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The estimation of oral microbiome (OM) taxonomic composition in periodontally healthy individuals can often be biased because the clinically periodontally healthy subjects for evaluation can already experience dysbiosis. Usually, they are included just based on the absence of clinical signs of periodontitis. Additionally, the age of subjects is used to be higher to correspond well with tested groups of patients with chronic periodontitis, a disorder typically associated with aging. However, the dysbiosis of the OM precedes the clinical signs of the disease by many months or even years. The absence of periodontal pockets thus does not necessarily mean also good periodontal health and the obtained image of “healthy OM” can be distorted.To overcome this bias, we taxonomically characterized the OM in almost a hundred young students of dentistry with precise oral hygiene and no signs of periodontal disease. We compared the results with the OM composition of older periodontally healthy individuals and also a group of patients with severe periodontitis (aggressive periodontitis according to former classification system). The clustering analysis revealed not only two compact clearly separated clusters corresponding to each state of health, but also a group of samples forming an overlap between both well-pronounced states. Additionally, in the cluster of periodontally healthy samples, few outliers with atypical OM and two major stomatotypes could be distinguished, differing in the prevalence and relative abundance of two main bacterial genera:  Streptococcus  and  Veillonella . We hypothesize that the two stomatotypes could represent the microbial succession from periodontal health to starting dysbiosis. The old and young periodontally healthy subjects do not cluster separately but a trend of the OM in older subjects to periodontitis is visible. Several bacterial genera were identified to be typically more abundant in older periodontally healthy subjects.

Porphyromonas gingivalis is a Gram-negative oral anaerobe that is involved in the pathogenesis of periodontitis and is a member of more than 500 bacterial species that live in the oral cavity. This anaerobic bacterium is a natural member of the oral microbiome, yet it can become highly destructive (termed pathobiont) and proliferate to high cell numbers in periodontal lesions: this is attributed to its arsenal of specialized virulence factors. The purpose of this review is to provide an overview of one of the main periodontal pathogens—Porphyromonas gingivalis. This bacterium, along with Treponema denticola and Tannerella forsythia, constitute the “red complex,” a prototype polybacterial pathogenic consortium in periodontitis. This review outlines Porphyromonas gingivalis structure, its metabolism, its ability to colonize the epithelial cells, and its influence upon the host immunity.

CRP is a plasma protein that reflects a measure of the acute phase response to inflammation and is one of the markers of choice in monitoring this response. CRP can be used for the prediction and early detection of periodontal disease. The aim of this study was to compare and evaluate the systemic levels of CRP in the peripheral blood samples of patients with chronic and aggressive periodontitis, gingivitis, and gingival recessions and compare them with periodontal clinical parameters. All patients (N=158) were examined prior to the initiation of periodontal treatment. Patients were divided into four groups. Group A consisted of 26 patients with aggressive periodontitis, Group B consisted of 111 patients with chronic periodontitis, Group C consisted of 13 patients with gingivitis, and Group D consisted of 8 patients with gingival recessions. Our study results indicate that CRP levels increase subsequently with the severity of the periodontal disease and that the bleeding on probing index showed much better positive correlation with the CRP levels compared to the pocket depth index in both periodontitis patients groups, especially in aggressive periodontitis patients.

Over the last two decades, the amount of evidence corroborating an association between dental plaque bacteria and coronary diseases that develop as a result of atherosclerosis has increased. These findings have brought a new aspect to the etiology of the disease. There are several mechanisms by which dental plaque bacteria may initiate or worsen atherosclerotic processes: activation of innate immunity, bacteremia related to dental treatment, and direct involvement of mediators activated by dental plaque and involvement of cytokines and heat shock proteins from dental plaque bacteria. There are common predisposing factors which influence both periodontitis and atherosclerosis. Both diseases can be initiated in early childhood, although the first symptoms may not appear until adulthood. The formation of lipid stripes has been reported in 10-year-old children and the increased prevalence of obesity in children and adolescents is a risk factor contributing to lipid stripes development. Endothelium damage caused by the formation of lipid stripes in early childhood may lead to bacteria penetrating into blood circulation after oral cavity procedures for children as well as for patients with aggressive and chronic periodontitis.

