Anna Skalniak

The usefulness of biotyping in the determination of selected pathogenicity determinants in Streptococcus mutans.

BackgroundStreptococcus mutans is known to be a primary etiological factor of dental caries, a widespread and growing disease in Polish children. Recognition of novel features determining the pathogenicity of this pathogen may contribute to understanding the mechanisms of bacterial infections.The goal of the study was to determine the activity of prephenate dehydrogenase (PHD) and to illuminate the role of the enzyme in S. mutans pathogenicity. The strains were biotyped based on STREPTOtest 24 biochemical identification tests and the usefulness of biotyping in the determination of S. mutans pathogenicity determinants was examined.ResultsOut of ninety strains isolated from children with deciduous teeth fifty three were classified as S. mutans species. PDH activity was higher (21.69 U/mg on average) in the experimental group compared to the control group (5.74 U/mg on average) (P <0.001). Moreover, it was demonstrated that biotype I, established basing on the biochemical characterization of the strain, was predominant (58.5%) in oral cavity streptococcosis. Its dominance was determined by higher PDH activity compared to biotypes II and III (P = 0.0019).ConclusionsThe usefulness of biotyping in the determination of Streptococcus mutans pathogenicity determinants was demonstrated. The obtained results allow for better differentiation of S. mutans species and thus may contribute to recognition of pathogenic bacteria transmission mechanisms and facilitate treatment.

Dietary patterns as risk factors of differentiated thyroid carcinoma.

UNLABELLED Nutritional factors are known to be important in the development of different metabolic diseases. The history of nodular or diffuse goiter is closely related to risk of thyroid carcinoma. On account of the function of the thyroid gland, many studies focus on iodine intake. The aim of the study was to assess whether dietary patterns could be risk factors of differentiated thyroid carcinoma. MATERIAL/METHODS The case-control study was based on a questionnaire, which included information about dietary patterns and was carried out on 284 patients comprising 30 males (mean age 58.4±13.7 years), and 254 females (mean age 52.1±13.8 years), as well as 345 randomly selected controls: 58 males (mean age 60.2±12 years) and 287 females (mean age 53.4±14.3 years) randomly selected from the Population Register and adjusted by age and gender to the group of TC. The main groups of nutritional products, i.e. starchy foods, meat, dairy products, vegetables, fruits, and beverages, were analyzed. RESULTS Consumption of vegetables, fruits, saltwater fish and cottage cheese was significantly lower in patients with differentiated thyroid carcinoma than in controls, quite the contrary to starchy foods, especially white bread. CONCLUSIONS Dietary patterns appear to modify the risk of thyroid carcinoma. A diet rich in vegetables and fruit, as well as saltwater fish (a source of iodine) and low-fat meat, could be an important protective factor.

The role of the saliva antioxidant barrier to reactive oxygen species with regard to caries development

ABSTRACT Objectives: The aim of this study was to evaluate the role of the antioxidant barrier in the saliva of children with caries, and its impact on the colonization of cariogenic bacteria. Methods: This is a cross-sectional study of 81 children aged 1–5 years. Antioxidant levels and salivary bacterial profiles were measured. Patients were divided into two groups as follows: initial stage decay, termed non-cavitated (1–2 in International Caries Detection and Assessment System (ICDAS)), and extensive decay, termed cavitated lesions (5–6 in ICDAS). The control group includes children without caries. Results: The linear regression model demonstrated that the GSH, GSSG, GSH/GSSG, and total antioxidant capacity levels are influenced (P < 0.05) by: the stage of caries and the dominant bacterial strain. Compared with the other groups (P < 0.001), the highest antioxidant parameters were recorded in the saliva of patients with cavitated lesions. Discussion: Our results indicate that the high levels of antioxidants in saliva increase significantly in children in line with the salivary cariogenic bacterial profiles and caries progression.

Relationship between Pyruvate Kinase Activity and Cariogenic Biofilm Formation in Streptococcus mutans Biotypes in Caries Patients

Streptococcus mutans (MS) and its biotype I are the strains most frequently found in dental plaque of young children. Our results indicate that in children pyruvate kinase (PK) activity increases significantly in dental plaque, and this corresponds with caries progression. The MS strains isolated in this study or their main glycolytic metabolism connected with PK enzymes might be useful risk factors for studying the pathogenesis and target points of novel therapies for dental caries. The relationship between PK activity, cariogenic biofilm formation and selected biotypes occurrence was studied. S. mutans dental plaque samples were collected from supragingival plaque of individual deciduous molars in 143 subjects. PK activity was measured at different time points during biofilm formation. Patients were divided into two groups: initial stage decay, and extensive decay. Non-parametric analysis of variance and analysis of covariance were used to determine the connections between S. mutans levels, PK activity and dental caries biotypes. A total of 143 strains were derived from subjects with caries. Biotyping data showed that 62, 23, 50, and 8 strains were classified as biotypes I, II, III, IV, respectively. PK activity in biotypes I, II, and IV was significantly higher in comparison to that in biotype III. The correlation between the level of S. mutans in dental plaque and PK activity was both statistically significant (p < 0.05) and positive. The greater the level of S. mutans in the biofilm (colony count and total biomass), the higher the PK activity; similarly, a low bacterial count correlated with low PK activity.

A novel in-frame deletion in MEN1 (p.Ala416del) causes familial multiple endocrine neoplasia type 1 with an aggressive phenotype and unexpected inheritance pattern

The present study describes a family with multiple endocrine neoplasia type 1 (MEN1) caused by a previously undescribed in-frame deletion c.1246_1248delGCC (Ala416del) in the MEN1 gene. Evidence for the pathogenic character of this mutation, which triggers an aggressive clinical outcome, is demonstrated. Aggregation analysis in the tested family was strongly suggestive of causality of the detected mutation. This was supported by the analysis of LOH (loss of heterozygosity) in tumor-derived DNA and by computational analysis of the functional and structural implications of the mutation. Different phenotypic characteristics were identified among family members, which is typical for MEN1. Additionally, an unexpected disease inheritance pattern was observed in this kindred, in which either all or none of the siblings of one branch inherited the disease.