Diversity of Lactic Acid Bacteria Isolated from Brazilian Water Buffalo Mozzarella Cheese

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Use of probiotics to reduce faecal shedding of Shiga toxin-producing Escherichia coli in sheep

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sub-MICs of Mentha piperita essential oil and menthol inhibits AHL mediated quorum sensing and biofilm of Gram-negative bacteria

Bacterial quorum sensing (QS) is a density dependent communication system that regulates the expression of certain genes including production of virulence factors in many pathogens. Bioactive plant extract/compounds inhibiting QS regulated gene expression may be a potential candidate as antipathogenic drug. In this study anti-QS activity of peppermint (Menthe piperita) oil was first tested using the Chromobacterium violaceum CVO26 biosensor. Further, the findings of the present investigation revealed that peppermint oil (PMO) at sub-Minimum Inhibitory Concentrations (sub-MICs) strongly interfered with acyl homoserine lactone (AHL) regulated virulence factors and biofilm formation in Pseudomonas aeruginosa and Aeromonas hydrophila. The result of molecular docking analysis attributed the QS inhibitory activity exhibited by PMO to menthol. Assessment of ability of menthol to interfere with QS systems of various Gram-negative pathogens comprising diverse AHL molecules revealed that it reduced the AHL dependent production of violacein, virulence factors, and biofilm formation indicating broad-spectrum anti-QS activity. Using two Escherichia colt biosensors, MG4/pKDT17 and pEAL08-2, we also confirmed that menthol inhibited both the las and pqs QS systems. Further, findings of the in vivo studies with menthol on nematode model Caenorhabditis elegans showed significantly enhanced survival of the nematode. Our data identified menthol as a novel broad spectrum QS inhibitor.

Denture stomatitis--presence of bacteria and yeasts

The presence of yeasts and bacteria was studied in 26 patients with denture stomatites, and the results compared with the data of the normal mucosa foi edentoulous patients, who used or not upper dentures. The use of dentures caused an increase in the amount of yeasts, and there was a correlation with the severity of the stomatitis. Gram positives cocci and bacilus predominated in all studied groups, but in cases of stomatitis there was an increase in the amount of Gram negative cocci and filamentous. These results suggest that besides yeasts, modifications of the bacteria flora can be relevant for the development of denture stomatitis.

Induction of short gut syndrome and transplantation in a porcine model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Formation of a ternary complex for selenocysteine biosynthesis in bacteria

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fermentation by gut microbiota cultured in a simulator of the human intestinal microbial ecosystem is improved probiotic Enterococcus faecium CRL 183

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Study of physical-chemical stability in contaminated conditioners by bacteria

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of the use of probiotic acid lactic bacteria in the development of chicken hambúrguer

The objective of this study was to investigate the effect of fermentation with Lactobacillus acidophilus CRL 1014 on the physicochemical, microbiological and sensory characteristics of a hamburger product like processed with chicken meat and okara flour, with reduction of curing salts. A mixture of ingredients containing 90% chicken meat and 10% okara flour was subjected to the following treatments: F1: fermented with Lactobacillus acidophilus; F2:75 mg nitrite/kg and fermented with Lactobacillus acidophilus; F3: 150 mg nitrite/kg and unfermented. The quality of the “hamburgers” was assessed by physical and chemical analysis (pH, cooking yield and shrinkage), chemical composition, microbiological tests (Salmonella spp., count of sulphite-reducing clostridia, staphylococos coagulase-positive, total coliforms and Escherichia coli) and sensory analysis (sensory acceptance and purchase intent). During the first six days of fermentation, there was a decrease in pH from approximately 6.33 to 5.10. All the samples showed the same chemical composition (p < 0.05). The fermentation process was observed to inhibit the multiplication of microorganisms of several groups: coagulasepositive staphylococci, sulphite-reducing clostridia, Salmonella spp. and E. coli. The different “hamburgers” formulations showed high scores for all the sensory attributes evaluated, without differing from each other (p < 0.05). The results showed that the use of L. acidophilus CRL 1014 enabled the production of a safe product, with good physicochemical and sensory characteristics, in the absence of curing salts.

