摘要:

Tosufloxacin, a quinolone, showed a broad antibacterial spectrum against gram-positive and gram-negative bacteria including anaerobic bacteria. Tosufloxacin was 4- to 8-fold more active than levofloxacin and ciprofloxacin. The MIC90 of tosufloxacin for clinical isolates of Bacteroides fragilis, Bacteroides vulgatus, Bacteroides thetaiotaomicron and Peptostreptococcus asaccharolyticus were 0.78, 0.39, 1.56 and 0.39 μg/ml, respectively. Morphological observation with the scanning and transmission electron microscope revealed that exposure of B. fragilis ATCC 25285 to tosufloxacin resulted in the formation of filamentous cells with mesosome-like structures. Tosufloxacin also induced the mini-cell resulting from the unusual cell division system and a number of holes in the outer membrane. Tosufloxacin at 4 MIC caused some change in cell wall organization and cell lysis. After exposure of P. asaccharolyticus ATCC 1495 3 to tosufloxacin, the cells increased considerably in size and the cell wall and cross wall thickening was observed

ISSN:0009-3157    

DOI:10.1159/000239551

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Ninety-four clinical isolates of Moraxella catarrhalis were examined for susceptibility to 21 antimicrobial drugs; 67 isolates (= 71.3%) produced βlactamase(s). In terms of antibiotic resistance, the number of isolates resistant to penicillin G, ampicillin, and cotrimoxazole were 56, 32, and 1, respectively. The number of isolates with intermediate susceptibility to penicillin G, ampicillin, ciprofloxacin, ofloxacin, cotrimoxazole, and fosfomycin were 11, 34, 1, 2, 2, and 47, respectively. All 94 isolates proved susceptible to ampicillin + 10 μg/ml of sulbactam, amoxicillin + 4 μg/ml of clavulanic acid, cefurox-ime, cefotaxime, cefepime, cefixime, imipenem, meropenem, chloramphenicol, doxycycline, tetracycline, fusidic acid, erythromycin, clarithromycin, and rifampin, as based on currently valid NCCLS criteria, where applicable. There were no very major or major discrepancies between agar dilution and agar disk diffusion test results. There were only a few minor discrepancies between test results, specifically: penicillin G (category IV = 4, category VI = 1); ampicillin (category IV = 4, category V = 1, category VI = 7), amoxicillin + clavulanic acid (category III =11), cotrimoxazole (category IV = 1, category V = 1, category VI = 1), ciprofloxacin (category V = 1), and ofloxacin (category VI = 2). The sole exception was fosfomycin, with a total of 25 minor discrepancies encountered (category III = 14, category V = 9, category VI = 2). Wilkins-Chalgren agar compared favorably with Mueller-Hinton agar following examination with 11 selected antimicrobial drugs against 31 representative isolates of M. catarrhalis.<

ISSN:0009-3157    

DOI:10.1159/000239552

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

The in vitro susceptibility of 55 strains of Neisseria meningitidis isolated in 1993 and 1994 at the Valme and Macarena Hospitals, Sevilla, Spain, to penicillin, ampicillin, cefotaxime, cefpodoxime, imipenem, rifampin, ciprofloxacin, chloramphenicol, tetracycline, erythromycin and trimethoprim- sulfamethoxazole were determined by a microdilution method in Mueller-Hinton broth. Among our N. meningitidis isolates, 36.4% were found to be moderately resistant to penicillin, 43.6% were resistant to trimethoprim/sulfamethoxazole. All the strains were susceptible to tetracycline, ciprofloxacin, cefotaxime and rifampin.

ISSN:0009-3157    

DOI:10.1159/000239553

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

To evaluate the synergistic antimicrobial effects of tazobactam (TAZ), a β-lactamase inhibitor, and piperacillin (PIPC) on Pseudomonas aeruginosa, we compared the antimicrobial effects of TAZ/PIPC with those of PIPC alone on bacteria inducibly or constitutively producing β-lactamase. TAZ/PIPC had more potent antimicrobial effects compared with PIPC on clinical isolates producing β-lactamase. In the treatment of mouse systemic infection, the therapeutic effect of PIPC was markedly decreased by β-lactamase, but that of TAZ/PIPC was only slightly decreased. In the treatment of local infections in mice, the therapeutic effects of PIPC were decreased due to the induction of β-lactamase and the emergence of bacterial strains constitutively producing β-lactamase, while those of TAZ/ PIPC were not aff

ISSN:0009-3157    

DOI:10.1159/000239554

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

The aim was to determine the increase and present standing of penicillin-resistant Streptococcus pneumoniae in Cádiz, Spain. We have studied retrospectively a total of 385 strains of S. pneumoniae obtained during the years 1991, 1993 and 1995. Strains tested were isolated from clinical samples of patients attended at the University Hospital Puerta del Mar of Cadiz, Spain. The resistance rate to penicillin was 71.2% (47.0% in 1991, 72.8% in 1993 and 89.3% in 1995). The percentage of strains with high resistance was 51.4%. The increase was from 29.4% in 1991 to 75.2% in 1995. The incidence of penicillin-resistant pneumococci was more marked in nasopharyngeal carrier children (75.8%) than in invasive strains (30.2%). The increase in high resistance to penicillin in clinical isolates of S. pneumoniae is very pronounced in Cadiz, Spain

