Ex vivo synergy of arachidonate-enriched serum with ceftazidime and amikacin on multidrug-resistant Pseudomonas aeruginosa.

Three multidrug-resistant strains of Pseudomonas aeruginosa were incubated ex vivo with sera sampled after a 10 min intravenous infusion of 25 mg/kg of arachidonic acid (AA) in 10 rabbits in the presence of ceftazidime and amikacin. Lipid peroxidation was assessed during bacterial growth. A statistically significant decrease in bacterial cells was found by the interaction of antimicrobials and serum sampled in the middle of infusion and 15 and 30 min after infusion of AA and was accompanied by elevated levels of malonodialdehyde. This effect of AA is probably attributed to lipid peroxidation and raises the possibility of its application in experimental infections.