Optimization of the Production Technology of a Specific Chlamydia Antigen and Assessment of Its Biological Activity and Potential Applications in Feline Chlamydiosis.

Abstract

This study presents the results of investigations aimed at examining chlamydiosis in domestic cats and improving methods for obtaining a specific antigen of the pathogen. An analysis of clinical manifestations was conducted, and the circulation of the pathogen among the examined animals was confirmed using serological methods. The obtained data made it possible to identify diagnostically significant features of the infection and to substantiate the need for improving the efficiency of laboratory diagnostics. The main focus of the study was the development of an improved technology for obtaining chlamydial antigen. A novel approach was proposed based on replacing toxic ethyl mercaptan with ethanol and applying a combined processing scheme involving detergent-mediated disruption of cellular structures followed by ether extraction. This approach allowed increasing the degree of purification of the antigenic material and improving its functional properties. To verify this hypothesis, three batches of previously prepared antigens were subjected to extraction with medical ether. Five volumes of ether were added to one volume of the “detergent” antigen, and extraction was carried out at room temperature for 24 hours with periodic stirring. The mixture separated into three layers: the upper layer containing ether with dissolved antigen, the middle layer consisting of ballast tissue substances, and the lower aqueous phase containing dissolved salts. The obtained antigen demonstrated high specificity, stability, and pronounced activity in the complement fixation test, without exhibiting anticomplementary properties. The use of safer reagents increases the practical applicability of the proposed technology. The results indicate that the developed method is promising for use in serological diagnostics and may serve as a basis for further research in the development of immunobiological preparations against feline chlamydiosis.