ISSN:0009-3157    

DOI:10.1159/000239555

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

New N-1-adamantylcitraconimide (compound 1) and N-l-diamantylcitraconimide (compound 2) were synthesized by reaction of citraconic anhydride with 1-aminoadamantane, and 1-aminodiamantane, respectively, followed by imidiza-tion with acetic anhydride and sodium acetate. Compound 1, N-1-adamantylmaleimide (compound 3) and N-1-diamantyl-maleimide (compound 4) exhibited strong growth-inhibitory activity against four cancer cell lines (Colo 205, Hep G2, SK-BR-3 and Molt-4). Moreover, compound 1 showed relatively specific cytoxicity against the test tumor cell lines. Compound 2 exhibited growth inhibitory activity against Colo 205, and SK-BR-3 cells, similar to 5-fluorouracil. It was noted that compound 2 showed relatively low cytotoxicity against Molt-4 cells, approximately 42 times lower than 5-fluorouracil. The N-substituents of imides with adamantyl substituents have a more potent antitumor activity than the imides with diaman-tyl substituents. The imides with methyl substituents (compounds 1 and 2) showed relatively higher selectivity against the tested cancer cell lines than the imides without methyl substituents (compounds 3 and 4). Compounds 3 and 4 show good in vitro activities against Staphylococcus aureus and Trichophyton mentagrophytes. Compound 1 had weak antimicrobial activity against T. mentagrophytes.

ISSN:0009-3157    

DOI:10.1159/000239557

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

A rational choice of an antimicrobial agent must take into account not only the activity against the specific pathogen but also any possible negative or positive effects on the host defense system. Rokitamycin (RKM) is an orally active 16-membered-ring macrolide; there are no reports of specific investigations of these activities in the literature. Polymorphonuclear neutrophils (PMNs) from healthy adult donors were incubated in medium alone or in medium containing increasing concentrations (1, 10, 50, 100 μg/ml) of RKM. In unwashed PMNs phagocytosis was unaffected by RKM, while luminol-amplified chemiluminescence (LACL) was significantly reduced by 50 and 100 μg/ml. When PMNs were washed after incubation phagocytosis was not modified but LACL was significantly restored. These characteristics of RKM were similar to those of roxithromycin and can be put in correlation with the cellular/extracellular ratio (30.5 for PMNs and 120 for macrophages) that was similar to that of roxithromycin but higher than of other macrolides. The molecular mechanisms by which high concentrations of these two macrolides produce such an impairment of LACL are still unclear. RKM has no unwanted effects on PMNs because the serum concentrations that can be obtained with the highest doses administered to man are lower than the concentrations which did not affect PMN functions in our stud

ISSN:0009-3157    

DOI:10.1159/000239560

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

We investigated the efficacy of fluconazole on experimental disseminated candidiasis in mice immunocompromised by chronic morphine treatment. CD1 mice were severely immunosuppressed by repeated morphine administrations, i.e., subcutaneous (s.c.) injections of 75 mg/kg/day, 3 days before and 5 days after a systemic Candida albicans infection induced by intravenous administration of 1 x 106 fungal cells/mouse. Fluconazole (2.5 mg/kg, s.c, at 6, 24 and 48 h postinfection) was very effective in prolonging survival time of morphine-treated mice. Fluconazole treatment also promotes a recovery of killing activity of polymorphonuclear leukocyte cells suppressed by morphine administrations.

ISSN:0009-3157    

DOI:10.1159/000239561

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Liposomes of the stable multilamellar type, which previously demonstrated great efficiency in antibiotic transport [Vitas et al: Antimicrob Agents Chemother 1996;40:146-151] were used in this study as carriers of gentamicin for treatment of mice lethally infected with Brucella abortus. Treatment with gentamicin in positively charged liposomes produced a protective effect when it was administered 1 day after lethal challenge (70% of protection). On the other hand, the use of free gentamicin or in liposomes with a negative net charge did not produce a protective effect. Moreover, the results reported here also indicated that cationic liposomes themselves had a therapeutic effect on the course of the infection (up to 50% of protection). In conclusion, we observed that cationic liposomal encapsulation of gentamicin resulted in an enhancement of the therapeutic activity of free gentamicin in this mouse model of acute infection.

ISSN:0009-3157    

DOI:10.1159/000239563

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

The effect of different natural and semi-synthetic polysaccharides on Chlamydia trachomatis glycogen. Data obtained suggested that antichlamydial activity was not only related to the electric charge of these molecules but could also be attributed to other features of their polymeric backbone. Since carbohydrate polymers have also been shown to inhibit the early stages of infection by viral agents causing sexually transmitted diseases, the employment of these molecules for prevention or treatment of mixed viral-C trachomatis infections can be hypothesized

ISSN:0009-3157    

DOI:10.1159/000239565

出版商:S. Karger AG    

年代:1997

数据来源: Karger