracts of Pulsatillae Radix, PatrinaeRadix, Sanguisorbae Radix, Sophorae Flos, and Sophorae Radix were detected using standard agar microdilution methods. In addition, the effects on the bacterial growth curve were also monitored at Minimal Incubation Concentration(MIC) and $MIC{\times}2$ levels. The effects on the intracellular killing and bacterial invasion of individual test materials were also observed using murine macrophage(Raw 264.7) and human mammary gland carcinoma cell(MCF-7). Results: MIC of aqueous extracts of Pulsatillae Radix, Patrinae Radix, Sanguisorbae Radix, Sophorae Flos, and Sophorae Radix against Staphylococcus aureus were detected as $0.215{\pm}0.107$ mg/ml, $0.273{\pm}0.107$ mg/ml, $0.469{\pm}0.297$ mg/ml, $11.850{\pm}8.406$ mg/ml, and $0.664{\pm}0.546$ mg/ml, respectively. MIC of Ciprofloxacin was detected as $0.469{\pm}0.297{\mu}g/ml$ at same conditions. In addition, all five single aqueous herbal extracts were also showed marked dosage-dependent inhibition of bacterial growth. The effects of intracellular killing with Raw 264.7 and inhibition of bacterial invasion with MCF-7 cells were detected, in the order of Sophorae Flos, Pulsatillae Radix, Patrinae Radix, Sanguisorbae Radix and Sophorae Radix aqueous extracts in the present study. Conclusions: The results obtained in this study suggest that all five single aqueous herbal extracts showed antibacterial effects against Staphylococcus aureus and they also showed dosage-dependent inhibitory effects on the bacterial growth. They showed the significant intracellular killing and inhibition of bacterial invasion effects. It means, all five single aqueous herbal extracts may show potent anti-infectious effects against Staphylococcus aureus for mastitis.

Formulation of a rational dosage regimen of ceftiofur hydrochloride oily suspension by pharmacokinetic-pharmacodynamic (PK-PD) model for treatment of swine Streptococcus suis infection

  • Luo, Wanhe;Wang, Dehai;Qin, Hua;Chen, Dongmei;Pan, Yuanhu;Qu, Wei;Huang, Lingli;Xie, Shuyu
    • Journal of Veterinary Science
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    • 제22권6호
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    • pp.41.1-41.14
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    • 2021
  • Background: Our previously prepared ceftiofur (CEF) hydrochloride oily suspension shows potential wide applications for controlling swine Streptococcus suis infections, while the irrational dose has not been formulated. Objectives: The rational dose regimens of CEF oily suspension against S. suis were systematically studied using a pharmacokinetic-pharmacodynamic model method. Methods: The healthy and infected pigs were intramuscularly administered CEF hydrochloride oily suspension at a single dose of 5 mg/kg, and then the plasma and pulmonary epithelial lining fluid (PELF) were collected at different times. The minimum inhibitory concentration (MIC), minimal bactericidal concentration, mutant prevention concentration (MPC), post-antibiotic effect (PAE), and time-killing curves were determined. Subsequently, the area under the curve by the MIC (AUC0-24h/MIC) values of desfuroylceftiofur (DFC) in the PELF was obtained by integrating in vivo pharmacokinetic data of the infected pigs and ex vivo pharmacodynamic data using the sigmoid Emax (Hill) equation. The dose was calculated based on the AUC0-24h/MIC values for bacteriostatic action, bactericidal action, and bacterial elimination. Results: The peak concentration, the area under the concentration-time curve, and the time to peak for PELF's DFC were 24.76 ± 0.92 ㎍/mL, 811.99 ± 54.70 ㎍·h/mL, and 8.00 h in healthy pigs, and 33.04 ± 0.99 ㎍/mL, 735.85 ± 26.20 ㎍·h/mL, and 8.00 h in infected pigs, respectively. The MIC of PELF's DFC against S. suis strain was 0.25 ㎍/mL. There was strong concentration-dependent activity as determined by MPC, PAE, and the time-killing curves. The AUC0-24h/MIC values of PELF's DFC for bacteriostatic activity, bactericidal activity, and virtual eradication of bacteria were 6.54 h, 9.69 h, and 11.49 h, respectively. Thus, a dosage regimen of 1.94 mg/kg every 72 h could be sufficient to reach bactericidal activity. Conclusions: A rational dosage regimen was recommended, and it could assist in increasing the treatment effectiveness of CEF hydrochloride oily suspension against S. Suis infections.