Bacteria on the hands of school-age children at a Pediatric Hospitalization Unit

Objective. To estimate the prevalence of bacteria isolated in samples from the hands of school-age children at a hospitalization unit. Methodology. In 2009, strains were cultured from the hands of 90 school-age children at the pediatric hospitalization unit of Hospital Estadual Bauru (São Paulo, Brazil). After culture of the samples, the isolated bacteria were identified. Results. In 98% of the samples taken from the children, bacteria were isolated. Coagulase-negative Staphilococcus was isolated in 64% of the samples, followed by Staphilococcus aureus (5%) and Pseudomonas aeruginosa (1%). Conclusion. In most of the samples from the children’s hands, bacteria were isolated. Therefore, educative actions about hygiene habits in- and outside the hospital environment should be reinforced, aimed at children and their companions.

P-233-Biodiversity of mucosa associated microbiome of Crohn's disease patients living in middle western São Paulo State, Brazil

Background: The intestinal microbiome (IM) has extensively been studied in the search for a link of bacteria with the cause of Crohn`s disease (CD). The association might result from the action of a specific pathogen and/or an eventual imbalance in bacterial species composition of the gut. The innumerous virulence associated markers and strategies described for adherent and invasive Escherichia coli (AIEC) have made them putative candidate pathogens for CD. IM of CD patients shows dysbiosis, manifested by the proliferation of bacterial groups such as Enterobacteriaceae and reduction of others such as Lactobacillus and Bifidobacterium. The augmented bacterial population comprising of commensal and/or pathogenic organisms super stimulates the immune system, triggering the inflammatory reactions responsible for the clinical manifestations of the disease. Considering the role played by IM in CD and the multiple variables influencing its species composition, resulting in differences among populations, the objective of this study was to determine the bacterial biodiversity in the mucosa associated microbiome of CD patients from a population not previously subject to this analysis, living in the middle west region of Sao Paulo state. Methods: A total of 4 CD patients and 5 controls subjects attending the Botucatu Medical School of the Sao Paulo State University (UNESP) for routine colonoscopy and who signed an informed consent were included in the study. A number of 2 biopsies, one from the ileum and other from any part of the terminal colon, were taken from each subject and immediately frozen at -70[degrees]C until DNA purification. The bacterial biodiversity was assessed by next generation (ion torrent) sequencing of PCR amplicons of the ribosomal DNA 16S V6 region (16S V6 rDNA). The bacterial identification was performed at the genus level, by alignment of the generated DNA sequences with those available at the ribosomal database project (RDP) website. Results: The overall DNA sequence output was based on an average number of 526,427 reads per run, matching 50 bacterial genus 16SrDNA sequences available at the RDB website, and 22 non matching sequences. Over 95% of the sequences corresponded to taxa belonging to the major phyla: Firmicutes, Bacterioidetes, Proteobacteria and Actinobacteria. Irrespective of the intestinal site analyzed, no case-control differences could be observed in the prevalence of Actinobacteria and Firmicutes. The prevalence of Proteobacteria was higher (40%) in the biopsies of control subjects as compared to that of DC patients (16%). For Bacterioidetes, the higher prevalence was observed among DC patients (33% as opposed to 14,5% in controls). The significance for all comparisons considered a p value < 0,05 in a Chi2 test. No mucosal site specific differences could be observed in IM comparisons of CD and control subjects. Conclusions: The rise in the number of Bacterioidetes observed here among CD patients seems to be in agreement with most of studies published thus far. Yet, the reduction in the number of Proteobacteria along with an apparently unaltered population of Actinobacteria and Firmicutes, which include the so called "beneficial" organisms Bifidobacterium and Lactobacillus were rather surprising. These data suggest that the analyses on the role of IM in CD should consider the multiple variables that may influence its species composition.

