title: The effect of the air sampling method on the recovery of Mycoplasma gallisepticum from experimentally produced aerosols.
abstract: BACKGROUND
  A reliable air sampling method is a prerequisite to calculate the inhaled aerosol dose by animals exposed to the aerosol as precise as possible.[Comp]: Set abstract according to the journal style.[/Comp]
  
  
  OBJECTIVE
  To examine if aerosol collection in a fluid medium (buffered peptone water (BPW) in the impinger) improves detection of viable mycoplasmas. Also the effect of adding Mycoplasma Experience (ME) broth and/or BPW to the aerosol fluid on aerosol titres was assessed.
  
  
  METHODS
  Aerosols containing a Mycoplasma gallisepticum field or vaccine strain were simultaneously sampled with gelatin filters and by impinger immediately after ending aerosolization and 25 min later.
  
  
  RESULTS
  Sampling of M. gallisepticum aerosols using the impinger did not yield higher aerosol titres compared to sampling with gelatin filters. Initial loss during generation of the field strain aerosol and the half-life time of viable mycoplasmas in the aerosol were 1.1-2.4 log10 and <4-15 min, respectively. The vaccine strain was more vulnerable compared to its field counterpart. In spite of higher aerosolized doses of the vaccine strain (10(8.0) to 10(8.1) versus 10(7.5) cfu per m(3) of air of the field strain), mycoplasmas were not recovered from the aerosols neither by gelatin filter nor by impinger. Therefore, half-life times could not be calculated. Addition of BPW to the aerosol fluid did not clearly improve the recovery of the field strain from the aerosol, while addition of ME broth and BPW did.
  
  
  CONCLUSIONS
  Gelatin filters likely due to their relative high moisture content (10-14% wt/wt) are at least as useful as the impinger for the recovery of M. gallisepticum from aerosols, provided exsiccation of the filters is prevented.
authors.affiliation: GD - Animal Health Service, Arnsbergstraat 7, 7418 EZ Deventer, the Netherlands. w.landman@gddeventer.com
authors.forename: W J M
authors.initials: WJ
authors.lastname: Landman
authors.forename: A
authors.initials: A
authors.lastname: Feberwee
authors.forename: J H H
authors.initials: JH
authors.lastname: van Eck
mesh_terms: D000336:Aerosols / Q000032:analysis*; D061808:Air Filters / Q000662:veterinary; D000391:Air Microbiology; D000818:Animals; D002645:Chickens; D003101:Collodion / Q000737:chemistry; D013293:Enterococcus faecalis / Q000302:isolation & purification*; D004784:Environmental Monitoring / Q000379:methods*; D005780:Gelatin / Q000737:chemistry; D019570:Inhalation Exposure; D045686:Mycoplasma gallisepticum / Q000302:isolation & purification*
chemical_list: D000336:Aerosols; D005780:Gelatin; D003101:Collodion