Rapid diagnosis of Mycoplasma synoviae in infected broiler breeder farms by using PCR & RT-PCR methods.

The aim of this study was to evaluate the ability of RT-PCR assay to find live Mycoplasma synoviae in breeder flocks to analyse the different results obtained by Mycoplasma culture method or PCR assay To this opinion, thirteen broiler breeder flocks with positive rapid serum plate agglutination test results had been selected. The specimens were obtained from choanal cleft and tracheal swabs which placed in PPLO broth and then immediately transported to laboratory. After short-term incubation, cultivation, PCR and RT-PCR assays were performed on the collected samples. In cultivation method at the first and fifth passages, respectively, there were found four (4/13) and six (6/13) positive results with the formation of significant Mycoplasma synoviae colonies on PPLO agar. PCR and RT-PCR assays were performed with Mycoplasma synoviae species and strain specific primers from known 16S rRNA sequences. PCR and RT-PCR assays were set up with standard strain of Mycoplasma synoviae and then all the specimens were evaluated in these assays. All the specimens had 161 bp fragments of Mycoplasma 16S rRNA in species-specific PCRs (13/13). Also, all the specimens had 207 bp fragments of Mycoplasma synoviae 16S rRNA in the Mycoplasma synoviae strain-specific PCRs (13/13). The 270 bp fragments of Mycoplasma 16S rRNA were obtained only with four (4/13) specimens in RT-PCR assay. Considering to the results, cultivation method has the ability to detect active Mycoplasma synoviae infection. Positive results of cultivation are depending on the stage of infection, correct sampling, sampleing location and condition of transporting to the laboratory (without any defect on bacterial livability) and culturing method. However, cultivation is too much time consuming and after the death of bacteria, detection of infection is impossible. In this study, other methods of Mycoplasma synoviae detection were PCR and RT-PCR. These assays are known as time saving. PCR has the ability to detect live or dead bacteria, but, RT-PCR assay has the ability to detect live or recently dead bacteria from specimens which correct sampling and short time transportation to the laboratory has occurred. However, RT-PCR is a reliable assay for detection of active Mycoplasma synoviae infection from broiler breeder flocks. Key words: Mycoplasma synoviae (MS), broiler breeder, PCR, and RT-PCR, poultry.