Abstract:
:In order to establish a screening system for xenosiderophores which can be utilized by mycobacteria, we generated a set of mutants of Mycobacterium smegmatis that are blocked in different steps of the well-known iron acquisition system. One mutant with a block in mycobactin biosynthesis was generated from strain mc(2)155 by chemical mutagenesis. The exochelin biosynthesis gene fxbA and the ferric exochelin uptake gene fxuA, previously identified by Fiss et al. (E. H. Fiss, S. Yu, and W. R. Jacobs, Jr., Mol. Microbiol. 14:557-559, 1994), were knocked out by gene replacement. Adjacent chromosomal fragments were used for homologous recombination in order to replace wild-type genes by the kanamycin resistance gene from transposon Tn903. Gene replacement was confirmed by PCR. The isolated mutants show the expected phenotype: fxbA mutants are defective in exochelin biosynthesis, whereas fxuA mutants excrete a significantly larger amount of exochelin compared to the amount excreted by the parent strain. This is due to their defectiveness in ferriexochelin uptake, as demonstrated in growth promotion assays. This new set of mutants allows differentiation of siderophores that supply mycobacteria with iron by ligand exchange with exochelin or mycobactin, by the use of separate siderophore uptake routes, or by the use of the exochelin permease. All these types of iron uptake routes were identified with 25 exogenous siderophores as test substances. Siderophores that act without ligand exchange are potential candidates as drug vectors that can be used to overcome permeability-mediated resistance.
journal_name
Antimicrob Agents Chemotherjournal_title
Antimicrobial agents and chemotherapyauthors
Schumann G,Möllmann Udoi
10.1128/AAC.45.5.1317-1322.2001subject
Has Abstractpub_date
2001-05-01 00:00:00pages
1317-22issue
5eissn
0066-4804issn
1098-6596journal_volume
45pub_type
杂志文章abstract::The K70E mutation in human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) has become more prevalent in clinical samples, particularly in isolates derived from patients for whom triple-nucleoside regimens that include tenofovir (TNV), abacavir, and lamivudine (3TC) failed. To elucidate the molecular m...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00683-06
更新日期:2007-01-01 00:00:00
abstract::The in vitro activities of penicillin, clindamycin, chloramphenicol, metronidazole, piperacillin, piperacillin-tazobactam, ticarcillin, ticarcillin-clavulanate, ampicillin-sulbactam, cefoxitin, ceftizoxime, cefotetan, moxalactam, and imipenem against 348 Bacteroides fragilis group isolates collected from six Canadian ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.36.2.343
更新日期:1992-02-01 00:00:00
abstract::A comparison of the daclatasvir (DCV [BMS-790052]) resistance barrier on authentic or hybrid replicons containing NS5A from hepatitis C virus (HCV) genotypes 1 to 6 (GT-1 to -6) was completed using a replicon elimination assay. The data indicated that genotype 1b (GT-1b) has the highest relative resistance barrier and...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02788-14
更新日期:2014-09-01 00:00:00
abstract::Isolates of Aspergillus fumigatus that demonstrate resistance to itraconazole (ITZ) have been described previously; however, the prevalence and clinical significance of ITZ resistance are not completely understood. In this study we assessed the ITZ susceptibilities of 128 A. fumigatus isolates that caused invasive inf...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.48.4.1197-1203.2004
更新日期:2004-04-01 00:00:00
abstract::The assembly of hepatitis B virus (HBV) core protein (HBc) into capsids represents a critical step of viral replication. HBc has multiple functions during the HBV life cycle, which makes it an attractive target for antiviral therapies. Capsid assembly modulators (CAMs) induce the formation of empty capsid or aberrant ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00835-18
更新日期:2018-09-24 00:00:00
abstract::The aim of this study was to characterize a novel extended-spectrum beta-lactamase that belongs to the TEM family, the TEM-149 enzyme, and that was isolated from the urine of two hospitalized patients from different hospitals in southern Italy. The peculiarity of this enzyme was the finding of a valine residue at posi...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01028-07
更新日期:2008-03-01 00:00:00
abstract::Meropenem-vaborbactam (Vabomere) is highly active against Gram-negative pathogens, especially Klebsiella pneumoniae carbapenemase (KPC)-producing, carbapenem-resistant Enterobacteriaceae The objective of these studies was to evaluate the efficacy of meropenem alone and in combination with vaborbactam in mouse thigh an...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01446-17
更新日期:2017-12-21 00:00:00
