[CA antibodies (Enterobacteriaceae common antigen) in the sera of domestic animals].

The research article explores the presence of antibodies against Enterobacteriaceae common antigen (CA) in the sera of various domestic animals through an indirect hemagglutination test. The study additionally compares the antibody levels for somatic antigens from different E. coli serogroups and S. typhimurium, revealing the antibody level to these antigens to be higher than to the Enterobacteriaceae antigen.

Methodology

• The researchers have used an indirect hemaglutination test to detect the presence of CA antibodies in the sera of 123 horses, 142 cows, 108 sheep, 142 mature pigs and 60 piglets with the age of 3-4 weeks.
• The antibody levels and titers for somatic antigens were compared to those for various E. coli serogroups (0149, 0138, 0115, 078, 09) and S. typhimurium.

Findings

• The study found 100% presence of CA antibodies in the sera of examined horses and cows when the titer was equal or higher than 1:15. Similarly, in the sera of 92% sheep, 80% of mature pigs and 60% of piglets, antibodies to the common Enterobacterial antigen were present when the titer was equal or higher than 1:7.5.
• The researchers found that the antibody level to somatic antigens of E. coli and S. typhimurium were higher than to the Enterobacteriaceae common antigen in all sera examined.

Additional Observations

• The study also examined the influence of absorption of sera with CA preparation on the antibody level to heterologous antigens.
• It was observed that absorption caused a statistically significant decrease of the titers to O antigens E. coli and S. typhimurium compared to those found in unabsorbed sera.