Abstract:
:The trypanocidal action of green tea catechins against two different developmental stages of Trypanosoma cruzi is reported for the first time. This activity was assayed with the nonproliferative bloodstream trypomastigote and with the intracellular replicative amastigote parasite forms. An ethyl acetate fraction from Camellia sinensis green tea leaves, which contains most of the polyphenolic compounds and the maximal trypanocidal activity, was obtained by fractionation of the aqueous extract with organic solvents. The active compounds present in this extract were further purified by LH-20 column chromatography and were identified by high-performance liquid chromatography analysis with a photo diode array detector and gas chromatography coupled to mass spectroscopy. The following flavan-3-ols derivatives, known as catechins, were identified: catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate. The purified compounds lysed more than 50% of the parasites present in the blood of infected BALB/c mice at concentrations as low as 0.12 to 85 pM. The most active compounds were gallocatechin gallate and epigallocatechin gallate, with minimal bactericidal concentrations that inhibited 50% of isolates tested of 0.12 and 0.53 pM, respectively. The number of amastigotes in infected Vero cells decreased by 50% in the presence of each of these compounds at 100 nM. The effects of the catechins on the recombinant T. cruzi arginine kinase, a key enzyme in the energy metabolism of the parasite, were assayed. The activity of this enzyme was inhibited by about 50% by nanomolar concentrations of catechin gallate or gallocatechin gallate, whereas the other members of the group were less effective. On the basis of these results, we suggest that these compounds could be used to sterilize blood and, eventually, as therapeutic agents for Chagas' disease.
journal_name
Antimicrob Agents Chemotherjournal_title
Antimicrobial agents and chemotherapyauthors
Paveto C,Güida MC,Esteva MI,Martino V,Coussio J,Flawiá MM,Torres HNdoi
10.1128/aac.48.1.69-74.2004subject
Has Abstractpub_date
2004-01-01 00:00:00pages
69-74issue
1eissn
0066-4804issn
1098-6596journal_volume
48pub_type
杂志文章abstract::The in vitro activity of BMS-207147 against 80 clinical isolates of Aspergillus was compared with that of itraconazole and amphotericin B, using a validated microtiter method. Geometric mean MICs (in microg/ml) were as follows: 1.71 for BMS-207147, 0.67 for itraconazole, and 0.63 for amphotericin B. The range of conce...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.44.2.441-443.2000
更新日期:2000-02-01 00:00:00
abstract::The emergence of resistant strains among common and rare Candida species necessitates continuous monitoring of the in vitro susceptibilities of those isolates. We therefore assessed the in vitro activities of micafungin against 1,099 molecularly identified isolates belonging to 5 common and 20 rare Candida species by ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01027-16
更新日期:2016-09-23 00:00:00
abstract::The effects of 6-amino-2-n-pentylthiobenzothiazole (APB), a new antifungal agent, on ergosterol biosynthesis in Candida albicans and Saccharomyces cerevisiae were studied, using [14C]acetate incorporation. In C. albicans, the inhibition of growth was accompanied by a marked inhibition of acetate incorporation in 4-des...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.39.7.1538
更新日期:1995-07-01 00:00:00
abstract::The need for daily parenteral administration is an important limitation in the clinical use of pentavalent antimonial drugs against leishmaniasis. In this study, amphiphilic antimony(V) complexes were prepared from alkylmethylglucamides (L8 and L10, with carbon chain lengths of 8 and 10, respectively), and their poten...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00639-13
更新日期:2013-09-01 00:00:00
abstract::In 2002, the first two clinical isolates of vancomycin-resistant Staphylococcus aureus (VRSA) containing vanA were recovered in Michigan and Pennsylvania. Tn1546, a mobile genetic element that encodes high-level vancomycin resistance in enterococci, was present in both isolates. With PCR and DNA sequence analysis, we ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.49.1.470-472.2005
更新日期:2005-01-01 00:00:00
abstract::Ten beta-lactamase-producing Enterococcus faecalis isolates were examined for the presence of the staphylococcal beta-lactamase repressor and antirepressor genes. Four isolates, previously shown to be unrelated to each other by pulsed-field gel electrophoresis analysis, were positive for both genes by PCR, although be...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.40.5.1170
更新日期:1996-05-01 00:00:00
abstract::The activity of two cefoperazone-sulbactam combinations against anaerobic bacteria was tested and compared both with that of cefoperazone alone and with that of other commonly used antimicrobial agents. Imipenem was the most active of the tested agents, followed by chloramphenicol, metronidazole, and cefoperazone-sulb...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.32.3.403