abstract::In response to the need for rapid, inexpensive, high-throughput assays for antimycobacterial drug screening, a microplate-based assay which uses Alamar blue reagent for determination of growth was evaluated. MICs of 30 antimicrobial agents against Mycobacterium tuberculosis H37Rv, M. tuberculosis H37Ra, and Mycobacter...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.41.5.1004
更新日期:1997-05-01 00:00:00
abstract::Clostridioides difficile causes severe antibiotic-associated diarrhea and colitis. C. difficile is an anaerobic, Gram-positive sporeformer that is highly resistant to β-lactams, the most commonly prescribed antibiotics. The resistance of C. difficile to β-lactam antibiotics allows the pathogen to replicate and cause d...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01496-19
更新日期:2019-12-20 00:00:00
abstract::The lipopeptidic antibiotic daptomycin is reported to reduce experimental tobramycin nephrotoxicity (D. Beauchamp, M. Pellerin, P. Gourde, M. Pettigrew and M. G. Bergeron, Antimicrob. Agents Chemother. 34:139-147, 1990; C. A. Wood, H. C. Finkbeiner, S. J. Kohlhepp, P. W. Kohnen, and D. C. Gilbert, Antimicrob. Agents C...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.38.4.742
更新日期:1994-04-01 00:00:00
abstract::Aminoglycoside acetyltransferase was detected in Mycobacterium kansasii and M. fortuitum but not in M. avium-M. intracellulare when they were screened by a radioassay. Aminoglycoside phosphotransferase and nucleotidyltransferase activities were absent from all three species tested. Acetyltransferases from both M. kans...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.44.1.39-42.2000
更新日期:2000-01-01 00:00:00
abstract::In 1891 Guttmann and Ehrlich (P. Guttmann and P. Ehrlich, Berlin Klin. Wochenschr. 28:953-956, 1891) were the first to report the antimalarial properties of a synthetic, rather than a natural, material when they described the clinical cure of two patients after oral administration of a thiazine dye, methylene blue. Si...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.39.12.2671
更新日期:1995-12-01 00:00:00
abstract::In this study, we characterized two tigecycline-resistant Klebsiella pneumoniae isolates from dog urine samples. The isolates were genetically unrelated, belonging to sequence type 11 (ST11) and ST147, both classically related to human isolates. To the best of our knowledge, this is the first identification of tigecyc...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02640-16
更新日期:2017-05-24 00:00:00
abstract::Indwelling device infections are associated with considerable morbidity and extremely high cost. Pseudomonas aeruginosa is the most frequent gram-negative etiologic agent associated with infections of indwelling catheters and foreign body implants. It is generally agreed that eradication of infection in the presence o...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 临床试验,杂志文章
doi:10.1128/aac.39.11.2423
更新日期:1995-11-01 00:00:00
abstract::For 177 gram-negative isolates, the MICs for ciprofloxacin ranged from 0.02 microgram/ml (Escherichia coli) to 0.31 microgram/ml (Pseudomonas aeruginosa). In time-kill curves, ciprofloxacin at 8 X the MIC almost completely killed 10(6) CFU of P. aeruginosa by 24 h. Ciprofloxacin at 4 X the MIC allowed bacterial regrow...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.26.4.597
更新日期:1984-10-01 00:00:00
abstract::In this study, a chromosomally encoded putative drug efflux pump of the SMR family, named AbeS, from a multidrug-resistant strain of Acinetobacter baumannii was characterized to elucidate its role in antimicrobial resistance. Expression of the cloned abeS gene in hypersensitive Escherichia coli host KAM32 resulted in ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00748-09
更新日期:2009-12-01 00:00:00
abstract::BMY-28864, a water-soluble pradimicin derivative, had potent in vitro activity against a wide variety of fungi, including those associated with deep-seated mycosis; it inhibited the growth of standard strains and clinical isolates at concentrations of 12.5 micrograms/ml or less. At the MIC or higher concentrations, BM...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.35.11.2185
更新日期:1991-11-01 00:00:00
abstract::(1,3)Beta-D-glucan synthase (EC 2.4.1.34. UDP-glucose: 1,3-beta-D-glucan 3-beta-glucosyltransferase) uses UDP-glucose as substrate and catalyzes the polymerization of glucose ([1,3]-beta-linkages) to form the major carbohydrate component of the fungal cell wall. We have optimized in vitro assay conditions for (1,3)bet...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.49.7.2851-2856.2005
更新日期:2005-07-01 00:00:00
abstract::The organic salt triethyl-n-hexylammonium triethyl-n-hexylboride (N(2226)B(2226)) has biostatic effects against two gram-positive bacteria, Bacillus subtilis and Micrococcus luteus, and the yeast Candida albicans. Escherichia coli and chicken embryo fibroblasts grown in tissue culture are more refractory to this compo...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.8.4.510
