Changes

|species            = Actinobacillus suis

|species            = Actinobacillus suis

}}

}}

==Introduction==

==Introduction==

''A.suis'' is a beta-haemolytic Gram-negative bacterium.  Strains of ''A.Suis'' vary due to differences in their lipopolysaccharides (LPS), which is known as the 'O' antigen and is referred to as O1,O2 and O3 and capsules (CPS), called 'K' antigen with variants described as K1, K2 and K3.

''A.suis'' is a beta-haemolytic Gram-negative bacterium.  Strains of ''A.Suis'' vary due to differences in their lipopolysaccharides (LPS), which is known as the 'O' antigen and is referred to as O1,O2 and O3 and capsules (CPS), called 'K' antigen with variants described as K1, K2 and K3.

In piglets aged 1 to 8 weeks old the organism causes acute and rapidly fatal septicaemia, and localized infections such as endocarditis, polyarthritis, and respiratory distress may also been seen with additional neurological signs. Adult pigs can suffer pneumonia like symptoms, see [[Actinobacillus suis#Clinical signs| clinical signs]] for more details. Although ''A.suis'' mainly affects pigs it has also 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.  It is not considered a zoonosis but there has been a report of human infection after a pig bite <ref>Escande F, Bailly A, Bone S, Lemozy J, 1996. Actinobacillus suis infection after a pig bite. Lancet (British edition), 348(9031):888; 5 ref.</ref>.

In piglets aged 1 to 8 weeks old the organism causes acute and rapidly fatal septicaemia, and localized infections such as endocarditis, polyarthritis, and respiratory distress may also been seen with additional neurological signs. Adult pigs can suffer pneumonia like symptoms, see [[Actinobacillus suis| clinical signs]] for more details. Although ''A.suis'' mainly affects pigs it has also 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.  It is not considered a zoonosis but there has been a report of human infection after a pig bite <ref>Escande F, Bailly A, Bone S, Lemozy J, 1996. Actinobacillus suis infection after a pig bite. Lancet (British edition), 348(9031):888; 5 ref.</ref>.

''A.suis'' have genes that encode toxins similar to apxI and apxII of ''A. pleuropneumoniae'', but are less virulent as they produce less Apx toxins than ''A. pleuropneumoniae''.  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 ''A. pleuropneumoniae'', but are less virulent as they produce less Apx toxins than ''A. pleuropneumoniae''.  Once an animal is infected with ''A.suis'' it can provide partial cross protection against ''A. pleuropneumoniae''.  

Neurological signs include head tilt, circling, temors, nystagmus, strabismus, decreased or absent menace response, ptosis, miosis or meiosis, photophobia, headshaking, opisthotonus, facial paralysis, paraparesis and ataxia.

Neurological signs include head tilt, circling, temors, nystagmus, strabismus, decreased or absent menace response, ptosis, miosis or meiosis, photophobia, headshaking, opisthotonus, facial paralysis, paraparesis and ataxia.

==Diagnosis==

==Diagnosis==

Diagnosis can be difficult as it shares clinical signs with pathogens, such as Streptococcus suis and Haemophilus parasuis, both being able to induce a septicemic infection with sudden death. Infection can be confirmed by the isolation of A. suis, from culturing different tissues of affected organs on post mortem.  

Diagnosis can be difficult as it shares clinical signs with pathogens, such as ''Streptococcus suis'' and ''Haemophilus parasuis'', both being able to induce a septicaemic infection with sudden death. Infection can be confirmed by the isolation of ''A. suis'', from culturing different tissues of affected organs on post mortem.  

Differential diagnosis include  A. pleuropneumoniae,  erysipelas, Glasser’s disease, streptococcus suis, and mulberry heart disease.

'''Differential diagnosis''': ''A. pleuropneumoniae'',  ''Erysipelas'', ''Glasser’s disease'', ''Streptococcus suis'', and ''Mulberry heart disease''.

On post-mortem serous or fibrinous exudates can be found in the thorax and pericardium and ecchymotic haemorrhages can be seen in kidneys, lungs, liver, spleen and other organisms.

On post-mortem serous or fibrinous exudates can be found in the thorax and pericardium and ecchymotic haemorrhages can be seen in kidneys, lungs, liver, spleen and other organisms.

==Treatment==

==Treatment==

A.suis has good sensitivity to ceftioufur, gentamicin and trimethoprim/sulfadiazine, and moderate sensitivity to ampicillin, neomycin, sulfadimethoxine and tiamulin. Culture and sensitivity is recommended.

''A.suis'' has good sensitivity to ceftioufur, gentamicin and trimethoprim/sulfadiazine, and moderate sensitivity to ampicillin, neomycin, sulfadimethoxine and tiamulin. Culture and sensitivity is recommended.

==Control==

==Control==

Routine biosecurity and disinfection should be followed and maintained.  At present there is no commercial vaccine for A. suis Radostitis et al, 2007 but there is evidence that autogenous vaccines in a herd could help stabilize antibody levels in the whole population Lapointe et al., 2001.

Routine biosecurity and disinfection should be followed and maintained.  At present there is no commercial vaccine for ''A. suis'' Radostitis et al, 2007 but there is evidence that autogenous vaccines in a herd could help stabilize antibody levels in the whole population Lapointe et al., 2001.

==References==

==References==

<references/>

<references/>