The effect of a plasma needle on bacteria in planktonic samples and on peripheral blood mesenchymal stem cells

In this paper, we study the application of a plasma needle to induce necrosis in planktonic samples containing a single breed of bacteria. Two different types of bacteria, Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), were covered in this study. In all experiments with bacteria, the samples were liquid suspensions of several different concentrations of bacteria prepared according to the McFarland standard. The second system studied in this paper was human peripheral blood mesenchymal stem cells (hPB-MSC). In the case of hPB-MSC, two sets of experiments were performed: when cells were covered with a certain amount of liquid (indirect) and when the cell sample was in direct contact with the plasma. Most importantly, the study is made with the aim to see the effects when the living cells are in a liquid medium, which normally acts as protection against the many agents that may be released by plasmas. It was found that a good effect may be expected for a wide range of initial cell densities and operating conditions causing destruction of several orders of magnitude even under the protection of a liquid. It was established independently that a temperature increase could not affect the cells under the conditions of our experiment, so the effect could those hPB-MSC that were not protected by a liquid, gas flow proved to produce a considerable effect, presumably due to poor adhesion of the cells, but in a liquid the effect was only due to the plasma. Further optimization of the operation may be attempted, opening up the possibility of localized in vivo sterilization

Antifungal Susceptibility of <i>Candida albicans</i> Isolated from Tongue and Subgingival Biofilm of Periodontitis Patients

The subgingival biofilm, as the most complex microbial community, has been proven to be reservoir of Candida spp. The main concept of this study was to investigate if there is a difference between the sensitivity of Candida albicans (C. albicans) isolated from tongue and subgingival areas of periodontitis patients to antifungal agents. The aim of the study was to determine: (1) the distribution of different Candida species in the tongue and subgingival samples of periodontitis patients; (2) the susceptibility of Candida albicans strains from tongue and subgingival biofilm to the effects of commonly used antifungal agents: fluconazole, amphotericin B and itraconazole; (3) the correlation between the susceptibility of Candida albicans and clinical periodontal parameters. Tongue and subgingival biofilm samples of periodontitis subjects (N = 163) were examined. Susceptibility was tested when the same Candida species was isolated from both sites (17 subjects). Candida spp. were isolated in 23.3% of tongue and 21.5% of the subgingival samples. All isolates were susceptible to amphotericin B, while 64.71% of tongue and 52.94% of subgingival isolates were susceptible to fluconazole. A low frequency of itraconazole susceptibility was observed for tongue (17.64%) and subgingival isolates (11.76%). The correlations between full-mouth plaque score and Minimal Inhibitory Concentration (MIC) for tongue isolates were strongly positive for all antimycotics. Positive correlation was also observed between moderate periodontal destruction and MICs for tongue and subgingival isolates. The susceptibility of C. albicans to antifungals correlate with oral hygiene and moderate periodontal destruction. There is no difference in antifungal susceptibility between tongue and subgingival isolates

Subgingival areas as potential reservoirs of different Candida spp in type 2 diabetes patients and healthy subjects.

ObjectivesThe aim of this cross-sectional observational study was to compare the prevalence of different oral Candida spp. in patients with Type 2 Diabetes and chronic periodontitis in two oral sites: dorsal surface of the tongue and subgingival area. In order to determine subgingival areas as potential reservoirs of yeasts, this study aimed to find differences in the yeasts' detection between the dorsum of the tongue, as the oral site most commonly inhabited with microorganisms, and subgingival samples. Additionally, potential predictors for the yeasts prevalence were determined.Material and methodsSubjects (N = 146) were divided into four groups: group A- healthy individuals without periodontitis, group B- healthy individuals with chronic periodontitis, group C- Type 2 Diabetes patients with good glycoregulation and Chronic periodontitis and group D- Type 2 Diabetes patients with poor glycoregulation and Chronic periodontitis. Samples were obtained from the tongue by swabbing. Subgingival plaque samples were taken by paper points and periodontal curette. Isolation and identification of different Candida spp. was done using ChromAgar medium. In addition, germ-tube production and carbohydrate assimilation tests were performed.ResultsThe prevalence of Candida spp. was higher in diabetics with poor glycoregulation. The most frequently isolated species was Candida albicans followed by Candida glabrata and Candida tropicalis. In 15.6% of cases, Candida spp. was present in the subgingival area while absent on the tongue. Multivariate regression model showed that HbA1c was Candida spp. predictor for both locations.ConclusionsOur results confirmed that there are Candida spp. carriers among subjects with clinically healthy oral mucosa. Also, this study identified subgingival areas as potential reservoirs of these pathogenic species. Glycoregulation has been recognized as a positive predictor factor of Candida spp

Use of saliva as a diagnostic fluid in dentistry

Saliva is a secretion of the salivary and mucous glands and is of major importance in the maintainance of oral health. Over the last few decades, saliva has been evaluated as a diagnostic fluid in medicine for determining systemic disease markers as well as for monitoring numerous drugs, narcotics, and hormones. The biochemical analysis of saliva is particularly important in dentistry. The estimation of the risk of appearance and diagnosis of disease, monitoring of disease progression, evaluation of therapy efficacy for caries, periodontitis, premalignant and malignant oral lesions, as well as infectious diseases of the oral cavity, can be assessed by analyzing different constituent: of saliva, individuals at risk of caries can be identified using test: that determine saliva flow rate, saliva buffer capacity, and colonization of the oral cavity by cariogenic bacteria. Today, these rapid and simple diagnostic tests are used routinely in caries risk determination. The study and use of saliva-based diagnostics have increased over the last few decades. Clinical testing of saliva shows much promise. However, there is a need for much additional research in this area, before the true clinical value of saliva as a diagnostic fluid in dentistry can be determined.Pljuvačka je sekret pljuvačnih i mukoznih žlezda koji je značajan za održavanje oralnog zdravlja. Poslednjih decenija sve više se razmatra mogućnost njene primene kao zamena krvi, odnosno krvnom serumu i plazme, radi dokazivanja pokazatelja sistemskih oboljenja, kao i za nadgledanje primene lekova, droga i hormona. Analiziranje biohemijskog sastava pljuvačke posebno je značajno u stomatologiji za procenu rizika nastanka, praćenja toka bolesti i kontrole rezultata primenjenog lečenja zubnog karijesa, parodontopatije, oralnih karcinoma i infektivnih oboljenja usne duplje. U proceni rizika nastanka karijesa na zubima rutinski se izvode ispitivanja kojima se određuju količina izlučene pljuvačke, njen puferski kapacitet i stepen kolonizacije usne duplje kariogenim vrstama bakterija. Jednostavnost izvođenja ovih ispitivanja omogućava da ih u stomatološkoj ordinaciji primenjuje lekar praktičar, što predstavlja veliku pomoć u proceni rizika za nastanak zubnog karijesa. Zbog bliskog kontakta s oralnim tkivima, pljuvačka sadrži brojne biohemijske pokazatelje patoloških procesa lokalizovanih u ovim tkivima (enzimi, imunoglobulini, ostali proteini, fenotipski pokazatelji). Ispitivanje pomenutih pokazatelja je značajno kao dopuna kliničkom dijagnostikovanju ukoliko ono ne pruža dovoljno informacija