Methicillin-resistant staphylococcal strains isolated from clinical samples.

Infections caused by methicillin-resistant Staphylococcus strains (MRSS) have become an increasing problem both as community-acquired and nosocomial infections. In order to eradicate colonization as well as to cure infections, optimal antibiotic treatment is required. In this study we examined the incidence of MRSS in clinical samples and compared the antibiotic susceptibility pattern of methicillin-resistant Staphylococcus aureus with that of methicillin-resistant Staphylococcus non-aureus strains. All the MRSS were resistant to penicillin. Among them there was a variation in the percentage of strains resistant to various antimicrobial agents. Within MRSS the most frequent resistances were those to erythromycin and norfloxacin. Ciprofloxacin and teicoplanin were the most effective antibiotics tested against MRSS, followed in activity by vancomycin and imipenem. The incidence of antibiotic resistance among MRSS was significantly higher than that among methicillin-susceptibility staphylococcal species.

Basis for nebulized antibiotics: droplet characterization and in vitro antimicrobial activity versus Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.

The aims of this study were to (1) quantify the particle size characteristics of several antibiotics considered suitable for aerosol therapy after aerosolization with the PARI IS/2 nebulizer (Pari GmbH, Sarnberg, Germany) and (2) determine the degree to which in vitro antimicrobial activity of these antibiotics is maintained after nebulization. The aerosolized drugs were tobramycin sulfate, streptomycin, and imipenem, with saline solution as the control. Mean mass aerodynamic diameter of the nebulized drugs was 3.25 microns for tobramycin, 2.26 microns for imipenem, and 2.38 microns for streptomycin. In vitro tests showed that tobramycin and imipenem were unaltered in their bacteriostatic activity against strains of Escherichia coli (American Type Culture Collection [ATCC] 25922) and Staphylococcus aureus (ATCC 29213) as well as against Pseudomonas aeruginosa (ATCC 27853) with minimal inhibitory concentration (MIC) values less than 0.3 microgram/mL. Nebulized streptomycin showed significantly higher MIC values against P. aeruginosa (ATCC 27853). These results suggest that tobramycin and imipenem may be prescribed as an aerosol generated by jet nebulization (PARI IS/2) to treat S. aureus, E. coli, and P. aeruginosa infections without any risk of altering the drugs minimum bacteriostatic activity by the nebulization process. Aerosolization of streptomycin with this nebulizer may not be as effective against P. aeruginosa because it seems to alter the bacteriostatic activity.

[New heterocyclic derivatives with germicidal activity. VI. Synthesis and activity of new 2-benzoxazoyl-2'-furanes and -thiophenes variously substituted in 5 and 5' positions]. / Nuovi derivati eterociclici ad attività germicida. VI. Sintesi ed attività di nuovi 2-benzossazolil-2'-furani e-tiofeni, variamente sostituiti in 5 e 5'.

Seventeen derivatives of 2'-furyl-2-benzoxazole and three derivatives of 2'-thienyl-2-benzoxazole, having different substituents in the benzene moiety (position 5) and in the furanic or thiophenic ring (position 5'), are described, with the aim of studying antibacterial and antimycotic structure-activity relationships. None of the compounds show an important antibacterial and/or antimycotic activity, when tested against nine bacteria and Candida albicans cultures; in any case it was much lower than that previously reported for the corresponding benzimidazoles. It seems that the = NH group of the imidazole ring, which is absent in the benzoxazole derivatives, might be important for the biological activity of this class of compounds.

Comparative in vitro activity of imipenem against gram-positive and gram-negative aerobic bacteria from clinical isolates.

Imipenem is a member of a new class of beta-lactam antibiotics, carbapenems, with a very broad antibacterial spectrum. In this work we evaluated the in vitro activity of imipenem against a variety of bacterial strains isolated from clinical specimens as well as the activity of other beta-lactam antibiotics. The results obtained with 501 bacterial strains show that imipenem is active on both gram-negative and gram-positive microorganisms isolated from different infections. The in vitro inhibitory activity is greater than that of aztreonam, cefotaxime, ceftriaxone, piperacillin, amikacin, and netilmicin, against the majority of strains tested.

