Introduction and objective. In recent decades the use of orthodontic appliances in Poland has increased; however, data on their influence on changes of components of the microbiome connected with oral biofilm are scarce. The objective of this study was to evaluate oral microbiota in terms of their role as risk factors for health complications. Materials and method. The study included 100 patients treated with removable or fixed appliances. Oral hygiene and gingival health were determined, and periodontal swabs taken from each patient for parasitological, bacteriological and mycological microscopic and in vitro examinations. Results. Oral protists and various pathogenic and opportunistic bacterial and fungal strains were identified in the superficial layer of biofilm. A higher prevalence of bacteria, Enterococcus faecalis, E. faecium, Staphylococcus aureus and Escherichia coli, and various strains of yeast-like fungi from the Candida albicans group, occurred in patients treated with the fixed appliance than in those using a removable appliance or not treated orthodontically. In some periodontal samples from patients treated with fixed appliances, cysts of the Acanthamoeba spp. were found. Conclusions. The use of orthodontic appliances alters the status of the oral cavity; it has impact on the colonization of oral biofilm by opportunistic/pathogenic strains, and increases the risk of their dissemination to various human tissues and organs. Pretreatment examination of oral microbiome, its monitoring particularly during treatment with fixed appliances, and preventive elimination of the potentially pathogenic strains to avoid health complications, are highly recommended, especially in patients with impaired immunity.

It was proved that T. tenax, considered so far as a human specific parasite, can also inhabit the oral cavity of dog, cat and horse. To summarize, T. tenax was detected in the mouths of different domesticated animals, indicating that in Poland it can colonize a wider range of hosts than previously known. The owners of 3 dogs showed oral tissue inflammation of different intensity and were also positive for T. tenax; therefore, oral trichomonosis spread from humans to domestic animals and conversely should be taken into consideration.

Introduction. Various Acanthamoeba species are free-living organisms widely distributed in the human environment. Amphizoic amoebae as facultative parasites may cause vision-threatening eye disease-Acanthamoeba keratitis, mostly among contact lens wearers. As the number of cases is increasing, and applied therapy often unsuccessful, proper hygienic measures and effective contact lenses disinfection are crucial for the prevention of this disease. Available contact lens solutions are not fully effective against amphizoic amoebae; there is a need to enhance their disinfecting activity to prevent amoebic infections. The use of developing nanotechnology methods already applied with success in the prevention, diagnostic and therapy of other infectious diseases might be helpful regarding amoebic keratitis. This study assesses the in vitro effect of selected contact lens solutions conjugated with nanoparticles against Acanthamoeba trophozoites. Materials and method. Three selected contact lens solutions conjugated with silver and gold nanoparticles in concentration of 0.25-2.5 ppm were used in vitro against the axenically cultured ATCC 30010 type Acanthamoeba castellanii strain. The anti-amoebic efficacy was examined based on the oxido-reduction of AlamarBlue. The cytotoxicity tests based on the measurement of lactate dehydrogenase (LDH) activity were performed using a fibroblast HS-5 cell line. Results. Enhancement of the anti-amoebic activity of contact lens solutions conjugated with selected nanoparticles expressed in the dose dependent amoebic growth inhibition with a low cytotoxicity profile was observed. Conclusions. Results of the study showed that conjugation of selected contact lens solutions with silver nanoparticles might be a promising approach to prevent Acanthamoeba keratitis among contact lens users.

Identification of infectious microbiota from oral cavity environment of various population group patients as a preventive approach to human health risk factors.

Background Free-living amoebae of the genus Acanthamoeba are cosmopolitan, widely distributed protozoans that cause a severe, vision-threatening corneal infection known as Acanthamoeba keratitis (AK). The majority of the increasing number of AK cases are associated with contact lens use. Appropriate eye hygiene and effective contact lens disinfection are crucial in the prevention of AK because of the lack of effective therapies against it. Currently available multipurpose contact lens disinfection systems are not fully effective against Acanthamoeba trophozoites and cysts. There is an urgent need to increase the disinfecting activity of these systems to prevent AK infections. Synthesized nanoparticles (NPs) have been recently studied and proposed as a new generation of anti-microbial agents. It is also known that some plant metabolites, including tannins, have anti-parasitic activity. The aim of this study was to evaluate the anti-amoebic activity and cytotoxicity of tannic acid-modified silver NPs (AgTANPs) conjugated with selected multipurpose contact lens solutions. Methods The anti-amoebic activities of pure contact lens care solutions, and NPs conjugated with contact lens care solutions, were examined in vitro by a colorimetric assay based on the oxido-reduction of alamarBlue. The cytotoxicity assays were performed using a fibroblast HS-5 (ATCC CRL-11882) cell line. The results were statistically analysed by ANOVA and Student-Newman-Keuls test using P < 0.05 as the level of statistical significance. Results We show that the NPs enhance the anti-Acanthamoeba activities of the tested contact lens solutions without increasing their cytotoxicity profiles. The activities are enhanced within the minimal disinfection time recommended by the manufacturers. Conclusions The conjugation of the selected contact lens solutions with AgTANPs might be a novel and promising approach for the prevention of AK infections among contact lens users.