Test 2- Actinobacillus Flashcards Preview

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Flashcards in Test 2- Actinobacillus Deck (28):
1

Actinobacillus

• Pasteurellaceae

• A. lignieresii

• A. equuli

• A. suis

• A. arthritidis

• A. pleuropneumoniae

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Actinobacillus pleuropneumoniae General

• Very important disease in swine rearing

• Worldwide

• Younger pigs, in general

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Actinobacillus pleuropneumoniae General

• 2 biotypes

• Biotype 1: NAD-dependent

• Biotype 2: NAD-independent

 

with and with staph.

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Actinobacillus pleuropneumoniae

16 serotypes of which some are divided in subtypes

• Difference in virulence between serotypes

But also within serotypes their may be differences in virulence

• Geographical differences in prevalence

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NAD: Nicotinamide Adenine Dinucleotide

A co-enzyme that functions as a biochemical electron carrier

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Actinobacillus pleuropneumoniae Epidemiology

• Spread from pig to pig via

------------- Direct contact

-------------Aerosol (only short distances)

• Spread through the stable (from pen to pen) take care of pigs around the infected pen

------------- Ventilation

-------------Regrouping of pigs

------------- Farmer

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Actinobacillus pleuropneumoniae Epidemiology • Carriers:

Carriers:

• Nose

• Tonsils

• long noduli

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Actinobacillus pleuropneumoniae Pathogenesis

Inhalation or Tonsils/nose into Terminal bronchioli Alveoli

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Actinobacillus pleuropneumoniae Pathogenesis • Predisposing factors

• Bacteria dependent, virulence factors

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Actinobacillus pleuropneumoniae Pathogenesis

• Host dependent: stress

• Host dependent: stress

• Transport

• Pen exchanges

 • Overpopulation

• Climate not adapted

• Ventilation

• After another infection like M. hyopneumoniae, Aujeszki disease,...

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Actinobacillus pleuropneumoniae Virulence factors

MOST VIRULENCE FACTORS OF ANY BACTERIA- VERY PATHOGENIC

1. adhesion: fimbriae

• 2. xxx: Fe necessary

-------------Transferrin binding proteins

-------------Hemoglobin binding proteins

• 3. exotoxin production: Apx toxins

• 4. Capsule

• 5.LPS:LipidAendotoxin

• 6.OMPs(majorandminorOMPs)

• 7. Enzymes • Proteases • Cu-Zn- SOD

• 8.HSP

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Actinobacillus pleuropneumoniae Virulence factors

• 3. exotoxin production: Apx toxins

• 3. exotoxin production: Apx toxins

• RTX toxins (Repeat in toxins, leukotoxin like): make pores into cells (blood cells, endothelial cells, alveolar epithelial cells, NF, MF)

• Recombinant toxins produce lung lesions, APP toxin deletion mutants are non pathogenic

• Effects on phagocytes

• Low dose: O2 radicals

• High dose: lytic

 

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Actinobacillus pleuropneumoniae Symptoms

• Symptoms • Respiratory distress • General symptoms • Hyperacute • Acute • Chronic

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Actinobacillus pleuropneumoniae Immunity

• Antibodies • Protective antigens (included in vaccines) • Type IV fimbriae • Transferrin binding proteins • Apx toxins

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Actinobacillus pleuropneumoniae Diagnosis

• Symptoms • Autopsia • Bacterial culture • Samples need to be fast in the lab (little resistant, Post mortem contaminants may overgrow), evt. freeze at -20 • Slow grower • Staphylococcus necessary (NAD) • CO2 enriched environment • Selective media • Serology (paired sera) • Only of value at farm level • Detection of carriers (you do not want these in your farm!) • Antibodies (not always conclusive) • Bacterial culture (PCR) • Swab from nose • Swab from tonsils

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Actinobacillus pleuropneumoniae Treatment and prevention

• Hygiene • Antimicrobials • Sick: parenteral then if better, per os • Frequently too late • Not sick (yet): per os • Not so much acquired resistance • Vaccine • Bacterins: +/- • APX toxins: + • APX & transferrin binding proteins: ++ • APX & TBP & Type 4 fimbriae: +++

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A. suis General

• Obligate symbiotic • Facultative pathogenic • Lesion similar to APP but less extensive • Toxins related to Apx I and II • Carriers: tonsils & vagina • Pathogenic for mice • Sporadic

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A. suis Symptoms

• Limited number of animals affected • Acute: young animals • Acute mortality • Clinical symptoms = APP • Less acute: older piglets • General symptoms (fever, anorexia) • Respiratorydistress • Polyarthritis • Adult • subcutaneous abscesses • Anorexia and fever • Meningitis possible

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A. suis dx and tx

• Diagnosis • Bacterial culture • Care: little resistant • Treatment • antibiotics

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A. equuli General

• Subspecies haemolyticus (reservoir horse) • Subspecies equuli (reservoir horse & pig) • Obligate symbiotic • Facultative pathogen • Easy culture

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A. equuli Carriers and Symptoms

A. equuli • Carriers • Mouth • GI tract • AQX toxins (RTX) • Symptoms • Bronchitis • Pleuritis • pneumonia

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A. Equuli Foal

• Septicaemiae • “sleepy foal disease” • Enteritis • More general localization: slimy pus • Treatment (Ab): fails most of the times • Colostrum

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A. Equuli Adult horses

• Abortions or birth of “sleepy foal disease” foal • Septicaemiae • Frequently localization in joints • Treatment: antibiotics

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names for Actinobacillus lignieresii

Wooden tongue Timber tongue

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A. Lignieresii General

• Obligate symbiont • Facultative pathogenic • Inhabitant of nasopahrynx • Infection of weak tissues: connective tissue proliferation • Mainly tongue (small lesions as entry)

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A. Lignieresii rare or common outbreak lesions

• Rare endogenic infection • Outbreak: • Contaminated surgical material of a vet! • Lesions at surgical site • Lesions: • Capsule of connective tissue with multiple granuloma’s containing yellowish pus and “sulfur granules”

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A. Lignieresii • Diagnosis

• Diagnosis • Histology • Microscopy of granules • Native or HE: typical structure • Gram: Gram negative microorganisms • DD: Actinomycosis (affects the bones) (Actinomyces bovis) • Nocardiosis(severalspp.)

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A. Lignieresii Therapy:

Therapy: prognosis only positive in initial phase (be fast) • Surgery: resection or opening of abscesses • Local unguents base on iodine or Kalium iodine po. or Na iodine iv. (care toxicity) • Frequent relapses