Detection of naturally aerosolized Actinobacillus pleuropneumoniae on pig farms by cyclonic air sampling and qPCR

Vet Microbiol. 2020 Nov:250:108856. doi: 10.1016/j.vetmic.2020.108856. Epub 2020 Sep 18.

Abstract

Respiratory infections caused by Actinobacillus pleuropneumoniae have a large impact on commercial pig farms globally. As current vaccines have limited efficacy, animal care and air hygiene are critical for disease control. Here we used a Coriolis μ cyclonic air sampler and an A. pleuropneumoniae-specific apxIV gene qPCR assay to detect the organism. Air samples were collected into a liquid medium by the Coriolis μ sampler for A. pleuropneumoniae detection by plate culture and qPCR assay. The method was validated by comparing the Coriolis μ sampler and a plate impactor (Millipore Air-T) in a specially designed aerosolization chamber. Two commercial farms, housing pigs between 3 and 21 weeks of age, were tested. On one farm, A. pleuropneumoniae was detected in low numbers (1000 organisms/m3 air) by qPCR, but not by culture, from sheds containing 8, 12, 16, and 18 weeks-old pigs. To our knowledge this is the first successful detection of naturally aerosolised A. pleuropneumoniae in commercial farms with the Coriolis μ air sampler, potentially allowing the identification of sub-clinically infected populations of pigs in the field.

Keywords: Actinobacillus pleuropneumoniae; Air sampling; Swine.

MeSH terms

  • Actinobacillus Infections / diagnosis
  • Actinobacillus Infections / microbiology
  • Actinobacillus Infections / veterinary*
  • Actinobacillus pleuropneumoniae / genetics
  • Actinobacillus pleuropneumoniae / isolation & purification*
  • Aerosols / analysis*
  • Air Microbiology*
  • Animal Husbandry
  • Animals
  • Antibodies, Bacterial / blood
  • Australia
  • Farms*
  • Female
  • Male
  • Pleuropneumonia / microbiology
  • Real-Time Polymerase Chain Reaction
  • Swine / microbiology
  • Swine Diseases / diagnosis
  • Swine Diseases / microbiology

Substances

  • Aerosols
  • Antibodies, Bacterial