임상가검물에서 분리한 Candida sp.의 항진균제 Ketoconazole, 5-Fluorocytosine 및 Amphotericin B의 단독 혹은 복합처리에 의한 항진균력에 대한 연구 (In Vitro Studies of Ketoconazole in Combination with the 5-Fluorocytosine and Amphotericin B against Candida sp. Isolated from Clinical Specimens)

  • 고춘명;박전한
    • 대한미생물학회지
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    • 제21권1호
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    • pp.63-71
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    • 1986
  • The antifungal activities of amphotericin B, 5-fluorocytosine, and ketoconazole in combination of amphotericin B/ketoconazole and 5-fluorocytosine/ketoconazole were determined against 42 strains of Candida spp. isolated from oral cavity. Among 42 strains of Candida species, 36 strains of Candida albicans, 2 strains of Candida parapsilosis and Candida tropicalis 1 strain of Candida krusei and Candida stellatoidea were identified. The minimum inhibitory concentrations(MICs) of amphotericin B, 5-fluorocytosine and ketoconazole for these strains were ranged from 0.05-1.56 mcg/ml, 12.5->100.0 mcg/ml and 0.2-50.0 mcg/ml. In all of the experimental strains, amphotericin B had the greatest antifungal activity on a dilution basis. When a microtiter checkerboard technique was used 5-fluorocytosine acted synergistically with ketoconazole against all strains, whereas amphotericin B has a reduced effect. The killing curve experiments with on strain of Candida albicans WMC-85024 demonstrated that the combination of amphotericin B/ketoconazole and 5-fluorocytosine/ketoconazole produced a decrease in number of colony forming unit of >3 logs in 72 hours.

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연교김패전(連翹金貝煎)의 Escherichia coli에 대한시험관내 항균력 평가 (In Vitro Antibacterial Effects of Yeonkyokeumpae-jeon against Escherichia coli)

  • 한상겸;김동철
    • 대한한방부인과학회지
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    • 제28권1호
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    • pp.29-45
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    • 2015
  • Objectives: The object of this study was to observe the in vitro antibacterial effects of Yeonkyokeumpae-jeon (YKKPJ) have been used for treating various gynecological diseases including mastitis in Korea, and individual six kinds of herbal composition aqueous extracts - Forsythiae Fructus (FF), Millettiae Caulis (MC), Lonicerae Flos (LF), Fritillaria Thunbergii Bulb (FT), Taraxci Herba (TH) and Prunellae Spica (PS) against E. coli. Methods: Antibacterial activities against E. coli of YKKPJ, FF, MC, LF, FT, TH and PS aqueous extracts were detected using standard agar microdilution methods. In addition, the effects on the bacterial growth curve were also monitored at MIC and $MIC{\times}2$ levels. The effects on the intracellular killing and bacterial invasion of individual test materials were also observed using Raw 264.7 and MCF-7. The results were compared with ciprofloxacin, a second generation of quinolone antibiotics in the present study. Results: MIC of YKKPJ, FF, MC, LF, FT, TH, PS aqueous extracts against E. coli were detected as $0.039{\pm}0.013mg/ml$, $0.064{\pm}0.033mg/ml$, $0.108{\pm}0.053mg/ml$, $0.078{\pm}0.027mg/ml$, $16.250{\pm}8.385mg/ml$, $15.625{\pm}9.375mg/ml$, $0.254{\pm}0.131mg/ml$, repectively. YKKPJ, FF, MC, LF, FT, TH, PS aqueous extracts showed antibacterial effects against to E. coli, except for FT and TH, which were showed negligible antibacterial effects, respectively. In addition, ciprofloxacin with YKKPJ, FF, MC, LF and PS aqueous extracts also showed marked dosage-dependent inhibition of bacterial growth, and favorable inhibitory effects on the both bacterial invasion and intracellular killing assays using MCF-7 and Raw 264.7 cells were detected in this experiment. Conclusions: The results obtained in this study suggest that traditional polyherbal formula YKKPJ aqueous extracts showed more favorable antibacterial activities as compared to individual six kinds of herbal composition aqueous extracts. The antibacterial effects of YKKPJ against E. coli considered as results of complicated synergic effects of their six kinds of herbal components rather than simple antibacterial effects of single herbal components. It means, YKKPJ aqueous extracts may show potent anti-infectious effects against E. coil for mastitis.

