• 제목/요약/키워드: time-kill method

검색결과 42건 처리시간 0.024초

Assessment of Clinical Outcome in Dogs with Naturally Infected with Dirofilaria immitis after American Heartworm Society Protocol vs Slow Kill Method

  • Choi, Miru;Yoon, Won-Kyoung;Suh, Sang-IL;Hyun, Changbaig
    • 한국임상수의학회지
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    • 제34권1호
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    • pp.1-6
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    • 2017
  • Heartworm disease (HWD) in dogs is a life-threatening mosquito-borne disease resulting in right-sided congestive heart failure and inflammatory pulmonary disease. Due to complications from adulticidal therapy with melarsomine, slow kill protocol either with preventive dose of ivermectin or combined with doxycycline has been proposed for an alternative adultcidal therapy in dogs with HWD. Therefore, this study evaluated the clinical outcome of adultcidal therapy in dogs with class II stage of HWD after treating either American Heartworm Society (AHS) or slow kill protocol for 10 months. Clinical outcome after therapy was evaluated by clinical, radiographic and echocardiographic examination along with hematology before (D0) and after therapy (D300). Although clinical signs associated with HWD were all resolved after therapy in both groups, the infection was not cleared out 67% of dogs treated by slow kill protocol at the end of therapy. Furthermore, pulmonary arterial flow of acceleration time to ejection time ratio (AT/ET) and the right pulmonary artery distensibility index (RPADI) have been firstly used for detecting pulmonary hypertension in this study group. The pulmonary hypertension was more common in dogs with mild clinical signs, although tricuspid and pulmonary regurgitation were not detectable in most dogs in this study. Our study findings suggested that the slow kill protocol might not be efficacious enough to clear out HWD in dogs and more attention on the presence of pulmonary hypertension might be necessary for effective management of HWD in dogs.

Antipseudomonal Activity and Nephrotoxicity of Cephradine-Netilmicin Combination

  • El Emam, M.A.;El Naggar, W.A.;Ibrahiem, T.M.
    • Archives of Pharmacal Research
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    • 제12권2호
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    • pp.114-118
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    • 1989
  • The effects of intraperitoneal injection of cephradine in a dose of 75 mg/kg and netilmicin in dose of 50 mg/kg and their combination on creatinine and urea serum levels of rabbits were studied as well as the antipseudomonal activity against three multiresistant clinicial isolates. The antibacterial activity was investigated by two methods: Checkerboard titration method and time-kill studies. Finally, the antibacterial activity of the sera obtained from the rabbits receiving the used drugs in the previous regimen was studied using time-kill study method against Pseudomonas aeruginosa isolates. Results obtained from this study indicated that both creatinine and urea serum levels of the rabbits receiving both drugs were not significantly different from those of the rabbits receiving either cephradine or netilmicin alone. At the same time the in vitro antibactrial activity (either of the prepared solutions of the used drugs and their combination or of the sera obtained from the rabbits receiving these drugs as mentioned before) showed a synergistic effect against the tested strains of Pseudomonas aeruginosa

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Synergistic Effect in Combination of Danshen (Salvia miltiorrhiza) Extracts with Antibiotics against Methicillin-resistant Staphylococcus aureus

  • Cha, Jeong-Dan
    • Food Science and Biotechnology
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    • 제18권5호
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    • pp.1263-1272
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    • 2009
  • Danshen (Salvia miltiorrhiza Bunge) is a traditional Korean medicine that is commonly used for the treatment of inflammatory diseases such as edema, arthritis, hepatitis, and endangitis. The several extracts of danshen were tested for antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) isolated in clinic by broth microdilution method, the checkerboard, and time-kill methods to evaluate the synergistic effects of the combination of the extracts with antibiotics. The chloroform ($CHCl_3$) and n-hexane (HEX) extracts [minimum inhibitory concentration (MIC), 0.0078-0.3125${\mu}g/mL$; minimum bactericidal concentration (MBC), 0.019-0.625${\mu}g/mL$] were found to have strong antibacterial activity against MRSA. Additionally, when the $CHCl_3$ and HEX extracts were co-administered with ampicillin or oxacillin, a synergistic effect against MRSA was observed. Furthermore, a time-kill study evaluating the effects of the extracts against MRSA indicated that treatment with the $CHCl_3$ extract in combination with ampicillin or oxacillin produced rapid bactericidal activity. These results suggest that danshen extracts may have potently antimicrobial activity and thus, it can be a suitable phytotherapeutic agent for treating MRSA infections.

