Pasteurella multocida RIRDC MLST Databases
Introduction
Pasteurella multocida is a facultative Gram-negative coccobacillus that causes a wide range of diseases in both wild and domestic animals (Adler et al., 1996). Some serovars of P. multocida are the aetiologic agents of severe conditions such as fowl cholera in poultry, haemorrhagic septicaemia in cattle and buffalo and atrophic rhinitis in pigs (Adler et al., 1996).
Fowl cholera is a common and widely distributed disease of poultry and is of major economic importance (Glisson et al., 2003). The disease can express itself in an acute or a chronic form. In the acute form, clinical signs are seen only in the few hours before death. Hence, if the birds are not observed in this short period, the first indication of the disease is often death. Chickens in the acute stage of the disease will show signs of fever, have ruffled feathers, have a mucus discharge from the mouth, suffer diarrhoea and show an increased breathing rate (Glisson et al., 2003).
The chronic form of the disease can follow an acute stage or may be the only form of the disease present in a flock. The signs of this form of the disease are generally linked to localized infections. Wattles, sinuses, leg or wing joints, foot pads may become swollen. Swollen eyes (more correctly know as serous inflammation of the conjunctiva), twisted necks (more formally called torticollis), respiratory gurgles (rales) can occur. Chronically affected birds can progress to death, can recover or may stabilise (Glisson et al., 2003). A chronically infected bird can remain infected for life, with survivors of an acute outbreak having been shown to act as reservoirs of infection (Glisson et al., 2003).
Fowl cholera can be prevented by eliminating all reservoirs of infection within a property and then preventing any re-entry of the organism into the property. Implementation of standard good management practices, an effective sanitation regime and a good biosecurity program will mean that fowl cholera can be prevented (Blackall, 2003).
This MLST data-base was created using 63 isolates of P. multocida from Australian poultry - all associated with fowl cholera outbreaks. All 63 isolates had been examined in a prior study based on multi-locus enzyme electrophoresis (Blackall et al., 1998). As well, three international reference strains, representing the three subspecies within P. multocida were included.
References
- Adler, B., Chancellor, R., Homchampa, P., Hunt, M., Ruffolo, C., Strugnell, R. & Wapling, D. (1996). Immunity and vaccine development in Pasteurella multocida infections. J Biotechnol 44, 139-144.
- Blackall, P. J. (2003). Fowl cholera - an emerging disease in free-range chickens? In Queensland Poultry Science Symposium. Gatton, Queensland.
- Blackall, P. J., Fegan, N., Chew, G. T. & Hampson, D. J. (1998). Population structure and diversity of avian isolates of Pasteurella multocida from Australia. Microbiology 144, 279-289.
- Glisson, J. R., Hofacre, C. L. & Christensen, J. P. (2003). Fowl cholera. In Diseases of Poultry, pp. 658-676. Edited by Y. M. Saif, H. J. Barnes, J. R. Glisson, A. M. Fadly, L. R. McDougald & D. A. Swayne. Ames: Iowa State University Press.