감마선과 온열치료 병용시 세포 치사 능력 증강에 관한 실험적 연구 (Combined Effects of Gamma-irradiation and Hyperthermia on the Human Cell Lines for Various Temperatures and Time Sequences)

  • 고경환;조철구;박우윤;윤형근;류성렬;심재원;이미정
    • Radiation Oncology Journal
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    • 제11권1호
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    • pp.51-58
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    • 1993
  • 원자력 병원 치료방사선과에서 사용 중인 극초단파 온열치료장치에 의한 온열치료시 온열치료의 적정화로 암 치료기술 향상을 도모함을 최종 목표로 하여 인체 암세포주에서 방사선과 온열에 의한 세포생존곡선의 기본적인 특징과 방사선과의 병용에 따른 치료효과의 증강을 파악하여 임상적 응용의 기초적인 근거를 확립하고자 하였다. 본 실험에서는 2개의 세포주, 즉 위 선암 세포주와 만성 골수성 백혈병 세포주를 사용하였다. 위암은 한국인에서 가장 발생빈도가 높고, 국소적으로 진행된 경우, 주위 장기의 한계선량으로 인하여 방사선 단독으로는 적용의 한계가 있어 온열치료와의 병용이 요구되며, 백혈병 세포는 방사선에 민감한 대표적인 세포의 하나로 온열치료와의 병용시 발생할 수 있는 미묘한 차이를 보다 분명히 관찰할 수 있을 것으로 기대하여 본 실험에 사용하였다. 감마선과 온열치료를 겸한 경우 두가지 방법을 동시에 시행한 경우, 치료효과가 가장 높았고 온열을 감마선 치료 후에 시행한 경우가 감마선 치료 전에 시행한 경우보다 약간 높았으나, 그 차이는 크지 않았고, 6시간 이상의 간격에서는 같았다. 온일치료의 온도 및 치료시간과 치료효과는 온도가 높을수록 치료시간이 길수록 치료효과가 높았고, $43^{\circ}C$에서는 온열내성을 시간경과에 따라볼 수 있었다. 같은 온도로 30분간 온열치료시 온열치료효과 증진비는 섭씨 43도, 44도, 45도의 경우, D 0.01을 기준으로 $2.5{\pm}0.08,\;3.75{\pm}0.18,\;5.0{\pm}0.15$였다. 본 연구는 기초 생물학적 실험이나, 이 결과는 임상 암치료에 직접 이용되는 것이며 또한 치료수행에 반드시 필요한 과정이다. 따라서, 치료방법의 결정, 성적분석, 치료 부작용의 예측 및 대책 확립 등에 적용되고 본원 온열치료의 특성 제시에 활용될 수 있다.

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새로운 퀴놀론계 항균제 DWQ-013의 항균작용 (In vitro and in vivo Antibacterial Activities of the New Quinolone, DWQ-013)

