Difference between revisions of "Actinobacillus suis"
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==Introduction== | ==Introduction== | ||
| − | ''A.suis'' is a beta-haemolytic '''Gram-negative bacterium'''. Strains of ''A. | + | ''A.suis'' is a beta-haemolytic '''Gram-negative bacterium'''. Strains of ''A.suis'' vary due to differences in their '''lipopolysaccharides (LPS)''', which are known as ''''O' antigens''' and are referred to as '''O1,O2''' and '''O3''' and '''capsules (CPS)''', refered to as''''K' antigen''' with variants described as '''K1, K2''' and '''K3'''. More than 95% of A. suis clinical isolates are cross-reactive with O1/K1 or O2/K3 antiserum and more severe infection were noted with O2/K2 srain <ref name="Slavic et al., 2000">Slavic, D., DeLay, J., Hayes, M.A., MacInnes, J.I.(2000) '''Comparative pathogenicity of different Actinobacillus suis O/K serotypes'''. ''Canadian Journal of Veterinary Research'', 64(2):81-87.</ref>. This '''opportunistic''' bacteria causes [[Actinobacillosis - Pig| '''actinobacillosis in pigs''']], and has been linked to septicaemia, acute haemorrhagic pulmonary infarction and necrotizing pneumonia in horses, airsaculitis in waterfowl, neonatal calf pneumonia and localised infections and polyarthritis in alpacas. [[Actinobacillus equuli| horses]],[[Actinobacillosis - Cattle| cattle]] and can infect [[Actinobacillus suis#signalment| various other species. |
''A.suis'' have genes that encode toxins similar to apxI and apxII of [[Actinobacillus pleuropneumoniae| ''A. pleuropneumoniae'']], but they are less virulent. Once an animal is infected with ''A.suis'' it can provide partial '''cross protection against ''A. pleuropneumoniae'''''. | ''A.suis'' have genes that encode toxins similar to apxI and apxII of [[Actinobacillus pleuropneumoniae| ''A. pleuropneumoniae'']], but they are less virulent. Once an animal is infected with ''A.suis'' it can provide partial '''cross protection against ''A. pleuropneumoniae'''''. | ||
Revision as of 10:19, 23 June 2011
Also known as: A.suis
| Scientific Classification | |
|---|---|
| Kingdom | Bacteria |
| Phylum | Proteobacteria |
| Class | Zymobacteria |
| Sub-class | Alphaproteobacteria |
| Order | Pasteurellales |
| Family | Pasteurellaceae |
| Genus | Actinobacillus |
| Species | Actinobacillus suis |
Introduction
A.suis is a beta-haemolytic Gram-negative bacterium. Strains of A.suis vary due to differences in their lipopolysaccharides (LPS), which are known as 'O' antigens and are referred to as O1,O2 and O3 and capsules (CPS), refered to as'K' antigen with variants described as K1, K2 and K3. More than 95% of A. suis clinical isolates are cross-reactive with O1/K1 or O2/K3 antiserum and more severe infection were noted with O2/K2 srain [1]. This opportunistic bacteria causes actinobacillosis in pigs, and has been linked to septicaemia, acute haemorrhagic pulmonary infarction and necrotizing pneumonia in horses, airsaculitis in waterfowl, neonatal calf pneumonia and localised infections and polyarthritis in alpacas. horses, cattle and can infect [[Actinobacillus suis#signalment| various other species.
A.suis have genes that encode toxins similar to apxI and apxII of A. pleuropneumoniae, but they are less virulent. Once an animal is infected with A.suis it can provide partial cross protection against A. pleuropneumoniae.
A.suis strains are able to resist bile and serum,
Signalment
A.Suis can be found in the tonsils and upper respiratory tract of both healthy and diseased animals, and isolates are genetically and biochemically similar. It is believed to be spread via aerososl infection and invasion of the upper respiratory tract. The incidence of the disease is increasing, especially in
Wild hosts include anatidae (ducks, geese and swans) and Coypu but A.suis can also affect domestic species including pigs, horses, cattle, sheep, goats, alpacas, zebu, dogs, and cats.
Diagnosis
A.Suisis difficult to culture and most of the O1 strains analyzed possess pustulan (1-6,beta-D-glucan)which is a major component of fungal and lichen cell walls. Therefore, many animals have antibodies to this polysaccharide in the absence of exposure to A. suis. Thses antibodies may provide naive pigs with some level of protection against the O1 strains [2], [1]
Distribution
Worldwide
References
- ↑ 1.0 1.1 Slavic, D., DeLay, J., Hayes, M.A., MacInnes, J.I.(2000) Comparative pathogenicity of different Actinobacillus suis O/K serotypes. Canadian Journal of Veterinary Research, 64(2):81-87.
- ↑ MacInnes, J.I., Desrosiers, R.(1999) Agents of the "suis-ide diseases" of swine: Actinobacillus suis, Haemophilus parasuis, and Streptococcus suis. Canadian Journal of Veterinary Research, 63(2):83-89; 52 ref.