更新日期:1988-03-01 00:00:00
abstract::A single Klebsiella pneumoniae strain isolated in a Bulgarian hospital was found to produce CTX-M-71, a new CTX-M variant characterized by one amino acid substitution from glycine to cysteine at position 238 in comparison to CTX-M-15. This exchange decreased the hydrolytic activity of the beta-lactamase for cefotaxime...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00461-09
更新日期:2009-10-01 00:00:00
abstract::Peroxide antimalarials, including artemisinin, are important for the treatment of multidrug-resistant malaria. These peroxides are known to react with iron or heme to produce reactive intermediates that are thought to be responsible for their antimalarial activities. This study investigated the potential interaction o...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00363-09
更新日期:2009-08-01 00:00:00
abstract::We report patient-to-patient transmission of Enterobacter hormaechei isolates with reduced susceptibility to ceftazidime-avibactam due to production of KPC-40, a variant of KPC-3 with a two-amino-acid insertion in the Ω-loop region (L167_E168dup). The index patient had received a prolonged course of ceftazidime-avibac...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00955-19
更新日期:2019-09-23 00:00:00
abstract::An open, randomized comparison of ofloxacin (200 mg, every 12 h) given orally for 5 days and ceftriaxone (3 g, once daily) given intravenously for 3 days in the treatment of uncomplicated enteric fever was conducted in Ho Chi Minh City, Vietnam. Salmonella paratyphi type A was isolated from six patients. Salmonella ty...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1128/aac.38.8.1716
更新日期:1994-08-01 00:00:00
abstract::Chromosomally mediated penicillin resistance in Neisseria gonorrhoeae occurs in part through alterations in penicillin-binding proteins (PBPs) and a decrease in outer membrane permeability. However, the genetic and molecular mechanisms of transformation of a penicillin-susceptible strain of N. gonorrhoeae to high-leve...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.46.3.769-777.2002
更新日期:2002-03-01 00:00:00
abstract::HMR 3647 (telithromycin), a new ketolide, is active on intracellular pathogens. It was previously demonstrated that it inhibits superoxide anion production in a time- and concentration-dependent manner, at concentrations which inhibit 50% of the control response of about 55 microg/ml (5 min) to 30 microg/ml (30 min); ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.46.5.1364-1374.2002
更新日期:2002-05-01 00:00:00
abstract::The mortality rate associated with Vibrio vulnificus sepsis remains high. An in vitro time-kill assay revealed synergism between tigecycline and ciprofloxacin. The survival rate was significantly higher in mice treated with tigecycline plus ciprofloxacin than in mice treated with cefotaxime plus minocycline. Thus, com...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00310-19
更新日期:2019-09-23 00:00:00
abstract::Beta-lactamase-negative ampicillin-resistant (BLNAR) isolates of Haemophilus influenzae have been emerging in some countries, including Japan. The Clinical and Laboratory Standards Institute has only a susceptible MIC breakpoint (< or = 1 microg/ml) for piperacillin-tazobactam and a disclaimer comment that BLNAR H. in...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00192-09
更新日期:2009-10-01 00:00:00
abstract::During the second quarter each of 1988, 1989, and 1990, a French collaborative study group, including 12 university hospital laboratories, surveyed the resistance to beta-lactams of clinical isolates from hospitalized patients: consecutively, 10,641, 10,692, and 9,382 isolates were tested. The distribution of bacteria...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.36.8.1677
更新日期:1992-08-01 00:00:00
abstract::We report the ex vivo lysogenic transfer of erythromycin and tetracycline resistance genes among group A streptococci (GAS). Of 42 susceptible strains, 69% acquired erythromycin/tetracycline resistance when infected with purified supernatants from strain m46 culture containing the phage Φm46.1. A significant emm-type-...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01318-09
更新日期:2010-10-01 00:00:00
abstract::The pathogenic yeast Candida albicans can exist in multiple morphological states, including budded, pseudohyphal, and true hyphal forms. The ability to convert between the budded and hyphal forms, termed the budded-to-hyphal-form transition, is important for virulence and is regulated by multiple environmental and cel...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.49.3.963-972.2005
更新日期:2005-03-01 00:00:00
