Abstract:
:Strains of Enterobacter cloacae were selected on the basis of resistance to aztreonam, ceftazidime, moxalactam, or imipenem. All strains produced the same E2 beta-lactamase, with an isoelectric point greater than 9.5 and with high hydrolytic activity in the presence of cephaloridine. Resistance to beta-lactams could not be correlated with the amount of beta-lactamase present in the various strains. beta-Lactamase activity was induced strongly by moxalactam and imipenem in the wild-type and moxalactam-resistant strains, with beta-lactamase representing as much as 4% of the total cellular protein after induction (2 X 10(5) molecules per cell). Ceftazidime and aztreonam were poor inducers. None of the antibiotics studied was readily hydrolyzed by the E2 beta-lactamase; aztreonam and moxalactam inhibited the enzyme with apparent Ki values of 1.2 and 100 nM, respectively. Aztreonam, which bound covalently to the E2 beta-lactamase with a half-life of 2.3 h at 25 degrees C, was used to measure penetrability of beta-lactam into the periplasmic space of the resistant E. cloacae strains. In all of the E2-producing organisms studied, a significant permeability barrier existed. A maximum concentration of 0.02 microgram of aztreonam per ml should have saturated the periplasmic beta-lactamase in the highest enzyme producers studied. However, fully active beta-lactamase was observed in the periplasm of cells exposed to aztreonam at concentrations at least 1,000-fold higher than that theoretically necessary to inhibit the total enzyme within the cell. Thus, the major cause for resistance to beta-lactam antibiotics in these E. cloacae strains was lack of penetration across the outer membrane.
journal_name
Antimicrob Agents Chemotherjournal_title
Antimicrobial agents and chemotherapyauthors
Bush K,Tanaka SK,Bonner DP,Sykes RBdoi
10.1128/aac.27.4.555subject
Has Abstractpub_date
1985-04-01 00:00:00pages
555-60issue
4eissn
0066-4804issn
1098-6596journal_volume
27pub_type
杂志文章abstract::Mammalian serum amyloid A (SAA) is a major acute phase protein that shows a massive increase in plasma concentration during inflammation. In the present study, we demonstrate that the expression of mouse SAA1 in serum was increased when infected with Candida albicans, a major human fungal pathogen, in a systemic infec...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01975-19
更新日期:2019-12-20 00:00:00
abstract::Oral Fusobacterium nucleatum populations from 20 young, healthy children were examined for beta-lactamase production. Ten children (50%) harbored, altogether, 25 beta-lactamase-positive F. nucleatum isolates that were identified as F. nucleatum subsp. polymorphum, F. nucleatum subsp. nucleatum, and F. nucleatum subsp....
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.43.5.1270
更新日期:1999-05-01 00:00:00
abstract::A survey conducted between 1987 and 1994 at the University Hospital of Besançon, France, demonstrated a dramatic increase (from 0 to 42. 5%) in the prevalence of amoxicillin resistance among Salmonella spp. Of the 96 resistant isolates collected during this period (including 77 Typhimurium), 54 were found to produce T...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.43.10.2430
更新日期:1999-10-01 00:00:00
abstract::The antimalarial drug quinine has been shown to impair human polymorphonuclear leukocyte (PMN) functions. To gain insight into the mechanism of this phenomenon, we investigated quinine uptake by PMN with a fluorometric assay based on the fluorescence properties of this drug. After 30 min of incubation at 37 degrees C ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.35.7.1474
更新日期:1991-07-01 00:00:00
abstract::In this study, two identical copies of a 23S-5S gene cluster, which are separately situated within the Helicobacter pylori UA802 chromosome, were cloned and sequenced. Comparison of the DNA sequence of the H. pylori 23S rRNA gene with known sequences of other bacterial 23S rRNA genes indicated that the H. pylori UA802...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.41.12.2621
更新日期:1997-12-01 00:00:00
abstract::The accumulation of OPC-17116 by human polymorphonuclear leukocytes was studied by comparison with three other new quinolones, ofloxacin, levofloxacin, and DR-3354. The intracellular/extracellular concentration ratio was the highest for OPC-17116, being 66.2, followed by 9.8 for levofloxacin, 7.6 for ofloxacin, and 5....
