684 research outputs found
[Antimicrobial characteristics of a tincture of dequalinium chloride].
No full textDequalinium is a quaternary ammonium salt. From about 30 years Dequalinium (D.C.) was used in the treatment of the initial respiratory organs infections. It can be given orally and topically yet it cannot be given systemically cause its probable systemic toxicity. D.C. has a wide range of antimicrobial activity that is extended to Gram positive, Gram negative bacteria, protozoa and yeast. Its mechanism of action is directed to the cytoplasmatic membrane where D.C. caused its damage and consequently release of cellular components. Our study has been evaluated the antimicrobial activity of D.C. both as commercial product that pure substance. We tested 27 Gram positive bacteria, 49 Gram negative bacteria, 83 strains of fungi, we also tested the antimicrobial activity of D.C. commercial product and pure substance against 8 strains of protozoa; Trichomonas vaginalis. The antimicrobial activity was estimated in some experimental conditions, (cultural and no cultural conditions); in these experiments we can observed that the commercial product presents higher activity than pure substance. In cultural condition commercial product presents antimicrobial activity against Gram positive and negative bacteria and yeast; its interesting to evaluate that bacteria, that are resistant to the common antimicrobial agents were inhibited by D.C. tinture and pure substances. Our data exhibit that serum didn't interfere until the 2\% concentration with the antimicrobial activity of D.C., moreover this antimicrobial activity is not influenced by the inoculum size until 10(5) cell/ml. D.C. presents higher activity at alkaline pH than acid pH but strains of C. albicans were killed by D.C. at acid pH. In no cultural conditions D.C. has demonstrated a rapid antimicrobial activity in short contact time (15 minute); the cells of some microorganisms were killed in 60 minutes. Against mycelial form, the commercial product demonstrates good activity higher than pure substance. The activity of D.C. against the formation of germ-tube from blastospores of C. albicans in N-acetyl-glucosamine solution (no culture medium) was markedly high; this is very important because in C. albicans the germ-tube production and yeast-mycelial conversion are prominent for pathogenicity and resistance to host defences. Our data demonstrate the good activity of D.C. against Trichomonas vaginalis; we can also observed that the antimicrobial activity of commercial product is higher than pure substance.(ABSTRACT TRUNCATED AT 400 WORDS
[Antimicrobial activity exerted by sodium dichloroisocyanurate].
No full textSodium dichloroisocyanurate is a chlorinated cleaner. It was used for swimming pool sanitation and for the sterilisation of linen. Not recently ago sodium dichloroisocyanurate has substituted hypochlorite for the sterilisation of infant feeding bottles and teats. Sodium dichloroisocyanurate is soluble in water; this condition causes the hydrolysis of sodium dichloroisocyanurate in hypochlorous acid, that is the active agent, isocyanurate and isocyanurate chlorine. These compounds form a chlorine protein that carry out microbicidal activity. In a toxicology study has been shown that no severe changes in the normal metabolic function occurred, furthermore sodium dichloroisocyanurate has not shown teratogenic effects at the concentration of 200 mg/kg. The antimicrobial activity of sodium dichloroisocyanurate was evaluated against Gram negative bacteria such as E. coli or Salmonella typhimurium and against some fungi. This study illustrates a rapid antimicrobial activity using concentrations. Our study concentrated on the antimicrobial activity of sodium dichloroisocyanurate in some experimental conditions. We tested 66 strains of fungi, 28 Gram positive bacteria and 29 Gram negative bacteria. We also evaluated the antimicrobial activity of sodium dichloroisocyanurate against protozoa such as Trichomonas vaginalis. The antimicrobial activity was evaluated in cultural conditions and non cultural conditions; in these experiments we observed similar action in both the commercial product and pure substance. In cultural conditions sodium dichloroisocyanurate shows a good activity against fungi and bacteria, moreover it can be observed that the serum didn't interfere with its activity. In a non cultural condition the Candida was killed rapidly by the sodium dichloroisocyanurate but this activity is influenced by the growth phase of the yeast. Against mycelial form such as Penicillium and Aspergillus the sodium dichloroisocyanurate needs a longer contact time than yeast form for its activity. It is interesting to note that well known bacteria, that are resistant to the common antimicrobial agents, such as Pseudomonas aeruginosa, were inhibited by sodium dichloroisocyanurate in a rapid bactericidal action. Our data demonstrates that no significant adverse influence on the activity of sodium dichloroisocyanurate was shown by pH and by temperature even if in some experimental conditions increased activity was noticed at pH = 6.6. The sodium dichloroisocyanurate has demonstrated good activity against Trichomonas vaginalis. This fact extends the broad-spectrum activity of sodium dichloroisocyanurate to the protozoa. In conclusion, sodium dichloroisocyanurate has demonstrated a good activity against all tested strains, furthermore its activity did not decrease in the presence of 1\% of organic substance (serum etc.).(ABSTRACT TRUNCATED AT 400 WORDS
ATTIVITA' ANTIBATTERICA ED ANTIFUNGINA DELLA PROPOLI
No full textSamples of wax-removal propolis by a cold working and physic extractive method
*E.P.I.D.® and crude propolis , were investigated for their antibacterial and fungicidal activity against
clinical isolates Gram-positive strains and fungi.
All the samples were active against tested microrganisms .
E.P.I.D® propolis compared with crude propolis, shows a better antimicrobial activity against bacterial
strains with MICs ranging from 0,156 to 1,25 mg/ml and fungi ranging from 0,6-5 mg/ml for
Candida spp. and from 2,5-5 mg/ml against dermathophytes.
Introduzione
La propoli è una sostanza resinosa prodotta dalle api
bottonatrici raccolta da diverse piante, da molto tempo
conosciuta per le sue caratteristiche farmacologiche.
