+49 30 838 51845
Methicillin-resistant Staphylococcus aureus (MRSA) emerged shortly after the introduction of methicillin in 1959 (Robinson and Enright, 2004). Since 2004 MRSA was found to be widespread in food producing animals, particularly in pigs (Voss et al., 2005). Since MRSA was found in barn and ambient air of pig farms (Friese et al., Schulz et al, 2012) an airborne transmission and its relevance for environmental and public health is discussed. Therefore, one aim of our study is to evaluate the dose for a successful colonization of pigs with MRSA ST398 via the airborne route. Groups of nine MRSA negative piglets each are exposed to MRSA aerosols of different concentrations using an aerosol chamber. During three weeks after the aerosol exposition the piglets were sampled three times a week by spotting different locations. In the first group we found only one nasal swab positive after aerosol exposition with MRSA (dose: 102 fu/m3) whereas all piglets in group two were MRSA positive the day after the exposition with MRSA of a dose of 104 cfu/m3. Over the time the number of positive animals varied and after two weeks all pigs remained MRSA negative. One more dose is under investigation currently. The two tested doses which are comparable to MRSA concentrations found in farm air do not cause a stable colonization in the piglets after the exposition for 24 hours.