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.37.9.1877
更新日期:1993-09-01 00:00:00
abstract::A pyridodiazepine amine inhibitor of Helicobacter pylori glutamate racemase (MurI) was characterized. The compound was selectively active against H. pylori, and growth suppression was shown to be mediated through the inhibition of MurI by several methods. In killing kinetics experiments, the compound showed concentrat...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.04410-14
更新日期:2015-04-01 00:00:00
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 ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.48.1.69-74.2004
更新日期:2004-01-01 00:00:00
abstract::The in vitro susceptibility of 409 clinical isolates to HR 810, a new cephalosporin, was evaluated and compared with their susceptibility to aztreonam, cefazolin, ceftazidime, imipenem, moxalactam, piperacillin, and gentamicin. On a weight basis, the activity of HR 810 against gram-negative bacilli was equivalent or s...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.26.2.277
更新日期:1984-08-01 00:00:00
abstract::This report describes linezolid susceptibility testing results for 6,741 Gram-positive pathogens from 60 U.S. sites collected during 2015 for the LEADER Program. In addition, the report summarizes linezolid in vitro activity, resistance mechanisms, and molecular typing obtained for 2011 to 2015. During 2015, linezolid...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00609-17
更新日期:2017-06-27 00:00:00
abstract::The diversity and evolution of the class A OXY beta-lactamase from Klebsiella oxytoca were investigated and compared to housekeeping gene diversity. The entire bla(OXY) coding region was sequenced in 18 clinical isolates representative of the four K. oxytoca beta-lactamase gene groups bla(OXY-1) to bla(OXY-4) and of t...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.49.8.3453-3462.2005
更新日期:2005-08-01 00:00:00
abstract::The chromosome-encoded class C β-lactamase CHE-1 produced by Enterobacter cloacae exhibits a lower sensitivity to avibactam than the P99 enzyme from which it is derived by a 6-residue deletion in the H-10 helix. In the present study, we investigated the sensitivity of CHE-1 to two other β-lactamase inhibitors: LK-157 ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02062-15
更新日期:2016-01-04 00:00:00
abstract::Ampicillin and erythromycin were shown to act synergistically in vitro against the majority of strains of Nocardia asteroides tested. With these strains, the minimal inhibiting concentration (MIC) of each drug when combined was reduced 4- to more than 512-fold as compared with the MIC of each antibiotic acting individ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.5.3.344
更新日期:1974-03-01 00:00:00
abstract::Different mechanisms of erythromycin resistance predominate in group C and G streptococcus (GCS and GGS, respectively) isolates collected from 1992 to 1995 in Finland. Of the 21 erythromycin-resistant GCS and 32 erythromycin-resistant GGS isolates, 95% had the mefA or mefE drug efflux gene and 94% had the ermTR methyl...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.42.6.1493
更新日期:1998-06-01 00:00:00
abstract::A clinical isolate of Pseudomonas aeruginosa, PAe191, was found to be highly resistant to all anti-Pseudomonas beta-lactam antibiotics (except imipenem) and resistant also to aminoglycosides. It produced a beta-lactamase (with an apparent pI of 7.6) which was not inhibited by clavulanic acid. Cloning and characterizat...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.42.12.3113
更新日期:1998-12-01 00:00:00
abstract::Thirty-two strains of Trichophyton rubrum and 16 strains of Trichophyton mentagrophytes isolated from patients with tinea unguium in various parts of Germany were subjected to a microdilution test with six systemic or topical antimycotic agents. Apart from griseofulvin, there were no species-specific differences betwe...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章,多中心研究
doi:10.1128/aac.39.5.1206
更新日期:1995-05-01 00:00:00
abstract::PPI-0903M is a novel N-phosphono-type cephalosporin active against oxacillin-resistant staphylococci and many other gram-positive organisms. This study evaluated the in vitro activity and spectrum of PPI-0903M against 1,478 recent clinical isolates collected from 80 medical centers (22 countries). PPI-0903M demonstrat...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.49.8.3501-3512.2005
更新日期:2005-08-01 00:00:00
abstract::Fifty-seven cultures of Haemophilus influenzae were tested for production of beta-lactamase by use of a modified, 1-min test. Only the 24 cultures that were ampicillin resistant, whether type b or not, yielded positive results for the enzyme; all ampicillin-susceptible isolates were uniformly negative. The beta-lactam...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.9.1.196
