Detection For Concentrations Of Airborne Microbes With Stain Method And Identification For Transmition Of Airborne Fungus In Cow Houses

This research aims to learn more about bioaerosol concentration and transmission mechanism of fungi aerosol in houses, then to provide the first-hand material for the scientific management of houses.Samples were collected from 5 diary farms in taian,jining and zibo, Shandong province. AGI-30 air sampler was applied. Aerobic bacteria was cultured in nutrient agar in traditional method through which the bacteria concentration was confirmed; while the fungi was cultured in Sabouraud's Medium through which the fungi concentration could be known. Comparatively, the DNA staining method was used with the media DAPI. Under the fluorescence microscope, directed counting was conducted with the DNA dye's characteristic of fluorescing to confirm the concentration of airbornes microbes. The difference of bioaerosol concentration measured by the two different method was further compared.At the same time, Anderson air applied. The air sample was collected in the Sabouraud's Medium and cultured, also the cattle manure and scar tissues. Then confirm the Trichophytes mentagrophytes by morphological identification. DNA of dermatophytes was extracted for PCR and RFLP of IGS region. Further the Airborne transmission of dematophytes was confirmed by allogenic analysis.The result shows that the concentrations of bioaerosol were 38.9×10~5cfu/m~3, 27.1×10~5cfu/m~3, 26.3×10~5cfu/m~3, 2.09×10~5cfu/m~3, 5.92×10~5cfu/m~3 seperately measured by culture counting method, and that of DAPI staining method were 166×10~6 cell/m~3,166×10~6 cell/m~3, 136×10~6 cell/m~3, 0.836×10~6 cell/m~3, 3.73×10~6 cell/m~3 respectively in the five cow houses. The concent of airbornes microbes measured by DAPI staining method is 9.6～2500 times of the former in the houses. The statistical analysis showed that the difference of the two method was extremely significant.In this research the IGS conserved sequence of Trichophytes mentagrophytes was amplified using the universal primers and cut by restriction enzymes MspⅠ, PstⅠand XhoⅠ. Through the fragment cut by enzyme MspⅠwe find that some of the RFLP atlas isolated from manure and scar are the same and have different similarity level with the samples isolated from indoor and outdoor air( upwind 10m and downwind 50m,100m,200m and 500m away). Thus it can be seen that Trichophytes mentagrophytes could be dispersed into the air and form into fungi aerosol. Further more it could transmit with the air flowing to the distance of 500m, which shows that pathogenic fungi from the animal body could form into aerosol, and transmit with the air exchanging to farms and its surroundings, even to the communities.The conclusion of this research is that staining counting method could mirror the content of airborne microbes in the environment more objective and is helpful to make scientific evaluation for environmental health risk. Moreover, airborne transmission of dermatophytes was confirmed which provides more accurate basis for the scientific management of the houses .