[New heterocyclic derivatives of benzimidazole with germicidal activity. V. Synthesis and activity of new derivatives of di-2-benzimidazolyl-2,5-furan]. / Nouveaux derives heterocycliques du benzimidazole a activite germicide. V. Synthese et activité de nouveaux di-2-benzimidazolyl-2,5-furranes asymétriques.

In continuation of the research in the field of germicidal and antimycotic agents, the synthesis of 14 new derivatives of di-2-benzimidazolyl-2,5-furan is described. These derivatives are differently substituted (R not equal to R') in the position 5 of the two benzene rings. These new compounds showed no germicidal or fungicidal activity, when tested on different cultures. New compounds are under investigation.

[New heterocyclic derivatives of benzimidazole with germicidal activity. III. Synthesis and activity of derivatives of (formyl-5'-furyl-2')-2-benzimidazole with different substitutions at position 5]. / Nouveaux dérivés hétérocycliques du benzimidazole à activité germicide. III--Synthèse et activité de derivés du (formyl-5'-furyl-2')-2-benzimidazole, différemment substitués en position 5.

The synthesis and germicidal properties of 28 new derivatives of furyl-2-benzimidazole are described. The compounds are substituted both in position 5 of the benzene moiety and in position 5' of the heterocycle moiety. The germicidal properties of the new molecules were tested using 9 strains of bacteria and Candida albicans. Some of them exhibited germicidal properties versus Gram + bacteria and versus Candida. Some derivatives were also tested using Mycobacterium aurum: two isonicotinoylhydrazones derivatives exhibited tubercolostatic activity comparable to that of streptomycin and not much lower than that of isoniazide.

New heterocyclic derivatives of benzimidazole with germicidal activity. IV--In vivo anticandida activity of 5-fluoro-2-(5'-nitro-2'-furyl) benzimidazole (F-O-NO2).

We have studied the possible in vitro and in vivo antibacterial activity of 5-fluoro-2-(5'-nitro-2'-furyl)benzimidazole (F-O-NO2). Our data demonstrate that F-O-NO2 is able to inhibit the in vitro growth of different mycetes and bacteria, including Candida albicans and Cryptococcus neoformans. We also tested the possible in vivo activity against Candida albicans. The results clearly show that treatment with F-O-NO2 is able to significantly augment the survival of all treated animals; in particular, when injected i.p. at the dose of 120 mg/kg, 30' or 1 hr after Candida albicans challenge, it givens a MST (Medium Survival Time) longer than 60 days. These data demonstrate that F-O-NO2 has antibacterial and antimycotic activity.

[New heterocyclic derivatives of benzimidazole with germicidal activity. II. Mechanism of action of fluoro-5-(nitro-2'-furyl)-2-benzimidazole in B. subtilis and C. albicans]. / Nouveaux dérivés heterocycliques du benzimidazole à activité germicide. II. Etude du mecanisme d'action du fluoro-5-(nitro-2'-furyl)-2-benzimidazole sur B. subtilis et C. albicans.

Study of the microbiological activity of 5-fluoro-(2'-nitrofuryl)-2-benzimidazole F-O-NO2 (I) was continued. The substance was tested on cultures of B. subtilis and C. albicans. From the microbial strains studied, the mortality rate, the minimum inhibitory and bacterial concentrations and the cytotoxicity were determined. The action mechanism was studied using tritiated leucin, uracil and thymidine. Acute toxicity in the mouse (DL50 = 275 mg/kg) was also determined. The germicidal activity of (II), homologous N-ethyl derivative of (I), was also studied. On the basis of the results obtained, a possible mechanism of action of compound (I) is discussed.