Difference between revisions of "Actinobacillus suis"

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Also known as: '''''A.suis''''', '''''Actinobacillosis''''', '''''A. equuli in swine''''', '''''Actinobacillus suis septicaemia in horses''''', '''''Actinobacillus suis septicaemia in pigs''''', '''''Acute haemorhagic pulmonary infarction and necrotizing pneumonia in horses''''', '''''Otitis media, externa, interna, middle and inner ear infections'''''.
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{{OpenPagesTop}}
 
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Also known as: '''''A. suis'''''
 
{{Taxobox
 
{{Taxobox
|name              =''Scientific Classification''
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|name              =''Actinobacillus suis''
 
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|kingdom            = [[:Category:Bacteria|Bacteria]]
|kingdom            = Bacteria
 
 
|sub-kingdom        =
 
|sub-kingdom        =
 
|phylum            = Proteobacteria
 
|phylum            = Proteobacteria
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|family            = Pasteurellaceae
 
|family            = Pasteurellaceae
 
|sub-family        =
 
|sub-family        =
|genus              = Actinobacillus
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|genus              = [[Actinobacillus species|Actinobacillus]]
|species            = Actinobacillus suis
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|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.
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[[File:Actinobacillus suis.jpg|thumb|200px|right| ''Actinobacillus suis'' Gram stain]]
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>.
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''A.suis'' is a beta-haemolytic '''Gram-negative bacterium'''. It has many strains 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 strain <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 mainly causes [[Actinobacillosis - Pig|'''actinobacillosis in pigs''']], but has also been linked to diseases in neonatal calves, waterfowl, alpacas, horses and [[Actinobacillus suis#Signalment|various other species]].
''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''.  
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Other haemolytic strains of ''Actinobacillus'' species have been linked to various diseases in horses such as [[Actinobacillus equuli| ''Actinobacillus equuli'']] and [[Actinobacillosis - Cattle|''Actinobacillus ligneresii'']]. The latter species also causes [[Actinobacillosis - Cattle|wooden tongue in cattle]].  
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''A. suis''-like organism may cause acute haemorhagic pulmonary infarction and necrotizing pneumonia as well as septicaemia in horses.
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''A. suis'' are able to resist bile and serum and 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'''''.  
  
 
==Signalment==
 
==Signalment==
''A.Suis'' can be found worldwide in both healthy and diseased animals which are genetically and biochemically similar. Wild hosts include anatidae (ducks, geese and swans) and [http://en.wikipedia.org/wiki/ Coypu] but A.suis can also affect domestic species including dogs, cats, horses, cattle, pigs, sheep, goats, alpacas and zebu
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''A.suis'' can infect all ages of pigs and it is thought that incidence of the disease is increasing, especially in North American high-health-status herds.
High health status herds with lower immune challenges are more at risk then conventional herds.  Piglets from high health status herds can suddenly die without any premonitory signs. Excessive temperature fluctuation, high humidity, mixing of pigs of different ages and overcrowding may also have an important role in the development of disease.
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==Clinical Signs==
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Wild hosts include anatidae (ducks, geese and swans) and [http://en.wikipedia.org/wiki/Coypu coypu] but ''A. suis'' can also affect domestic species including cattle, sheep, goats, alpacas, zebu, dogs, cats and tenuous links to equine disease have been recorded (although this is thought to be an ''A.suis''-like microorganism rather than ''A. suis'' itself). ''A. suis'' is not considered to be a zoonosis, but there is a report of a 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>.
Clinical signs vary from fever, lethargy, depression, erysipelas-like lesions, abscesses, haemorrhage, vomiting/regurgitation and lameness and multiple joint swelling. More serious cases progress to pneumonia (clinical signs similar to [[Actinobacillus pleuropneumoniae#Clinical Signs|''A. pleuropneumoniae'') and sudden death.  Cardiorespiratory signs include tachycardia, heart murmurs, purulent or serous occulonasal discharges, sneezing, coughing, abnormal lung sounds, dyspnoea, changes in heart rate and open mouthed breathing. Aural purulent mucoid discharge and increased amounts of wax are present along with a foul odour. Pigs can become deaf and are often found rubbing and scratching their ears. Affected animals are in a lot of pain and discomfort and which manifests as dysphagia lymphadenopathy , anorexia, and unthriftiness. Pregnant sows can suffer from agalactia, mastitis, abortions, still births or weak piglets.
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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.
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==Clinical signs==
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For clinical signs in pigs see [[Actinobacillosis - Pig| '''actinobacillosis in pigs''']].  In other species, ''A. suis'' causes pneumonia like symptoms and localised infections in neonatal calf, airsaculitis in waterfowl, and polyarthritis in alpacas and acute haemorrhagic pulmonary infarction and necrotizing pneumonia in horses.  
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==Epidemiology==
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The epidemiology of ''A. suis'' is poorly understood, although it can be found in the tonsils and upper respiratory tract of both healthy and diseased pigs, and isolates are genetically and biochemically similar. It is believed to be spread via '''aerosol infection''' and '''invasion of the upper respiratory tract'''. Systemic disease can be seen when infected emboli spread haematogenously throughout the body adhering to the endothelium of blood vessels or becoming trapped in smaller vessels.  It is thought to colonise piglets in the first three weeks of life but not all piglets become clinically affected and some can become carriers.  
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==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.  
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''A. suis'' is difficult to culture and most of the O1 strains analysed 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''These antibodies may provide naive pigs with some level of protection against the O1 strains <ref name="MacInnes and Desrosiers, 1999">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.</ref>, <ref name="Slavic et al., 2000"/>.
Differential diagnosis include A. pleuropneumoniae, erysipelas, Glasser’s disease, streptococcus suis, and mulberry heart disease.
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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.
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For more information see [[Actinobacillosis - Pig|'''actinobacillosis in pigs''']].
==Treatment==
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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.
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==Distribution==
==Control==
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Worldwide
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.
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==References==
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{{Learning
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|flashcards = [[Actinobacillus suis Flashcards| ''Actinobacillus suis'' Flashcards ]]
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}}
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== References ==
 
