Characterization and Serotyping of Pasteurella multocida isolated from Deep Litter and Free-range Chickens in Vom, Plateau State, Nigeria

Fowl cholera caused by Pasteurella multocida is a signifant threat to the poultry industry that  hampers profit margin for poultry production. This study was conducted to investigate the prevalence and  serotypes of P. multocida among deep litter and free-range chickens in Vom, Nigeria. A total of 200 cloacal  swabs, comprising of 100 each from healthy deep litter and free-range chickens were aseptically collected for  the isolation of P. multocida by standard isolating procedures. Biotyping, capsular and somatic serotyping of  the isolates was carried out by sugar fermentation test, hyaluronic acid test and agar gel diffusion precipitin test  respectively. The prevalence of P. multocida in deep litter and free-range chickens was 7% and 4%  respectively. All the isolates from deep litter and free-range were P. multocida as confirmed by the detection of  KMT1 sequence using PM-PCR and were subsp. multocida and subsp. septica by sugar fermentation test.  Capsular type A and somatic type 4  were detected among 6 out of 7 from deep litter isolates, while one  remained untypeable using both the capsular and the somatic typing methods. All the isolates (n=4) from free range chickens remained untypeable by both methods used in this study. This study elucidates the importance  of periodic epidemiological survey for P. multocida in different chicken management system in other to  understand the nature of the causative organism in terms of capsular and somatic types so that it may be  incorporated in the fowl cholera vaccine production