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PubMedDate not supplied

Fluoroquinolone antibiotics: properties of the class and individual agents.

The broad spectrum of activity and bactericidal nature of the fluoroquinolones, together with their excellent absorption, rapid distribution, and high tissue concentration, make them excellent therapeutic agents for the management of a number of complicated community-acquired and nosocomial infections of the urinary tract, bone and soft tissue, gastrointestinal tract, and prostate, as well as some respiratory tract infections and sexually transmitted diseases. Data are presented and reviewed concerning the in vitro activity, pharmacology, and clinical use of ciprofloxacin, norfloxacin, and ofloxacin, which have been available for some time, and lomefloxacin and temafloxacin, which are recently approved agents. The comparable qualities and differences in activity and clinical applications of these agents are considered. For many infections in selected patients, quinolones are excellent substitutes for parenteral agents. In general, adverse effects have been infrequent and rarely require drug discontinuation. Significant interactions, such as with theophylline and caffeine, have occurred but are quinolone dependent. Antacids can markedly impair the absorption of all quinolones. Because emerging resistance to Pseudomonas and Staphylococcus species have been observed, the improper use of the quinolones must be avoided, and the clinician must be aware that an unfavorable response may signal resistance. The development of future agents with better gram-positive activity, improved gram-negative coverage, and activity against unusual pathogens such as Chlamydia species and Mycobacterium species, will make these oral agents invaluable. Assessing the usefulness and safety of these antibiotics in children is an ongoing challenge.

4-Quinolones↗
PubMed1991

[Antibiotic sensitivity of El Tor Vibrio cholerae after exposure to various pesticides and mineral fertilizers].

The strains of El Tor Vibrio cholerae were exposed to different concentrations of pesticides (fazolone, treflane, prometrine, magnesium chlorate, omait and gardon) and mineral fertilizers (superphosphate, ammophos and carbamide) for 2 to 135 days. The subcultures of various ages were tested for their sensitivity to 16 antibiotics. The whole of 229 cultures were tested. There was a general tendency to lowering of the El Tor vibrio sensitivity to the majority of the antibiotics tested. The vibrio strains resistant to the antibiotics widely used in medical practice i. e. levomycetin, streptomycin, tetracycline, lincomycin, neomycin and kanamycin were isolated.

Anti-Bacterial Agents↗
PubMed1991

Co2+ and Ni2+ resistance in Saccharomyces cerevisiae associated with a reduction in the accumulation of Mg2+.

A mutant strain of Saccharomyces cerevisiae (NR 6), which can be associated with a reduction in the accumulation of Mg2+ has been isolated. This mutant strain displays resistance to both Ni2+ and Co2+, but not, however, towards Cu2+, Cd2+, Mn2+, Zn2+ and Cr2O7(2-). Both Co2+ and Ni2+ uptake by the mutant strain is less than by the wild type (CMR-50). The inhibitory effects of Ni2+ and Co2+ on the growth of both strains NR-6 and CMR-50 can be cancelled by increasing the concentrations of Mg2+ in the medium and to a lower extent by the addition of Ca2+ which results in a decreased uptake of these metals. It therefore appears that the resistant mechanisms of this mutant strain NR-6 is due to a reduction in the uptake of Co2+ and Ni2+ via a Mg2+ transport system.

Biological Transport↗
PubMed1991

[The effect of sulbactam on the in vitro activity of mezlocillin, piperacillin and cefotaxime].

