Biofilm formation on different types of central venous catheters in vitro.

OBJECTIVE

To determine the intensity of biofilm formation on different types of central venous catheters in vitro by clinical isolates of bloodstream infection pathogens in Ukraine.

METHODS

Four clinical strains of Klebsiella pneumonia, four clinical strains of Staphylococcus aureus and four clinical strains of Pseudomonas aeruginosa were isolated from patients from Ukrainian tertial level children`s hospitals during 2023 with bloodstream infections including central line associated blood stream infections. Capacity to form biofilms was assessed using microtiter plate assay and ability to form biofilms in vitro was evaluated on three types of catheters: 1st catheter- surface from medical polyvinyl chloride; 2nd- surface from long-chain polymer based on methacrylate, polyethylene glycol and antiseptic polymeric biguanide; 3rd- silicon surface impregnated with an antimicrobial combination of chlorhexidine acetate and chlorhexidine. Scanning electron microscopy was conducted to assess biofilm formation on the surface of catheters.

RESULTS

Clinical isolates of K pneumonia had similar intensity of biofilm formation on different types of catheters: 1st catheter type- intensity of biofilm formation 0.30-0.34 OD; 2nd catheter type- 0.28-0.37 OD; 3rd catheter type- 0.32-0.37. Clinical isolates of S. aureus form biofilms on all types of catheters by biofilm formation on first type of catheter was lower compared to third type: 1st catheter type- 0.26-0.38 OD; 2nd catheter type- 0.3-0.4 OD; 3rd catheter type- 0.31-0.4 OD (p < 0.05 comparing with 1st catheter). Clinical isolates of P. aeruginosa had the highest ability to form biofilms on catheters. The ability to form biofilms was the most prominent of 3rd types of catheters: 1st catheter type- intensity of biofilm formation 0.38-0.66 OD; 2nd catheter type- 0.44-0.6 OD; 3rd catheter type- 0.54-0.91 OD (p < 0.05 comparing with 1st and 2nd catheter).

CONCLUSIONS

P.aeruginosa clinical strains form stronger biofilms compared to other bacteria on all types of catheters. All clinical isolates were able to form biofilm on catheter after 24 h incubation however intensity of biofilm formation by S.aureus and P.aeruginosa on catheters from medical polyvinyl chloride was lower than on other types. There was no difference in biofilm formation on different types of catheters by K.pneumonia strains in vitro.