Antibacterial activity of amicacin, cefotaxime and meropenem impregnated into bone cement discs against gram-negative bacteria Pseudomonas aeruginosa, Klebsiella pneumoniae

BACKGROUND: Today, there is a need to develop new compositions of bone cements with antibiotics, including those effective against resistant bacterial strains, which would create a local antibacterial environment that helps suppress growth and destroy pathogens without causing toxic reactions.

AIM: To evaluate the efficacy of amikacin, cefotaxime and meropenem impregnated into bone cement-based discs against gram-negative bacteria Pseudomonas aeruginosa, Klebsiella pneumoniae.

MATERIALS AND METHODS: A single-center, continuous, prospective, unblinded experimental in vitro study was performed. Museum strains of bacteria belonging to 2 taxonomic groups were used as test cultures: Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 700603. Discs with a diameter of 5 mm and a thickness of 2 mm were made from bone cement (Synicem 1) based on polymethyl methacrylate (PMMA); antibiotics were added to the cement in three weight proportions (groups 1, 2 and 3). The antibacterial effect of discs impregnated with antibiotics was assessed against the studied bacterial strains using the disc diffusion method. The experiment was carried out for six days. The results were recorded after 24, 48, 72 and 144 hours.

RESULTS: After 24 hours of the experiment on Petri dishes with disks impregnated with meropenem, amikacin and cefotaxime, a bactericidal effect was observed against P. aeruginosa strains; after 48 hours and on subsequent days of observation, a decrease in the zone of bacterial growth inhibition was noted. With respect to K. pneumoniae strains, there was no growth inhibition zone when using bone cement impregnated with amikacin in groups 1 and 2. An insignificant antibacterial effect was noted when using disks of group 3. Disks with cefotaxime had a weak antibacterial effect. Diffusion of meropenem (groups 2 and 3) and a bactericidal effect were observed for 6 days, a pronounced antibacterial effect was observed on the first day.

CONCLUSIONS: In experiments with P. aeruginosa, all antibiotics, regardless of their content in the disks, were characterized by maximum release during the first day, then the elution rate decreased and remained constant until the end of the experiment. In experiments with K. pneumoniae, the only effective drug was meropenem during the first day of the experiment. Among the studied drugs impregnated in disks with PMMA, only meropenem demonstrated efficacy against P. aeruginosa and K. pneumoniae bacteria, which can be used for local antibacterial therapy. Further in vitro and in vivo studies are necessary to determine the optimal concentration of the antibiotic and clinical efficacy in the prevention and treatment of chronic osteomyelitis.