Document Type : Full paper (Original article)
Pasteurella Research Laboratory, Razi Vaccine and Serum Research Institute, Karaj, Iran
Department of Biotechnology, Razi Vaccine and Serum Research Institute, Karaj, Iran
Department of Aerobic Bacterial Vaccines, Razi Vaccine and Serum Research Institute, Karaj, Iran
Department of Anaerobic Bacterial Vaccines, Razi Vaccine and Serum Research Institute, Karaj, Iran
Pasteurella multocida is known as an important heterogenic bacterial agent causes some severe diseases such as fowl cholera in poultry and haemorrhagic septicaemia in cattle and buffalo. A polymerase chain reaction (PCR) assay was developed using primers derived from conserved part of 16S-23S rRNA gene. The PCR amplified a fragment size of 0.7 kb using DNA from nine avian P. multocida isolates. Sequence alignment of the 16S-23S rRNA genes (ITS) revealed a considerable heterogenicity among the isolates. The percentage of similarity varied from 83.3 to 100% among the isolates. An interesting finding from this study was the presence of an inserted sequence (seven nucleotides) in the 16S-23S rRNA region in 55% of the isolates. According to phylogenic analysis based on ITS sequence alignment, the P. multocida isolates classified into 2 distinct clusters. The virulence of isolates in cluster II were higher than those in cluster I. Ribotyping of P. multocida by using 16S-23S rRNA gene PCR sequencing could be used as a marker in epidemiologic studies.