통현이팔단 에탄올 추출물의 Methicillin Resistant Staphylococcus aureus에 대한 항균활성 (Antibacterial activity of Tonghyeonipal-dan against Methicillin-resistant Staphylococcus aureus)

  • 김인원;강옥화;공룡;권동렬
    • 대한본초학회지
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    • 제30권5호
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    • pp.15-21
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    • 2015
  • Objectives : Methicillin-resistantStaphylococcus aureus(MRSA) is a human pathogen. New antibacterial agents are needed to treat MRSA-related infections. This study investigated the antibacterial activity of EtOH 70% extracts ofTonghyeonipal-dan(THD) which prescription is composed of oriental medicine against MRSA.Methods : The antibacterial activity of THD was evaluated against MRSA strains by using the Disc diffusion method, broth microdilution method, Checkerboard dilution test, and Time-kill test; its mechanism of action was investigated by bacteriolysis, detergent or ATPase inhibitors were used.Results : The minimum inhibitory concentration (MIC) of THD is 1,000~2,000 μg/mL against MRSA. In the checkerboard dilution test, fractional inhibitory concentration index (FICI) of THD in combination with antibiotics indicated synergy or partial synergism againstS. aureus. Furthermore, a time-kill assay showed that the growth of the tasted bacteria was considerably inhibited after 24 h of treatment with the combination of THD with selected antibiotics. For measurement of cell membrane permeability, THD 500 μg/mL along with concentration of Triton X-100 (TX) and Tris-(hydroxymethyl) aminomethane (TRIS) were used. In the other hand, N,N-dicyclohexylcarbodimide (DCCD) and Sodium azide (NaN3) were used as an inhibitor of ATPase. TX, TRIS, DCCD and NaN3 cooperation againstS. aureusshowed synergistic action.Conclusions : Accordingly, antimicrobial activity of THD was affected by cell membrane and inhibitor of ATPase were assessed. These results suggest that THD has antibacterial activity, and that THD extract offers great potential as a natural antibiotic against MRSA.

Antibacterial Activity of Sophoraflavanone G Isolated from the Roots of Sophora flavescens

  • Cha, Jeong-Dan;Jeong, Mi-Ran;Jeong, Seung-Il;Lee, Kyung-Yeol
    • Journal of Microbiology and Biotechnology
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    • 제17권5호
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    • pp.858-864
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    • 2007
  • This study investigated the antibacterial activities of sophoraflavanone G from Sophora flavescens in combination with two antimicrobial agents against oral bacteria. The combined effect of sophoraflavanone G and the antimicrobial agents was evaluated using the checkerboard method to obtain a fractional inhibitory concentration(FIC) index. The sophoraflavanone G+ampicillin(AM) combination was found to have a synergistic effect against S. mutans, S. sanguinis, S. sobrinus, S. gordonii, A. actinomycetemcomitans, F nucleatum, P. intermedia, and P. gingivalis, whereas the sophoraflavanone G+gentamicin(GM) combination had a synergistic effect against S. sanguinis, S. criceti, S. anginosus, A. actinomycetemcomitans, F nucleatum, P. intermedia, and P. gingivalis. Neither combination exhibited any antagonistic interactions(FIC index>4). In particular, the MICs/MBCs for all the bacteria were reduced to one-half$\sim$one-sixteenth as a result of the drug combinations. A synergistic interaction was also confirmed by time-kill studies for nine bacteria where the checkerboard suggested synergy. Thus, a strong bactericidal effect was exerted through the drug combinations, plus in vitro data suggested that sophoraflavanone G combined with other antibiotics may be microbiologically beneficial rather than antagonistic.

무기 목표물 배정 문제의 최대 치사인원 선택 알고리즘 (Maximum Kill Selection Algorithm for Weapon Target Assignment (WTA) Problem)

  • 이상운
    • 한국인터넷방송통신학회논문지
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    • 제19권2호
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    • pp.221-227
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    • 2019
  • 무기 목표물 배정 문제는 지금까지 다항시간 알고리즘이 제안되지 않는 NP-hard 문제로 알려져 왔다. 그럼에도 불구하고, 본 문제에 대해 가능한 모든 경우수를 검증하는 Brute-Force 법이나 분기한정법으로 최적 해를 구하거나 유전자 알고리즘, 입자군 최적화 등의 인공지능 방법으로 근사 해를 구하는 방법들이 제안되고 있다. 본 논문에서는 단지 무기의 총 대수 k, 무기 종류 수 m, 목표물 개수 n에 대해 O(mn)을 k회 수행하는 O(kmn) 다항시간으로 최적 해를 구하는 알고리즘을 제안하였다. 제안된 알고리즘은 Brute-Force 법에 비해 수행횟수를 최소화 시킬 뿐 아니라 최적해도 구하는 장점을 갖고 있다.

