Lipid peroxidation by Pseudomonas aeruginosa in the pathogenesis of nosocomial sepsis.
BACKGROUND
To study whether Pseudomonas aeruginosa may directly trigger peroxidation of polyunsaturated fatty acids, since lipid peroxidation is a mechanism involved in the pathogenesis of sepsis.


METHODS
Gamma-linolenic acid (GLA) was administered intravenously at a dose of 25mg/kg in an infusion time of 10 minutes to seven male rabbits. Blood samples were collected from the hepatic veins and from the carotid artery at regular time intervals. One clinical isolate was ex vivo incubated with the serum derived from the latter samples and concentrations of malondialdehyde (MDA) were determined during incubation in the growth medium by the thiobarbiturate assay.


RESULTS
Elevated concentrations of MDA compared to their basal levels were found over the first three hours of incubation in the presence of samples collected 30 to 60 minutes after the end of the infusion of GLA. After infusion of GLA concentrations of arachidonic acid in the serum increased to concentrations comparable to those detected in sepsis.


CONCLUSIONS
Direct triggering of lipid peroxidation by nosocomial isolates might be proposed as a pathogenetic mechanism of sepsis.
Giamarellos-Bourboulis
E J
EJ
4th Department of Internal Medicine, Sismanoglion General Hospital, 151 26 Maroussi Attikis, Greece. giamarel@internet.gr
Skiathitis
S
S
Dionyssiou-Asteriou
A
A
Hatziantoniou
S
S
Demetzos
K
K
Dontas
I
I
Papaioannou
G T
GT
Karatzas
G
G
Helen
G
G
D000818:Animals; D016718:Arachidonic Acid / Q000097:blood; D003428:Cross Infection / Q000097:blood / Q000382:microbiology*; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D011550:Pseudomonas aeruginosa / Q000378:metabolism / Q000472:pathogenicity*; D011817:Rabbits; D017965:gamma-Linolenic Acid / Q000008:administration & dosage
D016718:Arachidonic Acid; D008315:Malondialdehyde; D017965:gamma-Linolenic Acid