The dysbiosis of oral microbiome (OM) precedes the clinical signs of periodontal disease. Its simple measure thus could indicate individuals at risk of periodontitis development; however, such a tool is still missing. Up to now, numerous microbial taxa were associated with periodontal health or periodontitis. The outputs of most studies could, nevertheless, be slightly biased from following two reasons: First, the healthy group is often characterized only by the absence of the disease, but the individuals could already suffer from dysbiosis without any visible signs. Second, the healthy/diseased OM characteristics are frequently determined based on average data obtained for whole groups of periodontally healthy persons versus patients. Especially in smaller sets of tested individuals the typical individual variability can thus complicate the unambiguous assignment of oral taxa to respective state of health. In this work the taxonomic composition of OM was evaluated for 20 periodontally healthy individuals and 15 patients with chronic periodontitis. The narrowed selection set of the most diseased patients (confirmed by clinical parameters) and the most distant group of healthy individuals with the lowest probability of dysbiosis was determined by clustering analysis and used for identification of marker taxa. Based on their representation in each individual oral cavity we proposed the numeric index of periodontal health called R/G value. Its diagnostic potential was further confirmed using independent set of 20 periodontally healthy individuals and 20 patients with periodontitis with 95 percent of samples assigned correctly. We also assessed the individual temporal OM dynamics in periodontal health and we compared it to periodontitis. We revealed that the taxonomic composition of the system changes dynamically but generally it ranges within values typical for periodontal health or transient state, but far from values typical for periodontitis. R/G value tool, formulated from individually evaluated data, allowed us to arrange individual OMs into a continuous series, instead of two distinct groups, thus mimicking the gradual transformation of a virtual person from periodontal health to disease. The application of R/G value index thus represents a very promising diagnostic tool for early prediction of persons at risk of developing periodontal disease.

The presence of environmental mycobacteria was studied in drinking water supply systems in Olomouc County, Czech Republic, in order to detect the possible spread of M. kansasii from the neighbouring region in Ostrava County. Drinking water samples from water supply systems of 16 identical localities were investigated. The samples of running water, and tap swabs or tap scrapings were collected twice a year, in the spring and in the autumn. The most common cultivated and identified species were M. gordonae (20.4%), M. flavescens (13.8%), rapidly growing mycobacteria (5.0%) and then by occasional identification of M. fortuitum, M. terrae, M. scrofulaceum. M. kansasii was not detected. The prevalence rates showed no time trend over the period 1984-1989. We conclude that there is no evidence at present that endemic M. kansasii, isolated repeatedly from the environment in the Ostrava neighbouring region, has spread to Olomouc County.

Pupilla pratensis (Clessin, 1871) was recently confirmed as a distinct species based on morphological, ecological and molecular evidence. The main purpose of this study is to publish the first reliable data on the occurrence of P. pratensis in the Czech Republic and Slovakia. The second goal is to analyse conchometry of P. pratensis, P. muscorum (L., 1758), and P. alpicola (Charpentier, 1837) to find out whether it is possible to reliably distinguish these species solely based on shell measurements. For multidimensional analysis of shell measurement variation we used principal components analysis (PCA). We documented six populations of P. pratensis in the Czech Republic and one in SW Slovakia. The revision of voucher material showed that all previously reported records of P. alpicola from the Czech Republic belonged in fact to P. pratensis. This requires the exclusion of P. alpicola from the list of Czech molluscs. Based on multidimensional analysis of shell measurements it was possible to distinguish P. pratensis from P. muscorum with no overlapping specimens. Pupilla alpicola was almost completely different from P. muscorum with only few overlapping specimens, contrary to P. pratensis which was mostly impossible to distinguish from P. alpicola based on analysed shell measurements. Shell width was the best single shell measurement for distinguishing P. pratensis and P. muscorum. Shell measurements of two Swedish populations of P. pratensis did not differ from shell variation of Czech and Slovak populations. However, Scandinavian populations displayed some differences from central European populations in apertural barriers which are discussed in detail. Czech and Slovak populations of P. pratensis occurred in calcium-rich fen meadows which perfectly matches with site characteristics reported from Scandinavia. We assume that the observed morphometric differences between P. pratensis and P. muscorum can be useful for distinguishing the species also outside the Czech territory and for palaeoecological studies where only empty shells are available. Since these species occupy ecologically different habitats their reliable identification in fossil material can improve the reconstructions of past environments.