<references/>
 
<references/>
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{{CABI source
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|datasheet = [http://www.cabi.org/ahpc/Default.aspx?site=160&page=2144&LoadModule=datasheet&CompID=3&dsID=95732 Actinobacillus suis]
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|date = August 08, 2011
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}}
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{{review}}
  
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{{OpenPages}}
  
[[Category:Actinobacillus_species]][[Category:Pig Bacteria]][[Category:Respiratory Diseases - Pig]][[Category:Horse Bacteria]]
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[[Category:Actinobacillus_species]][[Category:Pig Bacteria]][[Category:Horse Bacteria]]
[[Category:To_Do_-_Bacteria]][[Category:To Do - Jaimie Meagor]]
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[[Category:CABI Expert Review]][[Category:CABI AHPC Pages]]

Latest revision as of 12:14, 17 August 2012


Also known as: A. suis

Actinobacillus suis
Kingdom Bacteria
Phylum Proteobacteria
Class Zymobacteria
Sub-class Alphaproteobacteria
Order Pasteurellales
Family Pasteurellaceae
Genus Actinobacillus
Species Actinobacillus suis

Introduction

Actinobacillus suis Gram stain

A.suis is a beta-haemolytic Gram-negative bacterium. It has many strains 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 strain [1]. This opportunistic bacteria mainly causes actinobacillosis in pigs, but has also been linked to diseases in neonatal calves, waterfowl, alpacas, horses and various other species.

Other haemolytic strains of Actinobacillus species have been linked to various diseases in horses such as Actinobacillus equuli and Actinobacillus ligneresii. The latter species also causes wooden tongue in cattle.

A. suis-like organism may cause acute haemorhagic pulmonary infarction and necrotizing pneumonia as well as septicaemia in horses.

A. suis are able to resist bile and serum and 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.

Signalment

A.suis can infect all ages of pigs and it is thought that incidence of the disease is increasing, especially in North American high-health-status herds.

Wild hosts include anatidae (ducks, geese and swans) and coypu but A. suis can also affect domestic species including cattle, sheep, goats, alpacas, zebu, dogs, cats and tenuous links to equine disease have been recorded (although this is thought to be an A.suis-like microorganism rather than A. suis itself). A. suis is not considered to be a zoonosis, but there is a report of a human infection after a pig bite [2].

Clinical signs

For clinical signs in pigs see actinobacillosis in pigs. In other species, A. suis causes pneumonia like symptoms and localised infections in neonatal calf, airsaculitis in waterfowl, and polyarthritis in alpacas and acute haemorrhagic pulmonary infarction and necrotizing pneumonia in horses.

Epidemiology

The epidemiology of A. suis is poorly understood, although it can be found in the tonsils and upper respiratory tract of both healthy and diseased pigs, and isolates are genetically and biochemically similar. It is believed to be spread via aerosol infection and invasion of the upper respiratory tract. Systemic disease can be seen when infected emboli spread haematogenously throughout the body adhering to the endothelium of blood vessels or becoming trapped in smaller vessels. It is thought to colonise piglets in the first three weeks of life but not all piglets become clinically affected and some can become carriers.

Diagnosis

A. suis is difficult to culture and most of the O1 strains analysed 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. These antibodies may provide naive pigs with some level of protection against the O1 strains [3], [1].

For more information see actinobacillosis in pigs.

Distribution

Worldwide



Actinobacillus suis Learning Resources
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Flashcards
Test your knowledge using flashcard type questions
Actinobacillus suis Flashcards



References

  1. 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
  2. Escande, F., Bailly, A., Bone, S., Lemozy, J. (1996) Actinobacillus suis infection after a pig bite. Lancet (British edition), 348(9031):888; 5 ref.
  3. 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.


CABIlogo

This article was originally sourced from The Animal Health & Production Compendium (AHPC) published online by CABI during the OVAL Project.

The datasheet was accessed on August 08, 2011.











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