Role of CFT and PCR in diagnosis of Chlamydia psittaci in experimentally infected rabbits

Abstract

Specific antibodies against сhlamydia were detected using complement fixation test and сhlamydia genome was detected using polymerase chain reaction in pregnant rabbits experimentally infected with Chlamydia psittaci. The infected rabbits developed a fever and respiratory signs and the infection was confirmed by specific antibodies against сhlamydia detected in their blood and by abnormalities in rabbit kindling. Complement fixation test of paired rabbit sera revealed an increase in the titers of specific antibodies against сhlamydia, which on Day 7 post infection varied within 1:7.5; on Day 14, mean concentration was 1:40 and by Day 30 mean titer increased to 1:60. However, when pathological materials from the urogenital tract of the experimental animals were tested in polymerase chain reaction and in smear microscopy, it was impossible to confirm that there is an etiological link between сhlamydia and kindling problems in experimental animals. At the same time, molecular and genetic tests of internal organs (liver) sampled from stillborn baby rabbits revealed the сhlamydia genome, thus, proving сhlamydia involvement into the pathological kindling. Therefore, such a retrospective method as complement fixation test with a сhlamydia antigen is of high diagnostic value for lifetime сhlamydia diagnosis.