更新日期:1976-01-01 00:00:00
abstract::A simple technique with antibiotic-impregnated disks has been developed to demonstrate the antibiotic synergism of penicillins and aminoglycosides against enterococci. The two antibiotic disks are placed on inoculated plates so that the distance between their centers is less than the sum of the two radii of their prev...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.7.1.82
更新日期:1975-01-01 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 fungus Saprochaete capitata causes opportunistic human infections, mainly in immunocompromised patients with hematological malignancies. The best therapy for this severe infection is still unknown. We evaluated the in vitro killing activity and the in vivo efficacy of posaconazole at 5, 10, or 20 mg/kg twice a day...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.01140-15
更新日期:2015-12-01 00:00:00
abstract::Combinations of caspofungin and posaconazole were evaluated by fractional inhibitory concentration index against 119 Candida glabrata isolates. Synergy was seen in 18% of all isolates and in 4% of fluconazole-resistant isolates at 48 h without evidence of antagonism. This antifungal combination may have utility agains...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.49.8.3544-3545.2005
更新日期:2005-08-01 00:00:00
abstract::Two methods for testing the susceptibility of Mycobacterium tuberculosis to rifapentine have been developed: the agar proportion method and the radiometric BACTEC technique. A critical concentration of 0.5 microg of rifapentine per ml is proposed for both methods since it provides a reliable means of distinguishing be...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.43.1.25
更新日期:1999-01-01 00:00:00
abstract::We investigated the antistaphylococcal activity of daptomycin, vancomycin, oxacillin, gentamicin, and rifampin in human monocyte-derived macrophages. Compared with vancomycin and oxacillin, daptomycin had the most rapid and greatest antibacterial activity, but that of oxacillin was most sustained. The combination of d...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.00973-06
更新日期:2007-04-01 00:00:00
abstract::Sixteen weeks of treatment with clarithromycin (CLARI) alone displayed significant bactericidal activity against Mycobacterium avium complex infection in beige mice. Only two combined regimens, CLARI combined with an initial 4 or 8 weeks of amikacin (AMIKA), displayed activity greater than that displayed by CLARI alon...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.39.3.608
更新日期:1995-03-01 00:00:00
abstract::Mycobacterium tuberculosis infection is responsible for a global pandemic. New drugs are needed that do not show cross-resistance with the existing front-line therapeutics. A triazine antitubercular hit led to the design of a related pyrimidine family. The synthesis of a focused series of these analogs facilitated exp...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02063-17
更新日期:2018-02-23 00:00:00
abstract::The respiratory syncytial virus (RSV) L protein is a viral RNA-dependent RNA polymerase that contains multiple enzyme activities required for RSV replication. The RSV L inhibitors described in literature are limited by their cytotoxicity or the lack of RSV B subtype coverage. Here, we characterize a new RSV L inhibito...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.02540-14
更新日期:2014-07-01 00:00:00
abstract::Rifampin was shown in vitro to decrease the amphotericin B minimal inhibitory concentrations of all of 10 strains of Coccidioides immitis tested. These decreases ranged from two- to fourfold and occurred with rifampin concentrations of 10 to 40 mug/ml. Rifampin alone was without effect. ...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/aac.6.6.783
更新日期:1974-12-01 00:00:00
abstract::Thirteen derivatives of the Streptococcus pneumoniae TIGR4 strain in which putative drug efflux pumps were genetically inactivated were constructed and characterized. The results indicate that two linked genes encoding the ABC-type transporters SP2073 and SP2075 function together to confer intrinsic resistance to a se...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.49.11.4781-4783.2005
更新日期:2005-11-01 00:00:00
abstract::Expression of eight transporter genes of Escherichia coli K-12 and its DeltaacrAB mutant prior to and after induction of both strains to tetracycline resistance and after reversal of induced resistance were analyzed by quantitative reverse transcriptase PCR. All transporter genes were overexpressed after induced resis...
journal_title:Antimicrobial agents and chemotherapy
pub_type: 杂志文章
doi:10.1128/AAC.49.8.3578-3582.2005
更新日期:2005-08-01 00:00:00