Evaluation of the use of lipopolysaccharides and synthetic O-polysaccharides in i-ELISA for the serological diagnosis of brucellosis

Authors: Songül Ötkün, Ahmet M. Saytekin, Ayfer G. Yücetepe, and Sevil EGürbilek

Ger. J. Microbiol. 2025. vol. 5, Iss. 2 pp:27-32
Doi: https://doi.org/10.51585/gjm.2025.2.0051

article-picture
Abstract:

Brucellosis remains one of the most significant diseases affecting both human and animal health in many countries worldwide, with substantial health and economic consequences. Serological tests play a key role in the diagnosis of brucellosis. This study aimed to evaluate the use of lipopolysaccharide (LPS) and synthetically derived Brucella antigens in an in-house indirect enzyme-linked immunosorbent assay (i-ELISA) for the serological diagnosis of brucellosis in milk samples collected from cattle that had experienced abortion. A total of 53 milk samples obtained from cattle herds in various provinces of Türkiye were analyzed by i-ELISA using smooth LPS (sLPS), synthetic disaccharide/trisaccharide/tetrasaccharide, and antigens prepared from the B. abortus RB51 strain. Seropositivity rates were found to be 52.8%, 39.6%, 50.9%, and 47.2% for s-LPS, disaccharide, trisaccharide, and tetrasaccharide antigens, respectively. Five serum samples reacted positively with the B. abortus RB51 antigen. Statistical analyses (McNemar and Fleiss' Kappa) revealed that s-LPS and synthetic antigens were diagnostically concordant in terms of positive/negative agreement. However, since the milk samples used in the study were not confirmed by culture or PCR, diagnostic performance parameters such as sensitivity and specificity were not calculated; classifications were made based on cutoff values determined using positive and negative control samples. As a result, although the s-LPS yielded the highest seropositivity rate, it was concluded that synthetic antigens may offer a more reliable alternative for the serological diagnosis of brucellosis due to the risk of false positives caused by crossreactions.

Keywords:

Synthetic OPS, Brucellosis, Serology, Diagnosis, Milk

Statistics:

Article Views: 810
PDF Download: 9