Test 2- Actinobacillus Flashcards
Actinobacillus
- Pasteurellaceae
- A. lignieresii
- A. equuli
- A. suis
- A. arthritidis
- A. pleuropneumoniae
Actinobacillus pleuropneumoniae General
- Very important disease in swine rearing
- Worldwide
- Younger pigs, in general
Actinobacillus pleuropneumoniae General
• 2 biotypes
- Biotype 1: NAD-dependent
- Biotype 2: NAD-independent
with and with staph.
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
NAD: Nicotinamide Adenine Dinucleotide
A co-enzyme that functions as a biochemical electron carrier
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
Actinobacillus pleuropneumoniae Epidemiology • Carriers:
Carriers:
• Nose
• Tonsils
• long noduli
Actinobacillus pleuropneumoniae Pathogenesis
Inhalation or Tonsils/nose into Terminal bronchioli Alveoli
Actinobacillus pleuropneumoniae Pathogenesis • Predisposing factors
• Bacteria dependent, virulence factors
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,…
Actinobacillus pleuropneumoniae Virulence factors
MOST VIRULENCE FACTORS OF ANY BACTERIA- VERY PATHOGENIC
- adhesion: fimbriae
• 2. xxx: Fe necessary
————-Transferrin binding proteins
————-Hemoglobin binding proteins
- exotoxin production: Apx toxins
- Capsule
- 5.LPS:LipidAendotoxin
- 6.OMPs(majorandminorOMPs)
- Enzymes • Proteases • Cu-Zn- SOD
- 8.HSP
Actinobacillus pleuropneumoniae Virulence factors
• 3. exotoxin production: Apx toxins
- 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
Actinobacillus pleuropneumoniae Symptoms
• Symptoms • Respiratory distress • General symptoms • Hyperacute • Acute • Chronic
Actinobacillus pleuropneumoniae Immunity
• Antibodies • Protective antigens (included in vaccines) • Type IV fimbriae • Transferrin binding proteins • Apx toxins
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
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: +++
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
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
A. suis dx and tx
• Diagnosis • Bacterial culture • Care: little resistant • Treatment • antibiotics
A. equuli General
• Subspecies haemolyticus (reservoir horse) • Subspecies equuli (reservoir horse & pig) • Obligate symbiotic • Facultative pathogen • Easy culture
A. equuli Carriers and Symptoms
A. equuli • Carriers • Mouth • GI tract • AQX toxins (RTX) • Symptoms • Bronchitis • Pleuritis • pneumonia
A. Equuli Foal
• Septicaemiae • “sleepy foal disease” • Enteritis • More general localization: slimy pus • Treatment (Ab): fails most of the times • Colostrum
A. Equuli Adult horses
• Abortions or birth of “sleepy foal disease” foal • Septicaemiae • Frequently localization in joints • Treatment: antibiotics
names for Actinobacillus lignieresii
Wooden tongue Timber tongue
A. Lignieresii General
• Obligate symbiont • Facultative pathogenic • Inhabitant of nasopahrynx • Infection of weak tissues: connective tissue proliferation • Mainly tongue (small lesions as entry)
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”
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.)
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