(-)-Epigalocatechin의 Fusobacterium nucleatum, Prevotella intermedia 및 Porphyromonas gingivalis에 대한 항균 효과 (Antimicrobial effect of (-)-epigalocatechin on Fusobacterium nucleatum, Prevotella intermedia and Porphyromonas gingivalis)

  • 박재윤;김화숙;국중기
    • 치위생과학회지
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    • 제10권3호
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    • pp.161-165
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    • 2010
  • 녹차의 폴리페놀류 중 수용성인 (-)-epigalocatechin을 이용하여 치주질환 원인균에 대한 항세균 작용을 조사한 결과 다음과 같은 결론을 얻었다. 1. (-)-epigalocatechin은 주요한 치주질환 원인균들인 F. nucleatum, P. intermedia 및 P. gingivalis에 대한 최소성장억제농도가 0.625 mg/ml 이하로 항균 작용이 높은 것으로 나타났다. 2. Time-kill 분석법을 실시한 결과 (-)-epigalocatechin은 F. nucleatum, P. intermedia 및 P. gingivalis에 살균작용이 있는 것으로 나타났다. 이상의 결과에서 (-)-epigalocatechin은 치주질환의 예방 및 치주 치료 후 예후를 증진시킬 수 있는 가글린 및 치약 등의 구강위생용품 개발에 이용할 수 있을 것으로 생각된다.

치아우식증유발세균에 대한 단삼 메탄올추출물과 항생제와의 병용효과 (Synergistic Effect of Methanol Extract of Salvia Miltiorrhiza and Antibiotics against Dental Caries Pathogens)

  • 장경애;김혜영
    • 한국미생물·생명공학회지
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    • 제38권3호
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    • pp.289-294
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    • 2010
  • 단삼(Salvia miltiorrhiza Bunge)은 우리나라에서 전통적으로 부종, 관절염, 간염 등과 같은 염증질환의 치료에 사용해왔다. 본 연구에서는 단삼 메탄올 추출물을 이용하여 구강미생물에 대한 항균활성을 확인하였다. 그 결과 메탄올추출물은 실험 되어진 모든 구강미생물에서 강한 항균활성을 나타내었다(MICs, 8 to $64\;{\mu}g/mL$; MBCs, 16 to $64\;{\mu}g/mL$). 추가적으로 ampicillin이나 gentamicin과의 병용투여서 최소억제농도(MIC)와 최소살균농도(MBC)가 감소하는 병용효과를 나타내었다. 더불어 메탄올추출물 단독 사용시 보다 항생제와 병용투여시 빠른 사멸효과를 보였다. 결론적으로 단삼 메탄올추출물이 치아우식을 유발하는 많은 세균들에 대한 항균효과가 뛰어남을 확인 할 수 있었으며, 안정성이 높은 천연 치아우식예방제로서의 개발가능성을 확인하였다.

Ultraviolet-C 조사의 살균 효과 (The Effect of Ultraviolet-C Radiation on Disinfection)

  • 최홍식;최규환;박소연
    • 한국전문물리치료학회지
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    • 제9권3호
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    • pp.93-99
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    • 2002
  • Traditionally, ultraviolet (UV) has been used for treating the pressure sore and skin wound. The effects of UVA and UVB radiation on disinfection have been reported. The purpose of this study was to examine the effectiveness of UVC radiation on disinfection of Escherichia coli, Staphylococcus aureus, Salmonella typhimurium in vitro. Three bacterium were radiated by UVC (250 nm, 20 seconds) and incubated at $37^{\circ}C$ for 24 hours at the agar culture medium. Kill rates of all three bacterium were 99.9%. UVC radiated on three kinds of bacterium for 30 or 60 seconds. Kill rates were 99.9% both 30 and 60 seconds. This data suggests that UV light at 250 nm could be a useful method to minimize infection and shorten healing time in pressure sore and skin wound condition.

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새로운 옥사졸리디논계 항균제 LCB01-0183의 항균 활성 (Antimicrobial Activities of LCB01-0183, a New Oxazolidinone)

  • 이현희;정성지;정지웅;조영락;김용주;곽진환
    • 약학회지
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    • 제57권2호
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    • pp.95-100
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    • 2013
  • This study was performed to analyze in vitro and in vivo activities of LCB01-0183, a new oxazolidinone, against clinical isolates of bacteria. In vitro antibacterial activity of LCB01-0183 was tested by the two fold agar dilution method. In vivo activity of LCB01-0183 was determined against systemic infections in mice. LCB01-0183 showed most potent activity among the test compounds against clinical isolates of Gram-positive bacteria. Furthermore, the protective activity of LCB01-0183 was very effective against systemic infections in mice by oral or subcutaneous administration. In time kill study, LCB01-0183 showed a bacteriostatic activity during 24 hours. LCB01-0183 had potent in vitro and in vivo activity against Gram-positive bacteria including drug-resistant strains.