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77 Cards in this Set
- Front
- Back
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Characteristics of Genus Pasteurella
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G-, small rods-coccobacilli, non-motile, Oxidase +, most are catalase +, facultative anaerobs, nutritionally fastidious, Giemsa stain-Bipolar staining
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Pasteurella species of major vet significance
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P. multocida
Bibersteinia trehalosi (P. trehalosi) |
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Pasteurella species of minor vet significance
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P. aerogenes
P. anatis P. canis P. avium P. cabalii P. dagmatis P. gallinarum P. pneumotropica Etc. |
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Pasteurella multocida
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Name means "killer of many"
Associated with a wide range of diseases in animals Zoonotic- human infection mostly derive from animal bites |
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Pasteurella multocida subspecies
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P. multocida spp. multocida (diseases in domestic animals)
P. multocida spp. gallicida (Birds, may cause fowl cholera) P. multocida spp. septica (Dogs and cats, some birds) |
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Pathogenicity and pathogenesis of P. multocida
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many infections are endogenous
Normally commensal of upper resp. tract but may invade tissues of immunosuppressed animals. Exogenous transmission can occur by direct contact or aerosol Development: adhesions to mucosa and avoidance of phagocytosis is important |
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Virulence factors !!
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Fimbriae may enhance mucosal attachment and hyaluronic capsule
Endotoxin? P. trehalosi- produces leukotoxin |
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Pasteurella serogroup strains !!
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A- major antiphagocytic role
B D E F |
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Division of pasteurella
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Identified on basis of differences in capsular polysaccharides by indirect hemaglutination reaction- A,B,C,E,F
Subdivided into 16 somatic types on basis of serological diff. in cell lipopolysaccharides |
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Antigens !!
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O (somatic)
H (flagellar K (capsular |
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Disease caused by:
P. multocida type A - in cattle |
Bovine pneumonic pasteurellosis (Shipping fever), enzootic pneumonia complex of calves, mastitis
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Disease caused by:
P. multocida type A - in sheep |
Pneumonia, mastitis
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Disease caused by:
P. multocida type A - in pigs |
Pneumonia, atrophic rhinitis
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Disease caused by:
P. multocida type A - in poultry |
Fowl cholera
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Disease caused by:
P. multocida type A - in rabbits |
Snuffles
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Disease caused by:
P. multocida type A - in other animals |
pneumonia following stress
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Disease caused by:
P. multocida type B |
Cattle, buffaloes
Haemorrhagic septicaemia (Asia) |
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Disease caused by:
P. multocida type D |
Pigs
Atrophic rhinitis, pneumonia |
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Disease caused by:
P. multocida type E |
Cattle, buffaloes
Haemorrhagic septicaemia (Africa) |
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Disease caused by:
Bibersteinia trehalosi |
Sheep
Septicaemia 5-12 months of age |
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Diseases of pathogenes of minor vet sign.
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Intestinal commensals, commensals in upper resp., commensals in oral cavity, lymphagitidis, etc.
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Haemorrhagic septicaemia/barbone; cause
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Acute, highly fatal of cattle and buffaloes
P. multocida serotype B:2 (Asia) and E:2 (africa) Overwork, poor body conditions, monsoon rains Older animals are latent carriers- pasteurella located in tonsillar crypts |
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Haemorrhagic septicaemia/barbone; symptoms
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Death without prior signs of illness may occur within 24h of infections.
Sudden onset of: fever, respiratory distress and oedema of laryngeal region Generalized petechiation, pulmonary oedema, enteritis, lymphadenopathy |
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Haemorrhagic septicaemia/barbone; epidemiology
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Outbreak usually because of episodes of stress; dramatic changes in weather, poor nutrition, overcrowding
Incubation period; 2-4 days (Mortality rate 50-100 %) |
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Bovine and Porcine pneumonia; cause
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P. multocida serotype A:3 - beef cattle, opportunistic pathogen of low virulence
Both type A and D toxogenic strains- Swine, one of the most economically most significant diseases in swine production |
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Fowl cholera; cause, resevoir, etc.