更新日期:1975-10-01 00:00:00
abstract::Aspergillus flavus is the second most significant pathogenic cause of invasive aspergillosis; however, its emergence risks and mechanisms of voriconazole (VRC) resistance have not yet been elucidated in detail. Here, we demonstrate that repeated exposure of A. flavus to subinhibitory concentrations of VRC in vitro cau...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01216-18
更新日期:2018-10-24 00:00:00
abstract::Liquid cultures of a Pseudomonas aeruginosa strain in Mueller-Hinton broth diluted at rates higher than the bacterial growth rate showed the expected decrease in CFU only for 1 to 2 h. Later the CFU started to increase. This phenomenon can be explained by a hypothesis that assumes that the bacteria multiply in two dif...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.29.5.765
更新日期:1986-05-01 00:00:00
abstract::Forty years after the last endemic smallpox case, variola virus (VARV) is still considered a major threat to humans due to its possible use as a bioterrorism agent. For many years, the risk of disease reemergence was thought to solely be through deliberate misuse of VARV strains kept in clandestine laboratories. Howev...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章,评审
doi:10.1128/AAC.01683-19
更新日期:2020-03-24 00:00:00
abstract::Iatrogenic Cushing's syndrome is an undesirable outcome of glucocorticoids treatment. It can be increased by pharmacologic interactions. Glucocorticoid therapy, given in association with ritonavir, and some azole treatments are causes of iatrogenic Cushing's syndrome. We present a patient with common-variable immunode...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00416-13
更新日期:2013-11-01 00:00:00
abstract::Plazomicin is a new FDA-approved aminoglycoside antibiotic for complicated urinary tract infections (cUTI). In the product labeling, trough-based therapeutic drug management (TDM) is recommended for cUTI patients with renal impairment to prevent elevated trough concentrations associated with serum creatinine increases...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00148-19
更新日期:2019-09-23 00:00:00
abstract::This paper reports an evaluation of a melamino nitroheterocycle, a potential lead for further development as an agent against human African trypanosomiasis (HAT). Studies on its efficacy, physicochemical and biopharmaceutical properties, and potential for toxicity are described. The compound previously had been shown ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01449-13
更新日期:2014-10-01 00:00:00
abstract::Antimicrobial susceptibility patterns of 112 clinical isolates, 28 type strains, and 9 reference strains of Nocardia were determined using the Sensititre Rapmyco microdilution panel (Thermo Fisher, Inc.). Isolates were identified by highly discriminatory multilocus sequence analysis and were chosen to represent the di...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02770-14
更新日期:2015-01-01 00:00:00
abstract::In patients with polytrauma or major surgery, severe bacterial infections leading to septic shock and multiorgan failure are still a major cause of death. Prevention of septic shock in patients at risk would be an alternative to treatment of patients with overt septic shock. We therefore conducted a trial with the mon...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.39.11.2535
更新日期:1995-11-01 00:00:00
abstract::There are limited long-term data on the trends in incidence and characteristics of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia (MRSAB) in intensive care units (ICUs) in which infection control measures have been adopted. We evaluated the trend of incidence and changes in characteristics of MRSA bacte...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01082-20
更新日期:2020-09-21 00:00:00
abstract::We examined the correlation of mutations in the pyrazinamidase (PZase) gene (pncA) with the pyrazinamide (PZA) resistance phenotype with 60 Mycobacterium tuberculosis isolates. PZase activity was determined by the method of Wayne (L. G. Wayne, Am. Rev. Respir. Dis. 109:147-151, 1974), and the entire pncA nucleotide se...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.44.9.2291-2295.2000
更新日期:2000-09-01 00:00:00
abstract::A fosmid library from genomic DNA of Streptomyces viridochromogenes DSM 40736 was constructed and screened for the presence of genes known to be involved in the biosynthesis of phosphinothricin tripeptide (PTT). Eight positives were identified, one of which was able to confer PTT biosynthetic capability upon Streptomy...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.49.1.230-240.2005
更新日期:2005-01-01 00:00:00