abstract::The mechanism of penetration of quinolones through the bacterial outer membrane was studied with lipopolysaccharide-deficient and porin-deficient mutants. The data indicated that the lipopolysaccharide layer might form a permeability barrier for hydrophobic quinolones such as nalidixic acid but not for hydrophilic qui...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.29.3.535
更新日期:1986-03-01 00:00:00
abstract::The mechanisms of fluconazole resistance in three clinical isolates of Candida krusei were investigated. Analysis of sterols of organisms grown in the absence and presence of fluconazole demonstrated that the predominant sterol of C. krusei is ergosterol and that fluconazole inhibits 14alpha-demethylase in this organi...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.42.10.2645
更新日期:1998-10-01 00:00:00
abstract::We investigated a possible synergistic effect of a macrolide and beta-lactams against Streptococcus pneumoniae strains with different resistance profiles. Checkerboard and time-kill assays of erythromycin combined with penicillin or cefotaxime essentially showed indifference, suggesting that these antibiotics in combi...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.47.3.1151-1153.2003
更新日期:2003-03-01 00:00:00
abstract::During its intraerythrocytic phase, the most lethal human malarial parasite, Plasmodium falciparum, digests host cell hemoglobin as a source of some of the amino acids required for its own protein synthesis. A number of parasite endopeptidases (including plasmepsins and falcipains) process the globin into small peptid...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01327-07
更新日期:2008-09-01 00:00:00
abstract::Antagonism of antibiotic activity by peritoneal dialysate has been postulated to be a cause of failure of treatment of peritonitis complicating continuous ambulatory peritoneal dialysis. We evaluated by a case-control study whether unexpected treatment failure could be attributed to such antagonism. Bacteria isolated ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.36.5.1097
更新日期:1992-05-01 00:00:00
abstract::The emergence in the United States of resistance to expanded-spectrum cephalosporin (e.g., ceftriaxone) within the salmonellae has been associated primarily with three large (>100-kb) plasmids (designated types A, B, and C) and one 10.1-kb plasmid (type D) that carry the blaCMY-2 gene. In the present study, the distri...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.48.8.2845-2852.2004
更新日期:2004-08-01 00:00:00
abstract::The in vitro activities of two new antimicrobial agents, apalcillin and cefpiramide (SM-1652), were evaluated against 324 strains of anaerobic bacteria. Apalcillin (a penicillin derivative) and cefpiramide (a semisynthetic cephalosporin) were compared with piperacillin, moxalactam, and cefoxitin. Organisms studied inc...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.25.2.162
更新日期:1984-02-01 00:00:00
abstract::We recently reported the chromosomal location of the staphylococcal beta-lactamase gene in four strains of Enterococcus faecalis. Transfer of this gene from strain CH19 to an enterococcal recipient was accompanied by transfer of numerous other antimicrobial resistance determinants in the absence of detectable plasmid ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.36.9.1843
更新日期:1992-09-01 00:00:00
abstract::Win 41258-3 (4-[6-(2-chloro-4-methoxyphenoxy)hexyl]-3,5-diethyl-1H-pyrazole methane sulfonate) has in vitro and in vivo activity against herpes simplex virus types 1 and 2. In cell culture, a concentration of 2 microgram/ml produced a greater than 50% inhibition of plaque formation of herpes simplex virus type 2, and ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.19.3.470
更新日期:1981-03-01 00:00:00
abstract::We previously reported the isolation of a laboratory-derived Staphylococcus aureus mutant, 523k, that has constitutive low-level resistance to vancomycin (MIC = 5 micrograms/ml) and teicoplanin (MIC = 5 micrograms/ml) and elaborates a ca. 39-kDa cytoplasmic protein that was not detected in the parent strain 523 (MIC =...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.40.1.166
更新日期:1996-01-01 00:00:00
abstract::Nemonoxacin (TG-873870) is a novel nonfluorinated quinolone with potent broad-spectrum activity against Gram-positive, Gram-negative, and atypical pathogens, including vancomycin-nonsusceptible methicillin-resistant Staphylococcus aureus (MRSA), quinolone-resistant MRSA, quinolone-resistant Streptococcus pneumoniae, p...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章,随机对照试验
doi:10.1128/AAC.02972-14
更新日期:2014-10-01 00:00:00
abstract::Pyronaridine, a Mannich base antimalarial, has demonstrated high in vivo and in vitro efficacy against chloroquine-resistant Plasmodium falciparum. Although this drug has the potential to become a prominent artemisinin combination therapy, little is known about its efficacy against drug-resistant Plasmodium vivax. The...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00801-10
更新日期:2010-12-01 00:00:00