Implants made of ceramic and metallic elements, which are used in dentistry, may either promote or hinder the colonization and adhesion of bacteria to the surface of the biomaterial to varying degrees. The increased interest in the use of dental implants, especially in patients with chronic systemic diseases such as cystic fibrosis (CF), is caused by an increase in disease complications. In this study, we evaluated the differences in the in vitro biofilm formation on the surface of biomaterials commonly used in dentistry (Ti-6Al-4V, cobalt-chromium alloy (CoCr), and zirconia) by Staphylococcus aureus isolated from patients with CF. We demonstrated that S. aureus adherence and growth depends on the type of material used and its surface topography. Weaker bacterial biofilm formation was observed on zirconia surfaces compared to titanium and cobalt-chromium alloy surfaces. Moreover, scanning electron microscopy showed clear differences in bacterial aggregation, depending on the type of biomaterial used. Over the past several decades, S. aureus strains have developed several mechanisms of resistance, especially in patients on chronic antibiotic treatment such as CF. Therefore, the selection of an appropriate implant biomaterial with limited microorganism adhesion characteristics can affect the occurrence and progression of oral cavity infections, particularly in patients with chronic systemic diseases.

Pseudomonas aeruginosa is a severe bacterial pathogen. Due to the genetic flexibility among strains, chronic airways infection can lead to mortality among cystic fibrosis (CF) patients. It is essential to develop patient-specific therapy which will rely on phenotypic and genomic diversity. The primary objective of this study was to assess the genomic variability of P. aeruginosa strains, using two different molecular techniques for tracking the epidemiological transmissions. This study applied a multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) for an efficient genotyping of clinical P. aeruginosa strains isolated from CF patients and compared results with a TRS-PCR typing. The percentage similarity analysis was performed using the categorical multi-state coefficient and UPGMA method. Based on the MLVA and TRS-PCR group assessment, 43 P. aeruginosa strains/variants were detected among the 63 clinical isolates from eight CF patients. The study of P. aeruginosa isolates has revealed that during chronic bacterial infections, CF patients harbor different P. aeruginosa strains or variants within the same host over the years. P. aeruginosa genotypes diversity may result from infection with several strains and result from a microevolution process of an initially acquired strain. The TRS-PCR method proposed in this work can complement the MLVA scheme. It can also be used as a preliminary method for genetic typing of P. aeruginosa isolates in CF patients.

Introduction: Cystic fibrosis (CF) is the most common genetic autosomal recessive genetic disease. The most serious symptoms are observed in the lungs. Recurrent respiratory infections are the main cause of hospitalization and death among cystic fibrosis patients. Pathogens that commonly infect the airways of adult CF patients include Staphylococcus aureus and Pseudomonas aeruginosa. The aim of this study was to analyse the microorganisms cultured from the airways of adult CF patients and to perform antimicrobial resistance tests of the most frequently isolated bacteria. Material and methods: In this study, 1422 isolates of 89 CF patients were collected during a 4-year period. The microorganisms were cultured and identified according to standard microbiological procedures. Identification and drug susceptibility were performed in a Phoenix (BD) automatic system, Vitek2Compact (bioMérieux) and disk-diffusion method by Kirby-Bauer. Among the 1422 strains, the most frequent pathogens were Pseudomonas aeruginosa (55.6%) and Staphylococcus aureus (37.8%). A total of 482 (61%) strains of 790 isolates of P. aeruginosa were identified as P. aeruginosa of mucoid phenotype. The isolates with mucoid phenotypes were more susceptible than non-mucoid. Eighty-six strains of S. aureus showed resistance to methicillin (MRSA), which accounted for 16.0% of all strains of S. aureus. Conclusions: The analysis of microbiological materials from adult CF patients treated in IGiChP allowed us to determine the prevalence of potentially pathogenic microorganisms. The data obtained are consistent with literature.

Patients with cystic fibrosis are predisposed to chronic respiratory tract infections caused by Pseudomonas aeruginosa. As the disease progresses, the microorganism diversifies into genotypically and phenotypically different strains which may coexist in the patient's airways for years. Adaptation of the microorganism to the airways of patients with cystic fibrosis probably occurs in response to the host's airway environment, the elements of the immune system and antibiotic therapy. Due to the chronic persistence of the microorganism in the airways, a comprehensive molecular analysis was conducted. The analysis included 120 strains isolated from 10 adult cystic fibrosis patients with chronic P. aeruginosa infection. The aim of the study was to analyze the molecular patterns of P. aeruginosa strains and to trace their transmission in the population of cystic fibrosis patients, as well as to study a relationship of the disease with specific phenotypic features. In the research, a genotypic analysis of P. aeruginosa was performed using pulsed-field gel electrophoresis. The results of a number of phenotypic features of the strains were added to the outcomes of the molecular studies. As a result, 28 different genotypes were distinguished. The study also showed cross-transmission of strains between patients. 3 transmissible clusters were identified, including IG1 and IG2 clusters with 9 strains of P. aeruginosa each, obtained from 2 patients and IG3 cluster with 6 strains of P. aeruginosa isolated from 3 patients. Moreover, it was found that in some patients, several unrelated strains of P. aeruginosa may transiently or permanently infect the respiratory tract. A comprehensive understanding of the P. aeruginosa adaptation may help to develop more effective antimicrobial therapies and to identify new targets for future drugs in order to prevent progression of the infection to chronic stages.