Gloria Burlacchini

Publications of Gloria Burlacchini

• Testing a low molecular mass fraction of a mushroom (Lentinus edodes) extract formulated as an oral rinse in a cohort of volunteers.

  Authors: Caterina Signoretto, Gloria Burlacchini, Anna Marchi, Marcello Grillenzoni, Giacomo Cavalleri, Lena Ciric, Peter Lingström, Elisabetta Pezzati, Maria Daglia, Egija Zaura, Jonathan Pratten, David A Spratt, Michael Wilson, Pietro Canepari

  Journal of biomedicine & biotechnology. 01/2011; 2011:857987.

  Although foods are considered enhancing factors for dental caries and periodontitis, laboratory researches indicate that several foods and beverages contain components endowed with antimicrobial andAlthough foods are considered enhancing factors for dental caries and periodontitis, laboratory researches indicate that several foods and beverages contain components endowed with antimicrobial and antiplaque activities. A low molecular mass (LMM) fraction of an aqueous mushroom extract has been found to exert these activities in in vitro experiments against potential oral pathogens. We therefore conducted a clinical trial in which we tested an LMM fraction of shiitake mushroom extract formulated in a mouthrinse in 30 young volunteers, comparing the results with those obtained in two identical cohorts, one of which received water (placebo) and the other Listerine. Plaque index, gingival index and bacterial counts in plaque samples were determined in all volunteers over the 11 days of the clinical trial. Statistically significant differences (P < 0.05) were obtained for the plaque index on day 12 in subjects treated with mushroom versus placebo, while for the gingival index significant differences were found for both mushroom versus placebo and mushroom versus Listerine. Decreases in total bacterial counts and in counts of specific oral pathogens were observed for both mushroom extract and Listerine in comparison with placebo. The data suggest that a mushroom extract may prove beneficial in controlling dental caries and/or gingivitis/periodontitis.

• Effects of mushroom and chicory extracts on the physiology and shape of Prevotella intermedia, a periodontopathogenic bacterium.

  Authors: Caterina Signoretto, Anna Marchi, Anna Bertoncelli, Gloria Burlacchini, Francesco Tessarolo, Iole Caola, Elisabetta Pezzati, Egija Zaura, Adele Papetti, Peter Lingström, Jonathan Pratten, David A Spratt, Michael Wilson, Pietro Canepari

  Journal of biomedicine & biotechnology. 01/2011; 2011:635348.

  Contrary to the common assumption that food has a negative impact on oral health, research has shown that several foods contain a number of components with antibacterial and antiplaque activity.Contrary to the common assumption that food has a negative impact on oral health, research has shown that several foods contain a number of components with antibacterial and antiplaque activity. These natural compounds may be useful for improving daily oral hygiene. In this study we evaluate the mode of antimicrobial action of fractions of mushroom and red chicory extracts on Prevotella intermedia, a periodontopathogenic bacterium. The minimal inhibitory concentration corresponded to 0.5x compared to the natural food concentration for both extracts. This concentration resulted in a bacteriostatic effect in mushroom extract and in a slightly bactericidal effect in chicory extract. Cell mass continued to increase even after division stopped. As regards macromolecular synthesis, DNA was almost totally inhibited upon addition of either mushroom or chicory extract, and RNA to a lesser extent, while protein synthesis continued. Cell elongation occurred after septum inhibition as documented by scanning electron microscopy and cell measurement. The morphogenetic effects are reminiscent of the mode of action of antibiotics such as quinolones or β-lactams. The discovery of an antibiotic-like mode of action suggests that these extracts can be advantageously employed for daily oral hygiene in formulations of cosmetic products such as mouthwashes and toothpastes.

• Drinking habits are associated with changes in the dental plaque microbial community.