The in vitro activity of mezlocillin (MZL, CAS 51481-65-3), piperacillin (PIP, CAS 61477-96-1) and cefotaxim (CTX, CAS 63527-52-6) alone and in combination with sulbactam (SBT; CAS 68373-14-8) against mezlocillin-resistant pathogens was determined in a multicenter study. A total of 870 strains were investigated (481 Enterobacteriaceae, 57 Pseudomonas aeruginos, 41 Acinetobaster spp., 194 Bacteroides fragilis, and 97 Staphylococcus spp.). Determinations of MIC were performed according to DIN-guidelines (agar-dilution method for aerobes and microbroth-dilution method for anaerobes). Sulbactam was added in fixed concentrations of 5 mg/l and 10 mg/l. In all sulbactam-combinations examined mean MIC as well as MIC50 and MIC90 were reduced compared to the respective values for the antibiotics alone. Consequently, percentages of susceptible strains increased significantly: i.e. for Enterobacteriaceae: MZL 1% vs. MZL + 10 mg/l SBT 53%; PIP 4% vs. PIP + 10 mg/l SBT 54%; CTX 52% vs. CTX + 10 mg/l SBT 68%. The effect of sulbactam was most pronounced in Bacteroides spp. with an increase in susceptible strains from 2% to 97% for MZL, from 6% to 95% for PIP and from 7% to 98% for CTX. The results indicate that by adding sulbactam the in vitro activity of mezlocillin, piperacillin and cefotaxim against resistant pathogens is augmented significantly. In addition, the spectrum of antibacterial activity is extended to anaerobic pathogens such as Bacteroides spp. The availability of sulbactam as a monosubstance for combination with various beta-lactam-antibiotics thus represents a useful improvement of therapeutic options in bacterial infections.

Acinetobacter↗
PubMed1991

[In vitro experiment showing that chemotherapy of tuberculosis by aminoglycoside antibiotics may influence successive chemotherapy with rifampicin].

When Mycobacterium tuberculosis strain H37Rv was cultivated in Ogawa egg medium containing 5 micrograms/ml streptomycin and/or 10 micrograms/ml kanamycin, which were considered as subinhibitory, it was observed that growing bacterial population contained several times more rifampicin-resistant mutants than did the parent strain. The ratio of isoniazid-resistant mutants did not change by the above treatment. The finding suggests that, even without the use of rifampicin, the bacterial population of patients becomes more resistant to rifampicin by chemotherapy in the past with streptomycin or kanamycin. Furthermore, it was shown that the ratio of streptomycin-resistant mutants increased by pre-treatment with kanamycin and the ratio of kanamycin-resistant mutants by pre-treatment with streptomycin. Parent, susceptible bacterial population develops 4R-phenotype mutants which are resistant to four drugs, high concentrations of kanamycin, lividomycin and paraomomycin and a low concentration of capreomycin, whereas streptomycin-resistant mutant population does not develop the 4R mutants but develops only mutants with the KR phenotype which is almost mono-resistant to kanamycin.

Anti-Bacterial Agents↗
PubMed1991

Microbiologic aspects of fluoroquinolones.

Fluoroquinolones are both old and new antimicrobial agents. The prototype agent of the class, nalidixic acid, was synthesized in 1962, whereas the new fluoroquinolones began to be used in the latter 1980s. During the past six years, orally administered fluoroquinolones have been used extensively in Japan and Europe to treat both community- and hospital-acquired infections. Most recently, one of the fluoroquinolones, ciprofloxacin, has also become available for parenteral and topical ophthalmic use. This article reviews the chemistry, antimicrobial activity, pharmacology, and clinical use of the fluoroquinolones.

4-Quinolones↗
PubMed1991

The place of quinolones in bacterial infections.

The quinolone antimicrobial agents are important therapeutic compounds for many infections. They have potential as substitutes for many parenteral agents, particularly in treating urinary tract, diarrheal, bone and joint, and some respiratory tract infections. The quinolones are important prophylactic agents for neutropenic patients. Adverse reactions to these compounds have been exceedingly infrequent. Important drug-drug interactions occur, and the absorption of the compounds can be markedly impaired by antacids. Resistance to quinolones is already a serious problem in some countries. Improper use in the United States will rapidly make the new quinolones ineffective treatment for staphylococcal, Pseudomonas, and even some Enterobacteriaceae infections. Careful attention to those situations in which resistance has been shown to develop is necessary.

4-Quinolones↗
PubMed1990

[Quinolones: confirmations and promises].

The authors review new and old quinolones and their pharmacokinetics. The clinical usefulness of these compounds is discussed on the basis of their bactericidal properties and of the uncommon development of resistance.

4-Quinolones↗
PubMed1990

[New quinolones].

Explore the source record for details and available documents.

Anti-Bacterial Agents↗
PubMed1989

[In vitro activity of clofazimine alone and in combination with amikacin, roxithromycin, rifampicin and rifapentine against Mycobacterium avium-intracellulare].