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P. multocida type A
Highly contagious Affect domectic and wild birds high morbidity, mortality 70 % Major resevoir: chronically infected birds |
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Fowl cholera; symptoms + postmortem
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Manifests as septicaemia
May occur in chronic form Postmortem lesions; haemorrhages on serous surface, accumulation of fluid in body cavities Sporadic chronic cases; wattles, sternal bursae and joints are swollen |
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Fowl cholera; acute
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Acute septicaemic case; bipolar-staining org. can be detected in blood, P. multocida can be isolated from blood, bone marrow, liver or spleen
Difficult to isolate from chronic lesions |
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Atrophic rhinitis; cause
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Upper respiratory disease
primarily in piglet 1-8 weeks of age Bordetella bronchiseptica- with P. multocida type D AR+ causes severe and progressive form |
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Atrophic rhinitis; symptoms
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Atrophy of turbinates, distortion of snout, severe nasal deviation
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Atrophic rhinitis; epidemiology
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Introduction of P. multocida AR+ carrier may initiate an outbreak
Other risk factors: incr. farrowing density, high levels of environmental ammonia or dust, presence of weaned pigs in farrowing buildings |
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Rabbit pasteurellosis; cause
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"snuffles"
purulent rhinitis P. multocida type A |
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Rabbit pasteurellosis; cause to clinical disease
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Clinical disease is precipitated by stress factors; overcrowdning, chilling, transportation, concurrent infection, poor ventilation- atmospheric ammonia
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Rabbit pasteurellosis; symptoms
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Purulent nasal discharges
Cakes on fore legs- affected rabbits paw their nose Sneezing, coughing, otitis externa, pneumonia, abscesses, conjunctivitis, mastitis, metritis, septicaemia, torticollis |
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Pasteurellosis caused by Bibersteina trehalosi
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Septicaemia, pneumonia
Especially in feeder lambs Sudden onset of fever, anorexia, respiratory distress, sudden death Occur late summer to early fall |
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Pasteurellosis caused by P. pneumotropica
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Opportunistic pathogen of rodents
In latency on respiratory/GI mucosae Disseminated by aerosol or faecal shedding, or by intimate contact Any factor lowering host resistance may precipitate secondary infection w P. pneumotropica Clinical signs: Dyspnea, abscess, abortion, cystitis, weight loss, infertility, conjuctivitis |
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Lab diagnosis of Pasteurella
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Based on isolation of causative organism from affected tissues.
Isolates are G- with variable morphology and colonial characteristics. Identification based on morphologic, cultural and biochemical characteristics. |
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Isolation medium for Pasteurella
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Blood agar: suppl. w. neomycin, bacitracin and acitidione
Chocolate agar: because of V-factor Incub.: under 3-5% CO2 37*C, 24-48h |
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Colony morphology of P. multocida
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Mucoid, smooth, iridescent or dry, rough w. odor
Some strains cause greenish discoloration on blood agar. Demonstration of toxicity of P. multocida AR+ strains for tissue culture cells, ELISA test for toxin detection |
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Characteristics of Mannheimia
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Ferment mannitol, Does not ferment D-mannose- differentiates it from Pasteurella
Small, nonmotile, G-, coccobacillary-rods |
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Species of Mannheimia
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M. haemolytica
M. granulomatis M. glucosida M. ruminalis M. varigena |
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Shipping fever/Bovine pneumonic pasteurellosis; cause
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Multifactoral; environmental factors, concurrent infections with viruses and other bacterias
M. Haemolytica |
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Shipping fever/Bovine pneumonic pasteurellosis; bacterial habitat, development factors
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Bacteria inhabits nasal cavity and tonsillar crypts- shedding from nasal cav. serve as source of inf. for other animals.
