Abstract:
:An axenic amastigote culture system was utilized to directly assess the stage-specific antileishmanial effects of antimony on amastigotes of Leishmania donovani devoid of the macrophage host cell. Pentostam, which contains antimony in the form of sodium stibogluconate and the preservative chlorocresol, was used. Cell density was quantified by measuring the activity of the stable enzyme ornithine decarboxylase. Dose-response curve analyses show that Leishmania promastigotes are susceptible to Pentostam, with the 50% inhibitory concentration (IC50) being 104 microg/ml, while amastigotes are more susceptible, with the IC50 being 24 microg/ml. Promastigotes and amastigotes are also susceptible to chlorocresol, with IC50s being 1.27 and 1.82 microg/ml, respectively. Given that promastigotes are insensitive to antimony, these results suggest that the increased susceptibility of amastigotes to Pentostam is due to the stage-specific activity of sodium stibogluconate. To further study this phenomenon, spontaneous resistance to Pentostam was induced in L. donovani promastigotes by increasing the concentration of Pentostam in the growth medium in a stepwise fashion. Two mutants, Ld1S.04 and Ld1S.20, grew at 0.4 and 2.0 mg of Pentostam per ml, respectively. Promastigotes of these mutants were 11 and 21 times, respectively, more resistant to Pentostam than the wild type. Amastigotes were 40 and 148 times, respectively, more resistant than the wild type. The mutants were also chlorocresol resistant; promastigotes were 6 and 9 times, respectively, more resistant than the wild type, and amastigotes were 14 and 35 times, respectively, more resistant than the wild type. These data show that resistance to Pentostam induced in antimony-insensitive promastigotes is manifested in amastigotes as resistance both to pentavalent antimony and to chlorocresol. The axenic amastigote system is a unique tool which enables direct evaluation of the activity of antileishmanial compounds on the amastigote devoid of its host cell.
journal_name
Antimicrob Agents Chemotherjournal_title
Antimicrobial agents and chemotherapyauthors
Ephros M,Waldman E,Zilberstein Ddoi
10.1128/AAC.41.5.1064subject
Has Abstractpub_date
1997-05-01 00:00:00pages
1064-8issue
5eissn
0066-4804issn
1098-6596journal_volume
41pub_type
杂志文章abstract::The emergence of resistance to last-resort antibiotics is a public health concern of global scale. Besides direct person-to-person propagation, environmental pathways might contribute to the dissemination of antibiotic-resistant bacteria and antibiotic resistance genes (ARGs). Here, we describe the incidence of blaNDM...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00236-16
更新日期:2016-08-22 00:00:00
abstract::Stenotrophomonas maltophilia is increasingly being isolated from the respiratory tract of individuals with cystic fibrosis, and, because of its multidrug-resistant nature, the selection of suitable treatment regimens can be problematical. Etest methodology was used to facilitate MIC and antimicrobial combination testi...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00072-12
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abstract::Pairs of 11 antimicrobial agents were tested in vitro for their ability to act synergistically against three strains of Mycobacterium avium complex isolated from patients with acquired immune deficiency syndrome. From the combinations tested, four drugs (ethambutol, rifampin, ciprofloxacin, and erythromycin) were sele...
journal_title:Antimicrobial agents and chemotherapy
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.35.9.1868
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
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pub_type: 杂志文章
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更新日期:2018-04-26 00:00:00
abstract::Two hundred and fifty-seven ampicillin-resistant clinical isolates of Haemophilus influenzae were tested by disk diffusion and MIC determination for susceptibility to aztreonam, imipenem, and amoxycillin combined with clavulanate. The modal MICs and MICs for 50 and 90% of isolates of all three antimicrobial agents for...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.31.12.1871
更新日期:1987-12-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.46.10.3168-3174.2002
更新日期:2002-10-01 00:00:00
abstract::Positive carbon-containing electrodes conveying 5 or more microA of constant direct current per cm2 showed bactericidal activity on intact back skin of 13 human subjects. This effect increased with the duration of stimulation up to a total surface bacterial kill at 20 h. When total current and current density were var...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.18.1.137
更新日期:1980-07-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
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更新日期:2014-09-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 临床试验,杂志文章
doi:10.1128/aac.35.12.2467
更新日期:1991-12-01 00:00:00
abstract::The activity of nalidixic acid combined with each of 10 other antimicrobial agents on 95 strains of Enterobacteriaceae was studied. Synergism was found less often than antagonism, and the commonest outcome was indifference. Combinations of nalidixic acid with kanamycin, gentamicin, or colistin were more often synergis...
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pub_type: 杂志文章
doi:10.1128/aac.4.3.201
更新日期:1973-09-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.1.3.242
更新日期:1972-03-01 00:00:00
abstract::While the neuraminidase (NA) inhibitor oseltamivir is currently our first line of defense against a pandemic threat, there is little information about whether in vitro testing can predict the in vivo effectiveness of antiviral treatment. Using a panel of five H5N1 influenza viruses (H5 clades 1 and 2), we determined t...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01667-08
更新日期:2009-07-01 00:00:00
abstract::A series of quaternary ammonium compounds that are esters of betaine and fatty alcohols with hydrocarbon chain lengths of 10 to 18 carbon atoms were tested with respect to antimicrobial activities and rates of hydrolysis. When the tetradecyl derivative was tested against some selected microorganisms, the killing effec...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.34.10.1949
更新日期:1990-10-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.04933-14
更新日期:2015-04-01 00:00:00
abstract::Anidulafungin concentrations were quantified with high-pressure liquid chromatography (HPLC) and UV detection of the ascites fluid and pleural effusion of 10 adult critically ill patients. Samples were collected from ascites fluid and from pleural drains or during paracentesis and thoracentesis, respectively. Anidulaf...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02326-17
更新日期:2018-03-27 00:00:00
abstract::Polyhexylcyanoacrylate nanoparticles loaded with either the human immunodeficiency virus (HIV) protease inhibitor saquinavir (Ro 31-8959) or the nucleoside analog zalcitabine (2',3'-dideoxycytidine) were prepared by emulsion polymerization and tested for antiviral activity in primary human monocytes/macrophages in vit...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.40.6.1467
更新日期:1996-06-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.7.1.74
更新日期:1975-01-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
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更新日期:2014-10-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
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更新日期:2008-11-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.41.4.838
更新日期:1997-04-01 00:00:00
abstract::Replication complexes of hepatitis C virus synthesized two major species of viral RNA in vitro, double stranded and single stranded. NS5B nonnucleoside inhibitors inhibited dose dependently the synthesis of single-stranded RNA but not double-stranded RNA. Moreover, replication complexes carrying a mutation resistant t...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00498-06
更新日期:2007-01-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
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更新日期:2019-06-24 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02464-12
更新日期:2013-06-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 临床试验,杂志文章,多中心研究
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更新日期:2005-03-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.41.9.1996
更新日期:1997-09-01 00:00:00
abstract::The aims of the study were to investigate the prevalence of azole resistance among Aspergillus fumigatus clinical isolates. A total of 533 clinical isolates that had been collected between 1995 and 2006, from 441 patients, were screened. No resistance was detected in isolates collected between 1995 and 1997. Starting ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02234-15
更新日期:2015-11-09 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.35.6.1181
更新日期:1991-06-01 00:00:00
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journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02468-14
更新日期:2014-08-01 00:00:00