  • 유영효;박남준;김병오;최문정;심점순;강태충;이재욱;김대영
    • 약학회지
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    • 제38권3호
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    • pp.265-273
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    • 1994
  • ln vitro and in vivo antibacterial activities of DWQ-013(1-cyclopropyl-6,8-difluoro-7-(3-methylthiomethylpyrrolidinyl)-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid), a new fluoroquinolone antibacterial agent, were compared with those of ciprofloxacin, sparfloxacin and ofloxacin against aerobic and anaerobic standard strains and clinical isolates. DWQ-013 had a broad spectrum and potent antibacterial activity against Gram-positive and Gram-negative bacteria. The antibacterial activity of DWQ-013 against Staphylococcus aureus was equal to that of sparfloxacin(SPFX) and superior to those of ciprofloxacin(CPFX). The antibacterial activity against Gram-negative bacteria was slightly lower than those of ciprofloxacin and sparfloxacin. MIC of DWQ-013 against Pseudomonas aeruginosa$(0.781{\sim}1.563\;{\mu}g/ml)$ was usually equal to that of sparfloxacin$(0.781\;{\mu}g/ml)$ and was inferior to that of ciprofloxacin$(0.098\;{\mu}g/ml)$. The number of viable cells was decreased rapidly after addition of DWQ-013 at concentration of $1{\sim}2$ folds of MIC.

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신합성 플로로퀴놀론계 항생물질인 DWP20367의 In vitro 항균효과 (In vitro Antibacterial Activities of Novel Fluoroquinolone DWP20367)

  • 김지연;최문정;한승희;심점순;정연의;손호정;이재욱;유영효;박명환
    • 약학회지
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    • 제41권2호
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    • pp.225-232
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    • 1997
  • The in vitro antibacterial activity of DWP20367 (1-Cyclopropyl-6-fluoro-8-chloro-7-(2,7-diazabicyclo[3,3,0]oct-4-ene-7-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid), a new broad-spectrum fluoroquinolone, was compared with those of ciprofloxacin (CPFX), sparfloxacin (SPFX) and ofloxacin (OFLX). DWP20367 was showed antibacterial activity much higher than CPFX, SPFX and OFLK against gram-positive bacteria, while it was slightly more superior to quinolones against gram-negative bacteria. DWP20367 was particularly effective against MRSA, and its $MlC_{90}$ against clinical isolates of methicillin-susceptible S. aureus, low methicillin-resistant S. aureus and high methicillin-resistant S. aureus were 0.098, 0.781 and 1.563 micro g/ml, respectively. Against S. pneumoniae, MIC90 of DWP20367 was 2- to 8-fold higher than those of CPFX. With a view of MIC90, DWP20367 showed slightly more potent activity against P. aeruginosa and E. coli isolates than the control quinolones. DWP20367 activity was not affected by inoculum size and medium pH. But addition of $Mg^{2+}, \;Ca^{2+} $Mg2+, Ca2+ or horse serum (25%) decreased its antibacterial activity. DWP20367 was showed rapidly bactericidal activity within 2 to 4 h, and regrowth was not observed even after 24 h incubation at concentrations near the 4-fold of MIC.

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새로운 카바페넴계 항생물질인 DWP20418의 In vitro 항균작용 (In vitro Antibacterial Activity of DWP20418, a New Carbapenem Antibiotic)

  • 김지연;최문정;박남준;임성수;변영석;유영효;박명환
    • 약학회지
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    • 제41권2호
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    • pp.233-240
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    • 1997
  • The in vitro antibacterial activity of DWP20418 (1R, 5S, 6S)-6-[1-(R)-Hydroxyethyl)-l-methyl-2-[(2S,4S)-2-(piperazinylcarbonyl)-1-(R)-hydroxyethyl)pyrrolidine-4-thio]carb apen-2-em-3-carboxylic acid), a new carbapenem antibiotic, was compared with those of imipenem (IPM) and meropenem (MEPM). DWP20418 was comparable or slightly more superior to MEPM against gram-positive bacteria, and it showed more potent activity to IPM against gram-negative bacteria. DWP20418 was particularly active against MRSA, and its $MIC_{90}$ of methicillin-susceptible S. aureus, low methicillin-resistant S. aureus and high methicillin-resistant S. aureus were 0.391, 25 and 50 ${\mu}g/ml$, respectively. With a view of $MIC_{90}$, DWP20418 was comparable than the other carbapenems against P. aeruginosa and E. coli isolates. The activity of DWP20418 was not affected in the presence of $Mg^{2+},\;Ca^{2+}$ or horse serum. But inoculum size and alterations in pH of medium affected its antibacterial activity. DWP20418 showed rapidly bactericidal activity within 1h, and regrowth was not observed even incubation of 24hrs at the concentrations near the MIC.

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