Abstract
Pasteurella multocida is a Gram-negative, non-motile coccobacillus. The organism is of special significance in the tropical countries including Pakistan where only in Punjab Province, it caused heavy economics losses as Rs. 2.17 billion per year. We Isolated and identified the disease causing serotypes in Pakistan by using cultural, morphological and biochemical tests. Pathogenicity was confirmed by inoculation of the isolates in rabbits. Serotyping of the isolates was done and our isolates were found to be P. multocida, B: 2 serotype. Polymerase chain reaction (PCR) of 16s ribosomal deoxyribonucleic acid (rDNA) was done which amplified 1500 bp deoxyribonucleic acid (DNA) fragment. DNA sequencing and phylogenetic analysis of the gene revealed that our isolates are different from each other and they belong to two different groups. Whereas these isolates are closely related with P. multocida, sub species multocida, P. multocida and sub species septica.