The activity of clofazimine, amikacin, roxithromycin, rifampicin and rifapentine was tested, alone and in association, against Mycobacterium avium intracellulare. Clofazimine, amikacin and rifapentine were shown to be very active. With all established associations, the MIC observed for each drug alone was appreciably reduced.

Amikacin↗
PubMed1989

The effects of heparin on rifampin activity against Staphylococcus epidermidis biofilms.

Rifampin shows unique antimicrobial activity against Staphylococcus epidermidis biofilms, although in the in vitro situation rifampin resistance emerges rapidly by the selection of preexisting resistant mutants present in a small number in any large bacterial population. Fresh peritoneal dialysis solution is synergistic with rifampin suppressing rifampin resisters. The antimicrobial properties of rifampin are affected by heparin and protamine in entirely different directions. Heparin blocks the action of rifampin whereas protamine is synergistic producing a total bactericidal outcome. Protamine, when combined with heparin, unexpectedly did not influence the ability of heparin to antagonize rifampin. The mechanisms involved are unknown. The results are discussed in terms of known characteristics of the drugs and of the biofilm surface.

Bacterial Adhesion↗
PubMed1989

Killing rate and serum bactericidal activity of oxacillin, rifampin and ciprofloxacin against Staphylococcus aureus.

The bacterial activity of oxacillin, rifampin and ciprofloxacin was examined at two concentrations by the serum bactericidal rate (SBR) technique against 5 strains of methicillin-susceptible Staphylococcus aureus. The activity of oxacillin plus ciprofloxacin and oxacillin plus rifampin was also determined for 5 strains of staphylococci examining in vitro the SBR and the serum bactericidal activity (SBA). We simulated SBR and SBA in vitro using pooled human serum containing know concentrations of antimicrobial agents. The rate at which the antibiotics kill S. aureus did not rise by increasing the concentrations over the MBC. The oxacillin-ciprofloxacin combination was indifferent when tested by the rate of killing, whereas an antagonistic interaction was frequently observed with the oxacillin-rifampin combination. The SBA was determined by two methods: the technique of the Mayo Clinic that uses Mueller-Hinton broth (MHB) as the diluent and the method of Stratton in which the diluent was prepared with MHB supplemented with Ca++ and Mg++ and combined with 50% pooled human serum. The activities of oxacillin and rifampin were decreased in the presence of human serum. These results were attributed to the high protein binding of these antibiotics. Rifampin in combination with oxacillin showed antagonism against S. aureus also by the SBA method. The inhibitory activity of drugs in combination remained substantially the same as the single more active one.

Ciprofloxacin↗
PubMed1989

[Drug sensitivity of Candida in patients with kidney diseases receiving immunosuppressive therapy].

It was shown that prednisolone and its combination with azathioprine++ increased contamination of the patients with yeast-like fungi and promoted development of candidiasis in them to a greater extent than cyclophosphamide. In the patients treated with the immunodepressants there was observed a carrier state in regard to various yeast-like fungi: 12 species belonging to 6 genera were isolated from the pathological materials. Determination of sensitivity to antifungal drugs in 200 Candida strains revealed that amphotericin B was the most active agent. Then followed mycoheptin, nystatin and nitroxolin. Levorin was the least active drug. The MICs of the drugs for the majority of the cultures were 0.5, 4-8, 8-16 and 32-64 micrograms/ml respectively. Candida resistant strains (mainly to levorin and mycoheptin) were isolated only from recipients of kidney transplants during the early postoperative period when the patients were subjected to intensive immunodepressive and prophylactic antifungal therapy. Among the fungi of the Candida genus C. guillermondii and C. parapsilosis proved to be the most resistant. Under the hospital conditions and in vitro studies it was found that cyclophosphamide and combinations of prednisolone with cytostatics increased resistance of Candida to the antifungal drugs. Rapid increasing of the fungi resistance to levorin and mycoheptin was observed. The increase in the resistance to amphotericin B was somewhat lower and that to nitroxolin and nystatin was extremely low. The study of the combined effect of the immunodepressants and antifungal drugs demonstrated that the immunodepressants increased the antifungal activity of amphotericin B, levorin and nitroxolin.(ABSTRACT TRUNCATED AT 250 WORDS)

Antifungal Agents↗