E.C.P. De Martinis

Improved treatment of vulvovaginal candidiasis with fluconazole plus probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14

Aims:  To determine the ability of probiotic lactobacilli to improve the treatment of vulvovaginal candidiasis (VVC) using a randomized, double‐blind and placebo‐controlled trial.

FUNDAMENTALS AND PERSPECTIVES FOR THE USE OF BACTERIOCINS PRODUCED BY LACTIC ACID BACTERIA IN MEAT PRODUCTS

Bacteriocins of lactic acid bacteria (LAB) are proteinaceous compounds that may present antimicrobial activity towards important foodborne pathogens and spoilage-related microflora. Due to these properties, bacteriocin-producing strains or purified bacteriocins have a great potential of use in biologically based food preservation systems. Despite the growing number of articles describing the isolation of bacteriocinogenic strains, genetic determinants for production, as well as the purification and biochemical characterization of these inhibitory substances, there are only limited reports of successful application of bacteriocins to meats. This paper presents a critical review of the methods available for screening of bacteriocin-producing LAB strains from meats and also discusses the proposed mechanisms of action for LAB bacteriocins. Additionally, an overview of the Brazilian experience in the application of LAB bacteriocins to meats and meat products is given.

Antilisterial activity of lactic acid bacteria inoculated on cooked ham

This study was conducted to evaluate the ability of Lactobacillus sakei 1, a bacteriocin-producing (bac(+)) lactic acid bacterium (LAB), isolated from Brazilian fresh pork sausage to inhibit two Listeria monocytogenes strains (serotypes 4b and 1/2a) on cooked, sliced vacuum-packaged ham. L. sakei ATCC 15521 was used as a non-bacteriocin producer (bac(-)). L. monocytogenes (ca. 2 logCFU/mL) and LAB (ca. 6 logCFU/ml) were inoculated on the sterilized ham, vacuum-sealed and incubated at 8°C for 10 days. A treatment with the bacteriocin Chrisin (UI/ml) was included. Both L. monocytogenes strains were significantly inhibited in the presence of either bac(+) and bac(-) LAB in comparison to the control (L. monocytogenes alone). Using a bacteriocinogenic strain of LAB did not offer an additional barrier to listerial growth in the studied meat system. The application of Chrisin did not affect at all the growth of L. monocytogenes.

Screening of lactic acid bacteria from Brazilian meats for bacteriocin formation

Abstract Twenty samples of vacuum-packaged meat products from Brazil were screened for the presence of bacteriocin-producing lactic acid bacteria, using an agar overlay method. Three bacteriocinogenic isolates were obtained and identified as Enterococcus sp. 18 (from bacon), Leuconostoc sp. 20 (from ham) and Lactobacillus sakei 29 (from hot home made “linguica”). Leuconostoc sp. 20 and Lactobacillus sakei 29 presented antilisterial activity, inhibiting all the strains of Listeria monocytogenes tested. However, the strains did not inhibit Brochothrix thermosphacta , Enterobacter sp., Salmonella sp. or Escherichia coli .

The significance of Helicobacter pylori in water, food and environmental samples

Abstract Infection by Helicobacter pylori is recognized as the major cause of gastric disease and its prevalence is elevated worldwide. It is hypothesised that the transmission of H. pylori involves multiple pathways: iatrogenic, oral–oral and faecal–oral. Food and water are suspects of serving as vehicles in the faecal–oral route of H. pylori infection. However, the difficult cultivation of H. pylori from samples with high loads of accompanying microflora and its conversion to viable but nonculturable state (VNC) impair the elucidation of the real role of waterborne and foodborne infections by this pathogen. In this sense, it is crucial the development of methods for isolation of H. pylori from environmental samples. In this work, an overview of the present knowledge on epidemiology and transmission of H. pylori is presented, attempting to the possible role of water and foods in the spread of the infection.

Quantitative evaluation of Listeria monocytogenes in fresh and processed surubim fish (Pseudoplatystoma sp)

L. monocytogenes is a foodborne psychrotrophic bacterial pathogen of special importance for minimally processed foods. In this work, it was enumerated in samples of surubim fish by MPN technique. The population of L. monocytogenes was estimated as < 0.012 MPN/cm 2 in fresh and < 0.03 MPN/g in minimally processed fish.

Improved adsorption-desorption extraction applied to the partial characterization of the antilisterial bacteriocin produced by Carnobacterium maltaromaticum C2

Bacteriocins are ribosomally produced peptides useful for food biopreservation. An improved adsorption-desorption process is proposed for the partial purification of the bacteriocin produced by the fish isolate Carnobacterium maltaromaticum C2. Analyzis of extract by SDS-PAGE indicated this method may offer an alternative to improve the yield of purification of bacteriocins.

In vitro protective effect of lactic acid bacteria on Listeria monocytogenes adhesion and invasion of Caco-2 cells

The adhesion of Listeria monocytogenes to intestinal endothelial cells is a crucial step in the infection process, which is not well understood. In this study, we evaluated the potential ability of bacteriocin-producing Enterococcus faecium, Leuconostoc mesenteroides and Lactobacillus sakei strains to prevent the adhesion and invasion of eukaryotic cells by ten different L. monocytogenes isolates. The results showed that E. faecium 130 co-cultured with L. monocytogenes was the most effective in preventing infection of Caco-2 cells, as the vast majority of isolates showed significantly lower adhesion counts and invasion rates below the quantification limit of the method (<30 cfu/plate). L. sakei 1 was the least effective strain in preventing L. monocytogenes infection; only one isolate presented a lower adhesion rate and two isolates reduced the invasion rate of Caco-2 cells. Fluorescence in situ hybridisation (FISH) assay was shown to be an effective tool to illustrate and identify species in co-culture with L. monocytogenes during the adhesion process to Caco-2 cells.The adhesion of Listeria monocytogenes to intestinal endothelial cells is a crucial step in the infection process, which is not well understood. In this study, we evaluated the potential ability of bacteriocin-producing Enterococcus faecium, Leuconostoc mesenteroides and Lactobacillus sakei strains to prevent the adhesion and invasion of eukaryotic cells by ten different L. monocytogenes isolates. The results showed that E. faecium 130 co-cultured with L. monocytogenes was the most effective in preventing infection of Caco-2 cells, as the vast majority of isolates showed significantly lower adhesion counts and invasion rates below the quantification limit of the method (<30 cfu/plate). L. sakei 1 was the least effective strain in preventing L. monocytogenes infection; only one isolate presented a lower adhesion rate and two isolates reduced the invasion rate of Caco-2 cells. Fluorescence in situ hybridisation (FISH) assay was shown to be an effective tool to illustrate and identify species in co-culture w...