  Authors: Caterina Signoretto, Franco Bianchi, Gloria Burlacchini, Francesca Sivieri, Dave Spratt, Pietro Canepari

  Journal of clinical microbiology. 12/2009;

  Caries and gingivitis are the most prevalent infectious diseases of humans and are due to the accumulation of dental plaque (a microbial biofilm) on tooth surface and at the gingival margin,Caries and gingivitis are the most prevalent infectious diseases of humans and are due to the accumulation of dental plaque (a microbial biofilm) on tooth surface and at the gingival margin, respectively. Several in vitro and in vivo studies have shown that many natural components of foods and beverages inhibit the adhesion of and/or exert an antimicrobial activity against oral bacteria. These biological activities have been attributed mainly to the polyphenol fraction. In order to explore the possibility that diet can alter the dental plaque community, in this study we evaluated the composition of the microbiota of supra- and subgingival plaque collected from 75 adult subjects with different drinking habits (drinkers of coffee, or red wine or water for two years at least) by analysing the microbial population through separation of PCR-amplified fragments using the denaturing gradient gel electrophoresis (DGGE) technique. The mean numbers of the bands of the DGGE profiles from all the three categories was evaluated. There were no significant differences between the two kinds of plaque collected from the control (water) group and this group showed the highest number of bands (supragingival = 18.98+/-3.16 and subgingival = 18.7+/-3.23). The coffee and wine drinker groups generated the lowest numbers of bands for both supra- (coffee = 8.25+/-3.53 and wine = 7.93+/-2.55) and sub-gingival (coffee = 8.3+/-3.03 and wine = 7.65+/-1.68) plaque. The differences between coffee drinkers or wine drinkers vs. the control (water) group, respectively, were statistically significant. A total of 34 microorganisms were identified and their frequency of distribution into the three subject categories was analysed. A greater percentage of subjects were positive for facultative aerobes when supragingival plaque was analysed while anaerobes were more frequent in subgingival samples. Relevantly, the frequency of anaerobe identification was significantly reduced when coffee and wine drinkers were compared with the subjects of the control group. DGGE profiles of both plaques samples from all groups were generated and used to construct dendrograms. A number of distinct clusters of water or coffee or wine drinkers were formed. The clustering of the some of DGGE results into cohort specific clusters implies similarities in the microbiota within these groups and relevant differences in the microbiota between cohorts. This supports the notion that the drinking habits of the subjects may influence the microbiota at both a supraginigival and subgingival level.

• Support for the role of Candida spp. in extensive caries lesions of children.

  Authors: Caterina Signoretto, Gloria Burlacchini, Fiorenzo Faccioni, Massimiliano Zanderigo, Nicolò Bozzola, Pietro Canepari

  The new microbiologica : official journal of the Italian Society for Medical, Odontoiatric, and Clinical Microbiology (SIMMOC). 02/2009; 32(1):101-7.

  Candida spp. are frequently detected in the mouths of children with extensive caries lesions compared with caries-free subjects. In this study we evaluated the presence of Candida spp. in associationCandida spp. are frequently detected in the mouths of children with extensive caries lesions compared with caries-free subjects. In this study we evaluated the presence of Candida spp. in association with mutans streptococci and lactobacilli in the saliva of children with dental decay, before and after anti-caries treatment. Samples of saliva from 14 children with caries lesions and from 13 caries-free subjects were evaluated for the presence of mutans streptococci, lactobacilli and Candida spp. by culture. Eleven of 14 carious subjects hosted Candida spp. in their saliva as against only 2 out of 13 subjects without caries lesions. Carious subjects were treated by adopting a conventional protocol for caries disease (rinses with a mouthwash containing 0.2% chlorhexidine and fluorine). After treatment, the salivary bacterial counts decreased for mutans streptococci and in some cases for lactobacilli, but large numbers of Candida spp. remained in the saliva of several children. The latter were treated with the antifungal drug nystatin (oral rinses) and evaluation of the level of yeasts in the saliva showed disappearance of the microorganism in several cases. The results indicate that antiseptic treatment alone for dental decay is not sufficient for the eradication of microorganisms potentially responsible for caries lesions, in particular when yeasts are present. We hypothesize that the oral cavity of children could act as a reservoir of fungi, and eradication could be needed to prevent both exacerbation of caries lesions, and colonization by Candida spp. of other host sites.

