Extraction and partial characterization of proteolytic activities from the cell surface of Lactobacillus helveticus Zuc2.

Proteolytic activities were extracted from a dairy Lactobacillus helveticus strain and partially characterized. A first cell envelope proteinase (CEP) was extracted using a high ionic strength buffer, both in the presence and in the absence of Ca2+. Moreover, cell treatment by 5 M LiCl allowed for the selective removal of the S-layer protein and CEP, suggesting an enzyme ionic linkage to the cell envelope similar to that observed for the Slayer structure. The enzyme specificity against alpha(s1)-CN (f1-23) showed unusual activity on the Lys3-His4 bond compared with other proteinases of the same species. A second proteinase appeared to be linked to the cell membrane because it was extractable only after membrane disgregation by detergents. Its specificity against CN fractions and alpha(s1)-CN (f1-23) was different from that of the first CEP; moreover, the measured activity was lower than that of CEP.

Exopolysaccharide production by Streptococcus thermophilus SY: production and preliminary characterization of the polymer.

AIMS: To evaluate the effect of yeast extract (YE) concentration, temperature and pH on growth and exopolysaccharide (EPS) production in a whey-based medium by Streptococcus thermophilus SY and to characterize the partially purified EPS. METHODS AND RESULTS: Factorial experiments and empirical model building were used to optimize fermentation conditions and the chemical composition, average molecular weight (MW) and rheological properties of aqueous dispersions of the EPS were determined. Exopolysaccharide production was growth associated and was higher (152 mg l(-1)) at pH 6.4 and 36 degrees C with 4 g l(-1) YE. High performance size exclusion chromatography of the partially purified EPS showed two peaks, with a weight average MW of 2 x 10(6) and 5 x 10(4), respectively. The EPS was a heteropolysaccharide, with a glucose : galactose : rhamnose ratio of 2 : 4.5 : 1. Its water dispersions had a pseudoplastic behaviour and showed a higher viscosity of xanthan solutions. SIGNIFICANCE AND IMPACT OF THE STUDY: The fermentation conditions and some properties of an EPS produced by Strep. thermophilus, a dairy starter organism, were described.

Partial characterization of a bacteriocin produced by Lactobacillus helveticus.

AIMS: To investigate the antimicrobial activity of a strain of Lactobacillus helveticus. METHODS AND RESULTS: The culture supernatant fluid Lact. helveticus G51 showed antimicrobial activity against thermophilic strains of Lactobacillus. Purification of the active compound was achieved after gel filtration and ion exchange chromatography. As revealed by SDS-PAGE, active fractions were relatively homogeneous, showing a protein with a molecular mass of 12.5 kDa. The antimicrobial compound was heat labile, inactivated by proteolytic enzymes and had a bactericidal mode of action. CONCLUSION: The antimicrobial activity expressed by Lact. helveticus G51 was correlated with the production of a bacteriocin with properties that were different to other helveticins. SIGNIFICANCE AND IMPACT OF THE STUDY: The study has provided further data on Lact. helveticus bacteriocins. The strong activity of the bacteriocin towards various thermophilic lactobacilli warrants further investigation for its potential to obtain attenuated cultures for the enhancement of the cheese-ripening process.

Partial characterization and plasmid linkage of a non-proteinaceous antimicrobial compound in a Lactobacillus casei strain of vegetable origin.

Lactobacillus casei IMPC LC34 of vegetable origin produces a non-proteinaceous inhibitory compound with a broad spectrum of activity towards Gram-positive and Gram-negative bacteria, including pathogens. The active substance, mainly produced in the stationary phase of growth, is insensitive to proteolytic enzymes, lipase and catalase, and is stable at 121 degrees C for 30 min. The inhibitory activity was detected either at 8 degrees C or at 37 degrees C. The active compound does not contain glucidic groups, is inactivated by Na-metaperiodate, and its molecular mass is between 2000 and 5000 Da. Plasmid curing experiments showed that both antimicrobial compound immunity and production determinants were encoded by an 8.8 kbp plasmid. The effectiveness of the active agent was verified on ready-to-use vegetables, using either the Lact. casei strain or its culture supernatant fluid as inoculant, compared with cured clone. The application potential of the Lact. casei strain or its culture supernatant fluid for assuring the microbiological safety of ready-to-use vegetables is discussed.

A comparison of nimesulide beta cyclodextrin and nimesulide in postoperative dental pain.

