Investigation of serum nitric oxide and malondialdehyde levels in cattle infected with Brucella abortus

The objective of this study was to determine serum nitric oxide (NO) and malondialdehyde (MDA) levels in cattle infected with Brucella abortus (B. abortus). Study cohort was comprised of 30 cattle aged between 2-3 years; 20 infected with B. abortus and 10 healthy cattle. B. abortus infection was determined in the animals by Serum Agglutination Test and Multiplex PCR assay. Serum NO level was determined by enzymatic Greiss reaction and MDA level by Yoshioka method. Mean serum NO and MDA levels of cases with confirmed B. abortus were 58.20 ± 6.50 μmol/L and 2.25 ± 0.10 nmol/ml, respectively whereas those of the controls were 38.07 ± 2.40 μmol/L and 1.74 ± 0.25 nmol/ml, respectively. We found that serum NO and MDA levels in infected cattle were significantly higher than healthy control cattle (p < 0.05 and p < 0.01, respectively). In conclusion, the increase in NO level in cattle infected with B. abortus is a result of stimulation of NO synthesis in macrophages by bacterial lipopolysaccharides, and the increase in MDA level is a result of excessive radical production due to brucellosis acting upon membrane lipids and can be used as an indicator of tissue damage.