• Microbiological evaluation of the effects of hyperbaric oxygen on periodontal disease.

  Authors: Caterina Signoretto, Franco Bianchi, Gloria Burlacchini, Pietro Canepari

  The new microbiologica : official journal of the Italian Society for Medical, Odontoiatric, and Clinical Microbiology (SIMMOC). 11/2007; 30(4):431-7.

  The term periodontitis indicates a variety of clinical manifestations of infectious disorders in which the supporting tissues of the teeth are attacked. The initiation and progression of periodontalThe term periodontitis indicates a variety of clinical manifestations of infectious disorders in which the supporting tissues of the teeth are attacked. The initiation and progression of periodontal disease are attributed to the presence of elevated levels of pathogenic bacteria within the gingival crevice. Approaches to periodontal treatment range from surgical to regenerative therapy and anti-infective chemotherapy. Anti-infective drug therapy should be rationally based on the composition of the pathogenic microbiota. It is also important to recognize that the periodontopathic plaque constitutes a bacterial biofilm infection that may render the resident microorganisms more resistant than the same organisms grown planktonically. Hyperbaric oxygen (HBO) has been successfully used in several medical applications. The therapeutic effect is related to elevated partial oxygen pressure in the tissues. The aim of this study was to evaluate the effects of HBO on a selected number of patients suffering from adult chronic periodontitis in comparison with surgical intervention (scaling and root planning, SRP), as well as the effects of a combination of both therapies on the evolution over time of the microflora of the periodontal pockets. Bacteria were detected either by culture or by a molecular method (PCR). Microbiological data indicate that the combination of HBO and SRP substantially reduced (by up to 99.9%) the gram-negative anaerobe loads of the subgingival microflora. The low values of pathogens persisted for at least two months after the therapy. HBO or SRP alone produced a temporarily more limited effect on periodontal anaerobes. Additional experimental confirmation of these results was provided by molecular detection of the main periodontopathogenic bacteria with a significant reduction in the number of dental sites which harboured them. It is also shown that HBO both alone and in combination with SRP reduced the Gingival Index value to zero and gingival health persisted for 3 months at least. Thus, in parallel with the loss of periodontopathogenic bacteria, a substantial improvement in oral health was observed. In conclusion, this study has shown that HBO may represent a useful aid, especially in combination with SRP, as far as non-surgical periodontal therapy is concerned.

• Differences in microbiological composition of saliva and dental plaque in subjects with different drinking habits.

  Authors: Caterina Signoretto, Gloria Burlacchini, Franco Bianchi, Giacomo Cavalleri, Pietro Canepari

  The new microbiologica : official journal of the Italian Society for Medical, Odontoiatric, and Clinical Microbiology (SIMMOC). 11/2006; 29(4):293-302.

  Several foods have been shown to contain natural components (especially polyphenols) which display anti-adhesive properties against Streptococcus mutans, the aetiological agent responsible for dentalSeveral foods have been shown to contain natural components (especially polyphenols) which display anti-adhesive properties against Streptococcus mutans, the aetiological agent responsible for dental crown caries, as well as inhibition of glucosyltransferases, which are the S. mutans enzymes involved in the synthesis of an adherent, water-insoluble glucan from sucrose. Other studies have demonstrated an in vitro action on oral plaque biofilm formation and desorption. This study evaluated whether the activity displayed in vitro by food compounds could affect the microbiological composition of saliva and dental plaque of subjects with a diet rich in these foods, comparing the results with those obtained from subjects with a different diet. The foods considered were: coffee, barley coffee, tea and wine. A total of 93 subjects were recruited into the study. Six samples of both plaque and saliva were collected from each subject at roughly one-monthly intervals. Total bacteria, total streptococci, S. mutans and lactobacilli counts were determined by culture in both saliva and dental plaque. The highest bacterial titres were recorded for the control population, while each drinking habit subgroup showed counts roughly one log lower than the controls. These differences in bacterial counts proved statistically significant (P<0.05). As far as dental plaque was concerned, while total counts did not significantly vary per mg of plaque in the subjects belonging to the different drinking habit subgroups, a significant decrease (P<0.05) was observed in those subjects drinking coffee, tea, barley coffee and wine when mutans streptococci and lactobacilli were evaluated. In several cases a more than one log decrease was observed. Plaque indices were also determined, and a significant (P<0.05) reduction in values was recorded in the subjects belonging the specific drinking habit subgroups compared to the control group. This study indicates that there is a correlation between consumption of specific foods and oral health in terms of reduced plaque deposition and lower counts of odontopathogens.

