Synthesis of eugenol esters by lipase-catalyzed reaction in solvent-free system.

Enzymatic esterification of eugenol is a matter of great scientific and technological interest due to the well-known drawbacks of the chemical-catalyzed route as well as the potential use of produced compounds as natural antimicrobials. This work reports the maximization of eugenil acetate production by esterification of eugenol and acetic anhydride in a solvent-free system using Novozym 435 as catalyst. The antimicrobial activity of eugenol and eugenil acetate was also determined. The operating conditions that maximized eugenil acetate production were 50 °C, eugenol to acetic anhydride of 1:3, 150 rpm, and 5.5 wt% of enzyme, with a conversion of 99 %. A kinetic study was performed to assess the influence of substrates molar ratio, enzyme concentration, and temperature on eugenil acetate yield. Results show that an excess of anhydride, low enzyme concentration (1 wt%), and 60 °C afforded nearly complete conversion after 6 h of reaction. The highest antimicrobial activity of eugenil acetate was observed against Acinetobacter sp. (48.66 mm) at concentration of 20 µL. Results indicate that the esterification of eugenol improved its antimicrobial properties. New experimental data on enzymatic esterification of eugenol and acetic anhydride are reported in this work, showing a promising perspective to overcome the inconvenient of the chemical-catalyzed route for obtaining antimicrobial natural compounds.

Fusarium peritonitis in peritoneal dialysis: report of two cases.

This report describes two cases of peritoneal dialysis-related peritonitis caused by Fusarium species which have been incriminated in a variety of disease conditions. Treatment with 5-Fluorocytosine was unsuccessful, but removal of the catheter resulted in a rapid resolution of the infections.

Source and route of microbial colonisation of parenteral nutrition catheters.

To assess the effectiveness of tunnelling the polyurethane venous catheter for parenteral nutrition in reducing the frequency of catheter microbial colonisation, and to investigate the routes taken by microorganisms colonising the central venous catheter, 109 patients were randomised to traditional subclavian catheterisation (58, group A) or to subcutaneous catheter tunnelling (51, group B). Samples were taken from patients and their nurse attendants to identify their indigenous flora. Cultures were also done of swabs from the catheter insertion site, blood, nutrient solution, segment of the catheter, and washings of the catheter hub. Intravascular segment colonisation was commoner in group A (18/58) than in group B patients (4/51), and bacterial migration from insertion site to intravascular segment was also commoner among group A (9/58) than among group B patients (1/51). Catheter hub contamination was responsible in 10 out of 22 cases of microbial colonisation; in 6 of these 10 the bacterium isolated was present on the skin of nurses who changed the bag. Contamination of the insertion site skin and of the CVC hub were equally responsible for the microbial colonisation of the intravenous segment of the catheter.

Ofloxacin: in vitro activity against recently isolated gram-negative bacterial strains.

The activity of ofloxacin was determined against 117 Enterobacteriaceae, 13 Acinetobacter var, anitratus, 124 Pseudomonas aeruginosa in comparison with other antibiotics. Its activity was very high: against Enterobacteriaceae the minimum inhibitory concentration (MIC)50 was 0.125 micrograms/ml, the MIC90 1 micrograms/ml, and the geometric mean (GM) was 0.4 micrograms/ml against Acinetobacter var. anitratus the MIC50 1 micrograms/ml, MIC90 4 micrograms/ml, GM 1.7 micrograms/ml. Unlike other authors we found that the activity of ofloxacin was influenced by the selection of P. aeruginosa resistant to carbenicillin and gentamicin.

Critical evaluation of bioluminescence methods for quantifying bacterial adhesion to polystyrene.

A total of 134 strains of Escherichia coli which included 60 fecal and 74 urinary isolates, cultured in liquid and on solid media, were examined for adhesive properties using bioluminescence and haemagglutination methods. The study aimed to verify whether irrespective of the absence or presence of flagella, there is any relation between haemagglutination and bioluminescence test. Examining the results we failed to note any correlation between the two methods: strains bearing MS, MR or MS-MR adhesins adhered to polystyrene at random. Even though it is fast and easy to perform, bioluminescence is not an alternative to traditional methods to reveal MS adhesins.

Patterns of haemagglutinating activity of Escherichia coli.

MR and MS adhesins on 169 strains of Escherichia coli subjected to different cultural conditions were detected. Haemagglutination Test (static settling test in plastic microtiter trays) was used and several species of red blood cells were employed. The results confirm that different media can influence the expression of the adhesins and that using as many species of red blood cells as possible one can detect different adhesins.

[Comparative evaluation of various direct and culture methods for the diagnosis of genital Chlamydia trachomatis infections]. / Valutazione comparativa di alcuni metodi diretti e colturali per la diagnosi di infezioni genitali da "Chlamydia trachomatis".

