Assessment of biofilm formation by clinical isolates of Klebsiella pneumoniae on biomaterials used in the production of tracheostomy tubes
Project manager: Dorota Ochońska, M.A
Implementation period: 2020 – 2021
A significant problem in modern medicine are Healthcare-Associated Infections (HCAIs) occurring in patients with tracheostomy. Moreover, an important group of infections are infections closely related to biomaterials widely used in medicine (Biomaterials Associated Infections (BAIs), an example of which are biomaterials intended for the production of tracheostomy tubes (TTs). In the light of current scientific literature data, it is known that bacterial biofilms are present in over 90% of tracheostomy tubes.
A wide spectrum of pathogenic microorganisms has the ability to adhere, colonize and, consequently, develop a biofilm on the surface of tracheostomy tubes. Among the Gram-negative bacteria, Klebsiella pneumoniae remains one of the most frequently reported bacterial pathogens capable of forming biofilms on these biomaterials, therefore they are the dominant bacilli isolated from colonized and/or symptomatic infections of tracheostomy patients.
The presented work was created in connection with the increasing frequency of K. pneumoniae isolation from clinical samples collected from hospitalized patients undergoing tracheostomy procedures in recent years. K. pneumoniae, as one of the most numerous etiological factors of nosocomial infections, is often responsible for nosocomial infections associated with respiratory tract infections manifested by Ventilator Associated Pneumonia (VAP), which may result from their ability to form a biofilm on biomaterials of tracheostomy tubes.
The study included 18 clinical strains of the species K. pneumoniae originating from tracheal aspirates obtained from tracheostomy tubes from patients of the 5th Military Clinical Hospital and Polyclinic SPZOZ in Krakow hospitalized from July 2017 to December 2019 in the Department of Otolaryngology and Oncological Surgery of the Head and Neck, as well as at the Department of Intensive Care and Anesthesiology. The main aim of the study was to assess the ability of the tested K. pneumoniae isolates to form a biofilm. Additionally, the biofilm structures produced on the surface of polyethylene (PE) and polyvinyl chloride (PVC) tracheostomy tubes were imaged using scanning electron microscopy. (Scanning Electron Microscopy, SEM). Moreover, all isolates were characterized to determine the extent of antibiotic resistance, the presence of genes encoding Extended Spectrum β-Lactamase (ESβL), the presence of selected virulence factors and genetic diversity. In the course of the conducted research, the simultaneous occurrence of blaCTX-M-1, blaSHV, and blaTEM genes was confirmed in three strains, producers of ESβL. Moreover, based on the results obtained from phenotypic methods, it was confirmed that 44.4% of the strains had the ability to form a biofilm and were characterized by a diverse fimbrial genotype and high genetic variability.
Due to the widespread use of tracheostomy procedures, the efforts of research groups should be focused on conducting further research aimed at deepening knowledge in the field of the characteristics of bacterial pathogens with the ability to form a biofilm on the surface of tracheostomy tubes, its structure and functioning mechanisms, as well as searching for innovative methods to limit the formation of these surfaces or modifying existing biomaterials to reduce the risk of its formation. We believe that the Polish experience in the presented research will be helpful and provide the necessary scientific contribution in the fields of medicine, microbiology and chemistry, which will allow in the future to design safe tracheostomy tubes with features that maximize patient comfort while minimizing complications during use.
Biofilm Formation of Clinical Klebsiella pneumoniae Strains Isolated from Tracheostomy Tubes and Their Association with Antimicrobial Resistance, Virulence and Genetic Diversity
Dorota Ochońska, Łukasz Ścibik, Monika Brzychczy-Włoch. Pathogens 2021 Oct 18;10(10):1345. DOI: https://doi.org/10.3390/pathogens10101345