• Persistence of Enterococcus faecalis in aquatic environments via surface interactions with copepods.

  Authors: Caterina Signoretto, Gloria Burlacchini, Carla Pruzzo, Pietro Canepari

  Applied and environmental microbiology. 06/2005; 71(5):2756-61.

  Several human pathogens and fecal-pollution indicators may persist as viable organisms in natural environments, owing to their ability to activate different types of survival strategies. TheseSeveral human pathogens and fecal-pollution indicators may persist as viable organisms in natural environments, owing to their ability to activate different types of survival strategies. These strategies include adhesion on both abiotic and biotic surfaces and the entrance to the so-called viable but nonculturable (VBNC) state. In an 18-month survey for the detection of enterococci in both lake water and seawater, C. Signoretto et al. (Appl. Environ. Microbiol. 70:6892-6896, 2004) have shown that Enterococcus faecalis was detected mostly bound to plankton and in the VBNC state. In the present study, we show that in vitro adhesion of E. faecalis to copepods accelerated the entry of cells into the VBNC state relative to that of planktonic bacteria. VBNC E. faecalis cells maintained their adhesive properties to copepods and chitin (the main component of the copepod carapace), though to a reduced extent in comparison with growing cells. Sugar competition experiments showed interference with adhesion to both copepods and chitin by GlcNAc and only to copepods by D-mannose. Four enterococcal cell wall proteins present in both growing and VBNC cells and lipoteichoic acid were shown to be capable of binding chitin. The results indicate that copepods may represent an additional environmental reservoir of enterococci, thus suggesting the advisability of redesigning the protocols currently used for microbial detection during the evaluation of the microbiological quality of environmental samples.

• Adhesion of Enterococcus faecalis in the nonculturable state to plankton is the main mechanism responsible for persistence of this bacterium in both lake and seawater.

  Authors: Caterina Signoretto, Gloria Burlacchini, Maria del Mar Lleò, Carla Pruzzo, Massimiliano Zampini, Luigi Pane, Giorgio Franzini, Pietro Canepari

  Applied and environmental microbiology. 12/2004; 70(11):6892-6.

  The presence of enterococci in lake and seawater in an 18-month survey comparing molecular (PCR and quantitative PCR) and culture methods was evaluated, as well as the possibility that zooplanktonThe presence of enterococci in lake and seawater in an 18-month survey comparing molecular (PCR and quantitative PCR) and culture methods was evaluated, as well as the possibility that zooplankton could act as reservoirs for enterococci. Samples of both water and zooplankton were collected monthly from a Lake Garda site and an Adriatic Sea site. In lake water, the positive samples numbered 13 of 54 (24%) by culture and 32 of 54 (59%) when PCR was applied. In seawater, they numbered 0 of 51 by culture and 18 of 51 (35%) by PCR. Enterococci were found either totally bound to plankton or totally in water, depending on the presence or absence of plankton, respectively. These results clearly indicate that the PCR assay is a powerful tool for detecting fecal indicators and pathogens in the environment, thus providing a much more sensitive method than culture.