Development depends on challenge dose of M. Haem. + immune status of host |
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Shipping fever/Bovine pneumonic pasteurellosis; symptoms, mortality/morbidity
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Severe bronchopneumonia
Depression, anorexia, fever, nasal discharge, soft moist cough Dyspnea and open mouth breathing can develop. Appears 6-10 days after stress episode Morbidity 50 %, mortality 1-10 % Postmortem: cranial lobes of lungs are read, swollen and consolidated + fibrinous pleurisy |
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Virulence factors of Mannheimia; Leukotoxin
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Virulence factors:
Leukotoxin- cytotoxin, induces lysis of ruminant leukocytes and platelets, impairs pulmonary macrophage function, damages lung parenchyma. Impairs pulmonary defences- because decr. antigen-pres. capasity of macrophages |
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Virulence factors of Mannheimia; LPS
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LPS induces haemorrhage, oedema, hypoxemia, acute inflammation
LPS+leukotoxin activating macrophages induces release of proinflammatory cytokines |
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Virulence factors of M. haemolytica; others
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Capsular polysaccharide- adherens, inhibition, mediates resistance
Iron-regulated proteins- siderophores Enzymes- neuraminidase, O-sialoglycoprotein endopeptidase Fimbriae- adherence |
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Pathogenesis
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Infects alveolar epithelium
Invasion lower resp. tract ass. w. rapid deterioration of lung function and structure Within hours: bronchi, bronchioles, alveoli are infiltrated by neutrophils, fibrin, blood, seroproteinaceous fluid. Results in acute fibrinous pleuropneumonia. |
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M. granulomatis with Dermatobia hominis; Disease etc.
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Infects Cattle
Lechiguana- Brazil Large, hard, subcutaneous swellings Progress rapidly, causes death after 3-11 moths untreated Microscopic lesions Eosinophilic abscesses, rosettes w. bacteria in center |
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M. varigena; Disease in cattle
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Sporadic bovine mastitis, calf pneumonia, septicaemia.
Bovine mastitis- trauma associated from perh. overvigorous suckling calf/poor milking equivalent |
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M. varigena in swine
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Normal resident of upper resp. tract of healthy pig, but also affected by pneumonia or enteritis
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Lab diagnosis of Mannheimia
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Based on bacterial isolation from clinical speciments.
Medium: Blood agar, glucose agar plate with serum Colonial morph.: smooth, greyish, variably beta-haemolytic, 1-2mm after 24 h incub. Differentiation: basis of phenotype Passive haemogglutination procedure/rapid plate agglutination test may identify serotype |
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Characteristics of Actinobacillus
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Nonmotile, G-, rods-coccobacilli
Variably haemolytic on blood agar Oxidase +, catalase variable, nitrate-reductase Facultative anaerobes, CO2 is needed for growth Morse code appearance NAD- dependant |
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Colony morphology of Actinobacillus !!
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Variably haemolytic, sticky or waxy,
Satellism with Staphylococcus |
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Species of Actinobacillus pathogenic for domestic animals
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A. lignieresii
A. pleuropneumoniae- does not grow on McC A. equuli A. suis A. seminis Aggregatibacter actinomycetemcomitans |
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Epidemiology of Actinobacillus
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Actinobacillus cannot survive for long in environment-carrier animals are major role of transmission
Diseases attributed to this bacteria occurs sporadically (Except for A. pleuropneumoniae) |
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Habitat of Actinobacillus
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Commensals on mucous membranes, esp. in upper resp. tract and oral cavity
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Subspecies of Actinobacillus equuli
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A. equuli spp. equuli- mucous membranes of eq. and su.