P-220-Escherichia coli displaying virulence features of multiple diarrheogenic pathotypes detected in a Crohn's disease patient

Background: The number of Escherichia coli in the gut of Crohn's disease (CD) patients is higher than that of normal subjects, but the virulence potential of these bacteria is not fully known. Previous studies have shown that these E. coli are closely related to extraintestinal pathogenic categories (ExPEC), are able to invade epithelial cells, and usually do not produce exotoxins. We report here the detection, in a CD patient, of an E. coli which belongs to a classical enteropathogenic (EPEC) serotype and displays virulence markers of enteroinvasive (EIEC), enteroaggregative (EAEC) and enterohemorrhagic (EHEC) pathotypes. Methods: The E. coli strain was isolated, in 2009, by classical bacteriological procedures from a 56 year old woman who underwent ileo-terminal resection 1 year before, due to intestinal obstruction. The bacterial characterization was carried out by in vitro adhesion and invasion assays to cultured epithelial cells and macrophages and screening by PCR to identify virulence genetic markers of diarrheogenic E. coli (DEC) and to detect one of the gene combinations which define the phylogroups of the E. coli reference (EcoR) collection. The strain was also tested for the ability to produce biofilm and shiga cytotoxins and had its whole genome sequenced by Ion Torrent Sequencing Technology. Results: The studied strain, which was detected both in ileum biopsies and the stools of the patient, displayed the aggregative adherence (AA) phenotype to Hep-2 cells and an ability to enter Caco-2 cells 3x as high as that of EIEC reference strain and 89% of that of the prototype AIEC LF82 strain. Although it could invade cultured macrophages, the strain was unable to replicate inside these cells. PCR screening revealed the presence of eae, aggR and stx1. Tests with bacterial culture supernatants in Vero cells demonstrating cytotoxicity suggested the production of Stx1. In addition, the strain revealed to be a strong biofilm producer, belonged to the B2 EcoR phylogroup, to the O126:H27 serogroup and to the multilocus sequencing type (MLST) ST3057. The 2 later features were deduced from the whole genome sequence of the strain. Conclusions: The characterization of this E. coli isolate from a CD patient revealed a combination of virulence markers of distinct DEC pathotypes, namely eae and stx1 of EHEC, AA, aggR and biofilm formation of EAEC, and invasiveness of EIEC. These features along with its serotype and phylogroup identity seem to suggest a potential to be involved in CD, an observation which should be tested with additional studies.

Gamma irradiation can control the number of psychotrophic bacteria in Agaricus bisporus during storage

We evaluated the effect of gamma irradiation doses (0, 125, 250, and 500 Gy) in control of psychrotrophic bacteria in different strains of Agaricus bisporus (ABI-07/06, ABI-05/03, and PB-1) during storage, cultivated in composts based on oat straw (Avena sativa) and Brachiaria spp. The experimental design was completely randomized in a factorial scheme 4  2  3 (irradiation doses  composts  strains), with 24 treatments, each consisting of 2 replicates, totaling 48 experimental units (samples of mushrooms). The mushrooms collected from all culture conditions were packaged in plastic polypropylene with 200 g each and subjected to Cobalt-60 irradiator, type Gammacell 220, and dose rate 0.740 kGy h–1 , according to the treatments. Subsequently, the control (nonirradiated) and other treatments were maintained at 4 ± 1°C and 90% relative humidity (RH) in a climatic chamber to perform the microbiological analysis of mushrooms on the 1st and 14th day of storage. According to the results, it was found that the highest mean colony psychotrophic count, after 14 days of storage, was observed in strain ABI-07/06 1.30 × 108 g -1 most probable number (MPN) in nonirradiated mushrooms, coming from Brachiaria grass-based compost, and this same strain under the same storage conditions, coming from the same type of compost that underwent a dose of 500 Gy, obtained a significant reduction in mean colonies of psychrotrophic bacteria (2.25 × 104 g –1 MPN). Thus, the irradiation doses tested favored reducing the number of colonies of psychrotrophic bacteria, regardless of the type of compound and strain of A. bisporus.

Influência do suco de laranja na microbiota intestinal humana

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)