The aim of this study was to assess the efficacy and tolerability of single doses of nimesulide beta cyclodextrin compared with nimesulide in patients with dental pain following surgical procedures. This was a randomised, double-blind, between-patient, multicentre study involving 148 outpatients suffering from moderate to severe pain, who received single doses of either 400 mg nimesulide beta cyclodextrin or 100 mg nimesulide. The principal criterion for efficacy was pain intensity assessed on a visual analogue scale (VAS) 15 minutes after drug intake. Pain intensity was further evaluated 30, 45, 90, 120, 180, 240 and 360 minutes after dosing. Pain relief was evaluated at the same time points by means of a categorical scale. The time point of first pain relief, the use of rescue medication and the global evaluation of efficacy were also recorded. The reduction in pain intensity was significantly more pronounced in the nimesulide beta cyclodextrin group at 15, 30, 45 and 60 minutes (p < 0.01). Pain relief was significantly greater (p < 0.05) and more rapid with nimesulide beta cyclodextrin. In the patient overall assessment of efficacy, nimesulide beta cyclodextrin and nimesulide were rated excellent or good by 95% and 92% respectively; only one patient in the nimesulide beta cyclodextrin group needed rescue medication. Both study drugs were effective and well tolerated in the treatment of acute dental pain, with nimesulide beta cyclodextrin showing a faster onset of analgesic action.

Application of antimicrobial-producing lactic acid bacteria to control pathogens in ready-to-use vegetables.

Five psychrotrophic strains of lactic acid bacteria (Lactobacillus casei, Lact. plantarum and Pediococcus spp.) were isolated from 22 samples of commercial salads. These strains were shown to inhibit Aeromonas hydrophila, Listeria monocytogenes, Salmonella typhimurium and Staphylococcus aureus on MRS agar, in salads and in juice prepared from vegetable salads. Lactobacillus casei IMPCLC34 was most effective in reducing total mesophilic bacteria and the coliform group; Aer. hydrophila, Salm. typhimurium and Staph. aureus disappeared after 6 d of storage, while the counts for L. monocytogenes remained constant. The potential application of antimicrobial-producing lactic acid bacteria as biopreservatives of ready-to-use vegetables is suggested.

Inhibitory effect of selected lactic acid bacteria on microflora associated with ready-to-use vegetables.

The addition of selected lactic acid bacteria strains had a remarkable inhibitory effect on the growth dynamics of microflora associated with ready-to-use vegetables, during refrigerated storage. In particular, coliforms and enterococci were strongly reduced or eliminated from the products from the third day of storage. Lactobacillus casei strains proved more effective than pediococci. The use of lactic cultures able to produce bacteriocins and to grow at low temperatures could be a useful tool to preserve fresh vegetables and to ensure their microbiological safety.

Antimicrobial compounds from Lactobacillus casei and Lactobacillus helveticus.

Three strains of Lactobacillus casei and one of Lactobacillus helveticus were examined for antagonistic activity toward twenty five indicator strains of different species. Under conditions eliminating the effects of organic acid and hydrogen peroxide, culture supernatants of all the Lactobacillus strains exhibited a wide spectrum of inhibitory activity toward microorganisms of different genera. The inhibitory compound secreted by one strain of L. casei was active against Clostridium tyrobutyricum. The active components were insensitive to proteolytic enzyme and heat treatment.

[The nimesulide treatment of inflammation and posttraumatic pain in maxillofacial surgery. A controlled study versus flurbiprofen]. / Trattamento con nimesulide della flogosi e del dolore post-traumatico in chirurgia maxillo-facciale. Studio controllato verso flurbiprofen.

Nimesulide has been employed in maxillofacial surgery so as to assess the drug's anti-pain and anti-inflammatory properties. The study was carried out in double blind controlled form, using flurbiprofen as a reference: both medications were administered in suppository form at a fixed dose of two per day, corresponding to 400 mg/die of nimesulide and 200 mg/die of flurbiprofen. Forty adult patients were entered into the experiment and they were assigned to one or other preparation at random until two groups of twenty units each had been formed. Duration of the treatment was just a little more than six days on average and at the end it was possible to conclude that the two therapies were useful in the whole constellation of parameters considered but with some diversification: nimesulide in fact showed an ability to resolve the inflammatory process more readily and consistently than the reference, a tendency that was also confirmed statistically. Tolerability of nimesulide was perfect. There was one episode of diarrhoea with the reference.

Local hemostasis after tooth extraction in patients with abnormal hemostatic function. Use of human fibrinogen concentrate.

Tooth extraction was carried out in 405 patients with various hemostatic disorders due to thrombocytopenia, chronic liver disease, hemophilia A and B, von Willebrand's disease and oral anticoagulants. Human fibrinogen concentrate was used as local hemostatic agent. Prophylactic replacement therapy (platelets or plasma concentrates) and antifibrinolytic agents were not administered. Oral anticoagulants were not discontinued. Minor postextraction bleeding occurred only in severe hemophilia A and occasionally in the oral anticoagulant group.

Behavioral versus pharmacological treatments for essential hypertension: a pilot study.

This is the only study so far in which a behavioral treatment is compared with standard pharmacological treatments for essential hypertension. Three groups of five subjects each were compared: 1. pharmacological treatment; 2. relaxation treatment (autogenic training); 3. the combination. The group given antihypertensive medication was significantly more improved (as determined by blood pressure decrease) by the fourth quarter of the treatment as compared with the relaxation treatment or with the combination. This advantage for routine amounts of antihypertensive medications vs. behavioral treatments is consistent with the only other data from a similar comparison that is available [1].