A. equuli spp. haemolyticus- normal microflora of horse |
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Actinobacillosis in cattle; cause, other name
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“Wooden tongue”
Aetiological agent- A. lignieresii Sporadic disease Confused with actinomycosis- affects bone, actinobacillosis affects soft tissues |
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Actinobacillosis in cattle; epidemiology
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Organism enters through erosions and lacerations in mucosa and skin
Spread through lymphatica to regional lymph nodes- may induce pyogranulomatous lymphadenitis |
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Actinobacillosis in cattle; symptoms
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Hard timorous masses in tongue
Localized pyogranulomatous response Hard to eat, drool saliva Can lead to intermittent tympany, enlargement of retropharyngal lymphnodes, difficulty swallowing, stertorous breathing Lesions of cutaneous actinobacillosis |
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Pleuropneumonia of pigs; cause, nr of serotypes
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A. pleuropneumoniae
15 serotypes, 2 biotypes |
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Pleuropneumonia of pigs; epidemiology?
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Colonizes tonsils and upper resp. tract of healthy pigs- obligate parasite
Outbreaks: ass. w. intensive pig production; high-stocking density, poor ventilation, low immunity |
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Pleuropneumonia of pigs; symptoms
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Sudden death, chronic pneumonia
Coughing, respiratory dyspnea, blood-stained froth, cyanosis, abortion Acute: haemorrhagic necrotizing pneumonia of caudal lung lobe, fibrinous pleurities |
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Pleuropneumonia of pigs; future effects
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Survivors grow poorly- inhibition of normal respiratory function- lung scarring with pleural adhesions
They continues to harbor A. pl. in their tonsillar crypts. |
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Sleepy foal disease; cause
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A. equuli
Acute, fatal septicaemia of newborns Habitat reproductive system and intestinal tract of mares Mares serve as source of infection |
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Sleepy foal disease; future effects
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Recovered foals may develop polyarthritis, nephritis, enteritis, pneumonia
May produce abortion, septicaemia and peritonitis in adult horses |
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Sleepy foal disease; epidemiology (speculations)
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Colostrum deprivation, stress, parasitism may predispose illness
Migrating larvae of Strongylus vulgaris carries agent from intestinal lumen into circulatory system |
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Actinobacillus suis infection of piglets; cause
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A. suis
Resides in tonsils, nostrils, vagina of healthy pigs Opportunistic pathogen Infected by aerosol or skin abrasions |
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Actinobacillus suis infection of piglets; symptoms
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Septicaemia, rapid death
Mortality 50 % fever, respiratory distress, prostration, padding of forelimbs Petechial and ecchymotic haemorrhages, interstitial pneumonia, pleuritis, meningoencephalitis, myocarditis, arthritis |
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Actinobacillus seminis infection of rams; cause
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A. seminis
Epididymitis in young rams Endemic in New Zealand, Australia, South Africa Found in prepuse Virgin rams are most affected |
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Actinobacillus seminis infection of rams; symptoms
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Abscess form in epididymides
purulent discharge through fistulae onto scrotal skin |
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Human infection of Actinobacillus
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Limited to periodontal disease- A. actinomycetecomitans
Sporadic of respiratory tract, blood, cerebrospinal fluid- A. hominis, A. ureae Upper respiratory of bite wound infections- A. equuli, A. suis |
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Virulence factors of Actinobacillus
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Polysaccharide capsule, RTX toxin (exotoxin), LPS, iron acquisition mechanisms, urease production, secreted proteases, possibly fimbriae
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RTX toxins for Actinobacillus
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4 types in A. pleuropneumoniae:
Apx I-IVA Have been discovered in A. suis, A. actinomycetemcomitans, A. lignieresii Act on immune cells; inducing production of infl. Mediators or exerts cytotoxic effects- resulting in infl./cell death |
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Lab diagnosis of Actinobacillus; examination, speciments, method
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Direct examination of Gram-stained smears
Speciments: pus from tongue lesions Bacteriological culture of A. from infected tissue Multiplex PCR based methods has replaced older assays |
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Lab diagnosis of Actinobacillus; differentiation
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Differentiation based on haemolytic properties, ability to grow on McC, hydrolyze esculin, dependency of NAD, ability to produce oxidase/catalase/urease/acid in carbohydrate substrates
If phenotyping charac. fails- analysis of seq. 16S rDNA |
