Clinical investigations on patients suffering from halitosis clearly reveal that in the vast majority of cases the source for an offensive breath odor can be found within the oral cavity (90%). Based on these studies, the main sources for intra-oral halitosis where tongue coating, gingivitis/periodontitis and a combination of the two. Thus, it is perfectly logical that general dental practitioners (GDPs) should be able to manage intra-oral halitosis under the conditions found in a normal dental practice.
View Article and Find Full Text PDFWe have reported previously that growth on alcohol vapors confers hemolytic properties on certain yeast species and strains ['microbial alcohol-conferred hemolysis' (MACH)]. In a recent study, we analyzed the genetic basis of MACH in Saccharomyces cerevisiae using the EUROSCARF mutant collection. The data suggested that intact mitochondrial and respiratory chain functions are critical for the observed alcohol-mediated hemolysis.
View Article and Find Full Text PDFMicrob Pathog
February 2010
It was recently shown that, as in yeast, alcohols selectively increase the hemolytic properties of certain staphylococci strains. This phenomenon has been called 'microbial alcohol-conferred hemolysis'(MACH). Here we present the changes in gene expression by Staphylococcus aureus 8325-4, in response to ethanol.
View Article and Find Full Text PDFHemolysis of blood agar is broadly used as a diagnostic tool for identifying and studying pathogenic microorganisms. We have recently shown that alcohol vapors can confer hemolytic properties on otherwise nonhemolytic fungi (microbial alcohol-conferred hemolysis; MACH). Until now, this phenomenon has been found in various yeast strains and other fungi, but only in a few bacterial species (e.
View Article and Find Full Text PDFWe have previously reported that growth on alcohol vapors confers hemolytic properties on certain yeast species and strains ('microbial alcohol conferred hemolysis'; MACH). Here, a Saccharomyces cerevisiae deletion library consisting of c. 4800 clones was screened for MACH mutants in the presence of n-butanol vapors; 136 mutants were MACH-negative, and 325 exhibited reduced hemolysis and/or growth.
View Article and Find Full Text PDFIt was recently found that alcohols can confer hemolytic properties on certain species of yeast. Here, it is reported that alcohol can promote hemolysis by various species of staphylococci, including strains of Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus hominis. In order to study this novel phenomenon in S.
View Article and Find Full Text PDFFEMS Microbiol Lett
September 2006
Twenty-five years ago this past autumn, we published a short article entitled 'Adherence of bacteria to hydrocarbons: a simple method for measuring cell-surface hydrophobicity' in Volume 9 of FEMS Microbiology Letters. Together with my Ph.D.
View Article and Find Full Text PDFBackground: The purpose of this review was to assess the relationship between mean organoleptic scores (using a 0-to-5 scale) and concentrations of putative odorants representative of those thought to be important in oral malodor, as well as to propose a simple model that explains the dose-response curves obtained from a group of odor judges.
Methods: The model assumes that the scale is rooted at the detection threshold (0), the maximum score (5) is fully saturating and the brain and olfactory nervous system can act as a faithful transducer of the state of binding (occupancy) of the smell receptors in the nose. The authors predicted that the response would be exponential or sigmoidal in nature.
Although yeast are generally non-haemolytic, we have found that addition of alcohol vapour confers haemolytic properties on many strains of yeast and other fungi. We have called this phenomenon 'microbial alcohol-conferred haemolysis' (MACH). MACH is species- and strain-specific: whereas all six Candida tropicalis strains tested were haemolytic in the presence of ethanol, none among 10 C.
View Article and Find Full Text PDFHalitosis (oral malodour or breath odour) is a fairly common complaint. Halitosis is most often a consequence of oral bacterial activity, typically from anaerobes. Occasional causes include systemic disease, and some patients have a psychogenic background to the complaint.
View Article and Find Full Text PDFBackground: In a previous study we showed that prolonged nasogastric tube feeding is associated with pathogenic oral flora.
Objective: To reexamine the impact of prolonged nasogastric tube feeding on the oral microbiota and to explore the salivary flow and composition in elderly patients in long-term care.
Methods: We compared a group of elderly patients fed by nasogastric tube with a control group of elderly patients in long-term care who are fed orally.
Background: Aspiration of infected oropharyngeal content is the main cause of aspiration pneumonia. This complication, mainly related to gram-negative bacteria, threatens percutaneous enterogastric tube as well as nasogastric tube (NGT) fed patients. The objective of this study was to examine the oral microbiota of tuboenterally fed patients and compare it with that of orally fed counterparts.
View Article and Find Full Text PDFOral Surg Oral Med Oral Pathol Oral Radiol Endod
August 2002
Objective: Present volumetric or gravimetric techniques for measuring saliva output are often cumbersome and, therefore, not generally used. In the present study, a simple approach to study the weight loss of a standard hard sugar candy after 3 minutes of passive incubation between tongue dorsum and palate was tested.
Study Design: Subjects (n = 59), 27 of whom had a subjective complaint of dry mouth and the rest who were healthy control subjects, were tested with this procedure, together with gravimetric measurements of stimulated and unstimulated saliva output from various glands (parotid, submandibular, and sublingual).