Essa è raccolta dalle api in particolare dall’Apis
mellifera, dai germogli, foglie e cortecce di differenti
piante (betulle, pioppi, olmi etc.) , successivamente
trasformata da enzimi presenti nella saliva.
Viene utilizzata dalle api stesse per restringere l’ingresso
dell’alveare, per chiudere le fessure presenti
nell’arnia e per imbalsamare eventuali insetti predatori
uccisi, dopo un’invasione dell’alveare.
E’ usata come “medicamento alternativo”,in infezioni
otorinolaringoiatriche, in odontoiatria, gastroenterologia,
e in infezioni ginecologiche.
Le proprietà antibatteriche e antifungine della propoli
sono note, ma la sua efficacia è correlata all’origine
geografica, a causa della diversa composizione
chimica dovuta alle diverse piante. (2)
Tra i vari costituenti: cere, resine, balsami, olii essenziali,
acidi aromatici, polline e costituenti polifenolici con predominanza
di composti a struttura flavonoide, aldeidi,
acido benzoico e caffeico sono le più importanti sostanze
riscontrate nella composizione della propoli, la loro
quantità è dipendente dal luogo e dal tempo di raccolta.
Sono sta
THE INHIBITORY-ACTION OF FLUCONAZOLE ON YEAST-TO-MYCELIAL PHASE CONVERSION IN CANDIDA-ALBICANS
No full textThe ability of fluconazole, a bis-triazole antifungal agent, to inhibit conversion of Candida albicans from the yeast (Y) to the pathogenic mycelial (M) form was studied under various in vitro cultural conditions. In growth-supporting media, fluconazole was able to inhibit Y to M conversion of the test organism at concentrations below those required to inhibit Y phase growth. Under nongrowth-supporting conditions (N-acetylglucosamine solution) fluconazole had only a small effect on Y to M conversion
Suceptibility assay of Candida tropicalis to miconazole
No full textIn vitro evaluation of antifungal activity of imidazole derivatives is made difficult by the inhibitory effects of several factors such as inoculum size, growth form of the fungus, incubation temperature, the presence of complex substances, including divalent ions, which strongly influence final results. This is particularly evident when testing clinical isolates of C. tropicalis strains resistant to imidazole drugs. Our data based on assays of miconazole nitrate and miconazole sulfosalicylate against C. tropicalis show that it is possible to abolish various interference activities on the antimicrobial activity by suitable modifications of some cultural conditions. Thus, a study has been carried out to assess miconazole sulfosalicylate activity on C. tropicalis throughout experiments performed by contact test and agar diffusion test. The use of these techniques made it possible to display some activity of the imidazoles even against strains of C. tropicalis, which were defined as resistant using usual susceptibility assay conditions. Experimental conditions which cause the increase of susceptibility of C. tropicalis are related to factors that modify the barrier function and cellular permeability as demonstrated mainly by the effect of electrical conductivity (E.C.), pH of the medium and pretreatment of fungal inoculum with sodium dioctylsulfosuccinate (SDSS). Our results suggest that the correlation between drug dosage and inhibitory activity in vitro can be improved by the modifications proposed in this paper. (C) 1997 Elsevier Science B.V
Visas e altre poesie. Con documenti e testimonianze e il CD Visas per Vittorio Reta di Stefano Scodanibbio
No full textIl libro comprende l'opera poetica integrale di Vittorio Reta: oltre a «Visas», infatti, apparso per Feltrinelli nel 1976, sono qui pubblicate per la prima volta più di sessanta poesie inedite, diverse per epoca e per connotazioni stilistiche. I testi sono introdotti da un ampio saggio storico-letterario ed ermeneutico e corredati da una nota filologica. Il libro offre anche una inedita documentazione fotografica dell'autore e un cd allegato con l'opera composta da Stefano Scodanibbio «Visas per Vittorio Reta», nata da una suggestione cui non è estraneo Edoardo Sanguineti.The book includes the integral poetic work of Vittorio Reta: in addition to «Visas», in fact, appeared for Feltrinelli in 1976, here are published for the first time more than sixty poems unpublished before, different by age and stylistic connotations. The texts are introduced by a large historical-literary and hermeneutic essay and accompanied by a philological note. The book also offers an unpublished photographic documentation of the author and a CD with the opera composed by Stefano Scodanibbio «Visas for Vittorio Reta», born from a suggestion received probably by Edoardo Sanguineti
Anticandidal activity of SPA-S-843, a new polyenic drug
No full textThe activity of a new, soluble and stable polyene (SPA-S-843) against Candida albicans was assessed by contact and culture tests and by inhibition of germ-tube formation. The drug demonstrated a higher contact activity and lower MICs than amphotericin B. This antimicrobial activity was more evident under acid pH and low ionic strength. In addition, the ability of SPA-S-843 to inhibit Candida so, conversion from yeast to mycelial form was evident at low drug concentrations (0.25-0.62 mg/L)
IN VITRO ACTIVITY OF TEA TREE OIL AGAINST CANDIDA ALBICANS MYCELIAL CONVERSION AND AGAINST OTHER PATHOGENIC FUNGI
No full textThe antifungal activity of Melaleuca alternifolia Maiden essential oil against some yeasts and dermatophytes is reported. The essential oil inhibited the conversion of C. albicans from yeast to the mycelial form at a concentration of 0.16% (v/v). The MICs ranged from 0.12% to 0.50% (v/v) for yeasts and 0.12% to 1% (v/v) for dermatophytes; the cytocidal activity was generally expressed at the same concentration. The results suggest that essential oil may be suitable for topical use in the treatment of fungal mucosal and cutaneous infection
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