Commercially produced fluorescein labelled monoclonal antibodies for Chlamydia trachomatis detection have been recently become available. We have compared the data obtained using two monoclonal antibodies, one for detecting inclusion on cell cultures (culture confirmation) and the other for detecting C. trachomatis in smears from urethral and cervical swabs, with our routine isolation method which utilizes Giemsa staining of cycloheximide treated McCoy cell cultures. We also evaluated an enzyme immunoassay for detecting C. trachomatis antigens in urethral and cervical specimens. The culture confirmation system was slightly more sensitive and simpler than Giemsa staining. Between the results of immunofluorescence direct test and culture there was 96.3% agreement. Sensitivity, specificity and predictive positive and negative value were 72.2, 98.4, 80 and 97.6%. Between results of culture and enzyme immunoassay there was 97.2% agreement. The immunoassay sensitivity, specificity predictive positive and negative value were, in women, 100, 97.1, 63.6 and 100%; in men, 100, 95.7, 81.8, 100%.

[Detection of bacteremia by biphasic and radiometric methods]. / Rilevamento di batteriemia con metodo bifasico e radiometrico.

During one year period our laboratory carried out 859 hemocultures. These have been evaluated with two methods: a conventional biphasic method (Castaneda bottles), and the automated radiometric method (Bactec System). 185 cultures were obtained with one or both methods. Of these 3.5% were considered contaminated, therefore the clinically significant isolation rate was 16.2%. Of these 86.4% was recovered by biphasic system and 79.8% by Bactec System. The recovery time to positivity and spectrum of isolates were similar for the two methods. Although there were substantially more contaminants isolated in the Vacutainer-Bactec System.

Comparative in vitro activity of eight antibiotics against Pseudomonas aeruginosa and infrequently isolated gram-negative bacilli.

Seventy-eight Gram-negative non-fermentative bacilli have been tested against eight antimicrobial agents (wide spectrum penicillins, newer generation cephalosporins and aminoglycosides). Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of each compound were determined by microdilution technique. Ceftazidime showed higher antibacterial activity against all bacterial strains.

[Case of Listeria monocytogenes meningitis with a benign course in a healthy adult]. / Osservazione di un caso di meningite da listeria monocytogenes a decorso benigno in adulto sano.

We herein describe the case of Lysteria monocytogenes meningitis. The isolation and identification of the bacteria causing the infection ollowed the antibiotic treatment followed by complete remission. Our data also support the hypothesis on intense immunological response producing a favourable evolution of the disease.

Torulopsis glabrata peritonitis complicating continuous ambulatory peritoneal dialysis: successful management with oral 5-fluorocytosine.

We report two cases of fungal peritonitis caused by Torulopsis glabrata, an uncommon opportunistic pathogen, in patients with end-stage renal disease receiving continuous ambulatory peritoneal dialysis (CAPD). The general clinical characteristic of T glabrata peritonitis was comparable to previously reported cases of Candida peritonitis. Although appropriate therapy of fungal peritonitis in patients undergoing CAPD still remains controversial, both for the drug of choice and for the dosage to be used, our study indicates that a 5-week course of oral 5-fluorocytosine (5-FC) may obviate the need to remove the peritoneal catheter during the management of peritonitis caused by susceptible strains of T glabrata.

[Comparative evaluation of 3 miniaturized systems (API 20E, Enterotube II, Sensititre AP60) commonly used in clinical microbiology laboratories]. / Valutazione comparativa di tre sistemi miniaturizzati (API 20E, Enterotube II, Sensititre AP60) largamente in uso nei laboratori di microbiologia clinica.

API 20E, Enterotube II, Sensititre AP60 have been evaluated. Some biochemical tests (lysine, ornithine, VP, H2S, adonitol , arabinose, citrate) have revealed significative differences among three systems. The total correlations about bacterial identifications have been very similar. The repetibility of identifications of strains isolated from clinical specimens has been 98.7% for Enterotube and API 20E, 95.5% for Sensititre . The biochemical tests have revealed repetibility greater than or equal to 94%, citrate repetibility instead has been 91%.

[Comparison of AMS and MS-2 in the identification and antibiotic sensitivity of clinically isolated bacterial strains]. / Confronto tra AMS e MS-2 nell'identificazione e nella sensibilità agli antibiotici su ceppi batterici di isolamento clinico.

282 clinical bacterial strains have been identified with AMS and MS-2. Among biochemical tests only lysine, adhonitol , glucose did not show significant differences. The overall correlation has been 86.3%. The results of the susceptibility to antimicrobial agents on 98 bacterial strains revealed an overall agreement of 79.3%, an essential agreement of 91%.